bauhaus.c

Go to the documentation of this file.

/*
    This file is part of darktable,
    Copyright (C) 2011-2016 johannes hanika.
    Copyright (C) 2012-2013 Henrik Andersson.
    Copyright (C) 2012 Jean-Sébastien Pédron.
    Copyright (C) 2012, 2014, 2017, 2019-2020 parafin.
    Copyright (C) 2012 Pascal de Bruijn.
    Copyright (C) 2012 Richard Wonka.
    Copyright (C) 2012-2014, 2016-2020 Tobias Ellinghaus.
    Copyright (C) 2012, 2016 Ulrich Pegelow.
    Copyright (C) 2013, 2019, 2021-2022 Aldric Renaudin.
    Copyright (C) 2013 Dennis Gnad.
    Copyright (C) 2013-2016 Roman Lebedev.
    Copyright (C) 2013 Simon Spannagel.
    Copyright (C) 2013 Yari Adan.
    Copyright (C) 2015 Jérémy Rosen.
    Copyright (C) 2016 Asma.
    Copyright (C) 2017 Christian Stussak.
    Copyright (C) 2017-2018, 2020-2021 Dan Torop.
    Copyright (C) 2017 luzpaz.
    Copyright (C) 2018 Matthieu Moy.
    Copyright (C) 2018-2022 Pascal Obry.
    Copyright (C) 2018 Peter Budai.
    Copyright (C) 2019-2020, 2022-2026 Aurélien PIERRE.
    Copyright (C) 2019-2022 Diederik Ter Rahe.
    Copyright (C) 2019 emeikei.
    Copyright (C) 2019-2021 Heiko Bauke.
    Copyright (C) 2019 Jakub Filipowicz.
    Copyright (C) 2019 jakubfi.
    Copyright (C) 2020-2022 Chris Elston.
    Copyright (C) 2020 Hubert Kowalski.
    Copyright (C) 2020 matt-maguire.
    Copyright (C) 2020-2021 Philippe Weyland.
    Copyright (C) 2020-2021 Ralf Brown.
    Copyright (C) 2020 Érico Rolim.
    Copyright (C) 2021 lhietal.
    Copyright (C) 2021 Mark-64.
    Copyright (C) 2021 Martin Straeten.
    Copyright (C) 2021 Paolo DePetrillo.
    Copyright (C) 2022 Martin Bařinka.
    Copyright (C) 2022 Nicolas Auffray.
    Copyright (C) 2023 Alynx Zhou.
    Copyright (C) 2023 Luca Zulberti.
    Copyright (C) 2025-2026 Guillaume Stutin.
    
    darktable is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    
    darktable is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    along with darktable.  If not, see <http://www.gnu.org/licenses/>.
*/
 
#include "widgets/gdkkeys.h"
#include "widgets/draw.h"
#include "widgets/widget_settings.h"
#include "widgets/paint.h"
#include "widgets/bauhaus.h"
#include "math/calculator.h"
#include "math/math.h"
#include "system/macros.h"
 
 
#include "widgets/accelerators.h"
#include "widgets/widget_style.h"
 
#include <glib/gi18n.h>
#ifdef GDK_WINDOWING_QUARTZ
#include "osx/osx.h"
#endif
 
#include <math.h>
 
#include <pango/pangocairo.h>
#include "system/surface_scaling.h"
#ifdef GDK_WINDOWING_WAYLAND
#include <gdk/gdkwayland.h>
#endif
 
G_DEFINE_TYPE(DtBauhausWidget, dt_bh, GTK_TYPE_DRAWING_AREA)
 
// WARNING
// A lot of GUI setters/getters functions used to have type checking on input widgets
// and silently returned early if the types were not ok (like trying to set a combobox using slider methods).
// This only hides programmers mistakes in a way that prevents the soft to crash,
// but it still leads to faulty GUI interactions and inconsistent widgets values that might be hard to spot.
// In november 2023, they got removed in order to fail explicitly and possibly crash.
// If that's not enough, we can always add assertions in the code.
 
#define DEBUG 0
 
// fwd declare
static gboolean dt_bauhaus_popup_draw(GtkWidget *widget, cairo_t *cr, gpointer user_data);
static gboolean dt_bauhaus_popup_key_press(GtkWidget *widget, GdkEventKey *event, gpointer user_data);
static gboolean _widget_draw(GtkWidget *widget, cairo_t *crf);
static gboolean _widget_scroll(GtkWidget *widget, GdkEventScroll *event);
static gboolean _widget_key_press(GtkWidget *widget, GdkEventKey *event);
static void _get_preferred_width(GtkWidget *widget, gint *minimum_size, gint *natural_size);
static void _get_preferred_height(GtkWidget *widget, gint *minimum_size, gint *natural_size);
static void _style_updated(GtkWidget *widget);
static void dt_bauhaus_widget_accept(struct dt_bauhaus_widget_t *w);
static void dt_bauhaus_widget_reject(struct dt_bauhaus_widget_t *w);
static void _combobox_set(GtkWidget *widget, const int pos);
 
// !!! EXECUTIVE NOTE !!!
// Sizing and spacing need to be declared once only in getters/setters functions below.
// The rest of the code accesses those values only through the getters.
// Doxygen docstrings need to be added to explain what is computed, based on what.
// Code changes that recompute sizing or coordinates outside of getters/setters will be refused.
 
static void _margins_retrieve(struct dt_bauhaus_widget_t *w)
{
  if(IS_NULL_PTR(w->margin)) w->margin = gtk_border_new();
  if(IS_NULL_PTR(w->padding)) w->padding = gtk_border_new();
  GtkStyleContext *context = gtk_widget_get_style_context(GTK_WIDGET(w));
  const GtkStateFlags state = gtk_widget_get_state_flags(GTK_WIDGET(w));
  gtk_style_context_get_margin(context, state, w->margin);
  gtk_style_context_get_padding(context, state, w->padding);
 
  // Deal with borders by extending margins because we don't care
  GtkBorder *borders = gtk_border_new();
  gtk_style_context_get_border(context, state, borders);
  w->margin->left += borders->left;
  w->margin->right += borders->right;
  w->margin->top += borders->top;
  w->margin->bottom += borders->bottom;
  gtk_border_free(borders);
}
 
static float _bh_get_row_height(struct dt_bauhaus_widget_t *w)
{
  return w->bauhaus->line_height * 1.4;
}
 
static float _bh_get_combobox_entry_height(struct dt_bauhaus_widget_t *w,
                                           const dt_bauhaus_combobox_entry_t *entry)
{
  const float row_height_factor = (entry->is_separator) ? MAX(entry->row_height_factor, 0.1f) : 1.f;
  return _bh_get_row_height(w) * row_height_factor;
}
 
static double _widget_get_quad_width(struct dt_bauhaus_widget_t *w)
{
  if(w->show_quad)
    return w->bauhaus->quad_width;
  else
    return 0.;
}
 
static double _widget_get_total_width(struct dt_bauhaus_widget_t *w, GtkWidget *widget)
{
  GtkWidget *box_reference = (widget) ? widget : GTK_WIDGET(w);
  GtkAllocation allocation;
  gtk_widget_get_allocation(box_reference, &allocation);
  return allocation.width - w->margin->left - w->margin->right - w->padding->left - w->padding->right;
}
 
static double _widget_get_main_width(struct dt_bauhaus_widget_t *w, GtkWidget *widget, double *total_width)
{
  const double tot_width = _widget_get_total_width(w, widget);
  // Slider cursors are centered on the scale bounds, so the scale starts one
  // cursor radius after the text origin while keeping its right edge flush.
  const double slider_cursor_radius = (w->type == DT_BAUHAUS_SLIDER) ? 0.5 * w->bauhaus->marker_size : 0.0;
  if(total_width) *total_width = tot_width;
  return tot_width - _widget_get_quad_width(w) - 2. * INNER_PADDING - slider_cursor_radius;
}
 
static double _widget_get_main_height(struct dt_bauhaus_widget_t *w, GtkWidget *widget)
{
  GtkWidget *box_reference = (widget) ? widget : GTK_WIDGET(w);
  GtkAllocation allocation;
  gtk_widget_get_allocation(box_reference, &allocation);
  return allocation.height - w->margin->top - w->margin->bottom - w->padding->top - w->padding->bottom;
}
 
static double _get_combobox_height(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  return w->margin->top + w->padding->top + w->margin->bottom + w->padding->bottom
         + w->bauhaus->line_height;
}
 
static double _get_slider_height(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  return w->margin->top + w->padding->top + w->margin->bottom + w->padding->bottom + INNER_PADDING / 2.
         + 2. * w->bauhaus->border_width + w->bauhaus->line_height + w->bauhaus->marker_size;
}
 
static double _get_indicator_y_position(struct dt_bauhaus_widget_t *w)
{
  return w->bauhaus->line_height + INNER_PADDING + w->bauhaus->baseline_size / 2.0f;
}
 
static double _get_slider_bar_height(struct dt_bauhaus_widget_t *w)
{
  // Total height of the text label + slider baseline, discarding padding
  return w->bauhaus->line_height + INNER_PADDING + w->bauhaus->baseline_size;
 
}
 
static double _get_combobox_popup_height(struct dt_bauhaus_widget_t *w)
{
  dt_gui_module_t *module = (dt_gui_module_t *)(w->module);
  const dt_bauhaus_combobox_data_t *d = &w->data.combobox;
 
  // Need to run the populating callback first for dynamically-populated ones.
  if(d->populate) d->populate(GTK_WIDGET(w), module);
  if(!d->entries->len) return 0.;
 
  double height = 0.;
 
  // Add an extra sit for user keyboard input if any
  if(w->bauhaus->keys_cnt > 0) height += _bh_get_row_height(w);
 
  for(int i = 0; i < d->entries->len; i++)
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
    height += _bh_get_combobox_entry_height(w, entry);
  }
 
  return height;
}
 
 
static void _translate_cursor(double *x, double *y, struct dt_bauhaus_widget_t *const w)
{
  const double slider_cursor_radius = (w->type == DT_BAUHAUS_SLIDER) ? 0.5 * w->bauhaus->marker_size : 0.0;
  const double left_offset = w->margin->left + w->padding->left + slider_cursor_radius;
  *x -= left_offset;
  *y -= w->margin->top + w->padding->top;
}
 
// Convenience state for cursor position over widget
typedef enum _bh_active_region_t
{
  BH_REGION_OUT = 0, // we are outside the padding box
  BH_REGION_MAIN,    // we are on the slider scale or combobox label/value, aka out of the quad button
  BH_REGION_QUAD,    // we are on the quad button
} _bh_active_region_t;
 
static _bh_active_region_t _bh_get_active_region(GtkWidget *widget, double *x, double *y, double *width, GtkWidget *popup)
{
  struct dt_bauhaus_widget_t *const w = DT_BAUHAUS_WIDGET(widget);
 
  // The widget to use as a reference to fetch allocation and compute sizes
  GtkWidget *box_reference = (popup) ? popup : widget;
  double total_width;
  const double main_width = _widget_get_main_width(w, box_reference, &total_width);
  const double main_height = _widget_get_main_height(w, box_reference);
 
  if(width) *width = main_width;
  _translate_cursor(x, y, w);
 
  // Check if we are within popup frame
  if(*y < 0. || *y > main_height || *x < 0. || *x > total_width)
    return BH_REGION_OUT;
 
  // Check where we are horizontally
  // The quad now begins exactly 2*INNER_PADDING past the main area for both
  // sliders and comboboxes (see the quad draw sites), so use the same boundary.
  if(*x <= main_width + 2. * INNER_PADDING)
    return BH_REGION_MAIN;
  else
    return BH_REGION_QUAD;
 
  return BH_REGION_OUT;
}
 
static float _bh_round_to_n_digits(const struct dt_bauhaus_widget_t *const w, float x)
{
  const dt_bauhaus_slider_data_t *const d = &w->data.slider;
  const float factor = (float)ipow(10, d->digits);
  return roundf(x * factor) / factor;
}
 
static float _bh_slider_get_min_step(const struct dt_bauhaus_widget_t *const w)
{
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return d->factor * (float)ipow(10, d->digits);
}
 
static double _bh_slider_get_scale(struct dt_bauhaus_widget_t *w)
{
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return 10.0 / (_bh_slider_get_min_step(w) * (d->max - d->min));
}
 
static void _bh_combobox_get_hovered_entry(struct dt_bauhaus_widget_t *w)
{
  if(w->bauhaus->current->type == DT_BAUHAUS_COMBOBOX)
  {
    dt_bauhaus_combobox_data_t *d = &w->bauhaus->current->data.combobox;
    double y = w->bauhaus->mouse_y;
    d->hovered = -1;
    gtk_widget_set_tooltip_text(w->bauhaus->popup_area, NULL);
 
    // If the combobox has a user input row, it is always the first one and has the regular row height.
    if(w->bauhaus->keys_cnt > 0)
    {
      y -= _bh_get_row_height(w);
      if(y < 0.) return;
    }
 
    // Separators may use less vertical space than regular entries.
    // Accumulate actual row heights so mouse hit-testing stays aligned with drawing.
    for(int i = 0; i < d->entries->len; i++)
    {
      const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
      const double entry_height = _bh_get_combobox_entry_height(w, entry);
      if(y < entry_height)
      {
        d->hovered = i;
        gtk_widget_set_tooltip_text(w->bauhaus->popup_area, entry->tooltip);
        return;
      }
      y -= entry_height;
    }
  }
}
 
static _bh_active_region_t _popup_coordinates(dt_bauhaus_t *bh, const double x_root, const double y_root, double *event_x, double *event_y)
{
  // Because the popup widget is a floating window, it keeps capturing motion events even if they don't
  // overlap it. In those events, (x, y) coordinates are expressed in the space of the hovered third-party widget,
  // meaning their coordinates will seem ok from here (right range regarding height/width of widget) but will belong to something else.
  // We need to grab absolute coordinates in the main window space to ensure we overlay the widget popup.
  gint wx, wy;
  GdkWindow *window = gtk_widget_get_window(bh->popup_window);
  gdk_window_get_origin(window, &wx, &wy);
  *event_x = x_root - (double)wx;
  *event_y = y_root - (double)wy;
  return _bh_get_active_region(GTK_WIDGET(bh->current), event_x, event_y, NULL, bh->popup_window);
}
 
// Ensure the programmatically-focused widget is visible,
// and all its parents containers expose the right page before grabbing focus.
#define DT_BAUHAUS_FOCUS_IDLE_SOURCE_KEY "dt-bauhaus-focus-idle-source"
#define DT_BAUHAUS_FOCUS_IDLE_TRIES_KEY "dt-bauhaus-focus-idle-tries"
#define DT_BAUHAUS_FOCUS_IDLE_MAX_TRIES 20
static gboolean ensure_focus_idle(gpointer data)
{
  GtkWidget *target = GTK_WIDGET(data);
  if(!GTK_IS_WIDGET(target)) return G_SOURCE_REMOVE;
 
  GtkWidget *child = target;
 
  for(GtkWidget *w = child; w; w = gtk_widget_get_parent(w))
  {
    if(GTK_IS_NOTEBOOK(w))
    {
      GtkWidget *page = child;
      while(!IS_NULL_PTR(page) && gtk_widget_get_parent(page) != w)
        page = gtk_widget_get_parent(page);
 
      GtkNotebook *nb = GTK_NOTEBOOK(w);
      const gint page_num = !IS_NULL_PTR(page) ? gtk_notebook_page_num(nb, page) : -1;
      if(page_num >= 0) gtk_notebook_set_current_page(nb, page_num);
    }
    else if(GTK_IS_STACK(w))
    {
      GtkWidget *page = child;
      while(!IS_NULL_PTR(page) && gtk_widget_get_parent(page) != w)
        page = gtk_widget_get_parent(page);
 
      GtkWidget *visible_child = gtk_stack_get_visible_child(GTK_STACK(w));
      if(!IS_NULL_PTR(page) && visible_child != page) gtk_stack_set_visible_child(GTK_STACK(w), page);
    }
    child = w;
  }
 
  if(gtk_widget_is_drawable(target))
  {
    gtk_widget_grab_focus(target);
    dt_widget_set_scroll_focus(target);
    // The widget's own toplevel, rather than the application's main window: this is a debug
    // trace and has no business knowing which window the host considers primary.
    GtkWidget *toplevel = gtk_widget_get_toplevel(target);
    GtkWidget *gtk_focus = (toplevel && gtk_widget_is_toplevel(toplevel))
                           ? gtk_window_get_focus(GTK_WINDOW(toplevel)) : NULL;
    dt_widget_log("[bauhaus] ensure_focus_idle success target=%s(%p) gtk_focus=%s(%p) scroll_focus=%s(%p)\n",
             gtk_widget_get_name(target), (void *)target,
             !IS_NULL_PTR(gtk_focus) ? gtk_widget_get_name(gtk_focus) : "<null>", (void *)gtk_focus,
             !IS_NULL_PTR(dt_widget_scroll_focus()) ? gtk_widget_get_name(dt_widget_scroll_focus()) : "<null>",
             (void *)dt_widget_scroll_focus());
    g_object_set_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_SOURCE_KEY, NULL);
    g_object_set_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_TRIES_KEY, NULL);
    return G_SOURCE_REMOVE;
  }
 
  const int tries = GPOINTER_TO_INT(g_object_get_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_TRIES_KEY)) + 1;
  if(tries >= DT_BAUHAUS_FOCUS_IDLE_MAX_TRIES)
  {
    dt_widget_log("[bauhaus] ensure_focus_idle abort target=%s(%p) tries=%d drawable=%d\n",
             gtk_widget_get_name(target), (void *)target, tries, gtk_widget_is_drawable(target));
    g_object_set_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_SOURCE_KEY, NULL);
    g_object_set_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_TRIES_KEY, NULL);
    return G_SOURCE_REMOVE;
  }
 
  g_object_set_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_TRIES_KEY, GINT_TO_POINTER(tries));
  return G_SOURCE_CONTINUE;
}
 
gboolean dt_bauhaus_focus_in_callback(GtkWidget *widget, GdkEventFocus event, gpointer user_data)
{
  // Scroll focus needs to be managed separately from Gtk focus
  // because of Gtk notebooks (tabs): Gtk gives focus automatically to the first
  // notebook child, which is not what we want for scroll event capture.
  dt_widget_set_scroll_focus(widget);
  gtk_widget_queue_draw(widget);
  return FALSE;
}
 
gboolean dt_bauhaus_focus_out_callback(GtkWidget *widget, GdkEventFocus event, gpointer user_data)
{
  // Scroll focus is released from leave-notify so wheel capture survives
  // transient Gtk focus changes while the pointer is still over the widget.
  gtk_widget_queue_draw(widget);
  return FALSE;
}
 
 
gboolean dt_bauhaus_focus_callback(GtkWidget *widget, GtkDirectionType direction, gpointer data)
{
  // Let user focus on the next/previous widget on arrow up/down
  if(direction == GTK_DIR_UP || direction == GTK_DIR_DOWN) return FALSE;
 
  // Any other key stroke is captured
  return TRUE;
}
 
gboolean _action_request_focus(GtkAccelGroup *accel_group, GObject *accelerable, guint keyval,
                               GdkModifierType modifier, gpointer data)
{
  if(IS_NULL_PTR(data) || IS_NULL_PTR(accelerable))
  {
    dt_widget_message(_("The target widget of the action does not exist anymore"));
    fprintf(stderr, "The target widget of the action does not exist anymore");
    return FALSE;
  }
 
  dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(data);
 
  // Make sure the parent module widget is visible, if we know it,
  // because we can't grab focus on invisible widgets
  if(!IS_NULL_PTR(w->module))
  {
    // Whatever "become visible" means for this module type is the module's business.
    if(w->module->ensure_visible) w->module->ensure_visible(w->module);
    w->module->focus(w->module, FALSE);
  }
 
  GtkWidget *target = GTK_WIDGET(data);
  const guint previous_source = GPOINTER_TO_UINT(g_object_get_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_SOURCE_KEY));
  if(previous_source > 0)
    g_source_remove(previous_source);
 
  g_object_set_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_TRIES_KEY, GINT_TO_POINTER(0));
  const guint source = g_idle_add_full(G_PRIORITY_DEFAULT_IDLE, ensure_focus_idle, g_object_ref(target),
                                       (GDestroyNotify)g_object_unref);
  g_object_set_data(G_OBJECT(target), DT_BAUHAUS_FOCUS_IDLE_SOURCE_KEY, GUINT_TO_POINTER(source));
  return TRUE;
}
 
static void _combobox_next_sensitive(struct dt_bauhaus_widget_t *w, int delta)
{
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
 
  int new_pos = d->active;
  int inc = (delta) > 0 ? 1 : -1;
  int cur = new_pos + inc;
  while(delta && cur >= 0 && cur < d->entries->len)
  {
    dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, cur);
    if(entry->sensitive)
    {
      new_pos = cur;
      delta -= inc;
    }
    cur += inc;
  }
  d->hovered = new_pos;
  _combobox_set(GTK_WIDGET(w), new_pos);
}
 
static dt_bauhaus_combobox_entry_t *new_combobox_entry(const char *label, const char *tooltip,
                                                       dt_bauhaus_combobox_alignment_t alignment, gboolean sensitive,
                                                       void *data, void (*free_func)(void *))
{
  dt_bauhaus_combobox_entry_t *entry = (dt_bauhaus_combobox_entry_t *)calloc(1, sizeof(dt_bauhaus_combobox_entry_t));
  entry->label = g_strdup(label);
  entry->tooltip = g_strdup(tooltip);
  entry->alignment = alignment;
  entry->sensitive = sensitive;
  entry->row_height_factor = 1.f;
  entry->data = data;
  entry->free_func = free_func;
  return entry;
}
 
static dt_bauhaus_combobox_entry_t *new_combobox_separator(const float row_height_factor)
{
  dt_bauhaus_combobox_entry_t *entry = (dt_bauhaus_combobox_entry_t *)calloc(1, sizeof(dt_bauhaus_combobox_entry_t));
  entry->label = g_strdup("");
  entry->tooltip = NULL;
  entry->sensitive = FALSE;
  entry->is_separator = TRUE;
  entry->row_height_factor = CLAMPF(row_height_factor, 0.1f, 1.f);
  return entry;
}
 
static void free_combobox_entry(gpointer data)
{
  dt_bauhaus_combobox_entry_t *entry = (dt_bauhaus_combobox_entry_t *)data;
  dt_free(entry->label);
  dt_free(entry->tooltip);
  if(entry->free_func)
    entry->free_func(entry->data);
  dt_free(entry);
}
 
static GdkRGBA *default_color_assign()
{
  // helper to initialize a color pointer with red color as a default
  GdkRGBA color = {.red = 1.0f, .green = 0.0f, .blue = 0.0f, .alpha = 1.0f};
  return gdk_rgba_copy(&color);
}
 
// Vertical alignment of text in its bounding box
typedef enum _bh_valign_t
{
  BH_ALIGN_TOP = 0,
  BH_ALIGN_BOTTOM = 1,
  BH_ALIGN_MIDDLE = 2
} _bh_valign_t;
 
// Horizontal alignment of text in its bounding box
typedef enum _bh_halign_t
{
  BH_ALIGN_LEFT = 0,
  BH_ALIGN_RIGHT = 1,
  BH_ALIGN_CENTER = 2
} _bh_halign_t;
 
static void show_pango_text(struct dt_bauhaus_widget_t *w,
                            GtkStyleContext *context,
                            cairo_t *cr,
                            GdkRectangle *bounding_box,
                            const char *text,
                            _bh_halign_t halign,
                            _bh_valign_t valign,
                            PangoEllipsizeMode ellipsize,
                            GdkRGBA *bg_color,
                            float *width,
                            float *height,
                            GtkStateFlags state)
{
  if(IS_NULL_PTR(text)) return;
 
  // Prepare context and font properties
  PangoFontDescription *css_font = NULL;
  gtk_style_context_get(context, state, GTK_STYLE_PROPERTY_FONT, &css_font, NULL);
  PangoFontDescription *resolved = pango_font_description_copy(w->bauhaus->pango_font_desc);
 
  if(css_font)
  {
    // Apply only style-related fields, NOT size
    pango_font_description_set_weight(resolved, pango_font_description_get_weight(css_font));
    pango_font_description_set_style(resolved, pango_font_description_get_style(css_font));
    pango_font_description_set_variant(resolved, pango_font_description_get_variant(css_font));
    pango_font_description_set_stretch(resolved, pango_font_description_get_stretch(css_font));
    pango_font_description_set_family(resolved, pango_font_description_get_family(css_font));
    pango_font_description_free(css_font);
  }
 
  // --- Propagate GTK's font rendering settings to the Cairo context ---
  //
  // gtk_widget_update_pango_context() (called by GTK on realise / screen
  // change) already populated this context with the system's hinting,
  // anti-aliasing, subpixel order and hint-metrics settings, sourced from
  // GtkSettings / Xft / fontconfig.  This is the identical source used by
  // every native GTK widget for text rendering.
  //
  // pango_cairo_update_layout() copies font options FROM cr TO the layout's
  // Pango context.  When cr is an intermediate image surface (as used by the
  // bauhaus off-screen compositing path) Cairo initialises it with its own
  // defaults — anti-aliasing on, regardless of system settings.  Calling
  // pango_cairo_update_layout() without correcting cr first silently
  // overwrites everything GTK configured.
  //
  // Solution: push the widget Pango context's options onto cr before
  // pango_cairo_update_layout() runs.  The round-trip then becomes a no-op
  // on font options; only the CTM/DPI are synchronised.
  //
  // cairo_set_font_options() makes an internal copy, so the const pointer
  // lifetime is not a concern.
  PangoContext *pc = gtk_widget_get_pango_context(GTK_WIDGET(w));
  dt_gui_cairo_set_font_options(cr, GTK_WIDGET(w));
 
  // --- Build the layout ---
  PangoLayout *layout = pango_layout_new(pc);
  pango_layout_set_font_description(layout, resolved);
  pango_font_description_free(resolved);
 
  // Set the actual text
  pango_layout_set_text(layout, text, -1);
  
  // Sync layout with Cairo context (CTM, DPI).
  // Font options are now consistent between cr and pc, so no overwrite occurs.
  pango_cairo_update_layout(cr, layout);
 
  // --- Measure ---
  int pango_width, pango_height;
  pango_layout_get_size(layout, &pango_width, &pango_height);
  double text_width  = (double)pango_width  / PANGO_SCALE;
  double text_height = fmax((double)pango_height / PANGO_SCALE, w->bauhaus->line_height);
  if(width)  *width  = (float)text_width;
  if(height) *height = (float)text_height;
 
  // --- Ellipsise on overflow ---
  if(text_width > bounding_box->width)
  {
    pango_layout_set_ellipsize(layout, ellipsize);
    pango_layout_set_width(layout, (int)(PANGO_SCALE * bounding_box->width));
    text_width = bounding_box->width;
    if(width) *width = (float)text_width;
    pango_cairo_update_layout(cr, layout); // re-sync after constraint change
  }
 
  // Paint background color if any - useful to highlight elements in popup list
  if(!IS_NULL_PTR(bg_color))
  {
    cairo_save(cr);
    cairo_rectangle(cr, bounding_box->x, bounding_box->y,
                        bounding_box->width, bounding_box->height);
    cairo_set_source_rgba(cr, bg_color->red, bg_color->green,
                              bg_color->blue, bg_color->alpha);
    cairo_fill(cr);
    cairo_restore(cr);
  }
 
  // Compute the coordinates of the top-left corner as to ensure proper alignment
  // in bounding box given the dimensions of the label.
  double x = 0.;
  switch(halign)
  {
    case BH_ALIGN_CENTER:
      x = bounding_box->x + bounding_box->width / 2. - text_width / 2.;
      break;
    case BH_ALIGN_RIGHT:
      x = bounding_box->x + bounding_box->width - text_width;
      break;
    case BH_ALIGN_LEFT:
    default:
      x = bounding_box->x;
      break;
  }
 
  double y = 0.;
  switch(valign)
  {
    case BH_ALIGN_MIDDLE:
      y = bounding_box->y + bounding_box->height / 2. - text_height / 2.;
      break;
    case BH_ALIGN_BOTTOM:
      y = bounding_box->y + bounding_box->height - text_height;
      break;
    case BH_ALIGN_TOP:
    default:
      y = bounding_box->y;
      break;
  }
 
  // Actually (finally) draw everything in place
  cairo_move_to(cr, x, y);
  pango_cairo_show_layout(cr, layout);
 
  // Cleanup
  g_object_unref(layout);
}
 
static void dt_bauhaus_slider_set_normalized(struct dt_bauhaus_widget_t *w, float pos, gboolean raise);
static void _dt_bauhaus_slider_set_with_raise(GtkWidget *widget, float pos, gboolean raise);
 
static double get_slider_line_offset(const double pos, const double scale, const double x, double y, const double line_height)
{
  // handle linear startup and rescale y to fit the whole range again
  // Note : all inputs are in relative coordinates, except pos
  float offset = 0.f;
  if(y < line_height)
  {
    offset = x - pos;
  }
  else
  {
    // Renormalize y coordinates below the baseline
    y = (y - line_height) / (1.0 - line_height);
    offset = (x - sqf(y) * .5 - (1.0 - sqf(y)) * pos)
             / (.5 * sqf(y) / scale + (1.0 - sqf(y)));
  }
  // clamp to result in a [0,1] range:
  if(pos + offset > 1.0) offset = 1.0 - pos;
  if(pos + offset < 0.0) offset = -pos;
  return offset;
}
 
// draw a loupe guideline for the quadratic zoom in in the slider interface:
static void draw_slider_line(cairo_t *cr, const double pos, const double off, const double scale, const double width, const double height,
                             const double line_height, double line_width)
{
  // pos is normalized position [0,1], offset is on that scale.
  // ht is in pixels here
  const int steps = 128;
  const double corrected_height = (height - line_height);
 
  cairo_set_line_width(cr, line_width);
  cairo_move_to(cr, width * (pos + off), line_height);
  const double half_line_width = line_width / 2.;
  for(int j = 1; j < steps; j++)
  {
    const double y = (double)j / (double)(steps - 1);
    const double x = sqf(y) * .5f * (1.f + off / scale) + (1.0f - sqf(y)) * (pos + off);
    cairo_line_to(cr, x * width - half_line_width, line_height + y * corrected_height);
  }
}
// -------------------------------
 
static void _slider_zoom_range(struct dt_bauhaus_widget_t *w, float zoom)
{
  dt_bauhaus_slider_data_t *d = &w->data.slider;
 
  const float value = dt_bauhaus_slider_get(GTK_WIDGET(w));
 
  if(roundf(zoom) == 0.f)
  {
    d->min = d->soft_min;
    d->max = d->soft_max;
    dt_bauhaus_slider_set(GTK_WIDGET(w), value); // restore value (and move min/max again if needed)
    return;
  }
 
  // make sure current value still in zoomed range
  const float min_visible = _bh_slider_get_min_step(w);
  const float multiplier = exp2f(zoom / 2.f);
  const float new_min = value - multiplier * (value - d->min);
  const float new_max = value + multiplier * (d->max - value);
  if(new_min >= d->hard_min
      && new_max <= d->hard_max
      && new_max - new_min >= min_visible * 10)
  {
    d->min = new_min;
    d->max = new_max;
  }
 
  gtk_widget_queue_draw(GTK_WIDGET(w));
}
 
static gboolean dt_bauhaus_popup_scroll(GtkWidget *widget, GdkEventScroll *event, gpointer user_data)
{
  dt_bauhaus_t *bh = g_object_get_data(G_OBJECT(widget), "bauhaus");
  dt_bauhaus_widget_t *w = bh->current;
  dt_widget_set_scroll_focus(GTK_WIDGET(w));
  return _widget_scroll(GTK_WIDGET(w), event);
}
 
static gboolean dt_bauhaus_popup_motion_notify(GtkWidget *widget, GdkEventMotion *event, gpointer user_data)
{
  dt_bauhaus_t *bh = g_object_get_data(G_OBJECT(widget), "bauhaus");
  dt_bauhaus_widget_t *w = bh->current;
 
  double event_x;
  double event_y;
  const _bh_active_region_t active = _popup_coordinates(bh, event->x_root, event->y_root, &event_x, &event_y);
 
#if DEBUG
  fprintf(stdout, "x: %i, y: %i, active: %i\n", (int)event_x, (int)event_y, active);
#endif
 
  if(active == BH_REGION_OUT) return FALSE;
 
  // Pass-on new cursor coordinates corrected for padding and margin
  // and start a redraw. Nothing else.
  bh->mouse_x = event_x;
  bh->mouse_y = event_y;
 
  if(w->type == DT_BAUHAUS_COMBOBOX)
  {
    _bh_combobox_get_hovered_entry(w);
    gtk_widget_queue_draw(bh->popup_area);
  }
  else
  {
    dt_bauhaus_slider_data_t *d = &w->data.slider;
    const double main_height = _widget_get_main_height(w, widget);
    const float mouse_off = get_slider_line_offset(
        d->oldpos, _bh_slider_get_scale(w), bh->mouse_x / _widget_get_main_width(w, NULL, NULL),
        bh->mouse_y / main_height, _get_slider_bar_height(w) / main_height);
 
    if(d->is_dragging)
    {
      // On dragging (when holding a click), we commit intermediate values to pipeline for "realtime" preview
      dt_bauhaus_slider_set_normalized(w, d->oldpos + mouse_off, TRUE);
    }
    else
    {
      // If not dragging, assume user just wants to take his time to fine-tune the value.
      d->pos = d->oldpos + mouse_off;
      gtk_widget_queue_draw(bh->popup_area);
    }
  }
 
  return TRUE;
}
 
static gboolean dt_bauhaus_popup_leave_notify(GtkWidget *widget, GdkEventCrossing *event, gpointer user_data)
{
  gtk_widget_set_state_flags(widget, GTK_STATE_FLAG_NORMAL, TRUE);
  return TRUE;
}
 
static gboolean dt_bauhaus_popup_button_release(GtkWidget *widget, GdkEventButton *event, gpointer user_data)
{
  int delay = 0;
  g_object_get(gtk_settings_get_default(), "gtk-double-click-time", &delay, NULL);
  dt_bauhaus_t *bh = g_object_get_data(G_OBJECT(widget), "bauhaus");
  dt_bauhaus_widget_t *w = bh->current;
 
  if(w && (w->type == DT_BAUHAUS_COMBOBOX) && (event->button == 1)
     && (event->time >= bh->opentime + delay) && !bh->hiding)
  {
    gtk_widget_set_state_flags(widget, GTK_STATE_FLAG_ACTIVE, TRUE);
 
    dt_bauhaus_hide_popup(bh);
  }
  else if(bh->hiding)
  {
    dt_bauhaus_hide_popup(bh);
  }
  return TRUE;
}
 
static gboolean dt_bauhaus_popup_button_press(GtkWidget *widget, GdkEventButton *event, gpointer user_data)
{
  int delay = 0;
  g_object_get(gtk_settings_get_default(), "gtk-double-click-time", &delay, NULL);
 
  dt_bauhaus_t *bh = g_object_get_data(G_OBJECT(widget), "bauhaus");
  dt_bauhaus_widget_t *w = bh->current;
 
  if(event->button == 1)
  {
    if(w->type == DT_BAUHAUS_COMBOBOX
       && event->time < bh->opentime + delay)
    {
      // counts as double click, reset:
      const dt_bauhaus_combobox_data_t *d = &w->data.combobox;
      dt_bauhaus_combobox_set(GTK_WIDGET(w), d->defpos);
      dt_bauhaus_widget_reject(w);
    }
    else
    {
      // only accept left mouse click.
      // coordinates are set in motion_notify, which also makes sure they are within the valid range.
      // problems appear with the cornercase where user didn't move the cursor since opening the popup.
      // aka we need to re-read coordinates here.
      double event_x;
      double event_y;
      const _bh_active_region_t active = _popup_coordinates(bh, event->x_root, event->y_root, &event_x, &event_y);
 
      if(active == BH_REGION_OUT)
      {
        dt_bauhaus_widget_reject(w);
        dt_bauhaus_hide_popup(bh);
        return TRUE;
      }
 
      bh->end_mouse_x = bh->mouse_x = event_x;
      bh->end_mouse_y = bh->mouse_y = event_y;
 
      if(w->type == DT_BAUHAUS_SLIDER)
      {
        dt_bauhaus_slider_data_t *d = &w->data.slider;
        d->is_dragging = TRUE;
 
        // Trick to ensure new value ≠ d->pos (so we commit to pipeline), since
        // d->pos is used for uncommitted drawings.
        const float value = d->pos;
        d->pos = d->oldpos;
        dt_bauhaus_slider_set_normalized(w, value, TRUE);
      }
      else
      {
        _bh_combobox_get_hovered_entry(w);
        dt_bauhaus_widget_accept(w);
      }
    }
    bh->hiding = TRUE;
  }
  else if(event->button == 2 && w->type == DT_BAUHAUS_SLIDER)
  {
    _slider_zoom_range(w, 0);
    gtk_widget_queue_draw(widget);
  }
  else
  {
    dt_bauhaus_widget_reject(w);
    bh->hiding = TRUE;
  }
  return TRUE;
}
 
static void dt_bauhaus_window_show(GtkWidget *w, gpointer user_data)
{
  gtk_grab_add(GTK_WIDGET(user_data));
}
 
static void dt_bh_init(DtBauhausWidget *class)
{
  // not sure if we want to use this instead of our code in *_new()
  // TODO: the common code from bauhaus_widget_init() could go here.
}
 
static gboolean _enter_leave(GtkWidget *widget, GdkEventCrossing *event)
{
  if(event->type == GDK_ENTER_NOTIFY)
  {
    gtk_widget_set_state_flags(widget, GTK_STATE_FLAG_PRELIGHT, FALSE);
  }
  else
  {
    gtk_widget_unset_state_flags(widget, GTK_STATE_FLAG_PRELIGHT);
 
    // GUI refreshes can emit synthetic crossing events while the pointer never
    // physically leaves the widget. Only drop wheel capture on a real pointer
    // leave from the widget itself.
    const gboolean real_leave = event->mode == GDK_CROSSING_NORMAL
                                && event->detail != GDK_NOTIFY_INFERIOR
                                && !dt_gui_widgets_suppressed();
    if(real_leave && dt_widget_scroll_focus() == widget)
      dt_widget_set_scroll_focus(NULL);
  }
 
  gtk_widget_queue_draw(widget);
 
  return FALSE;
}
 
static void _widget_finalize(GObject *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
 
  const guint focus_source = GPOINTER_TO_UINT(g_object_get_data(G_OBJECT(widget), DT_BAUHAUS_FOCUS_IDLE_SOURCE_KEY));
  if(focus_source > 0)
  {
    g_source_remove(focus_source);
    g_object_set_data(G_OBJECT(widget), DT_BAUHAUS_FOCUS_IDLE_SOURCE_KEY, NULL);
    g_object_set_data(G_OBJECT(widget), DT_BAUHAUS_FOCUS_IDLE_TRIES_KEY, NULL);
  }
 
  const char *accel_path = g_object_get_data(G_OBJECT(widget), "accel-path");
  if(!IS_NULL_PTR(accel_path) && !IS_NULL_PTR(dt_accels_get_global()))
    dt_accels_remove_accel(dt_accels_get_global(), accel_path, widget);
 
  if(dt_widget_scroll_focus() == GTK_WIDGET(w))
    dt_widget_set_scroll_focus(NULL);
  if(w->type == DT_BAUHAUS_SLIDER)
  {
    dt_bauhaus_slider_data_t *d = &w->data.slider;
    dt_free(d->grad_col);
    dt_free(d->grad_pos);
  }
  else
  {
    dt_bauhaus_combobox_data_t *d = &w->data.combobox;
    g_ptr_array_free(d->entries, TRUE);
    dt_free(d->text);
  }
  gtk_border_free(w->margin);
  gtk_border_free(w->padding);
 
  G_OBJECT_CLASS(dt_bh_parent_class)->finalize(widget);
}
 
static void dt_bh_class_init(DtBauhausWidgetClass *class)
{
  class->signals[DT_BAUHAUS_VALUE_CHANGED_SIGNAL]
      = g_signal_new("value-changed", G_TYPE_FROM_CLASS(class), G_SIGNAL_RUN_LAST, 0, NULL, NULL,
                     g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);
  class->signals[DT_BAUHAUS_QUAD_PRESSED_SIGNAL]
      = g_signal_new("quad-pressed", G_TYPE_FROM_CLASS(class), G_SIGNAL_RUN_LAST, 0, NULL, NULL,
                     g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);
 
  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(class);
  widget_class->draw = _widget_draw;
  widget_class->scroll_event = _widget_scroll;
  widget_class->key_press_event = _widget_key_press;
  widget_class->get_preferred_width = _get_preferred_width;
  widget_class->get_preferred_height = _get_preferred_height;
  widget_class->enter_notify_event = _enter_leave;
  widget_class->leave_notify_event = _enter_leave;
  widget_class->style_updated = _style_updated;
  G_OBJECT_CLASS(class)->finalize = _widget_finalize;
}
 
void dt_bauhaus_load_theme(dt_bauhaus_t *bauhaus)
{
  bauhaus->line_height = 16;
  bauhaus->marker_size = 0.25f;
 
  GtkWidget *root_window = dt_widget_root_window();
  if(IS_NULL_PTR(root_window)) return;
  GtkStyleContext *ctx = gtk_widget_get_style_context(root_window);
  gtk_style_context_set_screen(ctx, gtk_widget_get_screen(root_window));
 
  gtk_style_context_lookup_color(ctx, "bauhaus_fg", &bauhaus->color_fg);
  gtk_style_context_lookup_color(ctx, "bauhaus_fg_insensitive", &bauhaus->color_fg_insensitive);
  gtk_style_context_lookup_color(ctx, "bauhaus_bg", &bauhaus->color_bg);
  gtk_style_context_lookup_color(ctx, "bauhaus_border", &bauhaus->color_border);
  gtk_style_context_lookup_color(ctx, "bauhaus_fill", &bauhaus->color_fill);
  gtk_style_context_lookup_color(ctx, "bauhaus_indicator_border", &bauhaus->indicator_border);
  if(!gtk_style_context_lookup_color(ctx, "bauhaus_value", &bauhaus->color_value))
    bauhaus->color_value = bauhaus->color_fill;
  if(!gtk_style_context_lookup_color(ctx, "bauhaus_value_insensitive", &bauhaus->color_value_insensitive))
    bauhaus->color_value_insensitive = bauhaus->color_fg_insensitive;
  if(!gtk_style_context_lookup_color(ctx, "bauhaus_value_text", &bauhaus->color_value_text))
    bauhaus->color_value_text = bauhaus->color_value;
  if(!gtk_style_context_lookup_color(ctx, "bauhaus_value_text_insensitive", &bauhaus->color_value_text_insensitive))
    bauhaus->color_value_text_insensitive = bauhaus->color_value_insensitive;
 
  gtk_style_context_lookup_color(ctx, "graph_bg", &bauhaus->graph_bg);
  gtk_style_context_lookup_color(ctx, "graph_exterior", &bauhaus->graph_exterior);
  gtk_style_context_lookup_color(ctx, "graph_border", &bauhaus->graph_border);
  gtk_style_context_lookup_color(ctx, "graph_grid", &bauhaus->graph_grid);
  gtk_style_context_lookup_color(ctx, "graph_fg", &bauhaus->graph_fg);
  gtk_style_context_lookup_color(ctx, "graph_fg_active", &bauhaus->graph_fg_active);
  gtk_style_context_lookup_color(ctx, "graph_overlay", &bauhaus->graph_overlay);
  if(!gtk_style_context_lookup_color(ctx, "graph_scope_restricted", &bauhaus->graph_scope_restricted))
    bauhaus->graph_scope_restricted = bauhaus->graph_fg; // For the "restricted" text in the scope
  gtk_style_context_lookup_color(ctx, "inset_histogram", &bauhaus->inset_histogram);
  gtk_style_context_lookup_color(ctx, "graph_red", &bauhaus->graph_colors[0]);
  gtk_style_context_lookup_color(ctx, "graph_green", &bauhaus->graph_colors[1]);
  gtk_style_context_lookup_color(ctx, "graph_blue", &bauhaus->graph_colors[2]);
  gtk_style_context_lookup_color(ctx, "colorlabel_red",
                                 &bauhaus->colorlabels[DT_COLORLABELS_RED]);
  gtk_style_context_lookup_color(ctx, "colorlabel_yellow",
                                 &bauhaus->colorlabels[DT_COLORLABELS_YELLOW]);
  gtk_style_context_lookup_color(ctx, "colorlabel_green",
                                 &bauhaus->colorlabels[DT_COLORLABELS_GREEN]);
  gtk_style_context_lookup_color(ctx, "colorlabel_blue",
                                 &bauhaus->colorlabels[DT_COLORLABELS_BLUE]);
  gtk_style_context_lookup_color(ctx, "colorlabel_purple",
                                 &bauhaus->colorlabels[DT_COLORLABELS_PURPLE]);
 
  // Publish the resolved palette to the widget layer: paint.c draws colour labels and must
  // not reach back into bauhaus for them. Re-published on every theme reload.
  dt_widget_set_colorlabels(bauhaus->colorlabels, DT_COLORLABELS_LAST);
 
 
  // make sure we release previously loaded font
  if(bauhaus->pango_font_desc)
    pango_font_description_free(bauhaus->pango_font_desc);
 
  // Create a scratch Cairo surface to draw on
  cairo_surface_t *cst = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 128, 128);
  cairo_t *cr = cairo_create(cst);
 
  // Let Gtk create a fake label and grab its font description
  GtkWidget *ref = gtk_label_new(NULL);
  ctx = gtk_widget_get_style_context(ref);
  gtk_style_context_get(ctx, GTK_STATE_FLAG_NORMAL, "font", &bauhaus->pango_font_desc, NULL);
  
  PangoContext *context = gtk_widget_get_pango_context(ref);
  PangoLayout *layout = pango_layout_new(context);
  pango_layout_set_text(layout, "em", -1);
  pango_layout_set_font_description(layout, bauhaus->pango_font_desc);
  //double dpi = pango_cairo_context_get_resolution(context);
  //double scale = gtk_widget_get_scale_factor(ref);
  //pango_cairo_context_set_resolution(context, dpi * scale);
 
  // Get advanced font options (system anti-aliasing/hinting/subpixel/kerning)
  dt_gui_cairo_set_font_options(cr, ref);
 
  // Render
  pango_cairo_update_layout(cr, layout);
  pango_cairo_show_layout(cr, layout);
 
  // Measure the text line height
  int pango_width;
  int pango_height;
  pango_layout_get_size(layout, &pango_width, &pango_height);
  g_object_unref(layout);
  cairo_destroy(cr);
  cairo_surface_destroy(cst);
 
  bauhaus->line_height = pango_height / PANGO_SCALE;
  bauhaus->quad_width = bauhaus->line_height;
 
  bauhaus->baseline_size = 5; // absolute size in Cairo unit
  bauhaus->border_width = 1; // absolute size in Cairo unit
  bauhaus->marker_size = pango_height / PANGO_SCALE * 0.6;
}
 
dt_bauhaus_t * dt_bauhaus_init()
{
  dt_bauhaus_t * bauhaus = (dt_bauhaus_t *)calloc(1, sizeof(dt_bauhaus_t));
  bauhaus->keys_cnt = 0;
  bauhaus->current = NULL;
  bauhaus->popup_area = gtk_drawing_area_new();
  bauhaus->pango_font_desc = NULL;
 
  dt_bauhaus_load_theme(bauhaus);
 
  // this easily gets keyboard input:
  // bauhaus->popup_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  // but this doesn't flicker, and the above hack with key input seems to work well.
  bauhaus->popup_window = gtk_window_new(GTK_WINDOW_POPUP);
#ifdef GDK_WINDOWING_QUARTZ
  dt_osx_disallow_fullscreen(bauhaus->popup_window);
#endif
  // this is needed for popup, not for toplevel.
  // since popup_area gets the focus if we show the window, this is all
  // we need.
 
  gtk_window_set_resizable(GTK_WINDOW(bauhaus->popup_window), FALSE);
  gtk_window_set_default_size(GTK_WINDOW(bauhaus->popup_window), 30, 30);
  gtk_window_set_modal(GTK_WINDOW(bauhaus->popup_window), TRUE);
 
  // Needed for Wayland and Sway :
  GtkWidget *root = dt_widget_root_window();
  if(root) gtk_window_set_transient_for(GTK_WINDOW(bauhaus->popup_window), GTK_WINDOW(root));
 
  gtk_window_set_decorated(GTK_WINDOW(bauhaus->popup_window), FALSE);
  gtk_window_set_attached_to(GTK_WINDOW(bauhaus->popup_window), NULL);
 
  // needed on macOS to avoid fullscreening the popup with newer GTK
  gtk_window_set_type_hint(GTK_WINDOW(bauhaus->popup_window), GDK_WINDOW_TYPE_HINT_POPUP_MENU);
 
  gtk_container_add(GTK_CONTAINER(bauhaus->popup_window), bauhaus->popup_area);
  gtk_widget_set_hexpand(bauhaus->popup_area, TRUE);
  gtk_widget_set_vexpand(bauhaus->popup_area, TRUE);
  gtk_window_set_keep_above(GTK_WINDOW(bauhaus->popup_window), TRUE);
  gtk_window_set_gravity(GTK_WINDOW(bauhaus->popup_window), GDK_GRAVITY_STATIC);
 
  gtk_widget_set_can_focus(bauhaus->popup_area, TRUE);
  gtk_widget_add_events(bauhaus->popup_area, GDK_POINTER_MOTION_MASK
                                                       | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK
                                                       | GDK_KEY_PRESS_MASK | GDK_LEAVE_NOTIFY_MASK
                                                       | dt_widget_scroll_mask());
 
  GObject *window = G_OBJECT(bauhaus->popup_window);
  GObject *area = G_OBJECT(bauhaus->popup_area);
  g_object_set_data(area, "bauhaus", bauhaus);
 
  g_signal_connect(window, "show", G_CALLBACK(dt_bauhaus_window_show), area);
  g_signal_connect(area, "draw", G_CALLBACK(dt_bauhaus_popup_draw), NULL);
  g_signal_connect(area, "motion-notify-event", G_CALLBACK(dt_bauhaus_popup_motion_notify), NULL);
  g_signal_connect(area, "leave-notify-event", G_CALLBACK(dt_bauhaus_popup_leave_notify), NULL);
  g_signal_connect(area, "button-press-event", G_CALLBACK(dt_bauhaus_popup_button_press), NULL);
  g_signal_connect(area, "button-release-event", G_CALLBACK (dt_bauhaus_popup_button_release), NULL);
  g_signal_connect(area, "key-press-event", G_CALLBACK(dt_bauhaus_popup_key_press), NULL);
  g_signal_connect(area, "scroll-event", G_CALLBACK(dt_bauhaus_popup_scroll), NULL);
 
  // Keys used by key-pressed event handler when the Bauhaus widget has the focus
  gchar *path = dt_accels_build_path(_("Darkroom/Controls/Sliders"), _("Increase value (normal step)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Right, 0);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Sliders"), _("Decrease value (normal step)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Left, 0);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Sliders"), _("Increase value (fine step)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Right, DT_PRIMARY_MASK);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Sliders"), _("Decrease value (fine step)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Left, DT_PRIMARY_MASK);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Sliders"), _("Increase value (coarse step)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Right, GDK_SHIFT_MASK);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Sliders"), _("Decrease value (coarse step)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Left, GDK_SHIFT_MASK);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Sliders"), _("Toggle color-picker"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Insert, 0);
  dt_free(path);
 
  path = dt_accels_build_path(_("Darkroom/Controls/Comboboxes"), _("Open editing mode"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Return, 0);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Comboboxes"), _("Exit editing mode"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Escape, 0);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Comboboxes"), _("Select previous (in editing mode)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Up, 0);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Comboboxes"), _("Select next (in editing mode)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Down, 0);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Comboboxes"), _("Validate result (in editing mode)"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Return, 0);
  dt_free(path);
  path = dt_accels_build_path(_("Darkroom/Controls/Comboboxes"), _("Toggle color-picker"));
  dt_accels_new_virtual_shortcut(dt_accels_get_global(), dt_accels_get_global()->darkroom_accels,
                                  path, NULL, GDK_KEY_Insert, 0);
  dt_free(path);
 
  return bauhaus;
}
 
void dt_bauhaus_cleanup(dt_bauhaus_t *bauhaus)
{
}
 
// fwd declare a few callbacks
static gboolean dt_bauhaus_slider_button_press(GtkWidget *widget, GdkEventButton *event, gpointer user_data);
static gboolean dt_bauhaus_slider_button_release(GtkWidget *widget, GdkEventButton *event, gpointer user_data);
static gboolean dt_bauhaus_slider_motion_notify(GtkWidget *widget, GdkEventMotion *event, gpointer user_data);
 
 
static gboolean dt_bauhaus_combobox_button_press(GtkWidget *widget, GdkEventButton *event, gpointer user_data);
 
// end static init/cleanup
// =================================================
 
 
 
// common initialization
static void _bauhaus_widget_init(dt_bauhaus_t *bauhaus, dt_bauhaus_widget_t *w, dt_gui_module_t *self)
{
  w->module = self;
  w->field = NULL;
 
  w->no_accels = FALSE;
  w->no_module_list = FALSE;
  w->bauhaus = bauhaus;
  w->use_default_callback = FALSE;
 
  // no quad icon and no toggle button:
  w->quad_paint = 0;
  w->quad_paint_data = NULL;
  w->quad_toggle = 0;
  w->show_quad = TRUE;
  w->expand = TRUE;
 
  gtk_widget_add_events(GTK_WIDGET(w), GDK_POINTER_MOTION_MASK
                                       | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK
                                       | GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK
                                       | GDK_FOCUS_CHANGE_MASK
                                       | dt_widget_scroll_mask());
 
  gtk_widget_set_can_focus(GTK_WIDGET(w), TRUE);
  gtk_widget_set_halign(GTK_WIDGET(w), GTK_ALIGN_FILL);
  gtk_widget_set_hexpand(GTK_WIDGET(w), TRUE);
  g_signal_connect(G_OBJECT(w), "focus-in-event", G_CALLBACK(dt_bauhaus_focus_in_callback), NULL);
  g_signal_connect(G_OBJECT(w), "focus-out-event", G_CALLBACK(dt_bauhaus_focus_out_callback), NULL);
  g_signal_connect(G_OBJECT(w), "focus", G_CALLBACK(dt_bauhaus_focus_callback), NULL);
 
  dt_gui_add_class(GTK_WIDGET(w), "dt_bauhaus");
}
 
void dt_bauhaus_combobox_set_default(GtkWidget *widget, int def)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  d->defpos = def;
}
 
 
void dt_bauhaus_slider_set_hard_min(GtkWidget* widget, float val)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  float current_position = dt_bauhaus_slider_get(widget);
  float desired_position = _bh_round_to_n_digits(w, val);
  d->min = MAX(d->min, d->hard_min);
  d->soft_min = MAX(d->soft_min, d->hard_min);
 
  if(desired_position > d->hard_max)
    dt_bauhaus_slider_set_hard_max(widget,val);
 
  if(current_position < desired_position)
    dt_bauhaus_slider_set(widget, desired_position);
  // else nothing : old position is the new position, just the bound changes
}
 
float dt_bauhaus_slider_get_hard_min(GtkWidget* widget)
{
  const struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return d->hard_min;
}
 
void dt_bauhaus_slider_set_hard_max(GtkWidget* widget, float val)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  float current_position = dt_bauhaus_slider_get(widget);
  float desired_position = _bh_round_to_n_digits(w, val);
  d->hard_max = desired_position;
  d->max = MIN(d->max, d->hard_max);
  d->soft_max = MIN(d->soft_max, d->hard_max);
 
  if(desired_position < d->hard_min)
    dt_bauhaus_slider_set_hard_min(widget, desired_position);
 
  if(current_position > desired_position)
    dt_bauhaus_slider_set(widget, desired_position);
  // else nothing : old position is the new position, just the bound changes
}
 
float dt_bauhaus_slider_get_hard_max(GtkWidget* widget)
{
  const struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return d->hard_max;
}
 
void dt_bauhaus_slider_set_soft_min(GtkWidget* widget, float val)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  float oldval = dt_bauhaus_slider_get(widget);
  d->min = d->soft_min = CLAMP(val, d->hard_min, d->hard_max);
  // a bound change is not a user edit: re-apply the value without raising
  _dt_bauhaus_slider_set_with_raise(widget, oldval, FALSE);
}
 
float dt_bauhaus_slider_get_soft_min(GtkWidget* widget)
{
  const struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return d->soft_min;
}
 
void dt_bauhaus_slider_set_soft_max(GtkWidget* widget, float val)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  float oldval = dt_bauhaus_slider_get(widget);
  d->max = d->soft_max = CLAMP(val, d->hard_min, d->hard_max);
  // a bound change is not a user edit: re-apply the value without raising
  _dt_bauhaus_slider_set_with_raise(widget, oldval, FALSE);
}
 
float dt_bauhaus_slider_get_soft_max(GtkWidget* widget)
{
  const struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return d->soft_max;
}
 
void dt_bauhaus_slider_set_default(GtkWidget *widget, float def)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->defpos = def;
}
 
void dt_bauhaus_slider_set_soft_range(GtkWidget *widget, float soft_min, float soft_max)
{
  dt_bauhaus_slider_set_soft_min(widget, soft_min);
  dt_bauhaus_slider_set_soft_max(widget, soft_max);
}
 
void dt_bauhaus_widget_set_label(GtkWidget *widget, const char *label)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(label)
  {
    g_strlcpy(w->label, label, sizeof(w->label));
    dt_capitalize_label(w->label);
  }
 
  if(w->module)
  {
    // Widgets auto-set by params introspection need to be added to the list of stuff to auto-update
    dt_gui_module_t *m = w->module;
    if(m && !w->no_module_list)
      m->widget_list = g_list_append(m->widget_list, w);
 
    if(m && w->field && !w->no_module_list)
      m->widget_list_bh = g_list_append(m->widget_list_bh, w);
 
    // Wire the focusing action
    // Note: once the focus is grabbed, interaction with the widget happens through arrow keys or mouse wheel.
    // No need to wire all possible events/interactions.
    if(m && !w->no_accels && !w->module->deprecated && label)
    {
      // The module name and the control label are two levels of the path: each one goes
      // through dt_accels_build_path() on its own, so that neither can split into more.
      gchar *module_name = g_strdup(m->name);
      dt_capitalize_label(module_name);
 
      gchar *scope = g_strdup_printf("%s/Modules", m->view);
      gchar *module_path = dt_accels_build_path(scope, module_name);
      dt_accels_new_darkroom_action(_action_request_focus, widget, widget, module_path, w->label, 0, 0,
                                    _("Focuses the control"));
      gchar *darkroom_path = dt_accels_build_path("Darkroom/Modules", module_name);
      g_object_set_data_full(G_OBJECT(widget), "accel-path",
                             dt_accels_build_path(darkroom_path, w->label), dt_free_gpointer);
      gtk_widget_set_has_tooltip(widget, TRUE);
      dt_free(darkroom_path);
      dt_free(module_path);
      dt_free(scope);
      dt_free(module_name);
    }
 
    gtk_widget_queue_draw(GTK_WIDGET(w));
  }
}
 
const char* dt_bauhaus_widget_get_label(GtkWidget *widget)
{
  const struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  return w->label;
}
 
void dt_bauhaus_widget_set_quad_paint(GtkWidget *widget, dt_bauhaus_quad_paint_f f, int paint_flags, void *paint_data)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  w->quad_paint = f;
  w->quad_paint_flags = paint_flags;
  w->quad_paint_data = paint_data;
}
 
void dt_bauhaus_widget_set_field(GtkWidget *widget, gpointer field, dt_introspection_type_t field_type)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(*w->label)
    fprintf(stderr, "[dt_bauhaus_widget_set_field] bauhaus label '%s' set before field (needs to be after)\n", w->label);
  w->field = field;
  w->field_type = field_type;
}
 
// make this quad a toggle button:
void dt_bauhaus_widget_set_quad_toggle(GtkWidget *widget, int toggle)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  w->quad_toggle = toggle;
}
 
void dt_bauhaus_widget_set_quad_active(GtkWidget *widget, int active)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if (active)
    w->quad_paint_flags |= CPF_ACTIVE;
  else
    w->quad_paint_flags &= ~CPF_ACTIVE;
  gtk_widget_queue_draw(GTK_WIDGET(w));
}
 
void dt_bauhaus_widget_set_quad_visibility(GtkWidget *widget, const gboolean visible)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  w->show_quad = visible;
  gtk_widget_queue_draw(GTK_WIDGET(w));
}
 
int dt_bauhaus_widget_get_quad_active(GtkWidget *widget)
{
  const struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  return (w->quad_paint_flags & CPF_ACTIVE) == CPF_ACTIVE;
}
 
void dt_bauhaus_widget_press_quad(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->quad_toggle)
  {
    w->quad_paint_flags ^= CPF_ACTIVE;
  }
  else
    w->quad_paint_flags |= CPF_ACTIVE;
 
  g_signal_emit_by_name(G_OBJECT(w), "quad-pressed");
}
 
void dt_bauhaus_widget_release_quad(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  gtk_widget_grab_focus(widget);
 
  if(!w->quad_toggle)
  {
    if (w->quad_paint_flags & CPF_ACTIVE)
      w->quad_paint_flags &= ~CPF_ACTIVE;
    gtk_widget_queue_draw(GTK_WIDGET(w));
  }
}
 
GtkWidget *dt_bauhaus_slider_new(dt_bauhaus_t *bh, dt_gui_module_t *self)
{
  return dt_bauhaus_slider_new_with_range(bh, self, 0.0, 1.0, 0.1, 0.5, 3);
}
 
GtkWidget *dt_bauhaus_slider_new_with_range(dt_bauhaus_t *bh, dt_gui_module_t *self, float min, float max, float step,
                                            float defval, int digits)
{
  return dt_bauhaus_slider_new_with_range_and_feedback(bh, self, min, max, step, defval, digits, 1);
}
 
GtkWidget *dt_bauhaus_slider_new_with_range_and_feedback(dt_bauhaus_t *bh, dt_gui_module_t *self, float min, float max,
                                                         float step, float defval, int digits, int feedback)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(g_object_new(DT_BAUHAUS_WIDGET_TYPE, NULL));
  return dt_bauhaus_slider_from_widget(bh, w,self, min, max, step, defval, digits, feedback);
}
 
static void _style_updated(GtkWidget *widget)
{
  // GTK's own handler applies the CSS opacity (the theme dims *:disabled) and queues the redraw;
  // without it, a widget keeps the opacity of whichever state its style was first computed in.
  GTK_WIDGET_CLASS(dt_bh_parent_class)->style_updated(widget);
 
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  _margins_retrieve(w);
 
  // gtk_widget_set_size_request is the minimal preferred, size.
  // it NEEDS to be defined and will be contextually adapted, possibly overriden by CSS.
  // Thing is Gtk CSS min-width in combination with hexpand is wonky so this is how it should be done.
  if(w->type == DT_BAUHAUS_COMBOBOX)
    gtk_widget_set_size_request(widget, -1, _get_combobox_height(widget));
  else if(w->type == DT_BAUHAUS_SLIDER)
    gtk_widget_set_size_request(widget, -1, _get_slider_height(widget));
}
 
GtkWidget *dt_bauhaus_slider_from_widget(dt_bauhaus_t *bh, dt_bauhaus_widget_t *w,dt_gui_module_t *self, float min, float max,
                                         float step, float defval, int digits, int feedback)
{
  w->type = DT_BAUHAUS_SLIDER;
  _bauhaus_widget_init(bh, w, self);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->min = d->soft_min = d->hard_min = min;
  d->max = d->soft_max = d->hard_max = max;
  d->step = step;
  // normalize default:
  d->defpos = defval;
  d->pos = (defval - min) / (max - min);
  d->oldpos = d->pos;
  d->digits = digits;
  d->format = "";
  d->factor = 1.0f;
  d->offset = 0.0f;
 
  d->grad_cnt = 0;
  d->grad_col = NULL;
  d->grad_pos = NULL;
 
  d->fill_feedback = feedback;
 
  d->is_dragging = 0;
 
  dt_gui_add_class(GTK_WIDGET(w), "bauhaus_slider");
 
  g_signal_connect(G_OBJECT(w), "button-press-event", G_CALLBACK(dt_bauhaus_slider_button_press), NULL);
  g_signal_connect(G_OBJECT(w), "button-release-event", G_CALLBACK(dt_bauhaus_slider_button_release), NULL);
  g_signal_connect(G_OBJECT(w), "motion-notify-event", G_CALLBACK(dt_bauhaus_slider_motion_notify), NULL);
 
  return GTK_WIDGET(w);
}
 
GtkWidget *dt_bauhaus_combobox_new(dt_bauhaus_t *bh, dt_gui_module_t *self)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(g_object_new(DT_BAUHAUS_WIDGET_TYPE, NULL));
  dt_bauhaus_combobox_from_widget(bh, w, self);
  return GTK_WIDGET(w);
}
 
GtkWidget *dt_bauhaus_combobox_new_full(dt_bauhaus_t *bh, dt_gui_module_t *self, const char *label, const char *tip,
                                        int pos, GtkCallback callback, gpointer data, const char **texts)
{
  GtkWidget *combo = dt_bauhaus_combobox_new(bh, self);
  dt_bauhaus_widget_set_label(combo, label);
  dt_bauhaus_combobox_add_list(combo, texts);
  dt_bauhaus_combobox_set(combo, pos);
  gtk_widget_set_tooltip_text(combo, tip ? tip : _(label));
  if(callback) g_signal_connect(G_OBJECT(combo), "value-changed", G_CALLBACK(callback), data);
 
  return combo;
}
 
 
 
void dt_bauhaus_combobox_from_widget(dt_bauhaus_t *bh, dt_bauhaus_widget_t* w,dt_gui_module_t *self)
{
  w->type = DT_BAUHAUS_COMBOBOX;
  _bauhaus_widget_init(bh, w, self);
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  d->entries = g_ptr_array_new_full(4, free_combobox_entry);
  d->defpos = 0;
  d->active = -1;
  d->editable = 0;
  d->text_align = DT_BAUHAUS_COMBOBOX_ALIGN_RIGHT;
  d->entries_ellipsis = PANGO_ELLIPSIZE_END;
  d->populate = NULL;
  d->text = NULL;
 
  dt_gui_add_class(GTK_WIDGET(w), "bauhaus_combobox");
 
  g_signal_connect(G_OBJECT(w), "button-press-event", G_CALLBACK(dt_bauhaus_combobox_button_press), NULL);
}
 
static dt_bauhaus_combobox_data_t *_combobox_data(GtkWidget *widget)
{
  if(IS_NULL_PTR(widget)) return NULL;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return NULL;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
 
  if(d->active >= d->entries->len) d->active = -1;
 
  return d;
}
 
static int _combobox_selectable_count(const dt_bauhaus_combobox_data_t *d)
{
  int count = 0;
  for(int i = 0; !IS_NULL_PTR(d) && i < d->entries->len; i++)
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
    if(!entry->is_separator) count++;
  }
  return count;
}
 
static int _combobox_public_to_entry_pos(const dt_bauhaus_combobox_data_t *d, const int pos,
                                         const gboolean allow_end)
{
  if(IS_NULL_PTR(d) || pos < 0) return -1;
 
  int selectable_pos = 0;
  for(int i = 0; i < d->entries->len; i++)
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
    if(entry->is_separator) continue;
    if(selectable_pos == pos) return i;
    selectable_pos++;
  }
 
  return (allow_end && selectable_pos == pos) ? (int)d->entries->len : -1;
}
 
static int _combobox_entry_pos_to_public(const dt_bauhaus_combobox_data_t *d, const int entry_pos)
{
  if(IS_NULL_PTR(d) || entry_pos < 0 || entry_pos >= d->entries->len) return -1;
 
  int selectable_pos = 0;
  for(int i = 0; i <= entry_pos; i++)
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
    if(entry->is_separator) continue;
    if(i == entry_pos) return selectable_pos;
    selectable_pos++;
  }
 
  return -1;
}
 
void dt_bauhaus_combobox_add_populate_fct(GtkWidget *widget, void (*fct)(GtkWidget *w, void *module))
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type == DT_BAUHAUS_COMBOBOX)
    w->data.combobox.populate = fct;
}
 
void dt_bauhaus_combobox_add_list(GtkWidget *widget, const char **texts)
{
  while(texts && *texts)
    dt_bauhaus_combobox_add_full(widget, _(*(texts++)), DT_BAUHAUS_COMBOBOX_ALIGN_RIGHT, NULL, NULL, TRUE);
}
 
void dt_bauhaus_combobox_add(GtkWidget *widget, const char *text)
{
  dt_bauhaus_combobox_add_full(widget, text, DT_BAUHAUS_COMBOBOX_ALIGN_RIGHT, NULL, NULL, TRUE);
}
 
void dt_bauhaus_combobox_add_with_tooltip(GtkWidget *widget, const char *text, const char *tooltip)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  dt_bauhaus_combobox_entry_t *entry
      = new_combobox_entry(text, tooltip, DT_BAUHAUS_COMBOBOX_ALIGN_RIGHT, TRUE, NULL, NULL);
  g_ptr_array_add(d->entries, entry);
  if(d->active < 0) d->active = (int)d->entries->len - 1;
}
 
void dt_bauhaus_combobox_add_aligned(GtkWidget *widget, const char *text, dt_bauhaus_combobox_alignment_t align)
{
  dt_bauhaus_combobox_add_full(widget, text, align, NULL, NULL, TRUE);
}
 
void dt_bauhaus_combobox_add_full(GtkWidget *widget, const char *text, dt_bauhaus_combobox_alignment_t align,
                                  gpointer data, void (free_func)(void *data), gboolean sensitive)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  dt_bauhaus_combobox_entry_t *entry = new_combobox_entry(text, NULL, align, sensitive, data, free_func);
  g_ptr_array_add(d->entries, entry);
  if(d->active < 0) d->active = (int)d->entries->len - 1;
}
 
void dt_bauhaus_combobox_add_separator(GtkWidget *widget)
{
  dt_bauhaus_combobox_add_separator_with_height(widget, DT_BAUHAUS_COMBO_SEPARATOR_DEFAULT_HEIGHT_FACTOR);
}
 
void dt_bauhaus_combobox_add_separator_with_height(GtkWidget *widget, const float row_height_factor)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  g_ptr_array_add(d->entries, new_combobox_separator(row_height_factor));
}
 
void dt_bauhaus_combobox_set_entries_ellipsis(GtkWidget *widget, PangoEllipsizeMode ellipis)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  d->entries_ellipsis = ellipis;
}
 
 
void dt_bauhaus_combobox_set_editable(GtkWidget *widget, int editable)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  d->editable = editable ? 1 : 0;
  if(d->editable && IS_NULL_PTR(d->text))
    d->text = calloc(1, DT_BAUHAUS_COMBO_MAX_TEXT);
}
 
int dt_bauhaus_combobox_get_editable(GtkWidget *widget)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
 
  return d ? d->editable : 0;
}
 
void dt_bauhaus_combobox_set_selected_text_align(GtkWidget *widget, const dt_bauhaus_combobox_alignment_t text_align)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  d->text_align = text_align;
}
 
void dt_bauhaus_combobox_remove_at(GtkWidget *widget, int pos)
{
  dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
  if(IS_NULL_PTR(d)) return;
  const int entry_pos = _combobox_public_to_entry_pos(d, pos, FALSE);
 
  if(entry_pos < 0) return;
 
  // move active position up if removing anything before it
  // or when removing last position that is currently active.
  // this also sets active to -1 when removing the last remaining entry in a combobox.
  if(d->active > entry_pos || d->active == d->entries->len-1)
    d->active--;
 
  g_ptr_array_remove_index(d->entries, entry_pos);
}
 
void dt_bauhaus_combobox_insert(GtkWidget *widget, const char *text,int pos)
{
  dt_bauhaus_combobox_insert_full(widget, text, DT_BAUHAUS_COMBOBOX_ALIGN_RIGHT, NULL, NULL, pos);
}
 
void dt_bauhaus_combobox_insert_full(GtkWidget *widget, const char *text, dt_bauhaus_combobox_alignment_t align,
                                     gpointer data, void (*free_func)(void *), int pos)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  const int entry_pos = _combobox_public_to_entry_pos(d, pos, TRUE);
  if(entry_pos < 0) return;
  g_ptr_array_insert(d->entries, entry_pos, new_combobox_entry(text, NULL, align, TRUE, data, free_func));
  if(d->active < 0)
    d->active = entry_pos;
  else if(entry_pos <= d->active)
    d->active++;
}
 
void dt_bauhaus_combobox_insert_separator(GtkWidget *widget, int pos)
{
  dt_bauhaus_combobox_insert_separator_with_height(widget, pos, DT_BAUHAUS_COMBO_SEPARATOR_DEFAULT_HEIGHT_FACTOR);
}
 
void dt_bauhaus_combobox_insert_separator_with_height(GtkWidget *widget, int pos, const float row_height_factor)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  const int entry_pos = _combobox_public_to_entry_pos(d, pos, TRUE);
  if(entry_pos < 0) return;
  g_ptr_array_insert(d->entries, entry_pos, new_combobox_separator(row_height_factor));
  if(entry_pos <= d->active) d->active++;
}
 
int dt_bauhaus_combobox_length(GtkWidget *widget)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
 
  return _combobox_selectable_count(d);
}
 
const char *dt_bauhaus_combobox_get_text(GtkWidget *widget)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
  if(IS_NULL_PTR(d)) return NULL;
 
  if(d->active < 0)
  {
    return d->editable ? d->text : NULL;
  }
  else
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, d->active);
    if(entry->is_separator) return NULL;
    return entry->label;
  }
}
 
gpointer dt_bauhaus_combobox_get_data(GtkWidget *widget)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
  if(IS_NULL_PTR(d) || d->active < 0) return NULL;
 
  const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, d->active);
  if(entry->is_separator) return NULL;
  return entry->data;
}
 
void dt_bauhaus_combobox_clear(GtkWidget *widget)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_COMBOBOX) return;
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  d->active = -1;
  g_ptr_array_set_size(d->entries, 0);
}
 
const char *dt_bauhaus_combobox_get_entry(GtkWidget *widget, int pos)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
  const int entry_pos = _combobox_public_to_entry_pos(d, pos, FALSE);
  if(entry_pos < 0) return NULL;
 
  const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, entry_pos);
  return entry->label;
}
 
void dt_bauhaus_combobox_set_text(GtkWidget *widget, const char *text)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
  if(IS_NULL_PTR(d) || !d->editable) return;
 
  g_strlcpy(d->text, text, DT_BAUHAUS_COMBO_MAX_TEXT);
}
 
 
static void _commit_combobox_value(struct dt_bauhaus_widget_t *w)
{
  // Announce the new value. Whoever listens decides what it costs: the history commit
  // batches the pipeline recompute it triggers, so emitting on every scroll step is fine
  // and this widget has no reason to hold anything back.
 
  // Don't commit anything while a reset is in progress (reloading history, applying a
  // style, ...): those set widget values programmatically and must not reach history.
  if(dt_gui_widgets_suppressed()) return;
 
  if(w->use_default_callback)
  {
    if(w->bauhaus->default_value_changed_callback)
      w->bauhaus->default_value_changed_callback(GTK_WIDGET(w));
    else
      fprintf(stderr, "ERROR: %s - %s is set to use default callback but none is provided\n", w->module->name,
            w->label);
  }
  else
  {
    if(w->module)
      fprintf(stderr, "WARNING: %s - %s has an IOP module but doesn't use default callback\n", w->module->name,
            w->label);
  }
 
  // We need te emit this signal inconditionnaly
  g_signal_emit_by_name(G_OBJECT(w), "value-changed");
}
 
void _combobox_set(GtkWidget *widget, const int pos)
{
  if(IS_NULL_PTR(widget)) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  const int old_pos = d->active;
  const int new_pos = (d->entries) ? CLAMP(pos, -1, (int)d->entries->len - 1)
                                   : -1;
  if(new_pos >= 0)
  {
    // if the new position is a separator, don't change the active position but still redraw to update the visual selection
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, new_pos);
    if(entry->is_separator) return;
  }
 
  if(old_pos != new_pos)
  {
    d->active = new_pos;
 
    if(w->bauhaus->current == w)
      gtk_widget_queue_draw(w->bauhaus->popup_area);
 
    gtk_widget_queue_draw(GTK_WIDGET(w));
 
    _commit_combobox_value(w);
  }
}
 
// Public API function, called from GUI init and update
void dt_bauhaus_combobox_set(GtkWidget *widget, const int pos)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
  const int selectable_count = _combobox_selectable_count(d);
  const int public_pos = (selectable_count > 0) ? CLAMP(pos, -1, selectable_count - 1) : -1;
  const int entry_pos = _combobox_public_to_entry_pos(d, public_pos, FALSE);
  _combobox_set(widget, entry_pos);
}
 
 
gboolean dt_bauhaus_combobox_set_from_text(GtkWidget *widget, const char *text)
{
  if(IS_NULL_PTR(text)) return FALSE;
 
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
 
  for(int i = 0; d && i < d->entries->len; i++)
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
    if(entry->is_separator) continue;
    if(!g_strcmp0(entry->label, text))
    {
      _combobox_set(widget, i);
      return TRUE;
    }
  }
  return FALSE;
}
 
gboolean dt_bauhaus_combobox_set_from_value(GtkWidget *widget, int value)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
 
  for(int i = 0; d && i < d->entries->len; i++)
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
    if(entry->is_separator) continue;
    if(GPOINTER_TO_INT(entry->data) == value)
    {
      _combobox_set(widget, i);
      return TRUE;
    }
  }
  return FALSE;
}
 
int dt_bauhaus_combobox_get(GtkWidget *widget)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
 
  return _combobox_entry_pos_to_public(d, d ? d->active : -1);
}
 
void dt_bauhaus_combobox_entry_set_sensitive(GtkWidget *widget, int pos, gboolean sensitive)
{
  const dt_bauhaus_combobox_data_t *d = _combobox_data(widget);
  const int entry_pos = _combobox_public_to_entry_pos(d, pos, FALSE);
  if(entry_pos < 0) return;
 
  dt_bauhaus_combobox_entry_t *entry = (dt_bauhaus_combobox_entry_t *)g_ptr_array_index(d->entries, entry_pos);
  entry->sensitive = sensitive;
}
 
void dt_bauhaus_slider_clear_stops(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_SLIDER) return;
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->grad_cnt = 0;
}
 
void dt_bauhaus_slider_set_stop(GtkWidget *widget, float stop, float r, float g, float b)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->type != DT_BAUHAUS_SLIDER) return;
  dt_bauhaus_slider_data_t *d = &w->data.slider;
 
  if(IS_NULL_PTR(d->grad_col))
  {
    d->grad_col = malloc(DT_BAUHAUS_SLIDER_MAX_STOPS * sizeof(*d->grad_col));
    d->grad_pos = malloc(DT_BAUHAUS_SLIDER_MAX_STOPS * sizeof(*d->grad_pos));
  }
  // need to replace stop?
  for(int k = 0; k < d->grad_cnt; k++)
  {
    if(d->grad_pos[k] == stop)
    {
      d->grad_col[k][0] = r;
      d->grad_col[k][1] = g;
      d->grad_col[k][2] = b;
      return;
    }
  }
  // new stop:
  if(d->grad_cnt < DT_BAUHAUS_SLIDER_MAX_STOPS)
  {
    int k = d->grad_cnt++;
    d->grad_pos[k] = stop;
    d->grad_col[k][0] = r;
    d->grad_col[k][1] = g;
    d->grad_col[k][2] = b;
  }
  else
  {
    fprintf(stderr, "[bauhaus_slider_set_stop] only %d stops allowed.\n", DT_BAUHAUS_SLIDER_MAX_STOPS);
  }
}
 
static void dt_bauhaus_draw_indicator(struct dt_bauhaus_widget_t *w, float pos, cairo_t *cr, float wd)
{
  // draw scale indicator (the tiny triangle)
  const float size = w->bauhaus->marker_size;
  const float vertical_position = _get_indicator_y_position(w);
  const float horizontal_position = pos * wd;
 
  cairo_save(cr);
  cairo_translate(cr, horizontal_position, vertical_position);
 
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  const gboolean has_colored_background = d->grad_cnt > 0;
 
  if(!has_colored_background && d->fill_feedback)
  {
    // Plain indicator (regular sliders)
    cairo_arc(cr, 0, 0, size / 2., 0, M_PI * 2);
    set_color(cr, w->bauhaus->color_fg);
    cairo_set_line_width(cr, 0);
    cairo_fill(cr);
  }
  else
  {
    // Hollow indicator to keep the slider background visible through the marker.
    const float border = (size - w->bauhaus->baseline_size) / 2.;
    set_color(cr, w->bauhaus->color_fg);
    cairo_set_line_width(cr, border);
    const float radius = size / 2. - border / 2.;
    cairo_arc(cr, 0, 0, radius, 0, M_PI * 2);
    cairo_stroke(cr);
  }
  cairo_restore(cr);
}
 
static void dt_bauhaus_draw_quad(struct dt_bauhaus_widget_t *w, cairo_t *cr, const double x, const double y)
{
  if(!w->show_quad) return;
 
  cairo_save(cr);
  if(w->quad_paint)
  {
    // draw color picker
    w->quad_paint(cr, x, y,
                      w->bauhaus->quad_width,          // width
                      w->bauhaus->quad_width,          // height
                      w->quad_paint_flags, w->quad_paint_data);
  }
  else if(w->type == DT_BAUHAUS_COMBOBOX)
  {
    // draw combobox chevron
    // Inset the chevron from the right edge of the (now flush) quad box so it
    // doesn't crowd or overflow the widget border. The quad box itself is placed
    // identically to the slider's, so this keeps the chevron in line with slider
    // quad icons when widgets are stacked.
    // FIXME: Why do we need an extra half-pixel shift to the left for pixel-correctness ?
    cairo_translate(cr, x + w->bauhaus->quad_width / 2. - 0.5, y + w->bauhaus->line_height / 2.);
    const float r = w->bauhaus->quad_width * .2f;
    cairo_move_to(cr, -r, -r * .5f);
    cairo_line_to(cr, 0, r * .5f);
    cairo_line_to(cr, r, -r * .5f);
    cairo_stroke(cr);
  }
  cairo_restore(cr);
}
 
static void dt_bauhaus_draw_baseline(struct dt_bauhaus_widget_t *w, cairo_t *cr, float width)
{
  // draw line for orientation in slider
  cairo_save(cr);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  const gboolean has_colored_background = d->grad_cnt > 0;
  const float baseline_top = w->bauhaus->line_height + INNER_PADDING;
  const float baseline_height = w->bauhaus->baseline_size;
  const gboolean is_sensitive = gtk_widget_is_sensitive(GTK_WIDGET(w));
 
  // the background of the line
  // Note: to ensure the indicator is not clipped on the left side,
  // we push the whole slider of an indicator radius to the right.
  // Issue is that leaves a dent on the baseline, so the trick
  // is to make it overlap back by a radius on the left.
  const double x_origin = -w->bauhaus->marker_size / 3.;
  // The left edge was pushed by x_origin to overlap the indicator's leftmost
  // resting position. Extend the width by the same amount so the right edge
  // stays at `width` (flush with the right-aligned numeric value) instead of
  // retreating by |x_origin| and letting the value overhang the baseline.
  const double baseline_width = width - x_origin;
  // Make sure we use integer coordinates to limit anti-aliasing blur
  cairo_rectangle(cr, round(x_origin), round(baseline_top), 
                      round(baseline_width), round(baseline_height));
 
  cairo_pattern_t *gradient = NULL;
  if(has_colored_background && is_sensitive)
  {
    // gradient line as used in some modules for hue, saturation, lightness
    const double zoom = (d->max - d->min) / (d->hard_max - d->hard_min);
    const double offset = (d->min - d->hard_min) / (d->hard_max - d->hard_min);
    gradient = cairo_pattern_create_linear(x_origin, 0, width, baseline_height);
    for(int k = 0; k < d->grad_cnt; k++)
      cairo_pattern_add_color_stop_rgba(gradient, (d->grad_pos[k] - offset) / zoom,
                                        d->grad_col[k][0], d->grad_col[k][1], d->grad_col[k][2], 0.4f);
    cairo_set_source(cr, gradient);
  }
  else
  {
    // regular baseline
    set_color(cr, w->bauhaus->color_bg);
  }
 
  cairo_fill(cr);
 
 
  if(w->bauhaus->border_width > 0)
  {
    // Draw the border on top
    // We need to recess the coordinates by half a line-width for perfect border matching
    const double line_width = 1.;
    cairo_rectangle(cr, round(x_origin) + line_width / 2., round(baseline_top) + line_width / 2., 
                        round(baseline_width) - line_width, round(baseline_height) - line_width);
    cairo_set_line_width(cr, line_width);
    set_color(cr, w->bauhaus->color_border);
    cairo_stroke(cr);
  }
 
  if(gradient) cairo_pattern_destroy(gradient);
 
  // get the reference of the slider aka the position of the 0 value
  float origin = fmaxf(fminf((d->factor > 0 ? -d->min - d->offset/d->factor
                                            :  d->max + d->offset/d->factor)
                              / (d->max - d->min), 
                             1.0f) * width, 
                       0.f);
 
  // have a `fill ratio feel' from zero to current position
  if(!has_colored_background && d->fill_feedback && is_sensitive)
  {
    set_color(cr, w->bauhaus->color_value);
 
    const float position = d->pos * width;
    const float delta = position - origin;
    
    // origin = 0 means start on left, but our left is shifted to the right,
    // so offset it. (see x_origin)
    if(origin == 0.f)
      cairo_rectangle(cr, x_origin, baseline_top, delta - x_origin, baseline_height);
    else
      cairo_rectangle(cr, origin, baseline_top, delta, baseline_height);
 
    cairo_fill(cr);
  }
 
  // draw the 0 reference graduation if it's different than the bounds of the slider
  // If the max of the slider is 360, it is likely an absolute hue slider in degrees
  // a zero in periodic stuff has not much meaning so we skip it.
  if(d->hard_max != 360.0f && is_sensitive)
  {
    set_color(cr, w->bauhaus->color_fg);
 
    // If we are to put the 0 reference on the "left", this time we need to account for
    // actual leftmost resting position of the indicator, not the starting point of the baseline.
    cairo_arc(cr, origin, baseline_top + w->bauhaus->marker_size, w->bauhaus->border_width / 2., 0, 2 * M_PI);
    cairo_fill(cr);
  }
 
  cairo_restore(cr);
}
 
static void dt_bauhaus_widget_reject(struct dt_bauhaus_widget_t *w)
{
  switch(w->type)
  {
    case DT_BAUHAUS_COMBOBOX:
      break;
    case DT_BAUHAUS_SLIDER:
    {
      dt_bauhaus_slider_data_t *d = &w->data.slider;
      dt_bauhaus_slider_set_normalized(w, d->oldpos, TRUE);
    }
    break;
    default:
      break;
  }
}
 
static void dt_bauhaus_widget_accept(struct dt_bauhaus_widget_t *w)
{
  GtkWidget *widget = GTK_WIDGET(w);
 
  switch(w->type)
  {
    case DT_BAUHAUS_COMBOBOX:
    {
      dt_bauhaus_combobox_data_t *d = &w->data.combobox;
 
      if(d->editable && w->bauhaus->keys_cnt > 0)
      {
        // combobox is editable and we have text, assume it is a custom input
        memset(d->text, 0, DT_BAUHAUS_COMBO_MAX_TEXT);
        g_strlcpy(d->text, w->bauhaus->keys, DT_BAUHAUS_COMBO_MAX_TEXT);
        _combobox_set(widget, -1); // select custom entry
 
#if DEBUG
        fprintf(stdout, "combobox went the custom path\n");
#endif
      }
      else
      {
        if(w->bauhaus->keys_cnt > 0)
        {
          // combobox is not editable, but we have text. Assume user wanted to init a selection from keyboard.
          // find the closest match by looking for the entry having the maximum number
          // of characters in common with the user input.
          gchar *keys = g_utf8_casefold(w->bauhaus->keys, -1);
          int match = -1;
          int matches = 0;
 
          for(int j = 0; j < d->entries->len; j++)
          {
            const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, j);
            gchar *text_cmp = g_utf8_casefold(entry->label, -1);
            if(entry->sensitive && !strncmp(text_cmp, keys, w->bauhaus->keys_cnt))
            {
              matches++;
              match = j;
            }
            dt_free(text_cmp);
          }
          dt_free(keys);
 
          // Accept result only if exactly one match was found. Anything else is ambiguous
          if(matches == 1)
            _combobox_set(widget, match);
        }
        else {
          // Active entry (below cursor or scrolled)
          _combobox_set(widget, d->hovered);
        }
      }
 
      break;
    }
    case DT_BAUHAUS_SLIDER:
    {
      // The slider popup uses the quadratic magnifier for accurate setting.
      // We need extra conversions from cursor coordinates to set it right.
      // This needs to be kept in sync with popup_draw()
      dt_bauhaus_slider_data_t *d = &w->data.slider;
 
      // This is needed to accept the change.
      // d->pos is soft-updated with corrected coordinates for drawing purposes only in popup_redraw().
      // We need to reset it to the original value temporarily, and request a proper setting
      // with value-changed signal through dt_bauhaus_slider_set_normalized()
      const float value = d->pos;
      d->pos = d->oldpos;
      dt_bauhaus_slider_set_normalized(w, value, TRUE);
      break;
    }
    default:
      break;
  }
}
 
static gchar *_build_label(const struct dt_bauhaus_widget_t *w)
{
  return g_strdup(w->label);
}
 
static gboolean dt_bauhaus_popup_draw(GtkWidget *widget, cairo_t *crf, gpointer user_data)
{
  // Popups belong to the app, not to the bauhaus widget. That's confusing.
  // Also the *widget param here is the popup container, still not the bauhaus widget. Even more confusing.
  // This is the actual parent bauhaus widget :
  dt_bauhaus_t *bh = g_object_get_data(G_OBJECT(widget), "bauhaus");
  dt_bauhaus_widget_t *w = bh->current;
 
  // get area properties
  GtkAllocation allocation;
  gtk_widget_get_allocation(widget, &allocation);
  cairo_surface_t *cst = dt_cairo_surface_create_at_scale(CAIRO_FORMAT_ARGB32, allocation.width, allocation.height, dt_widget_ppd());
  cairo_t *cr = cairo_create(cst);
  GtkStyleContext *context = gtk_widget_get_style_context(widget);
 
  // look up some colors once
  GdkRGBA text_color, text_color_selected, text_color_hover, text_color_insensitive, text_color_focused;
  gtk_style_context_get_color(context, GTK_STATE_FLAG_NORMAL, &text_color);
  gtk_style_context_get_color(context, GTK_STATE_FLAG_SELECTED, &text_color_selected);
  gtk_style_context_get_color(context, GTK_STATE_FLAG_PRELIGHT, &text_color_hover);
  gtk_style_context_get_color(context, GTK_STATE_FLAG_INSENSITIVE, &text_color_insensitive);
  gtk_style_context_get_color(context, GTK_STATE_FLAG_FOCUSED, &text_color_focused);
 
  GdkRGBA *fg_color = default_color_assign();
  GdkRGBA *bg_color;
  GtkStateFlags state = gtk_widget_get_state_flags(widget);
 
  gtk_style_context_get(context, state, "background-color", &bg_color, NULL);
  gtk_style_context_get_color(context, state, fg_color);
 
  // draw background
  gtk_render_background(context, cr, 0, 0, allocation.width, allocation.height);
  gtk_render_frame(context, cr, 0, 0, allocation.width, allocation.height);
 
  const double main_height = _widget_get_main_height(w, widget);
  double total_width = 0.f;
  const double main_width = _widget_get_main_width(w, NULL, &total_width);
 
  // translate to account for the widget spacing
  cairo_translate(cr, w->padding->left, w->padding->top);
 
  // switch on bauhaus widget type (so we only need one static window)
  switch(w->type)
  {
    case DT_BAUHAUS_SLIDER:
    {
      dt_bauhaus_slider_data_t *d = &w->data.slider;
      const double slider_cursor_radius = 0.5 * w->bauhaus->marker_size;
      const double text_width = main_width + slider_cursor_radius;
      cairo_save(cr);
      cairo_translate(cr, slider_cursor_radius, 0.0);
      set_color(cr, *fg_color);
 
      float scale = _bh_slider_get_scale(w);
      const int num_scales = 1.f / scale;
      const float bottom_baseline = _get_slider_bar_height(w);
 
      for(int k = 0; k < num_scales; k++)
      {
        const float off = k * scale - d->oldpos;
        GdkRGBA fg_copy = *fg_color;
        fg_copy.alpha = scale / fabsf(off);
        set_color(cr, fg_copy);
        draw_slider_line(cr, d->oldpos, off, scale, main_width, main_height, bottom_baseline, 1);
        cairo_stroke(cr);
      }
      cairo_restore(cr);
 
      // Get the x offset compared to d->oldpos accounting for vertical position magnification
      const double mouse_off = d->pos - d->oldpos;
 
      cairo_save(cr);
      cairo_translate(cr, slider_cursor_radius, 0.0);
 
      // Draw the baseline with fill feedback if any (needs the new d->pos set before)
      dt_bauhaus_draw_baseline(w, cr, main_width);
 
      // draw mouse over indicator line
      set_color(cr, w->bauhaus->color_value_text);
      draw_slider_line(cr, d->oldpos, mouse_off, scale, main_width, main_height, bottom_baseline, 2);
      cairo_stroke(cr);
 
      // draw indicator
      dt_bauhaus_draw_indicator(w, d->pos, cr, main_width);
 
      cairo_restore(cr);
 
      // draw numerical value:
      cairo_save(cr);
      set_color(cr, w->bauhaus->color_value_text);
 
      float value_width = 0.f;
      char *text = dt_bauhaus_slider_get_text(GTK_WIDGET(w), dt_bauhaus_slider_get(GTK_WIDGET(w)));
      GdkRectangle bounding_value = { .x = 0.,
                                      .y = 0.,
                                      .width = text_width,
                                      .height = w->bauhaus->line_height };
      // Display user keyboard input if any, otherwise the current value
      show_pango_text(w, context, cr, &bounding_value,
                      (w->bauhaus->keys_cnt) ? w->bauhaus->keys : text, BH_ALIGN_RIGHT,
                      BH_ALIGN_MIDDLE, PANGO_ELLIPSIZE_NONE, NULL, &value_width, NULL, GTK_STATE_FLAG_NORMAL);
      dt_free(text);
 
      // label on top of marker:
      gchar *label_text = _build_label(w);
      const float label_width = text_width - value_width - INNER_PADDING;
      GdkRectangle bounding_label = { .x = 0.,
                                      .y = 0.,
                                      .width = label_width,
                                      .height = w->bauhaus->line_height };
      set_color(cr, *fg_color);
      show_pango_text(w, context, cr, &bounding_label, label_text, BH_ALIGN_LEFT, BH_ALIGN_MIDDLE,
                      PANGO_ELLIPSIZE_END, NULL, NULL, NULL, GTK_STATE_FLAG_NORMAL);
      dt_free(label_text);
 
      cairo_restore(cr);
    }
    break;
    case DT_BAUHAUS_COMBOBOX:
    {
      const dt_bauhaus_combobox_data_t *d = &w->data.combobox;
 
      // User keyboard input goes first
      double popup_y = 0.;
      if(w->bauhaus->keys_cnt > 0)
      {
        cairo_save(cr);
        set_color(cr, text_color_focused);
        const double query_height = _bh_get_row_height(w);
        GdkRectangle query_label = { .x = 0.,
                                     .y = popup_y,
                                     .width = main_width,
                                     .height = query_height };
        show_pango_text(w, context, cr, &query_label, w->bauhaus->keys, BH_ALIGN_RIGHT, BH_ALIGN_MIDDLE,
                        PANGO_ELLIPSIZE_NONE, NULL, NULL, NULL, GTK_STATE_FLAG_NORMAL);
        popup_y += query_height;
        cairo_restore(cr);
      }
 
      cairo_save(cr);
      gchar *keys = g_utf8_casefold(w->bauhaus->keys, -1);
      for(int j = 0; j < d->entries->len; j++)
      {
        const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, j);
        const double entry_height = _bh_get_combobox_entry_height(w, entry);
        if(entry->is_separator)
        {
          if(w->bauhaus->keys_cnt == 0)
          {
            cairo_set_source_rgba(cr, 0.5, 0.5, 0.5, 1.);
            cairo_move_to(cr, 0., popup_y + 0.5 * entry_height);
            cairo_line_to(cr, main_width, popup_y + 0.5 * entry_height);
            cairo_set_line_width(cr, 1.);
            cairo_stroke(cr);
          }
          popup_y += entry_height;
          continue;
        }
 
        gchar *text_cmp = g_utf8_casefold(entry->label, -1);
        if(!strncmp(text_cmp, keys, w->bauhaus->keys_cnt))
        {
          // If user typed some keys, display matching entries only
 
          // The GTK state flag is applied to the whole widget,
          // we need to dispatch it individually to each entry
          if(!entry->sensitive)
          {
            set_color(cr, text_color_insensitive);
            state = GTK_STATE_FLAG_INSENSITIVE;
          }
          else if(j == d->active)
          {
            set_color(cr, text_color_selected);
            state = GTK_STATE_FLAG_SELECTED;
          }
          else if(j == d->hovered)
          {
            set_color(cr, text_color_hover);
            state = GTK_STATE_FLAG_PRELIGHT;
          }
          else
          {
            set_color(cr, text_color);
            state = GTK_STATE_FLAG_NORMAL;
          }
 
          GdkRectangle bounding_label = { .x = 0.,
                                          .y = popup_y,
                                          .width = main_width,
                                          .height = entry_height };
#if DEBUG
          cairo_rectangle(cr, bounding_label.x, bounding_label.y, bounding_label.width, bounding_label.height);
          cairo_set_line_width(cr, 2);
          cairo_stroke(cr);
#endif
          show_pango_text(w, context, cr, &bounding_label, entry->label, BH_ALIGN_RIGHT, BH_ALIGN_MIDDLE,
                          d->entries_ellipsis, bg_color, NULL, NULL, state);
        }
 
        dt_free(text_cmp);
        popup_y += entry_height;
      }
      cairo_restore(cr);
      dt_free(keys);
    }
    break;
    default:
      // yell
      break;
  }
 
  cairo_destroy(cr);
  cairo_set_source_surface(crf, cst, 0, 0);
  cairo_paint(crf);
  cairo_surface_destroy(cst);
 
  gdk_rgba_free(bg_color);
  gdk_rgba_free(fg_color);
 
  return TRUE;
}
 
 
// Get the maximum width of a full combobox without ellipsization
static float _get_combobox_max_width(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
  GtkStyleContext *context = gtk_widget_get_style_context(widget);
  const GtkStateFlags state = gtk_widget_get_state_flags(widget);
 
  cairo_surface_t *cst = dt_cairo_surface_create_at_scale(CAIRO_FORMAT_ARGB32, 999, 999, dt_widget_ppd());
  cairo_t *cr = cairo_create(cst);
 
  float width = 0.f;
 
  // Get chevron width + padding if any
  if(w->show_quad)
    width += w->bauhaus->quad_width + 2 * INNER_PADDING;
 
  float label_width = 0.f;
  GdkRectangle bounding_label = { .x = 0.,
                                  .y = 0.,
                                  .width = 999,
                                  .height = 999 };
 
  show_pango_text(w, context, cr, &bounding_label, w->label, BH_ALIGN_LEFT, BH_ALIGN_MIDDLE,
    PANGO_ELLIPSIZE_NONE, NULL, &label_width, NULL, state);
 
  if(label_width > 0.f) width += label_width + INNER_PADDING;
 
  // Get width of the longest entry
  float max_entry = 0.f;
  for(int i = 0; i < d->entries->len; i++)
  {
    const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, i);
 
    // The value is shown right-aligned, ellipsized if needed.
    GdkRectangle bounding_value = { .x = 0,
                                    .y = 0.,
                                    .width = 999,
                                    .height = 999 };
    float entry_label_width = 0.f;
 
    show_pango_text(w, context, cr, &bounding_value, entry->label, BH_ALIGN_RIGHT, BH_ALIGN_MIDDLE, PANGO_ELLIPSIZE_NONE, NULL,
                    &entry_label_width, NULL, state);
 
    if(entry_label_width + INNER_PADDING > max_entry) max_entry = entry_label_width + INNER_PADDING;
  }
 
  width += max_entry;
  width += w->margin->left + w->margin->right + w->padding->left + w->padding->right;
 
  cairo_destroy(cr);
  cairo_surface_destroy(cst);
 
  return width;
}
 
static gboolean _widget_draw(GtkWidget *widget, cairo_t *crf)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  GtkStyleContext *context = gtk_widget_get_style_context(widget);
 
  // Get current Gtk allocation
  GtkAllocation allocation;
  gtk_widget_get_allocation(widget, &allocation);
 
  if(w->type == DT_BAUHAUS_COMBOBOX)
    allocation.height = _get_combobox_height(widget);
  else if(w->type == DT_BAUHAUS_SLIDER)
    allocation.height = _get_slider_height(widget);
 
  if(w->type == DT_BAUHAUS_COMBOBOX && !w->expand)
  {
    // For comboboxes that are not set to hexpand, limit the width span to what's needed
    // to display the internal text, aka prevent them to grow out of proportions
    float max_width = _get_combobox_max_width(widget);
    if(max_width < allocation.width)
      allocation.width = ceilf(max_width);
  }
 
  // Force allocate to our requirements. Yes, it's ugly.
  gtk_widget_size_allocate(widget, &allocation);
 
  cairo_surface_t *cst = dt_cairo_surface_create_at_scale(CAIRO_FORMAT_ARGB32, allocation.width, allocation.height, dt_widget_ppd());
  cairo_t *cr = cairo_create(cst);
 
  GdkRGBA *text_color = default_color_assign();
  GdkRGBA *value_color = default_color_assign();
  GdkRGBA *value_text_color = default_color_assign();
  GtkStateFlags state = gtk_widget_get_state_flags(widget);
  if(gtk_widget_has_focus(widget))
    state |= GTK_STATE_FLAG_FOCUSED;
 
  gtk_style_context_save(context);
  gtk_style_context_set_state(context, state);
  gtk_style_context_get_color(context, state, text_color);
 
  *value_color = gtk_widget_is_sensitive(widget) ? w->bauhaus->color_value : w->bauhaus->color_value_insensitive;
  *value_text_color = gtk_widget_is_sensitive(widget) ? w->bauhaus->color_value_text : w->bauhaus->color_value_text_insensitive;
  
  // Compute internal widget sizes, that is allocation minus margins
  _margins_retrieve(w);
  // Note : box is the border box in CSS conventions
  const float box_width = allocation.width - w->margin->left - w->margin->right;
  const float box_height = allocation.height - w->margin->top - w->margin->bottom;
 
  // Paint background and borders first
  gtk_render_background(context, crf, w->margin->left, w->margin->top, box_width, box_height);
  gtk_render_frame(context, crf, w->margin->left, w->margin->top, box_width, box_height);
 
  // Translate Cairo coordinates to account for the widget spacing
  cairo_translate(cr,
                  w->margin->left + w->padding->left,
                  w->margin->top + w->padding->top);
 
  const float available_width = _widget_get_main_width(w, NULL, NULL);
  const float inner_height = _widget_get_main_height(w, NULL);
 
  // draw type specific content:
  cairo_save(cr);
  set_color(cr, *text_color);
  cairo_set_line_width(cr, 1.0);
  switch(w->type)
  {
    case DT_BAUHAUS_COMBOBOX:
    {
      // draw label and quad area at right end
      // Gap must match the one reserved by _widget_get_main_width() (2*INNER_PADDING)
      // and used by the slider, so combobox quads stay flush and vertically aligned
      // with slider quad icons when stacked.
      if(w->show_quad)
        dt_bauhaus_draw_quad(w, cr, available_width + 2 * INNER_PADDING, 0.);
 
      dt_bauhaus_combobox_data_t *d = &w->data.combobox;
      const PangoEllipsizeMode combo_ellipsis = d->entries_ellipsis;
 
      float label_width = 0.f;
      float label_height = 0.f;
 
      GdkRectangle bounding_label = { .x = 0.,
                                      .y = 0.,
                                      .width = available_width,
                                      .height = inner_height };
      set_color(cr, *text_color);
      show_pango_text(w, context, cr, &bounding_label, w->label, BH_ALIGN_LEFT, BH_ALIGN_MIDDLE,
                      combo_ellipsis, NULL, &label_width, &label_height, state);
 
      // The value is shown right-aligned, ellipsized if needed.
      gchar *text = d->text;
      if(d->active >= 0 && d->active < d->entries->len)
      {
        const dt_bauhaus_combobox_entry_t *entry = g_ptr_array_index(d->entries, d->active);
        text = entry->label;
      }
      GdkRectangle bounding_value = { .x = label_width + INNER_PADDING,
                                      .y = 0.,
                                      .width = available_width - label_width - INNER_PADDING,
                                      .height = inner_height };
      set_color(cr, *value_text_color);
      show_pango_text(w, context, cr, &bounding_value, text, BH_ALIGN_RIGHT, BH_ALIGN_MIDDLE, combo_ellipsis, NULL,
                      NULL, NULL, state);
 
      break;
    }
    case DT_BAUHAUS_SLIDER:
    {
      const double slider_cursor_radius = 0.5 * w->bauhaus->marker_size;
      const double text_width = available_width + slider_cursor_radius;
 
      // line for orientation
      cairo_save(cr);
      cairo_translate(cr, slider_cursor_radius, 0.0);
      dt_bauhaus_draw_baseline(w, cr, available_width);
      cairo_restore(cr);
 
      // Paint the non-active quad icon with some transparency, because
      // icons are bolder than the neighbouring text and appear brighter.
      cairo_save(cr);
      if(!(w->quad_paint_flags & CPF_ACTIVE))
        cairo_set_source_rgba(cr, text_color->red, text_color->green, text_color->blue, text_color->alpha * 0.7);
 
      dt_bauhaus_draw_quad(w, cr, text_width + 2. * INNER_PADDING, 0.);
      cairo_restore(cr);
 
      float value_width = 0;
      if(gtk_widget_is_sensitive(widget))
      {
        cairo_save(cr);
        cairo_translate(cr, slider_cursor_radius, 0.0);
        dt_bauhaus_draw_indicator(w, w->data.slider.pos, cr, available_width);
        cairo_restore(cr);
 
        char *text = dt_bauhaus_slider_get_text(widget, dt_bauhaus_slider_get(widget));
        GdkRectangle bounding_value = { .x = 0.,
                                        .y = 0.,
                                        .width = text_width,
                                        .height = w->bauhaus->line_height };
        set_color(cr, *value_text_color);
        show_pango_text(w, context, cr, &bounding_value, text, BH_ALIGN_RIGHT, BH_ALIGN_MIDDLE,
                        PANGO_ELLIPSIZE_NONE, NULL, &value_width, NULL, state);
        dt_free(text);
      }
 
      // label on top of marker:
      gchar *label_text = _build_label(w);
      const float label_width = text_width - value_width - INNER_PADDING;
      GdkRectangle bounding_label = { .x = 0.,
                                      .y = 0.,
                                      .width = label_width,
                                      .height = w->bauhaus->line_height };
      set_color(cr, *text_color);
      show_pango_text(w, context, cr, &bounding_label, label_text, BH_ALIGN_LEFT, BH_ALIGN_MIDDLE,
                        PANGO_ELLIPSIZE_END, NULL, NULL, NULL, state);
      dt_free(label_text);
    }
    break;
    default:
      break;
  }
  cairo_restore(cr);
  cairo_destroy(cr);
  cairo_set_source_surface(crf, cst, 0, 0);
  cairo_paint(crf);
  cairo_surface_destroy(cst);
  gtk_style_context_restore(context);
 
  gdk_rgba_free(text_color);
  gdk_rgba_free(value_color);
  gdk_rgba_free(value_text_color);
 
  return TRUE;
}
 
static void _get_preferred_width(GtkWidget *widget, gint *minimum_size, gint *natural_size)
{
  // Nothing clever here : preferred size is the size of the container.
  // If user is not happy with that, it's his responsibility to resize sidebars.
  // Minimum size is left at 0 so the widget can shrink with its parent;
  // leaving it unset would read as uninitialized stack garbage and could
  // clamp natural_size up to a stale value, preventing the widget from
  // growing again when the parent grows.
  *minimum_size = 0;
 
  // The host knows which panel this sits in and how wide it is; -1 means it has no opinion.
  const gint host_width = dt_widget_natural_width(widget);
  *natural_size = (host_width >= 0) ? host_width : DT_PIXEL_APPLY_DPI(300);
}
 
static void _get_preferred_height(GtkWidget *widget, gint *minimum_size, gint *natural_size)
{
  // Resolve the height from the same getters used everywhere else so it is
  // always correct at measure time, regardless of when "style-updated" fires.
  // Relying solely on the size-request set in _style_updated is not enough:
  // when the widget lives inside a freshly popped-up GtkMenu, the menu measures
  // its children before their style context is resolved, so it would size
  // itself from a stale/zero height and end up showing scroll arrows.
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  _margins_retrieve(w);
  const gint height = (w->type == DT_BAUHAUS_COMBOBOX) ? (gint)ceil(_get_combobox_height(widget))
                                                       : (gint)ceil(_get_slider_height(widget));
  *minimum_size = height;
  *natural_size = height;
}
 
void dt_bauhaus_hide_popup(dt_bauhaus_t *bh)
{
  if(bh->current)
  {
    gtk_grab_remove(bh->popup_area);
    gtk_widget_hide(bh->popup_window);
    gtk_window_set_attached_to(GTK_WINDOW(bh->popup_window), NULL);
 
    // Give back focus to the attached widget
    gtk_widget_grab_focus(GTK_WIDGET(bh->current));
    dt_widget_set_scroll_focus(GTK_WIDGET(bh->current));
 
    bh->current = NULL;
  }
}
 
void dt_bauhaus_show_popup(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  if(w->bauhaus->current) dt_bauhaus_hide_popup(w->bauhaus);
 
  // Re-parent onto the window this widget actually lives in, which is not necessarily the
  // application's main window: modules shown in a modal (the export dialog) have their own
  // toplevel. The popup's position is computed relative to that same window below, so the two
  // must agree or the popup lands outside its parent.
  GtkWidget *parent_toplevel = gtk_widget_get_toplevel(widget);
  if(parent_toplevel && gtk_widget_is_toplevel(parent_toplevel))
    gtk_window_set_transient_for(GTK_WINDOW(w->bauhaus->popup_window), GTK_WINDOW(parent_toplevel));
  w->bauhaus->current = w;
  w->bauhaus->keys_cnt = 0;
  memset(w->bauhaus->keys, 0, sizeof(w->bauhaus->keys));
  w->bauhaus->change_active = 0;
  w->bauhaus->mouse_line_distance = 0.0f;
  w->bauhaus->hiding = FALSE;
 
  // Make sure all relevant widgets exist
  gtk_widget_realize(w->bauhaus->popup_window);
  gtk_widget_realize(widget);
  _margins_retrieve(w);
 
  GtkAllocation tmp;
  gtk_widget_get_allocation(widget, &tmp);
  int width = MAX(tmp.width, 1);
  int height = MAX(tmp.height, 1);
 
  switch(w->bauhaus->current->type)
  {
    case DT_BAUHAUS_SLIDER:
    {
      // Slider popup: make it square
      dt_bauhaus_slider_data_t *d = &w->data.slider;
      d->oldpos = d->pos;
      d->is_dragging = FALSE;
      height = tmp.width;
      break;
    }
    case DT_BAUHAUS_COMBOBOX:
    {
      height = roundf(_get_combobox_popup_height(w));
      break;
    }
    default:
    {
      fprintf(stderr, "[dt_bauhaus_show_popup] The bauhaus widget has an unknown type\n");
      break;
    }
  }
 
  /* Bind to CSS rules from parent widget */
  GtkStyleContext *context = gtk_widget_get_style_context(w->bauhaus->popup_area);
  gtk_style_context_add_class(context, "dt_bauhaus_popup");
  gtk_window_set_attached_to(GTK_WINDOW(w->bauhaus->popup_window), widget);
  #ifdef GDK_WINDOWING_WAYLAND
  if (GDK_IS_WAYLAND_DISPLAY(gdk_display_get_default())) {
    GtkWidget *toplevel = gtk_widget_get_toplevel(widget);
    gtk_window_set_transient_for(GTK_WINDOW(w->bauhaus->popup_window), GTK_WINDOW(toplevel));
  }
  #endif
 
  // The popup window stays transient for the main application window, so the anchor
  // rectangle needs to remain expressed in that coordinate space even when the popup is
  // logically attached to an enclosing popover on Wayland.
  gint wx = 0, wy = 0;
  GdkWindow *widget_window = gtk_widget_get_window(widget);
  if(widget_window) gdk_window_get_origin(widget_window, &wx, &wy);
  wx += w->margin->left;
  wy += w->margin->top;
 
  gint wwx = 0, wwy = 0;
  // The widget's OWN toplevel, not the host's main window: correct for popups raised from a
  // secondary window, and it removes the last reason to ask the host which window is primary.
  GtkWidget *toplevel = gtk_widget_get_toplevel(GTK_WIDGET(w));
  GdkWindow *main_window = (toplevel && gtk_widget_is_toplevel(toplevel))
                           ? gtk_widget_get_window(toplevel) : NULL;
  if(main_window) gdk_window_get_origin(main_window, &wwx, &wwy);
 
  GdkRectangle anchor = {
    .x = wx - wwx,
    .y = wy - wwy,
    .width = MAX(tmp.width, 1),
    .height = MAX(tmp.height, 1)
  };
 
  // Set desired size, but it's more a guide than a rule.
  gtk_widget_set_size_request(w->bauhaus->popup_area, width, height);
  gtk_widget_set_size_request(w->bauhaus->popup_window, width, height);
 
  // Need to call resize to actually change something
  gtk_window_resize(GTK_WINDOW(w->bauhaus->popup_window), width, height);
 
  GdkWindow *window = gtk_widget_get_window(w->bauhaus->popup_window);
  if(IS_NULL_PTR(window))
  {
    gtk_widget_show_all(w->bauhaus->popup_window);
    gtk_widget_grab_focus(w->bauhaus->popup_area);
    return;
  }
 
  // For Wayland (and supposed to work on X11 too) and Gtk 3.24 this is how you do it
  gdk_window_move_to_rect(GDK_WINDOW(window), &anchor, GDK_GRAVITY_STATIC, GDK_GRAVITY_STATIC,
                          GDK_ANCHOR_SLIDE, 0, 0);
 
  gtk_widget_show_all(w->bauhaus->popup_window);
  gtk_widget_grab_focus(w->bauhaus->popup_area);
}
 
static void _slider_add_step(GtkWidget *widget, float delta, guint state)
{
  if(delta == 0.f) return;
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
 
  delta *= dt_bauhaus_slider_get_step(widget);
  if(dt_modifier_is(state, DT_PRIMARY_MASK)) delta /= 5.f;
  else if(dt_modifier_is(state, GDK_SHIFT_MASK)) delta *= 5.f;
 
  // Ensure the requested delta is at least visible given current number of digits in display
  const float min_visible = 1.f / (fabsf(d->factor) * ipow(10, d->digits));
  if(fabsf(delta) < min_visible)
    delta = copysignf(min_visible, delta);
 
  const float value = dt_bauhaus_slider_get(widget);
  dt_bauhaus_slider_set(widget, value + delta);
}
 
static gboolean _widget_scroll(GtkWidget *widget, GdkEventScroll *event)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const gboolean popup_captured = (w->bauhaus->current == w);
  const gboolean scroll_captured = (dt_widget_scroll_focus() == widget);
  const gboolean key_captured = gtk_widget_has_focus(widget);
  const gboolean smooth = (event->direction == GDK_SCROLL_SMOOTH);
 
  // - native Gtk focus (keyboard), that takes precedence and records all keyboard events,
  // - custom scroll focus (mouse wheel), that should not overlap with vertical scrolling.
  // Scroll focus is a subset of Gtk focus, aka we can lose scroll focus while we have Gtk focus,
  // but delayed history commits may transiently steal Gtk focus while the
  // pointer never leaves the widget. In that case, keep trusting the explicit
  // scroll focus until leave-notify releases it.
  // We also extend widget focus with the popup window focus if it is captured
  // by the current widget.
  if(!key_captured && !popup_captured && !scroll_captured)
    return FALSE;
 
  // Keep ownership of the whole touchpad gesture sequence.
  dt_widget_set_scroll_focus(widget);
 
  int delta_x = 0;
  int delta_y = 0;
 
  if(!dt_gui_get_scroll_unit_deltas(event, &delta_x, &delta_y))
  {
    // Important: for touchpad scroll, sub-unit deltas and stop events must not
    // propagate to the parent scrolled window, otherwise the same gesture gets
    // re-accumulated there.
    return smooth;
  }
 
  const gboolean vscroll = delta_y != 0 && abs(delta_y) > abs(delta_x);
  const gboolean hscroll = delta_x != 0 && abs(delta_x) > abs(delta_y);
 
  if(w->type == DT_BAUHAUS_SLIDER)
  {
    if(hscroll)
    {
      // inconditionnaly record horizontal scroll on slider
      _slider_add_step(widget, delta_x, event->state);
      return TRUE;
    }
    else if(vscroll && dt_widget_scroll_focus())
    {
      // convert vertical scrolling to horizontal only if we have the scroll focus
      _slider_add_step(widget, -delta_y, event->state);
      return TRUE;
    }
 
    // Diagonal smooth gestures: consume them if captured, so they do not leak.
    return smooth;
  }
  else
  {
    if(vscroll && dt_widget_scroll_focus())
    {
      _combobox_next_sensitive(w, delta_y);
      return TRUE;
    }
 
    return smooth;
  }
}
 
static gboolean _widget_key_press(GtkWidget *widget, GdkEventKey *event)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  guint key = dt_keys_mainpad_alternatives(event->keyval);
 
  if(w->type == DT_BAUHAUS_SLIDER)
  {
    switch(key)
    {
      case GDK_KEY_Right:
        _slider_add_step(widget, 1, event->state);
        return TRUE;
 
      case GDK_KEY_Left:
        _slider_add_step(widget, -1, event->state);
        return TRUE;
 
      case GDK_KEY_Insert:
        if(w->quad_toggle)
        {
          dt_bauhaus_widget_press_quad(widget);
          dt_bauhaus_widget_release_quad(widget);
          return TRUE;
        }
 
      default:
        return FALSE;
    }
  }
  else if(w->type == DT_BAUHAUS_COMBOBOX)
  {
    switch(key)
    {
      case GDK_KEY_Return:
        dt_bauhaus_show_popup(widget);
        return TRUE;
 
      case GDK_KEY_Insert:
        if(w->quad_toggle)
        {
          dt_bauhaus_widget_press_quad(widget);
          dt_bauhaus_widget_release_quad(widget);
          return TRUE;
        }
 
      default:
        return FALSE;
    }
  }
  return FALSE;
}
 
static gboolean dt_bauhaus_combobox_button_press(GtkWidget *widget, GdkEventButton *event, gpointer user_data)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
 
  double event_x = event->x;
  double event_y = event->y;
  double width;
  _bh_active_region_t activated = _bh_get_active_region(widget, &event_x, &event_y, &width, NULL);
 
  dt_bauhaus_combobox_data_t *d = &w->data.combobox;
 
  if(activated == BH_REGION_OUT)
  {
    dt_widget_set_scroll_focus(NULL);
    return FALSE;
  }
 
  gtk_widget_grab_focus(widget);
  dt_widget_set_scroll_focus(widget);
 
  if(activated == BH_REGION_QUAD && w->quad_toggle)
  {
    dt_bauhaus_widget_press_quad(widget);
    return TRUE;
  }
  else
  {
    // If no quad toggle, treat the whole widget as unit pack.
    if(event->button == 3)
    {
      w->bauhaus->mouse_x = event_x;
      w->bauhaus->mouse_y = event_y;
      dt_bauhaus_show_popup(widget);
      return TRUE;
    }
    else if(event->button == 1)
    {
      // reset to default.
      if(event->type == GDK_2BUTTON_PRESS)
      {
        // never called, as we popup the other window under your cursor before.
        // (except in weird corner cases where the popup is under the -1st entry
        dt_bauhaus_combobox_set(widget, d->defpos);
        dt_bauhaus_hide_popup(w->bauhaus);
      }
      else
      {
        // single click, show options
        w->bauhaus->opentime = event->time;
        w->bauhaus->mouse_x = event_x;
        w->bauhaus->mouse_y = event_y;
        dt_bauhaus_show_popup(widget);
      }
      return TRUE;
    }
  }
  return FALSE;
}
 
float dt_bauhaus_slider_get(GtkWidget *widget)
{
  // first cast to bh widget, to check that type:
  const struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return d->min + d->pos * (d->max - d->min);
}
 
float dt_bauhaus_slider_get_val(GtkWidget *widget)
{
  const dt_bauhaus_slider_data_t *d = &DT_BAUHAUS_WIDGET(widget)->data.slider;
  return dt_bauhaus_slider_get(widget) * d->factor + d->offset;
}
 
char *dt_bauhaus_slider_get_text(GtkWidget *w, float val)
{
  const dt_bauhaus_slider_data_t *d = &DT_BAUHAUS_WIDGET(w)->data.slider;
  if((d->hard_max * d->factor + d->offset)*(d->hard_min * d->factor + d->offset) < 0)
    return g_strdup_printf("%+.*f%s", d->digits, val * d->factor + d->offset, d->format);
  else
    return g_strdup_printf( "%.*f%s", d->digits, val * d->factor + d->offset, d->format);
}
 
static void _dt_bauhaus_slider_set_with_raise(GtkWidget *widget, float pos, gboolean raise)
{
  // translate by bounds and call set_normalized.
  // raise == FALSE re-applies the value (re-clamped to the current bounds) and
  // redraws without committing to history or emitting "value-changed". This is
  // what bound changes (soft min/max) need: re-clamping the current value to a
  // new display range is not a user edit, and emitting would re-enter the
  // module's gui_changed handler -- which during gui_init runs before all
  // widgets exist (NULL deref), and at runtime would spuriously commit.
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  const float rpos = CLAMP(pos, d->hard_min, d->hard_max);
 
  // Restore soft min/max if we are in its range
  float rrpos = (rpos - d->soft_min) / (d->soft_max - d->soft_min);
  if(rrpos > 0.f)
    d->min = d->soft_min;
  else
    d->min = rpos;
 
  if(rrpos < 1.f)
    d->max = d->soft_max;
  else
    d->max = rpos;
 
  dt_bauhaus_slider_set_normalized(w, (rpos - d->min) / (d->max - d->min), raise);
}
 
void dt_bauhaus_slider_set(GtkWidget *widget, float pos)
{
  // this is the public interface function, it commits the value and emits "value-changed"
  _dt_bauhaus_slider_set_with_raise(widget, pos, TRUE);
}
 
void dt_bauhaus_slider_set_val(GtkWidget *widget, float val)
{
  const dt_bauhaus_slider_data_t *d = &DT_BAUHAUS_WIDGET(widget)->data.slider;
  dt_bauhaus_slider_set(widget, (val - d->offset) / d->factor);
}
 
void dt_bauhaus_slider_set_digits(GtkWidget *widget, int val)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->digits = val;
}
 
int dt_bauhaus_slider_get_digits(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  return d->digits;
}
 
void dt_bauhaus_slider_set_step(GtkWidget *widget, float val)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->step = val;
}
 
float dt_bauhaus_slider_get_step(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  const dt_bauhaus_slider_data_t *d = &w->data.slider;
  float step = d->step;
 
  if(step == 0.f)
  {
    const float min = d->soft_min;
    const float max = d->soft_max;
 
    // Derive the automatic keyboard/wheel step from the internal slider domain.
    // Display formatting may rescale that domain (for example "%" multiplies by 100),
    // but interaction needs to stay in the unformatted value space to avoid jumping
    // across the whole range in a single step for small-percent sliders.
    const float top = fminf(max-min, fmaxf(fabsf(min), fabsf(max)));
    if(top >= 100.f)
      step = 1.f;
    else
      step = top / 100.f;
  }
 
  return copysignf(step, d->factor);
}
 
void dt_bauhaus_slider_set_feedback(GtkWidget *widget, int feedback)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->fill_feedback = feedback;
  gtk_widget_queue_draw(widget);
}
 
void dt_bauhaus_slider_reset(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->min = d->soft_min;
  d->max = d->soft_max;
  dt_bauhaus_slider_set(widget, d->defpos);
  return;
}
 
void dt_bauhaus_slider_set_format(GtkWidget *widget, const char *format)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->format = g_intern_string(format);
 
  if(strstr(format,"%") && fabsf(d->hard_max) <= 10)
  {
    if(d->factor == 1.0f) d->factor = 100;
    // Scaling by 100 costs two decimals, but a slider declared with fewer than two must not end
    // up with a negative digit count : it is a decimal exponent, fed to ipow() on every value
    // change and every redraw, and there is no such thing as fewer than zero decimals.
    d->digits = MAX(d->digits - 2, 0);
  }
}
 
void dt_bauhaus_slider_set_factor(GtkWidget *widget, float factor)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->factor = factor;
}
 
void dt_bauhaus_slider_set_offset(GtkWidget *widget, float offset)
{
  struct dt_bauhaus_widget_t *w = DT_BAUHAUS_WIDGET(widget);
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  d->offset = offset;
}
 
static void _commit_slider_value(struct dt_bauhaus_widget_t *w)
{
  // Announce the new value. Whoever listens decides what it costs: the history commit
  // batches the pipeline recompute it triggers, so emitting on every scroll step is fine
  // and this widget has no reason to hold anything back.
 
  // Don't commit anything while a reset is in progress (reloading history, applying a
  // style, ...): those set widget values programmatically and must not reach history.
  if(dt_gui_widgets_suppressed()) return;
 
  if(w->use_default_callback)
  {
    if(w->bauhaus->default_value_changed_callback)
      w->bauhaus->default_value_changed_callback(GTK_WIDGET(w));
    else
      fprintf(stderr, "ERROR: %s - %s is set to use default callback but none is provided\n", w->module->name,
            w->label);
  }
  else
  {
    if(w->module)
      fprintf(stderr, "WARNING: %s - %s has an IOP module but doesn't use default callback\n", w->module->name,
            w->label);
  }
 
  // We need te emit this signal inconditionnaly
  g_signal_emit_by_name(G_OBJECT(w), "value-changed");
}
 
static void dt_bauhaus_slider_set_normalized(struct dt_bauhaus_widget_t *w, float pos, gboolean raise)
{
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  const float old_pos = d->pos;
  const float new_pos = CLAMP(pos, 0.0f, 1.0f);
 
  if(old_pos != new_pos || raise)
  {
    const float new_value = new_pos * (d->max - d->min) + d->min;
    const float precision = (float)ipow(10, d->digits) * d->factor;
    const float rounded_value = roundf(new_value * precision) / precision;
    d->pos = (rounded_value - d->min) / (d->max - d->min);
 
    if(w->bauhaus->current == w)
      gtk_widget_queue_draw(w->bauhaus->popup_area);
 
    gtk_widget_queue_draw(GTK_WIDGET(w));
 
    if(raise) _commit_slider_value(w);
  }
}
 
static gboolean dt_bauhaus_popup_key_press(GtkWidget *widget, GdkEventKey *event, gpointer user_data)
{
  dt_bauhaus_t *bh = g_object_get_data(G_OBJECT(widget), "bauhaus");
  dt_bauhaus_widget_t *w = bh->current;
 
  guint key = dt_keys_mainpad_alternatives(event->keyval);
 
  switch(w->type)
  {
    case DT_BAUHAUS_SLIDER:
    {
      if(bh->keys_cnt + 2 < 64
         && (key == GDK_KEY_space ||                                         // SPACE
             key == GDK_KEY_percent ||                                       // %
             (event->string[0] >= 40 && event->string[0] <= 57) ||           // ()+-*/.,0-9
             key == GDK_KEY_asciicircum || key == GDK_KEY_dead_circumflex || // ^
             key == GDK_KEY_X || key == GDK_KEY_x))                          // Xx
      {
        if(key == GDK_KEY_dead_circumflex)
          bh->keys[bh->keys_cnt++] = '^';
        else
          bh->keys[bh->keys_cnt++] = event->string[0];
        gtk_widget_queue_draw(bh->popup_area);
      }
      else if(bh->keys_cnt > 0
              && (key == GDK_KEY_BackSpace || key == GDK_KEY_Delete))
      {
        bh->keys[--bh->keys_cnt] = 0;
        gtk_widget_queue_draw(bh->popup_area);
      }
      else if(bh->keys_cnt > 0 && bh->keys_cnt + 1 < 64
              && (key == GDK_KEY_Return))
      {
        // accept input
        bh->keys[bh->keys_cnt] = 0;
        // unnormalized input, user was typing this:
        const float old_value = dt_bauhaus_slider_get_val(GTK_WIDGET(w));
        const float new_value = dt_calculator_solve(old_value, bh->keys);
        if(isfinite(new_value)) dt_bauhaus_slider_set_val(GTK_WIDGET(w), new_value);
        bh->keys_cnt = 0;
        memset(bh->keys, 0, sizeof(bh->keys));
        dt_bauhaus_hide_popup(bh);
      }
      else if(key == GDK_KEY_Escape)
      {
        // discard input ands close popup
        bh->keys_cnt = 0;
        memset(bh->keys, 0, sizeof(bh->keys));
        dt_bauhaus_hide_popup(bh);
      }
      else
        return FALSE;
 
      return TRUE;
    }
    case DT_BAUHAUS_COMBOBOX:
    {
      if(!g_utf8_validate(event->string, -1, NULL)) return FALSE;
      const gunichar c = g_utf8_get_char(event->string);
      const long int char_width = g_utf8_next_char(event->string) - event->string;
      if(bh->keys_cnt + 1 + char_width < 64 && g_unichar_isprint(c))
      {
        // only accept key input if still valid or editable?
        g_utf8_strncpy(bh->keys + bh->keys_cnt, event->string, 1);
        bh->keys_cnt += char_width;
        gtk_widget_queue_draw(bh->popup_area);
      }
      else if(bh->keys_cnt > 0
              && (key == GDK_KEY_BackSpace || key == GDK_KEY_Delete))
      {
        bh->keys_cnt
            -= (bh->keys + bh->keys_cnt)
               - g_utf8_prev_char(bh->keys + bh->keys_cnt);
        bh->keys[bh->keys_cnt] = 0;
        gtk_widget_queue_draw(bh->popup_area);
      }
      else if(bh->keys_cnt > 0 && bh->keys_cnt + 1 < 64
              && (key == GDK_KEY_Return))
      {
        // accept unique matches only for editable:
        if(w->data.combobox.editable)
          bh->end_mouse_y = FLT_MAX;
        else
          bh->end_mouse_y = 0;
        bh->keys[bh->keys_cnt] = 0;
        dt_bauhaus_widget_accept(w);
        bh->keys_cnt = 0;
        memset(bh->keys, 0, sizeof(bh->keys));
        dt_bauhaus_hide_popup(bh);
      }
      else if(key == GDK_KEY_Escape)
      {
        // discard input and close popup
        bh->keys_cnt = 0;
        memset(bh->keys, 0, sizeof(bh->keys));
        dt_bauhaus_hide_popup(bh);
      }
      else if(key == GDK_KEY_Up)
      {
        _combobox_next_sensitive(w, -1);
      }
      else if(key == GDK_KEY_Down)
      {
        _combobox_next_sensitive(w, +1);
      }
      else if(key == GDK_KEY_Return)
      {
        // return pressed, but didn't type anything
        bh->end_mouse_y = -1; // negative will use currently highlighted instead.
        bh->keys[bh->keys_cnt] = 0;
        bh->keys_cnt = 0;
        memset(bh->keys, 0, sizeof(bh->keys));
        dt_bauhaus_widget_accept(bh->current);
        dt_bauhaus_hide_popup(bh);
      }
      else
        return FALSE;
      return TRUE;
    }
    default:
      return FALSE;
  }
}
 
static gboolean dt_bauhaus_slider_button_press(GtkWidget *widget, GdkEventButton *event, gpointer user_data)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  dt_bauhaus_slider_data_t *d = &w->data.slider;
 
  double event_x = event->x;
  double event_y = event->y;
  double main_width = 0.;
  _bh_active_region_t activated = _bh_get_active_region(widget, &event_x, &event_y, &main_width, NULL);
  w->bauhaus->mouse_x = event_x;
  w->bauhaus->mouse_y = event_y;
 
  if(activated == BH_REGION_OUT)
  {
    dt_widget_set_scroll_focus(NULL);
    return FALSE;
  }
 
  gtk_widget_grab_focus(widget);
  dt_widget_set_scroll_focus(widget);
 
  if(activated == BH_REGION_QUAD && w->quad_toggle)
  {
    dt_bauhaus_widget_press_quad(widget);
    return TRUE;
  }
  else if(activated == BH_REGION_MAIN)
  {
    if(event->button == 1)
    {
      if(event->type == GDK_2BUTTON_PRESS)
      {
        // double left click on the main region : reset value to default
        dt_bauhaus_slider_reset(widget);
        d->is_dragging = 0;
      }
      else
      {
        // single left click on main region : redraw the slider immediately
        // but without committing results to pipeline yet.
        if(event_y < w->bauhaus->line_height)
        {
          // single left click on the header name : do nothing (only give focus)
          d->is_dragging = 0;
        }
        else
        {
          // single left click on slider bar : set new value
          d->is_dragging = 1;
          dt_bauhaus_slider_set_normalized(w, event_x / main_width, FALSE);
        }
      }
    }
    else if(event->button == 3)
    {
      // right click : show accurate slider setting popup
      d->oldpos = d->pos;
      dt_bauhaus_show_popup(widget);
    }
    else if(event->button == 2)
    {
      // middle click : reset zoom range to soft min/max
      _slider_zoom_range(w, 0);
    }
    return TRUE;
  }
  return FALSE;
}
 
static gboolean dt_bauhaus_slider_button_release(GtkWidget *widget, GdkEventButton *event, gpointer user_data)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  dt_bauhaus_slider_data_t *d = &w->data.slider;
 
  dt_bauhaus_widget_release_quad(widget);
 
  // is_dragging is set TRUE no matter what on button_press, except if it's a double click.
  // double click is the only event handled in button_press, otherwise we assume every event
  // is drag and drop, and handle the final drag coordinate here.
  if(d->is_dragging)
  {
    d->is_dragging = 0;
 
    if(event->button == 1)
    {
      dt_bauhaus_slider_set_normalized(w, w->bauhaus->mouse_x / _widget_get_main_width(w, NULL, NULL), TRUE);
      return TRUE;
    }
  }
  return FALSE;
}
 
static gboolean dt_bauhaus_slider_motion_notify(GtkWidget *widget, GdkEventMotion *event, gpointer user_data)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  dt_bauhaus_slider_data_t *d = &w->data.slider;
  _bh_active_region_t activated = BH_REGION_OUT; // = 0
 
  if(d->is_dragging && event->state & GDK_BUTTON1_MASK)
  {
    double event_x = event->x;
    double event_y = event->y;
    double main_width;
    activated = _bh_get_active_region(widget, &event_x, &event_y, &main_width, NULL);
 
    w->bauhaus->mouse_x = event_x;
    w->bauhaus->mouse_y = event_y;
    dt_bauhaus_slider_set_normalized(w, event_x / main_width, TRUE);
  }
 
  return activated;
}
 
void dt_bauhaus_disable_accels(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  w->no_accels = TRUE;
}
 
void dt_bauhaus_disable_module_list(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  w->no_module_list = TRUE;
}
 
void dt_bauhaus_set_use_default_callback(GtkWidget *widget)
{
  struct dt_bauhaus_widget_t *w = (struct dt_bauhaus_widget_t *)widget;
  w->use_default_callback = TRUE;
}
 
 
// clang-format off
// modelines: These editor modelines have been set for all relevant files by tools/update_modelines.py
// vim: shiftwidth=2 expandtab tabstop=2 cindent
// kate: tab-indents: off; indent-width 2; replace-tabs on; indent-mode cstyle; remove-trailing-spaces modified;
// clang-format on