preview_window.c

Go to the documentation of this file.

/*
    This file is part of the Ansel project.
    Copyright (C) 2025 Aurélien PIERRE.
    
    Ansel 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.
    
    Ansel 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 Ansel.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "common/darktable.h"
#include "control/control.h"
#include "common/image_cache.h"
#include "views/view.h"
 
#include <gtk/gtk.h>
 
#ifdef GDK_WINDOWING_QUARTZ
#include "osx/osx.h"
#endif
 
typedef struct dt_preview_window_t
{
  int32_t imgid;
  cairo_surface_t *surface;
  dt_view_image_surface_fetcher_t fetcher;
  GtkWidget *area;
  int width;
  int height;
} dt_preview_window_t;
 
void _preview_redraw(gpointer instance, dt_preview_window_t *preview);
 
static void _preview_window_destroy(GtkWidget *dialog, gpointer user_data)
{
  dt_preview_window_t *preview = (dt_preview_window_t *)user_data;
  // Disconnect from DARKROOM_UI_CHANGED before freeing: otherwise the handler keeps
  // firing with a dangling `preview` pointer and crashes on the next UI change
  // (e.g. moving the border-size slider).
  DT_DEBUG_CONTROL_SIGNAL_DISCONNECT(darktable.signals, G_CALLBACK(_preview_redraw), preview);
  dt_view_image_surface_fetcher_cleanup(&preview->fetcher);
  dt_free(preview);
}
 
static void _close_preview_popup(GtkWidget *dialog, gint response_id, gpointer data)
{
  gtk_widget_destroy(dialog);
}
 
static void _preview_window_size_allocate(GtkWidget *widget, GtkAllocation *allocation, gpointer user_data)
{
  dt_preview_window_t *preview = (dt_preview_window_t *)user_data;
  if(IS_NULL_PTR(preview) || IS_NULL_PTR(allocation)) return;
  if(allocation->width < 2 || allocation->height < 2) return;
  if(preview->width == allocation->width && preview->height == allocation->height) return;
 
  preview->width = allocation->width;
  preview->height = allocation->height;
 
  /* The async fetcher can stop its current pixelpipe through the request-owned
   * shutdown flag. Trigger that as soon as the popup size changes so we don't
   * keep rendering a surface for an obsolete allocation. */
  dt_view_image_surface_fetcher_invalidate(&preview->fetcher, &preview->surface);
  gtk_widget_queue_draw(widget);
}
 
// TODO: we color-manage the preview window assuming it sits on the same screen as the main window
// Will need to grab the color profile of the actual monitor where it sits.
void _colormanage_ui_color(const float L, const float a, const float b, dt_aligned_pixel_t RGB)
{
  dt_aligned_pixel_t Lab = { L, a, b, 1.f };
  dt_aligned_pixel_t XYZ = { 0.f, 0.f, 0.f, 1.f };
  dt_Lab_to_XYZ(Lab, XYZ);
  cmsDoTransform(darktable.color_profiles->transform_xyz_to_display, XYZ, RGB, 1);
}
 
static gboolean
_thumb_draw_image(GtkWidget *widget, cairo_t *cr, gpointer user_data)
{
  dt_preview_window_t *preview = (dt_preview_window_t *)user_data;
  if(IS_NULL_PTR(preview)) return TRUE;
 
  const double start = dt_get_wtime();
 
  int w = gtk_widget_get_allocated_width(widget);
  int h = gtk_widget_get_allocated_height(widget);
 
  // Paint background
  dt_aligned_pixel_t bg_color;
  _colormanage_ui_color((float)dt_conf_get_int("display/brightness"), 0., 0., bg_color);
  cairo_set_source_rgb(cr, bg_color[0], bg_color[1], bg_color[2]);
  cairo_paint(cr);
 
  int borders = DT_PIXEL_APPLY_DPI(dt_conf_get_int("plugins/darkroom/ui/border_size"));
  w -= 2 * borders;
  h -= 2 * borders;
 
  // FIXME: this gets the color-managed image surface using the color profile of the monitor
  // where the main window sits. Need to detect the monitor of the preview window instead.
  const dt_view_surface_value_t res =
      dt_view_image_get_surface_async(&preview->fetcher, preview->imgid, w, h, &preview->surface, widget, 0);
 
  if(preview->surface && res == DT_VIEW_SURFACE_OK)
  {
    // The image is immediately available
    int width = cairo_image_surface_get_width(preview->surface);
    int height = cairo_image_surface_get_height(preview->surface);
    double sx = 1.0, sy = 1.0;
    cairo_surface_get_device_scale(preview->surface, &sx, &sy);
    const double logical_width = width / sx;
    const double logical_height = height / sy;
 
    // we draw the image
    cairo_save(cr);
    double x_offset = (w - logical_width) / 2. + borders;
    double y_offset = (h - logical_height) / 2. + borders;
    cairo_set_source_surface(cr, preview->surface, x_offset, y_offset);
 
    // get the transparency value
    GdkRGBA im_color;
    GtkStyleContext *context = gtk_widget_get_style_context(widget);
    gtk_style_context_get_color(context, gtk_widget_get_state_flags(widget), &im_color);
    cairo_paint_with_alpha(cr, im_color.alpha);
 
    // and eventually the image border
    gtk_render_frame(context, cr, borders, borders, w, h);
    cairo_restore(cr);
  }
  else
  {
    dt_control_draw_busy_msg(cr, w, h);
  }
 
  dt_print(DT_DEBUG_LIGHTTABLE, "Redrawing the preview window for %i in %0.04f sec\n", preview->imgid,
    dt_get_wtime() - start);
 
  return TRUE;
}
 
 
void _preview_redraw(gpointer instance, dt_preview_window_t *preview)
{
  gtk_widget_queue_draw(preview->area);
}
 
 
void dt_preview_window_spawn(const int32_t imgid)
{
  dt_preview_window_t *preview = calloc(1, sizeof(dt_preview_window_t));
  preview->imgid = imgid;
  dt_view_image_surface_fetcher_init(&preview->fetcher);
 
  GtkWidget *dialog = gtk_dialog_new();
 
  const dt_image_t *img = dt_image_cache_get(darktable.image_cache, imgid, 'r');
  gchar *name = g_strdup_printf(_("Ansel - Preview : %s"), img->filename);
  dt_image_cache_read_release(darktable.image_cache, img);
  gtk_window_set_title(GTK_WINDOW(dialog), name);
  dt_free(name);
 
#ifdef GDK_WINDOWING_QUARTZ
  dt_osx_disallow_fullscreen(dialog);
  gtk_window_set_position(GTK_WINDOW(dialog), GTK_WIN_POS_CENTER_ON_PARENT);
#endif
 
  gtk_dialog_set_default_response(GTK_DIALOG(dialog), GTK_RESPONSE_CANCEL);
  gtk_window_set_modal(GTK_WINDOW(dialog), FALSE);
  gtk_window_set_transient_for(GTK_WINDOW(dialog), GTK_WINDOW(dt_ui_main_window(darktable.gui->ui)));
  gtk_window_set_default_size(GTK_WINDOW(dialog), 350, 350);
  g_signal_connect(G_OBJECT(dialog), "response", G_CALLBACK(_close_preview_popup), NULL);
  g_signal_connect(G_OBJECT(dialog), "destroy", G_CALLBACK(_preview_window_destroy), preview);
 
  preview->area = gtk_drawing_area_new();
  gtk_widget_set_hexpand(preview->area, TRUE);
  gtk_widget_set_vexpand(preview->area, TRUE);
  gtk_widget_set_halign(preview->area, GTK_ALIGN_FILL);
  gtk_widget_set_valign(preview->area, GTK_ALIGN_FILL);
  gtk_widget_set_size_request(preview->area, 350, 350);
  gtk_box_pack_start(GTK_BOX(gtk_dialog_get_content_area(GTK_DIALOG(dialog))), preview->area, TRUE, TRUE, 0);
  g_signal_connect(G_OBJECT(preview->area), "draw", G_CALLBACK(_thumb_draw_image), preview);
  g_signal_connect(G_OBJECT(preview->area), "size-allocate", G_CALLBACK(_preview_window_size_allocate), preview);
  DT_DEBUG_CONTROL_SIGNAL_CONNECT(darktable.signals, DT_SIGNAL_DARKROOM_UI_CHANGED, G_CALLBACK(_preview_redraw), preview);
 
  gtk_widget_set_visible(preview->area, TRUE);
  gtk_widget_show_all(dialog);
}