From 1d35f273d6ae7f145e7cf8102d423fd7451f57f5 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Tue, 26 Apr 2016 22:02:34 -0400
Subject: [PATCH] dnd: Fix some issues with drag icons

In non-composited environments, we were ending up with all-black
drag icons, because nothing was drawing the background of our new
toplevel. Fix this by drawing background when we are not composited.
We don't do this when composited, since we want to allow transparent
icons.
---
 gtk/gtkdnd.c | 85 +++++++++++++++++++++-------------------------------
 1 file changed, 34 insertions(+), 51 deletions(-)

diff --git a/gtk/gtkdnd.c b/gtk/gtkdnd.c
index d0b391c50c..9a5dd11642 100644
--- a/gtk/gtkdnd.c
+++ b/gtk/gtkdnd.c
@@ -2056,9 +2056,11 @@ gtk_drag_set_icon_widget_internal (GdkDragContext *context,
     {
       GdkScreen *screen;
       GdkVisual *visual;
+      gboolean has_rgba;
 
       screen = gdk_window_get_screen (gdk_drag_context_get_source_window (context));
       visual = gdk_screen_get_rgba_visual (screen);
+      has_rgba = visual != NULL && gdk_screen_is_composited (screen);
 
       info->icon_window = gtk_window_new (GTK_WINDOW_POPUP);
       gtk_window_set_type_hint (GTK_WINDOW (info->icon_window), GDK_WINDOW_TYPE_HINT_DND);
@@ -2067,7 +2069,10 @@ gtk_drag_set_icon_widget_internal (GdkDragContext *context,
       if (visual)
         gtk_widget_set_visual (info->icon_window, visual);
       gtk_widget_set_events (info->icon_window, GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
-      gtk_widget_set_app_paintable (info->icon_window, TRUE);
+
+      if (has_rgba)
+        gtk_widget_set_app_paintable (info->icon_window, TRUE);
+
       gtk_window_set_hardcoded_window (GTK_WINDOW (info->icon_window),
                                        gdk_drag_context_get_drag_window (context));
       gtk_widget_show (info->icon_window);
@@ -2123,6 +2128,25 @@ gtk_drag_draw_icon_pattern (GtkWidget *window,
   cairo_paint (cr);
 }
 
+static void
+gtk_drag_draw_icon_pattern_and_background (GtkWidget *window,
+                                           cairo_t   *cr,
+                                           gpointer   pattern)
+{
+  GtkStyleContext *context;
+  int width, height;
+
+  context = gtk_widget_get_style_context (window);
+  width = gtk_widget_get_allocated_width (window);
+  height = gtk_widget_get_allocated_height (window);
+
+  gtk_render_background (context, cr, 0, 0, width, height);
+  gtk_render_frame (context, cr, 0, 0, width, height);
+
+  cairo_set_source (cr, pattern);
+  cairo_paint (cr);
+}
+
 static void
 set_icon_helper (GdkDragContext     *context,
                  GtkImageDefinition *def,
@@ -2260,7 +2284,7 @@ _gtk_cairo_surface_extents (cairo_surface_t *surface,
  * cursor will be positioned at the (0,0) coordinate of the
  * surface.
  */
-void 
+void
 gtk_drag_set_icon_surface (GdkDragContext  *context,
                            cairo_surface_t *surface)
 {
@@ -2270,20 +2294,18 @@ gtk_drag_set_icon_surface (GdkDragContext  *context,
   cairo_pattern_t *pattern;
   GdkVisual *rgba_visual;
   gboolean has_rgba;
-      
+  cairo_matrix_t matrix;
+
   g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
   g_return_if_fail (surface != NULL);
 
   _gtk_cairo_surface_extents (surface, &extents);
 
-
   screen = gdk_window_get_screen (gdk_drag_context_get_source_window (context));
   rgba_visual = gdk_screen_get_rgba_visual (screen);
 
   window = gtk_window_new (GTK_WINDOW_POPUP);
-  has_rgba =
-    rgba_visual != NULL &&
-    gdk_screen_is_composited (screen);
+  has_rgba = rgba_visual != NULL && gdk_screen_is_composited (screen);
 
   gtk_window_set_screen (GTK_WINDOW (window), screen);
 
@@ -2298,53 +2320,14 @@ gtk_drag_set_icon_surface (GdkDragContext  *context,
   gtk_widget_set_size_request (window, extents.width, extents.height);
   gtk_widget_realize (window);
 
-  if (cairo_surface_get_content (surface) != CAIRO_CONTENT_COLOR &&
-      !has_rgba)
-    {
-      cairo_surface_t *saturated;
-      cairo_region_t *region;
-      cairo_t *cr;
-
-      region = gdk_cairo_region_create_from_surface (surface);
-      cairo_region_translate (region, -extents.x, -extents.y);
-
-      gtk_widget_shape_combine_region (window, region);
-      cairo_region_destroy (region);
-
-      /* Need to saturate the colors, so it doesn't look like semi-transparent
-       * pixels were painted on black.
-       */
-      saturated = gdk_window_create_similar_surface (gtk_widget_get_window (window),
-                                                     CAIRO_CONTENT_COLOR,
-                                                     extents.width,
-                                                     extents.height);
-      
-      cr = cairo_create (saturated);
-      cairo_push_group_with_content (cr, CAIRO_CONTENT_COLOR_ALPHA);
-      cairo_set_source_surface (cr, surface, -extents.x, -extents.y);
-      cairo_paint (cr);
-      cairo_set_operator (cr, CAIRO_OPERATOR_SATURATE);
-      cairo_paint (cr);
-      cairo_pop_group_to_source (cr);
-      cairo_paint (cr);
-      cairo_destroy (cr);
-    
-      pattern = cairo_pattern_create_for_surface (saturated);
-
-      cairo_surface_destroy (saturated);
-    }
-  else
-    {
-      cairo_matrix_t matrix;
-
-      pattern = cairo_pattern_create_for_surface (surface);
-      cairo_matrix_init_translate (&matrix, extents.x, extents.y);
-      cairo_pattern_set_matrix (pattern, &matrix);
-    }
+  pattern = cairo_pattern_create_for_surface (surface);
+  cairo_matrix_init_translate (&matrix, extents.x, extents.y);
+  cairo_pattern_set_matrix (pattern, &matrix);
 
   g_signal_connect_data (window,
                          "draw",
-                         G_CALLBACK (gtk_drag_draw_icon_pattern),
+                         has_rgba ? G_CALLBACK (gtk_drag_draw_icon_pattern)
+                                  : G_CALLBACK (gtk_drag_draw_icon_pattern_and_background),
                          pattern,
                          (GClosureNotify) cairo_pattern_destroy,
                          G_CONNECT_AFTER);
-- 
2.30.2