icon browser: Set up dnd from the detail popup

Allow dragging the various icon sizes as images.

demos/icon-browser/iconbrowserwin.c

@@ -58,11 +58,31 @@ search_text_changed (GtkEntry *entry, IconBrowserWindow *win)
   gtk_tree_model_filter_refilter (win->filter_model);
 }
 
+static GdkPixbuf *
+get_icon (GtkWidget *image, const gchar *name, gint size)
+{
+  GtkIconInfo *info;
+  GtkStyleContext *context;
+  GdkPixbuf *pixbuf;
+
+  context = gtk_widget_get_style_context (image);
+  info = gtk_icon_theme_lookup_icon (gtk_icon_theme_get_default (), name, size, 0);
+  pixbuf = gtk_icon_info_load_symbolic_for_context (info, context, NULL, NULL);
+  g_object_unref (info);
+
+  return pixbuf;
+}
+
 static void
 set_image (GtkWidget *image, const gchar *name, gint size)
 {
+  GdkPixbuf *pixbuf;
+
   gtk_image_set_from_icon_name (GTK_IMAGE (image), name, 1);
   gtk_image_set_pixel_size (GTK_IMAGE (image), size);
+  pixbuf = get_icon (image, name, size);
+  gtk_drag_source_set_icon_pixbuf (gtk_widget_get_parent (image), pixbuf);
+  g_object_unref (pixbuf);
 }
 
 static void
@@ -740,6 +760,40 @@ search_mode_toggled (GObject *searchbar, GParamSpec *pspec, IconBrowserWindow *w
     gtk_list_box_unselect_all (GTK_LIST_BOX (win->context_list));
 }
 
+static void
+get_image_data (GtkWidget        *widget,
+                GdkDragContext   *context,
+                GtkSelectionData *selection,
+                guint             target_info,
+                guint             time,
+                gpointer          data)
+{
+  GtkWidget *image;
+  const gchar *name;
+  gint size;
+  GdkPixbuf *pixbuf;
+
+  image = gtk_bin_get_child (GTK_BIN (widget));
+
+  gtk_image_get_icon_name (GTK_IMAGE (image), &name, NULL);
+  size = gtk_image_get_pixel_size (GTK_IMAGE (image));
+
+  pixbuf = get_icon (image, name, size);
+  gtk_selection_data_set_pixbuf (selection, pixbuf);
+  g_object_unref (pixbuf);
+}
+
+static void
+setup_image_dnd (GtkWidget *image)
+{
+  GtkWidget *parent;
+
+  parent = gtk_widget_get_parent (image);
+  gtk_drag_source_set (parent, GDK_BUTTON1_MASK, NULL, 0, GDK_ACTION_COPY);
+  gtk_drag_source_add_image_targets (parent);
+  g_signal_connect (parent, "drag-data-get", G_CALLBACK (get_image_data), NULL);
+}
+
 static void
 icon_browser_window_init (IconBrowserWindow *win)
 {
@@ -761,6 +815,12 @@ icon_browser_window_init (IconBrowserWindow *win)
 
   gtk_target_table_free (targets, n_targets);
 
+  setup_image_dnd (win->image1);
+  setup_image_dnd (win->image2);
+  setup_image_dnd (win->image3);
+  setup_image_dnd (win->image4);
+  setup_image_dnd (win->image5);
+
   win->contexts = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, g_free);
 
   gtk_tree_model_filter_set_visible_func (win->filter_model, icon_visible_func, win, NULL);

demos/icon-browser/window.ui

@@ -151,12 +151,17 @@
             <property name="row-spacing">10</property>
             <property name="column-spacing">10</property>
             <child>
-              <object class="GtkImage" id="image1">
+              <object class="GtkEventBox">
                 <property name="visible">True</property>
-                <property name="xpad">4</property>
+                <child>
-                <property name="ypad">4</property>
+                  <object class="GtkImage" id="image1">
-                <property name="halign">center</property>
+                    <property name="visible">True</property>
-                <property name="valign">end</property>
+                    <property name="xpad">4</property>
+                    <property name="ypad">4</property>
+                    <property name="halign">center</property>
+                    <property name="valign">end</property>
+                  </object>
+                </child>
               </object>
               <packing>
                 <property name="left-attach">0</property>
@@ -164,12 +169,17 @@
               </packing>
             </child>
             <child>
-              <object class="GtkImage" id="image2">
+              <object class="GtkEventBox">
                 <property name="visible">True</property>
-                <property name="xpad">4</property>
+                <child>
-                <property name="ypad">4</property>
+                  <object class="GtkImage" id="image2">
-                <property name="halign">center</property>
+                    <property name="visible">True</property>
-                <property name="valign">end</property>
+                    <property name="xpad">4</property>
+                    <property name="ypad">4</property>
+                    <property name="halign">center</property>
+                    <property name="valign">end</property>
+                  </object>
+                </child>
               </object>
               <packing>
                 <property name="left-attach">1</property>
@@ -177,12 +187,17 @@
               </packing>
             </child>
             <child>
-              <object class="GtkImage" id="image3">
+              <object class="GtkEventBox">
                 <property name="visible">True</property>
-                <property name="xpad">4</property>
+                <child>
-                <property name="ypad">4</property>
+                  <object class="GtkImage" id="image3">
-                <property name="halign">center</property>
+                    <property name="visible">True</property>
-                <property name="valign">end</property>
+                    <property name="xpad">4</property>
+                    <property name="ypad">4</property>
+                    <property name="halign">center</property>
+                    <property name="valign">end</property>
+                  </object>
+                </child>
               </object>
               <packing>
                 <property name="left-attach">2</property>
@@ -190,12 +205,17 @@
               </packing>
             </child>
             <child>
-              <object class="GtkImage" id="image4">
+              <object class="GtkEventBox">
                 <property name="visible">True</property>
-                <property name="xpad">4</property>
+                <child>
-                <property name="ypad">4</property>
+                  <object class="GtkImage" id="image4">
-                <property name="halign">center</property>
+                    <property name="visible">True</property>
-                <property name="valign">end</property>
+                    <property name="xpad">4</property>
+                    <property name="ypad">4</property>
+                    <property name="halign">center</property>
+                    <property name="valign">end</property>
+                  </object>
+                </child>
               </object>
               <packing>
                 <property name="left-attach">3</property>
@@ -203,12 +223,17 @@
               </packing>
             </child>
             <child>
-              <object class="GtkImage" id="image5">
+              <object class="GtkEventBox">
                 <property name="visible">True</property>
-                <property name="xpad">4</property>
+                <child>
-                <property name="ypad">4</property>
+                  <object class="GtkImage" id="image5">
-                <property name="halign">center</property>
+                    <property name="visible">True</property>
-                <property name="valign">end</property>
+                    <property name="xpad">4</property>
+                    <property name="ypad">4</property>
+                    <property name="halign">center</property>
+                    <property name="valign">end</property>
+                  </object>
+                </child>
               </object>
               <packing>
                 <property name="left-attach">4</property>