[glade] GladeDesignLayout, GladePalette: Use class icon and name + widget name as drag icon widget.

[Juan Pablo Ugarte <jpu src gnome org>]

commit 5b79610a34607f71bee67d9c372d11c831047526
Author: Juan Pablo Ugarte <juanpablougarte gmail com>
Date:   Fri Apr 19 19:19:44 2013 -0300

    GladeDesignLayout, GladePalette: Use class icon and name + widget name as drag icon widget.

 gladeui/glade-design-layout.c  | 103 ++++++++++++++++++++++++++++++++---------
 gladeui/glade-design-private.h |   4 ++
 gladeui/glade-palette.c        |  33 +++++++++++--
 3 files changed, 114 insertions(+), 26 deletions(-)
---
diff --git a/gladeui/glade-design-layout.c b/gladeui/glade-design-layout.c
index d8278ea..f8b5222 100644
--- a/gladeui/glade-design-layout.c
+++ b/gladeui/glade-design-layout.c
@@ -1901,47 +1901,108 @@ glade_design_layout_finalize (GObject *object)
 }
 
 static gboolean
-on_drag_icon_draw (GtkWidget *widget, cairo_t *cr, GtkWidget *drag_source)
+on_drag_icon_draw (GtkWidget *widget, cairo_t *cr, GladeDesignLayout *layout)
 {
-  cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR);
-  cairo_paint (cr);
+  GtkStyleContext *context = gtk_widget_get_style_context (widget);
+  cairo_pattern_t *gradient;
+  GtkAllocation alloc;
+  gint x, y, w, h;
+  gdouble h2;
+  GdkRGBA bg;
+  
+  gtk_widget_get_allocation (widget, &alloc);
+  x = alloc.x;
+  y = alloc.y;
+  w = alloc.width;
+  h = alloc.height;
+  h2 = h/2.0;
+
+  gtk_style_context_get_background_color (context, GTK_STATE_NORMAL, &bg);
+
+  gradient = cairo_pattern_create_linear (x, y, x, y+h);
+  cairo_pattern_add_color_stop_rgba (gradient, 0, bg.red, bg.green, bg.blue, 0);
+  cairo_pattern_add_color_stop_rgba (gradient, .5, bg.red, bg.green, bg.blue, .8);
+  cairo_pattern_add_color_stop_rgba (gradient, 1, bg.red, bg.green, bg.blue, 0);
+
+  cairo_set_source (cr, gradient);
+  cairo_rectangle (cr, x+h2, y, w-h, h);
+  cairo_fill (cr);
+  cairo_pattern_destroy (gradient);
 
-  cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
-  cairo_push_group (cr);
-  gtk_widget_draw (drag_source, cr);
-  cairo_pop_group_to_source (cr);
-  cairo_paint_with_alpha (cr, .5);
+  gradient = cairo_pattern_create_radial (x+h2, y+h2, 0, x+h2, y+h2, h2);
+  cairo_pattern_add_color_stop_rgba (gradient, 0, bg.red, bg.green, bg.blue, .8);
+  cairo_pattern_add_color_stop_rgba (gradient, 1, bg.red, bg.green, bg.blue, 0);
+
+  cairo_set_source (cr, gradient);
+  cairo_rectangle (cr, x, y, h2, h);
+  cairo_fill (cr);
+
+  cairo_translate (cr, w-h, 0);
+  cairo_set_source (cr, gradient);
+  cairo_rectangle (cr, x+h2, y, h2, h);
+  cairo_fill (cr);
+  
+  cairo_pattern_destroy (gradient);
 
   return FALSE;
 }
 
-static void
-glade_design_layout_drag_begin (GtkWidget *widget, GdkDragContext *context)
+GtkWidget *
+_glade_design_layout_dnd_icon_widget_new (GdkDragContext *context,
+                                          const gchar *icon_name,
+                                          const gchar *description)
 {
-  GladeDesignLayoutPrivate *priv = GLADE_DESIGN_LAYOUT_PRIVATE (widget);
-  GtkAllocation alloc;
+  GtkWidget *window, *box, *label, *icon;
   GdkScreen *screen;
   GdkVisual *visual;
-  GtkWidget *window;
-
-  gtk_widget_get_allocation (priv->drag_source, &alloc);
 
   screen = gdk_window_get_screen (gdk_drag_context_get_source_window (context));
   visual = gdk_screen_get_rgba_visual (screen);
   window = gtk_window_new (GTK_WINDOW_POPUP);
   
-  gtk_widget_set_size_request (window, alloc.width, alloc.height);
   gtk_window_set_type_hint (GTK_WINDOW (window), GDK_WINDOW_TYPE_HINT_DND);
   gtk_window_set_screen (GTK_WINDOW (window), screen);
   gtk_widget_set_visual (window, visual);
+
+  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
+  gtk_container_set_border_width (GTK_CONTAINER (box), 12);
+
+  icon = gtk_image_new_from_icon_name (icon_name, GTK_ICON_SIZE_BUTTON);
+  gtk_widget_set_opacity (icon, .8);
+  
+  label = gtk_label_new (description);
+
+  gtk_box_pack_start (GTK_BOX (box), icon, FALSE, TRUE, 0);
+  gtk_box_pack_start (GTK_BOX (box), label, FALSE, TRUE, 0);
+
+  gtk_widget_show_all (box);
+  gtk_container_add (GTK_CONTAINER (window), box);
+
   gtk_widget_set_app_paintable (window, TRUE);
+  g_signal_connect (window, "draw", G_CALLBACK (on_drag_icon_draw), NULL);
 
-  g_signal_connect_object (window, "draw",
-                           G_CALLBACK (on_drag_icon_draw),
-                           priv->drag_source, 0);
+  return window;
+}
 
-  priv->drag_icon = g_object_ref_sink (window);
-  gtk_drag_set_icon_widget (context, window, priv->drag_x, priv->drag_y);
+static void
+glade_design_layout_drag_begin (GtkWidget *widget, GdkDragContext *context)
+{
+  GladeDesignLayoutPrivate *priv = GLADE_DESIGN_LAYOUT_PRIVATE (widget);
+  GladeWidgetAdaptor *adaptor;
+  GladeWidget *gwidget;
+  const gchar *icon_name;
+  gchar *description;
+
+  gwidget = glade_widget_get_from_gobject (priv->drag_source);
+  adaptor = glade_widget_get_adaptor (gwidget);
+  icon_name = glade_widget_adaptor_get_icon_name (adaptor);
+  description = g_strdup_printf ("%s [%s]",
+                                 glade_widget_adaptor_get_name (adaptor),
+                                 glade_widget_get_name (gwidget));
+
+  priv->drag_icon = _glade_design_layout_dnd_icon_widget_new (context, icon_name, description);
+  g_object_ref_sink (priv->drag_icon);
+  gtk_drag_set_icon_widget (context, priv->drag_icon, 0, 0);
 }
 
 static void
diff --git a/gladeui/glade-design-private.h b/gladeui/glade-design-private.h
index a8046f4..c883312 100644
--- a/gladeui/glade-design-private.h
+++ b/gladeui/glade-design-private.h
@@ -59,6 +59,10 @@ void            _glade_design_layout_get_hot_point (GladeDesignLayout *layout,
 
 GtkTargetEntry *_glade_design_layout_get_dnd_target (void);
 
+GtkWidget *_glade_design_layout_dnd_icon_widget_new (GdkDragContext *context,
+                                                     const gchar *icon_name,
+                                                     const gchar *description);
+
 G_END_DECLS
 
 #endif /* __GLADE_DESIGN_PRIVATE_H__ */
diff --git a/gladeui/glade-palette.c b/gladeui/glade-palette.c
index 7d4d79e..c57bea1 100644
--- a/gladeui/glade-palette.c
+++ b/gladeui/glade-palette.c
@@ -46,6 +46,7 @@
 #include "glade-widget.h"
 #include "glade-widget-adaptor.h"
 #include "glade-popup.h"
+#include "glade-design-private.h"
 
 #include <glib/gi18n-lib.h>
 #include <gdk/gdk.h>
@@ -269,6 +270,31 @@ palette_item_toggled_cb (GtkToggleToolButton *button, GladePalette *palette)
     }
 }
 
+static void
+glade_palette_drag_end (GtkWidget *widget,
+                        GdkDragContext *context,
+                        GtkWidget *drag_icon)
+{
+  g_object_unref (drag_icon);
+  g_signal_handlers_disconnect_by_func (widget, glade_palette_drag_end, drag_icon);
+}
+
+static void
+glade_palette_drag_begin (GtkWidget *widget,
+                          GdkDragContext *context,
+                          GladeWidgetAdaptor *adaptor)
+{
+  GtkWidget *drag_icon;
+
+  drag_icon = _glade_design_layout_dnd_icon_widget_new (context,
+                                                        glade_widget_adaptor_get_icon_name (adaptor),
+                                                        glade_widget_adaptor_get_name (adaptor));
+  g_object_ref_sink (drag_icon);
+  gtk_drag_set_icon_widget (context, drag_icon, 0, 0);
+  g_signal_connect_object (widget, "drag-end",
+                           G_CALLBACK (glade_palette_drag_end), drag_icon, 0);
+}
+
 static gint
 palette_item_button_press_cb (GtkWidget      *button,
                              GdkEventButton *event, 
@@ -282,10 +308,6 @@ palette_item_button_press_cb (GtkWidget      *button,
       glade_popup_palette_pop (palette, adaptor, event);
       return TRUE;
     }
-  else
-    {
-      gtk_drag_source_set_icon_name (button, glade_widget_adaptor_get_icon_name (adaptor));                  
              
-    }
 
   return FALSE;
 }
@@ -326,7 +348,8 @@ glade_palette_new_item (GladePalette * palette, GladeWidgetAdaptor * adaptor)
   /* Fire Glade palette popup menus */
   g_signal_connect (G_OBJECT (button), "button-press-event",
                     G_CALLBACK (palette_item_button_press_cb), item);
-
+  g_signal_connect_object (button, "drag-begin",
+                           G_CALLBACK (glade_palette_drag_begin), adaptor, 0);
   gtk_widget_show (item);
 
   g_hash_table_insert (palette->priv->button_table,