Author: Arnaud Rebillout <arnaud@preev.io>

Date:   Tue Jun 13 15:03:02 2017 +0700

Fix use of GTK+ style context in GladeDesignLayout.

It seems like modifying the style context in the 'draw' handler is not

recommended, and we need to save/restore the context.

Otherwise, for some widgets (GtkButton, GtkComboBox), the

GladeDesignLayout gets trapped in draw-damage loop.

See 0c076cc8828cd80f1f156a08569199675bf35165 for reference.

diff --git a/gladeui/glade-design-layout.c b/gladeui/glade-design-layout.c

index b5970ce..17e9a60 100644

--- a/gladeui/glade-design-layout.c

+++ b/gladeui/glade-design-layout.c

@@ -1033,13 +1033,13 @@ draw_frame (GtkWidget *widget, cairo_t *cr, gboolean selected,

   if (priv->widget_name)

     {

       GdkRectangle *rect = &priv->south_east;

-

+      gtk_style_context_save (context);

       gtk_style_context_add_class (context, "handle");

       gtk_render_background (context, cr, rect->x, rect->y, rect->width, rect->height);

       gtk_render_frame (context, cr, rect->x, rect->y, rect->width, rect->height);

       gtk_render_layout (context, cr, rect->x + OUTLINE_WIDTH, rect->y + OUTLINE_WIDTH,

                          priv->widget_name);

-      gtk_style_context_remove_class (context, "handle");

+      gtk_style_context_restore (context);

     }

 }

@@ -1084,6 +1084,7 @@ draw_selection (cairo_t *cr,

   if (alloc.x < 0 || alloc.y < 0) return;

   context = gtk_widget_get_style_context (parent);

+  gtk_style_context_save (context);

   gtk_style_context_add_class (context, "selection");

   r = color->red; g = color->green; b = color->blue;

   gtk_widget_translate_coordinates (widget, parent, 0, 0, &x, &y);

@@ -1122,7 +1123,7 @@ draw_selection (cairo_t *cr,

   /* Draw Selection box */

   gtk_render_frame (context, cr, x - left, y - top, w + left + right, h + top + bottom);

-  gtk_style_context_remove_class (context, "selection");

+  gtk_style_context_restore (context);

 }

 #define DIMENSION_OFFSET 9