gtk3.20-fix custom BG change on applets

New file panel-plug.c used intact from 
github.com/GNOME/gnome-panel/commit/3115f77b536a7c79c7d43ded0591e2b8f45219c4 "restore custom background on applets)
Used only in gtk 3.20 builds, though not sure if whole file built but not used when it's header file is not included in anything due to build time
conditionals.

1 files changed, 100 insertions, 0 deletions

diff --git a/libmate-panel-applet/panel-plug.c b/libmate-panel-applet/panel-plug.c
new file mode 100644
index 00000000..549e98f9
--- /dev/null
+++ b/libmate-panel-applet/panel-plug.c
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2016 Alberts Muktupāvels
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "panel-plug-private.h"
+
+struct _PanelPlug
+{
+  GtkPlug parent;
+};
+
+G_DEFINE_TYPE (PanelPlug, panel_plug, GTK_TYPE_PLUG)
+
+static gboolean
+panel_plug_draw (GtkWidget *widget,
+                 cairo_t   *cr)
+{
+  GdkWindow *window;
+  cairo_pattern_t *pattern;
+
+  if (!gtk_widget_get_realized (widget))
+    return GTK_WIDGET_CLASS (panel_plug_parent_class)->draw (widget, cr);
+
+  window = gtk_widget_get_window (widget);
+  pattern = gdk_window_get_background_pattern (window);
+
+  if (!pattern)
+    {
+      GtkStyleContext *context;
+      gint width;
+      gint height;
+
+      context = gtk_widget_get_style_context (widget);
+      width = gtk_widget_get_allocated_width (widget);
+      height = gtk_widget_get_allocated_height (widget);
+
+      gtk_render_background (context, cr, 0, 0, width, height);
+    }
+
+  return GTK_WIDGET_CLASS (panel_plug_parent_class)->draw (widget, cr);
+}
+
+static void
+panel_plug_realize (GtkWidget *widget)
+{
+  GdkScreen *screen;
+  GdkVisual *visual;
+
+  screen = gdk_screen_get_default ();
+  visual = gdk_screen_get_rgba_visual (screen);
+
+  if (!visual)
+    visual = gdk_screen_get_system_visual (screen);
+
+  gtk_widget_set_visual (widget, visual);
+
+  GTK_WIDGET_CLASS (panel_plug_parent_class)->realize (widget);
+}
+
+static void
+panel_plug_class_init (PanelPlugClass *plug_class)
+{
+  GtkWidgetClass *widget_class;
+
+  widget_class = GTK_WIDGET_CLASS (plug_class);
+
+  widget_class->draw = panel_plug_draw;
+  widget_class->realize = panel_plug_realize;
+
+#if GTK_CHECK_VERSION (3, 19, 0)
+	gtk_widget_class_set_css_name (widget_class, "PanelApplet");
+#endif
+}
+
+static void
+panel_plug_init (PanelPlug *plug)
+{
+  gtk_widget_set_app_paintable (GTK_WIDGET (plug), TRUE);
+}
+
+GtkWidget *
+panel_plug_new (void)
+{
+  return g_object_new (PANEL_TYPE_PLUG, NULL);
+}