don't use GtkPlug/GtkSocket for in process applets

1. This will allow panel to exit/stop without crashing when using
in process applets. It was crashing because of following assert:
g_assert (widget->priv->verifying_invariants_count > 0);

2. In process applet will not have extra background. Transparency
should now work as expected. This fixes redrawing of in-process
applet backgrounds with GTK 3.22

based on   https://github.com/GNOME/gnome-panel/commit/df4ec78272624660e1e01b7382dac3e1f83cfc4a

2 files changed, 57 insertions, 11 deletions

diff --git a/libmate-panel-applet/mate-panel-applet.c b/libmate-panel-applet/mate-panel-applet.c
index bf7a1f35..e881667e 100644
--- a/libmate-panel-applet/mate-panel-applet.c
+++ b/libmate-panel-applet/mate-panel-applet.c
@@ -908,13 +908,19 @@ mate_panel_applet_can_focus (GtkWidget *widget)
 
 /* Taken from libmatecomponentui/matecomponent/matecomponent-plug.c */
 static gboolean
-mate_panel_applet_button_event (GtkWidget      *widget,
+mate_panel_applet_button_event (MatePanelApplet      *applet,
 			   GdkEventButton *event)
 {
+	GtkWidget *widget;
 	GdkWindow *window;
 	GdkWindow *socket_window;
 	XEvent     xevent;
 
+	if (!applet->priv->out_of_process)
+		return FALSE;
+
+	widget = applet->priv->plug;
+
 	if (!gtk_widget_is_toplevel (widget))
 		return FALSE;
 
@@ -998,7 +1004,7 @@ mate_panel_applet_button_press (GtkWidget      *widget,
 		return TRUE;
 	}
 
-	return mate_panel_applet_button_event (applet->priv->plug, event);
+	return mate_panel_applet_button_event (applet, event);
 }
 
 static gboolean
@@ -1007,7 +1013,7 @@ mate_panel_applet_button_release (GtkWidget      *widget,
 {
 	MatePanelApplet *applet = MATE_PANEL_APPLET (widget);
 
-	return mate_panel_applet_button_event (applet->priv->plug, event);
+	return mate_panel_applet_button_event (applet, event);
 }
 
 static gboolean
@@ -1882,6 +1888,9 @@ mate_panel_applet_constructor (GType                  type,
 	                                                                  construct_properties);
 	applet = MATE_PANEL_APPLET (object);
 
+	if (!applet->priv->out_of_process)
+		return object;
+
 	applet->priv->plug = gtk_plug_new (0);
 
 	GdkScreen *screen = gtk_widget_get_screen(GTK_WIDGET(applet->priv->plug));
@@ -2443,6 +2452,9 @@ guint32
 mate_panel_applet_get_xid (MatePanelApplet *applet,
 		      GdkScreen   *screen)
 {
+	if (applet->priv->out_of_process == FALSE)
+		return 0;
+
 	gtk_window_set_screen (GTK_WINDOW (applet->priv->plug), screen);
 	gtk_widget_show (applet->priv->plug);
 
@@ -2459,5 +2471,14 @@ G_MODULE_EXPORT GtkWidget *
 mate_panel_applet_get_applet_widget (const gchar *factory_id,
                                 guint        uid)
 {
-	return mate_panel_applet_factory_get_applet_widget (factory_id, uid);
+	GtkWidget *widget;
+
+	widget = mate_panel_applet_factory_get_applet_widget (factory_id, uid);
+	if (!widget) {
+		return NULL;
+	}
+
+	mate_panel_applet_setup (MATE_PANEL_APPLET (widget));
+
+	return widget;
 }
diff --git a/mate-panel/libmate-panel-applet-private/panel-applet-container.c b/mate-panel/libmate-panel-applet-private/panel-applet-container.c
index 4b4ffd2b..f1ed62f2 100644
--- a/mate-panel/libmate-panel-applet-private/panel-applet-container.c
+++ b/mate-panel/libmate-panel-applet-private/panel-applet-container.c
@@ -23,6 +23,7 @@
 #include <string.h>
 #include <gtk/gtk.h>
 #include <gtk/gtkx.h>
+#include <panel-applets-manager.h>
 #include "panel-applet-container.h"
 #include "panel-marshal.h"
 
@@ -32,6 +33,7 @@ struct _MatePanelAppletContainerPrivate {
 	guint       name_watcher_id;
 	gchar      *bus_name;
 
+	gchar      *iid;
 	gboolean    out_of_process;
 	guint32     xid;
 	guint32     uid;
@@ -88,20 +90,35 @@ static void mate_panel_applet_container_init(MatePanelAppletContainer* container
 {
 	container->priv = MATE_PANEL_APPLET_CONTAINER_GET_PRIVATE (container);
 
-	container->priv->socket = gtk_socket_new ();
-	g_signal_connect_swapped (container->priv->socket, "plug-removed", G_CALLBACK (mate_panel_applet_container_plug_removed), container);
-
 	container->priv->pending_ops = g_hash_table_new_full (g_direct_hash,
 							      g_direct_equal,
 							      NULL,
 							      (GDestroyNotify) g_object_unref);
-
-	gtk_container_add (GTK_CONTAINER (container),
-			   container->priv->socket);
-	gtk_widget_show (container->priv->socket);
 }
 
 static void
+panel_applet_container_setup (MatePanelAppletContainer *container)
+{
+	if (container->priv->out_of_process) {
+		container->priv->socket = gtk_socket_new ();
+
+		g_signal_connect_swapped (container->priv->socket,
+		                          "plug-removed",
+		                          G_CALLBACK (mate_panel_applet_container_plug_removed),
+		                          container);
+
+		gtk_container_add (GTK_CONTAINER (container), container->priv->socket);
+		gtk_widget_show (container->priv->socket);
+	} else {
+		GtkWidget *applet;
+
+		applet = mate_panel_applets_manager_get_applet_widget (container->priv->iid, container->priv->uid);
+
+		gtk_container_add (GTK_CONTAINER (container), applet);
+	}
+ }
+
+static void
 mate_panel_applet_container_cancel_pending_operations (MatePanelAppletContainer *container)
 {
 	GList *keys, *l;
@@ -135,6 +152,11 @@ mate_panel_applet_container_dispose (GObject *object)
 		container->priv->bus_name = NULL;
 	}
 
+	if (container->priv->iid) {
+		g_free (container->priv->iid);
+		container->priv->iid = NULL;
+	}
+
 	if (container->priv->name_watcher_id > 0) {
 		g_bus_unwatch_name (container->priv->name_watcher_id);
 		container->priv->name_watcher_id = 0;
@@ -349,6 +371,8 @@ on_proxy_appeared (GObject      *source_object,
 	g_simple_async_result_complete (result);
 	g_object_unref (result);
 
+	panel_applet_container_setup (container);
+
 	if (container->priv->xid > 0) {
 		gtk_socket_add_id (GTK_SOCKET (container->priv->socket),
 				   container->priv->xid);
@@ -496,6 +520,7 @@ mate_panel_applet_container_get_applet (MatePanelAppletContainer *container,
 
 	bus_name = g_strdup_printf (MATE_PANEL_APPLET_BUS_NAME, factory_id);
 
+	container->priv->iid = g_strdup (iid);
 	container->priv->name_watcher_id =
 		g_bus_watch_name (G_BUS_TYPE_SESSION,
 				  bus_name,