[linux-audio-dev] plugin GUIs

[Paul Davis]

the following is tiny example to show that its possible to use XEMBED
or just native X Window IDs to create host-managed plugin GUIs. GTK+2
and Qt3 both support XEMBED; GTK+2 supports use of native X Window ids
when creating new top level windows, i am not sure about Qt (does
anybody here know how to do it).

this means that a GTK host can manage a Qt GUI or vice versa, without
any toolkit specific hacks in the host or in a library linked by the
host. 

i offer this as a proof of concept. i believe that our problems with
GUIs for plugins are pretty much over, modulo defining some standards
as per another recent from me.

--p

----------------------------------------------------------------------

#include <stdio.h>
#include <stdlib.h>
#include <gtk/gtk.h>
#include <gdk/gdkx.h>

gboolean    
button_pressed (GtkWidget *widget,
		GdkEventButton *event,
		gpointer user_data)
{
	fprintf (stderr, "host: button press at %g,%g\n", event->x, event->y);
	return TRUE;
}

gboolean
delete_event (GtkWidget* widget,
	      GdkEvent* event,
	      gpointer user_data)
{
	fprintf (stderr, "host: window delete event\n");
	gtk_main_quit ();
	return TRUE;
}

gboolean    
plugin_button_pressed (GtkWidget *widget,
		GdkEventButton *event,
		gpointer user_data)
{
	fprintf (stderr, "plug: button press at %g,%g\n", event->x, event->y);
	return TRUE;
}

gboolean
plugin_delete_event (GtkWidget* widget,
	      GdkEvent* event,
	      gpointer user_data)
{
	fprintf (stderr, "plug: window delete event\n");
	gtk_main_quit ();
	return FALSE;
}

int
plugin_main (GdkNativeWindow window_id)
{
	GtkWidget* embedded_parent;
	GtkWidget* dummy_label;
	GdkWindow* foreign_window;
	int argc = 1;
	char **argv = (char **) malloc (sizeof (char*));
	argv[0] = "plugin";

	gtk_init (&argc, &argv);
	
#ifdef USE_XEMBED
	embedded_parent = gtk_plug_new (window_id);
#else
	embedded_parent = gtk_window_new (GTK_WINDOW_TOPLEVEL);
	foreign_window = gdk_window_foreign_new (window_id);
	gtk_widget_set_parent_window (embedded_parent, foreign_window);
#endif

	dummy_label = gtk_label_new ("This is a LADSPA Plugin GUI");
	
	gtk_container_add (GTK_CONTAINER(embedded_parent), 
			   dummy_label);


	gtk_signal_connect (GTK_OBJECT(embedded_parent),
			    "button-press-event",
			    GTK_SIGNAL_FUNC (plugin_button_pressed),
			    NULL);

	gtk_signal_connect (GTK_OBJECT(embedded_parent),
			    "delete-event",
			    GTK_SIGNAL_FUNC (plugin_delete_event),
			    NULL);

	gtk_widget_add_events (GTK_WIDGET (embedded_parent), 
			       GDK_BUTTON_PRESS_MASK|GDK_BUTTON_RELEASE_MASK);

	gtk_widget_show (embedded_parent);
	gtk_widget_show (dummy_label);
}

int
main (int argc, char *argv[])
{
	gtk_init (&argc, &argv);
	
	GtkWidget* embedded_parent;
	GtkWidget* embedded_window;
	
	embedded_window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

#ifdef USE_XEMBED
	embedded_parent = gtk_socket_new ();

	gtk_container_add (GTK_CONTAINER(embedded_window),
			   embedded_parent);
	gtk_widget_show (embedded_parent);
#endif	

	gtk_signal_connect (GTK_OBJECT(embedded_window),
			    "button-press-event",
			    GTK_SIGNAL_FUNC (button_pressed),
			    NULL);

	gtk_signal_connect (GTK_OBJECT(embedded_window),
			    "delete-event",
			    GTK_SIGNAL_FUNC (delete_event),
			    NULL);

	gtk_widget_add_events (GTK_WIDGET (embedded_window), 
			       GDK_BUTTON_PRESS_MASK|GDK_BUTTON_RELEASE_MASK);
	gtk_widget_set_size_request (GTK_WIDGET(embedded_window), 100, 100);
	gtk_window_set_title (GTK_WINDOW(embedded_window), "A Plugin");

	gtk_widget_show (embedded_window);
	gtk_widget_realize (embedded_window);

#ifdef USE_XEMBED
	plugin_main (gtk_socket_get_id (GTK_SOCKET(embedded_parent)));
#else
	plugin_main (GDK_WINDOW_XID (embedded_window->window));
#endif
	gtk_main ();
}