/* abstract base class for a vobject object ... watch an iobject and call 
 * _refresh in idle if it changes.
 */

/*

    Copyright (C) 1991-2003 The National Gallery

    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, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

/*

    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

/*
#define DEBUG
 */

/* Time each refresh
#define DEBUG_TIME
 */

#include "ip.h"

static GtkVBoxClass *parent_class = NULL;

static Queue *vobject_dirty = NULL;

static gint vobject_refresh_timeout = 0;

/* Remove from refresh queue.
 */
static void 
vobject_refresh_dequeue( vObject *vobject )
{
	if( vobject->dirty ) {
#ifdef DEBUG
		printf( "vobject_refresh_dequeue: \"%s\"\n", 
			G_OBJECT_TYPE_NAME( vobject ) );
#endif /*DEBUG*/

		vobject->dirty = FALSE;
		queue_remove( vobject_dirty, vobject );
	}
}

#ifdef DEBUG_TIME
/* Refresh all vobjects at once and time them.
 */
static gboolean
vobject_refresh_timeout_cb( gpointer user_data )
{
	static GTimer *refresh_timer = NULL;
	double last_elapsed;
	double worst_time = 0.0;
	int worst_index = -1;
	void *data;
	int n;

	vobject_refresh_timeout = 0;

	if( !refresh_timer )
		refresh_timer = g_timer_new();

	g_timer_reset( refresh_timer );

	printf( "vobject_idle_refresh: starting ...\n" );

	for( n = 0; (data = queue_head( vobject_dirty )); n++ ) {
		vObject *vobject = VOBJECT( data );
		double elapsed;

		vobject->dirty = FALSE;
		vobject_refresh( vobject );
		elapsed = g_timer_elapsed( refresh_timer, NULL );

		if( elapsed - last_elapsed > worst_time ) {
			worst_time = elapsed - last_elapsed;
			worst_index = n;
		}

		last_elapsed = elapsed;
	}

	printf( "vobject_idle_refresh: done after %gs (%d refreshes)\n",
		g_timer_elapsed( refresh_timer, NULL ), n );

	printf( "vobject_idle_refresh: worst %gs (refresh %d)\n", 
		worst_time, worst_index );

	return( FALSE );
}
#else /*DEBUG_TIME*/
/* Refresh stuff off the dirty list. 
 */
static gboolean
vobject_refresh_timeout_cb( gpointer user_data )
{
	void *data;

#ifdef DEBUG
	printf( "vobject_refresh_timeout_cb:\n" ); 
#endif /*DEBUG*/

	vobject_refresh_timeout = 0;

	while( (data = queue_head( vobject_dirty ) ) ) {
		vObject *vobject = VOBJECT( data );

#ifdef DEBUG
		printf( "vobject_refresh_timeout_cb: starting \"%s\" (%p)\n", 
			G_OBJECT_TYPE_NAME( vobject ), vobject );
#endif /*DEBUG*/

		/* We must clear dirty before we _refresh() so that if the
		 * _refresh() indirectly triggers another update, we will
		 * _refresh() again.
		 */
		vobject->dirty = FALSE;
		vobject_refresh( vobject );
	}

	return( FALSE );
}
#endif /*DEBUG_TIME*/

/* Mark something for refresh. Seldom call this directly ... just change the 
 * iobject and all vobjects will have a refresh queued.
 */
void *
vobject_refresh_queue( vObject *vobject )
{
	if( !vobject->dirty ) {
#ifdef DEBUG
		printf( "vobject_refresh_queue: %s (%p)", 
			G_OBJECT_TYPE_NAME( vobject ), vobject );
		if( vobject->iobject )
			printf( ", iobject %s \"%s\"", 
				G_OBJECT_TYPE_NAME( vobject->iobject ), 
				NN( vobject->iobject->name ) );
		printf( "\n" );
#endif /*DEBUG*/

		vobject->dirty = TRUE;
		queue_add( vobject_dirty, vobject );

		IM_FREEF( g_source_remove, vobject_refresh_timeout );
		vobject_refresh_timeout = g_timeout_add( 20, 
			(GSourceFunc) vobject_refresh_timeout_cb, NULL );
	}

	return( NULL );
}

/* Called for iobject changed signal ... queue a refresh. 
 */
static void
vobject_iobject_changed( iObject *iobject, vObject *vobject )
{
#ifdef DEBUG
	printf( "vobject_iobject_changed: %s %s \"%s\"\n", 
		G_OBJECT_TYPE_NAME( vobject ), 
		G_OBJECT_TYPE_NAME( iobject ), 
		NN( iobject->name ) );
#endif /*DEBUG*/

	vobject_refresh_queue( vobject );
}

/* Called for iobject destroy signal ... kill the vobject too.
 */
static void
vobject_iobject_destroy( iObject *iobject, vObject *vobject )
{
#ifdef DEBUG
	printf( "vobject_iobject_destroy: iobject %s \"%s\"\n", 
		G_OBJECT_TYPE_NAME( iobject ), NN( iobject->name ) );
#endif /*DEBUG*/

	gtk_widget_destroy( GTK_WIDGET( vobject ) );
}

/* Link to iobject. 
 */
void 
vobject_link( vObject *vobject, iObject *iobject )
{
	vObjectClass *vobject_class = VOBJECT_GET_CLASS( vobject );

	g_assert( !vobject->iobject );

	if( vobject_class->link ) 
		vobject_class->link( vobject, iobject );

	/* Queue a refresh ... we always need at least one.
	 */
	vobject_refresh_queue( vobject );
}

static void
vobject_destroy( GtkObject *object )
{
	vObject *vobject;

	g_return_if_fail( object != NULL );
	g_return_if_fail( IS_VOBJECT( object ) );

	vobject = VOBJECT( object );

#ifdef DEBUG
	printf( "vobject_destroy: \"%s\"\n", G_OBJECT_TYPE_NAME( object ) );
#endif /*DEBUG*/

	if( vobject->iobject ) {
		FREESID( vobject->changed_sid, vobject->iobject );
		FREESID( vobject->destroy_sid, vobject->iobject );
		vobject->iobject = NULL;
	}
	vobject_refresh_dequeue( vobject );

	GTK_OBJECT_CLASS( parent_class )->destroy( object );
}

static void 
vobject_finalize( GObject *gobject )
{
#ifdef DEBUG
	printf( "vobject_finalize: \"%s\"\n", G_OBJECT_TYPE_NAME( gobject ) );
#endif /*DEBUG*/

	G_OBJECT_CLASS( parent_class )->finalize( gobject );
}

static void
vobject_real_refresh( vObject *vobject )
{
#ifdef DEBUG
	printf( "vobject_real_refresh: %p %s\n", 
		vobject, G_OBJECT_TYPE_NAME( vobject ) );
#endif /*DEBUG*/
}

static void
vobject_real_link( vObject *vobject, iObject *iobject )
{
	vobject->iobject = iobject;

	vobject->changed_sid = g_signal_connect( iobject, "changed", 
		G_CALLBACK( vobject_iobject_changed ), vobject );
	vobject->destroy_sid = g_signal_connect( iobject, "destroy", 
		G_CALLBACK( vobject_iobject_destroy ), vobject );
}

static void
vobject_class_init( vObjectClass *class )
{
	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
	GtkObjectClass *object_class = (GtkObjectClass*) class;

	parent_class = g_type_class_peek_parent( class );

	gobject_class->finalize = vobject_finalize;

	object_class->destroy = vobject_destroy;

	/* Create signals.
	 */

	/* Init default methods.
	 */
	class->refresh = vobject_real_refresh;
	class->link = vobject_real_link;

	/* Static init.
	 */
	vobject_dirty = queue_new();
}

static void
vobject_init( vObject *vobject )
{
	/* Init our instance fields.
	 */
	vobject->iobject = NULL;
	vobject->changed_sid = 0;
	vobject->destroy_sid = 0;

	vobject->dirty = FALSE;

	/* All new vobjects will need refreshing.
	 */
	vobject_refresh_queue( vobject );
}

GtkType
vobject_get_type( void )
{
	static GtkType vobject_type = 0;

	if( !vobject_type ) {
		static const GtkTypeInfo vobject_info = {
			"vObject",
			sizeof( vObject ),
			sizeof( vObjectClass ),
			(GtkClassInitFunc) vobject_class_init,
			(GtkObjectInitFunc) vobject_init,
			/* reserved_1 */ NULL,
			/* reserved_2 */ NULL,
			(GtkClassInitFunc) NULL,
		};

		vobject_type = gtk_type_unique( GTK_TYPE_VBOX, &vobject_info );
	}

	return( vobject_type );
}

/* Trigger the refresh method for a vobject immediately ... we usually queue
 * and wait for idle, but this can be better for interactive stuff.
 */
void *
vobject_refresh( vObject *vobject )
{
	vObjectClass *vobject_class = VOBJECT_GET_CLASS( vobject );

	if( vobject_class->refresh ) 
		vobject_class->refresh( vobject );

	return( NULL );
}