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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* e-canvas.c
* Copyright (C) 2000 Helix Code, Inc.
* Author: Chris Lahey <clahey@helixcode.com>
*
* This library 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 library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <gnome.h>
#include "e-canvas.h"
static void e_canvas_init (ECanvas *card);
static void e_canvas_class_init (ECanvasClass *klass);
static gint e_canvas_key (GtkWidget *widget,
GdkEventKey *event);
static int emit_event (GnomeCanvas *canvas, GdkEvent *event);
static GnomeCanvasClass *parent_class = NULL;
GtkType
e_canvas_get_type (void)
{
static GtkType canvas_type = 0;
if (!canvas_type)
{
static const GtkTypeInfo canvas_info =
{
"ECanvas",
sizeof (ECanvas),
sizeof (ECanvasClass),
(GtkClassInitFunc) e_canvas_class_init,
(GtkObjectInitFunc) e_canvas_init,
/* reserved_1 */ NULL,
/* reserved_2 */ NULL,
(GtkClassInitFunc) NULL,
};
canvas_type = gtk_type_unique (gnome_canvas_get_type (), &canvas_info);
}
return canvas_type;
}
static void
e_canvas_class_init (ECanvasClass *klass)
{
GtkObjectClass *object_class;
GnomeCanvasClass *canvas_class;
GtkWidgetClass *widget_class;
object_class = (GtkObjectClass*) klass;
canvas_class = (GnomeCanvasClass *) klass;
widget_class = (GtkWidgetClass *) klass;
parent_class = gtk_type_class (gnome_canvas_get_type ());
widget_class->key_press_event = e_canvas_key;
widget_class->key_release_event = e_canvas_key;
}
static void
e_canvas_init (ECanvas *canvas)
{
}
GtkWidget *
e_canvas_new()
{
return GTK_WIDGET (gtk_type_new (e_canvas_get_type ()));
}
/* Returns whether the item is an inferior of or is equal to the parent. */
static int
is_descendant (GnomeCanvasItem *item, GnomeCanvasItem *parent)
{
for (; item; item = item->parent)
if (item == parent)
return TRUE;
return FALSE;
}
/* Emits an event for an item in the canvas, be it the current item, grabbed
* item, or focused item, as appropriate.
*/
static int
emit_event (GnomeCanvas *canvas, GdkEvent *event)
{
GdkEvent ev;
gint finished;
GnomeCanvasItem *item;
GnomeCanvasItem *parent;
guint mask;
/* Perform checks for grabbed items */
if (canvas->grabbed_item && !is_descendant (canvas->current_item, canvas->grabbed_item))
return FALSE;
if (canvas->grabbed_item) {
switch (event->type) {
case GDK_ENTER_NOTIFY:
mask = GDK_ENTER_NOTIFY_MASK;
break;
case GDK_LEAVE_NOTIFY:
mask = GDK_LEAVE_NOTIFY_MASK;
break;
case GDK_MOTION_NOTIFY:
mask = GDK_POINTER_MOTION_MASK;
break;
case GDK_BUTTON_PRESS:
case GDK_2BUTTON_PRESS:
case GDK_3BUTTON_PRESS:
mask = GDK_BUTTON_PRESS_MASK;
break;
case GDK_BUTTON_RELEASE:
mask = GDK_BUTTON_RELEASE_MASK;
break;
case GDK_KEY_PRESS:
mask = GDK_KEY_PRESS_MASK;
break;
case GDK_KEY_RELEASE:
mask = GDK_KEY_RELEASE_MASK;
break;
default:
mask = 0;
break;
}
if (!(mask & canvas->grabbed_event_mask))
return FALSE;
}
/* Convert to world coordinates -- we have two cases because of diferent
* offsets of the fields in the event structures.
*/
ev = *event;
switch (ev.type) {
case GDK_ENTER_NOTIFY:
case GDK_LEAVE_NOTIFY:
gnome_canvas_window_to_world (canvas,
ev.crossing.x, ev.crossing.y,
&ev.crossing.x, &ev.crossing.y);
break;
case GDK_MOTION_NOTIFY:
case GDK_BUTTON_PRESS:
case GDK_2BUTTON_PRESS:
case GDK_3BUTTON_PRESS:
case GDK_BUTTON_RELEASE:
gnome_canvas_window_to_world (canvas,
ev.motion.x, ev.motion.y,
&ev.motion.x, &ev.motion.y);
break;
default:
break;
}
/* Choose where we send the event */
item = canvas->current_item;
if (canvas->focused_item
&& ((event->type == GDK_KEY_PRESS) || (event->type == GDK_KEY_RELEASE) || (event->type == GDK_FOCUS_CHANGE)))
item = canvas->focused_item;
/* The event is propagated up the hierarchy (for if someone connected to
* a group instead of a leaf event), and emission is stopped if a
* handler returns TRUE, just like for GtkWidget events.
*/
finished = FALSE;
while (item && !finished) {
gtk_object_ref (GTK_OBJECT (item));
gtk_signal_emit_by_name (GTK_OBJECT (item), "event",
&ev,
&finished);
if (GTK_OBJECT_DESTROYED (item))
finished = TRUE;
parent = item->parent;
gtk_object_unref (GTK_OBJECT (item));
item = parent;
}
return finished;
}
/* Key event handler for the canvas */
static gint
e_canvas_key (GtkWidget *widget, GdkEventKey *event)
{
GnomeCanvas *canvas;
g_return_val_if_fail (widget != NULL, FALSE);
g_return_val_if_fail (GNOME_IS_CANVAS (widget), FALSE);
g_return_val_if_fail (event != NULL, FALSE);
canvas = GNOME_CANVAS (widget);
return emit_event (canvas, (GdkEvent *) event);
}
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