diff options
Diffstat (limited to 'widgets/e-canvas.c')
| -rw-r--r-- | widgets/e-canvas.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/widgets/e-canvas.c b/widgets/e-canvas.c new file mode 100644 index 0000000000..74af105b36 --- /dev/null +++ b/widgets/e-canvas.c @@ -0,0 +1,233 @@ +/* -*- 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); +} + |