gtk2/gtk/gtkoffscreenwindow.c

356 lines
10 KiB
C

/*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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.
*
* Authors: Cody Russell <crussell@canonical.com>
* Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include "gtkoffscreenwindow.h"
#include "gtkwidgetprivate.h"
#include "gtkcontainerprivate.h"
#include "gtkprivate.h"
/**
* SECTION:gtkoffscreenwindow
* @short_description: A toplevel to manage offscreen rendering of child widgets
* @title: GtkOffscreenWindow
*
* GtkOffscreenWindow is strictly intended to be used for obtaining
* snapshots of widgets that are not part of a normal widget hierarchy.
* Since #GtkOffscreenWindow is a toplevel widget you cannot obtain
* snapshots of a full window with it since you cannot pack a toplevel
* widget in another toplevel.
*
* The idea is to take a widget and manually set the state of it,
* add it to a GtkOffscreenWindow and then retrieve the snapshot
* as a #cairo_surface_t or #GdkPixbuf.
*
* GtkOffscreenWindow derives from #GtkWindow only as an implementation
* detail. Applications should not use any API specific to #GtkWindow
* to operate on this object. It should be treated as a #GtkBin that
* has no parent widget.
*
* When contained offscreen widgets are redrawn, GtkOffscreenWindow
* will emit a #GtkWidget::damage-event signal.
*/
G_DEFINE_TYPE (GtkOffscreenWindow, gtk_offscreen_window, GTK_TYPE_WINDOW);
static void
gtk_offscreen_window_get_preferred_width (GtkWidget *widget,
gint *minimum,
gint *natural)
{
GtkBin *bin = GTK_BIN (widget);
GtkWidget *child;
gint border_width;
gint default_width;
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
*minimum = border_width * 2;
*natural = border_width * 2;
child = gtk_bin_get_child (bin);
if (child != NULL && gtk_widget_get_visible (child))
{
gint child_min, child_nat;
gtk_widget_get_preferred_width (child, &child_min, &child_nat);
*minimum += child_min;
*natural += child_nat;
}
gtk_window_get_default_size (GTK_WINDOW (widget),
&default_width, NULL);
*minimum = MAX (*minimum, default_width);
*natural = MAX (*natural, default_width);
}
static void
gtk_offscreen_window_get_preferred_height (GtkWidget *widget,
gint *minimum,
gint *natural)
{
GtkBin *bin = GTK_BIN (widget);
GtkWidget *child;
gint border_width;
gint default_height;
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
*minimum = border_width * 2;
*natural = border_width * 2;
child = gtk_bin_get_child (bin);
if (child != NULL && gtk_widget_get_visible (child))
{
gint child_min, child_nat;
gtk_widget_get_preferred_height (child, &child_min, &child_nat);
*minimum += child_min;
*natural += child_nat;
}
gtk_window_get_default_size (GTK_WINDOW (widget),
NULL, &default_height);
*minimum = MAX (*minimum, default_height);
*natural = MAX (*natural, default_height);
}
static void
gtk_offscreen_window_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
{
GtkBin *bin = GTK_BIN (widget);
GtkWidget *child;
gint border_width;
gtk_widget_set_allocation (widget, allocation);
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
if (gtk_widget_get_realized (widget))
gdk_window_move_resize (gtk_widget_get_window (widget),
allocation->x,
allocation->y,
allocation->width,
allocation->height);
child = gtk_bin_get_child (bin);
if (child != NULL && gtk_widget_get_visible (child))
{
GtkAllocation child_alloc;
child_alloc.x = border_width;
child_alloc.y = border_width;
child_alloc.width = allocation->width - 2 * border_width;
child_alloc.height = allocation->height - 2 * border_width;
gtk_widget_size_allocate (child, &child_alloc);
}
gtk_widget_queue_draw (widget);
}
static void
gtk_offscreen_window_realize (GtkWidget *widget)
{
GtkAllocation allocation;
GtkBin *bin;
GtkWidget *child;
GdkWindow *window;
GdkWindowAttr attributes;
gint attributes_mask;
bin = GTK_BIN (widget);
gtk_widget_set_realized (widget, TRUE);
gtk_widget_get_allocation (widget, &allocation);
attributes.x = allocation.x;
attributes.y = allocation.y;
attributes.width = allocation.width;
attributes.height = allocation.height;
attributes.window_type = GDK_WINDOW_OFFSCREEN;
attributes.event_mask = gtk_widget_get_events (widget) | GDK_EXPOSURE_MASK;
attributes.visual = gtk_widget_get_visual (widget);
attributes.wclass = GDK_INPUT_OUTPUT;
attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
window = gdk_window_new (gtk_widget_get_parent_window (widget),
&attributes, attributes_mask);
gtk_widget_set_window (widget, window);
gdk_window_set_user_data (window, widget);
child = gtk_bin_get_child (bin);
if (child)
gtk_widget_set_parent_window (child, window);
gtk_style_context_set_background (gtk_widget_get_style_context (widget),
window);
}
static void
gtk_offscreen_window_resize (GtkWidget *widget)
{
GtkAllocation allocation = { 0, 0 };
GtkRequisition requisition;
gtk_widget_get_preferred_size (widget, &requisition, NULL);
allocation.width = requisition.width;
allocation.height = requisition.height;
gtk_widget_size_allocate (widget, &allocation);
}
static void
move_focus (GtkWidget *widget,
GtkDirectionType dir)
{
gtk_widget_child_focus (widget, dir);
if (!gtk_container_get_focus_child (GTK_CONTAINER (widget)))
gtk_window_set_focus (GTK_WINDOW (widget), NULL);
}
static void
gtk_offscreen_window_show (GtkWidget *widget)
{
gboolean need_resize;
GtkContainer *container;
_gtk_widget_set_visible_flag (widget, TRUE);
container = GTK_CONTAINER (widget);
need_resize = _gtk_container_get_need_resize (container) || !gtk_widget_get_realized (widget);
_gtk_container_set_need_resize (container, FALSE);
if (need_resize)
gtk_offscreen_window_resize (widget);
gtk_widget_map (widget);
/* Try to make sure that we have some focused widget */
if (!gtk_window_get_focus (GTK_WINDOW (widget)))
move_focus (widget, GTK_DIR_TAB_FORWARD);
}
static void
gtk_offscreen_window_hide (GtkWidget *widget)
{
_gtk_widget_set_visible_flag (widget, FALSE);
gtk_widget_unmap (widget);
}
static void
gtk_offscreen_window_check_resize (GtkContainer *container)
{
GtkWidget *widget = GTK_WIDGET (container);
if (gtk_widget_get_visible (widget))
gtk_offscreen_window_resize (widget);
}
static void
gtk_offscreen_window_class_init (GtkOffscreenWindowClass *class)
{
GtkWidgetClass *widget_class;
GtkContainerClass *container_class;
widget_class = GTK_WIDGET_CLASS (class);
container_class = GTK_CONTAINER_CLASS (class);
widget_class->realize = gtk_offscreen_window_realize;
widget_class->show = gtk_offscreen_window_show;
widget_class->hide = gtk_offscreen_window_hide;
widget_class->get_preferred_width = gtk_offscreen_window_get_preferred_width;
widget_class->get_preferred_height = gtk_offscreen_window_get_preferred_height;
widget_class->size_allocate = gtk_offscreen_window_size_allocate;
container_class->check_resize = gtk_offscreen_window_check_resize;
}
static void
gtk_offscreen_window_init (GtkOffscreenWindow *window)
{
}
/* --- functions --- */
/**
* gtk_offscreen_window_new:
*
* Creates a toplevel container widget that is used to retrieve
* snapshots of widgets without showing them on the screen.
*
* Return value: A pointer to a #GtkWidget
*
* Since: 2.20
*/
GtkWidget *
gtk_offscreen_window_new (void)
{
return g_object_new (gtk_offscreen_window_get_type (), NULL);
}
/**
* gtk_offscreen_window_get_surface:
* @offscreen: the #GtkOffscreenWindow contained widget.
*
* Retrieves a snapshot of the contained widget in the form of
* a #cairo_surface_t. If you need to keep this around over window
* resizes then you should add a reference to it.
*
* Returns: (transfer none): A #cairo_surface_t pointer to the offscreen
* surface, or %NULL.
*
* Since: 2.20
*/
cairo_surface_t *
gtk_offscreen_window_get_surface (GtkOffscreenWindow *offscreen)
{
g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
return gdk_offscreen_window_get_surface (gtk_widget_get_window (GTK_WIDGET (offscreen)));
}
/**
* gtk_offscreen_window_get_pixbuf:
* @offscreen: the #GtkOffscreenWindow contained widget.
*
* Retrieves a snapshot of the contained widget in the form of
* a #GdkPixbuf. This is a new pixbuf with a reference count of 1,
* and the application should unreference it once it is no longer
* needed.
*
* Returns: (transfer full): A #GdkPixbuf pointer, or %NULL.
*
* Since: 2.20
*/
GdkPixbuf *
gtk_offscreen_window_get_pixbuf (GtkOffscreenWindow *offscreen)
{
cairo_surface_t *surface;
GdkPixbuf *pixbuf = NULL;
GdkWindow *window;
g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
window = gtk_widget_get_window (GTK_WIDGET (offscreen));
surface = gdk_offscreen_window_get_surface (window);
if (surface != NULL)
{
pixbuf = gdk_pixbuf_get_from_surface (surface,
0, 0,
gdk_window_get_width (window),
gdk_window_get_height (window));
}
return pixbuf;
}