gtk2/gtk/gtkwidgetpaintable.c

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/*
* Copyright © 2018 Benjamin Otte
*
* 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 2.1 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, see <http://www.gnu.org/licenses/>.
*
* Authors: Benjamin Otte <otte@gnome.org>
*/
#include "config.h"
#include "gtkwidgetpaintableprivate.h"
#include "gtkintl.h"
#include "gtksnapshot.h"
#include "gtkrendernodepaintableprivate.h"
#include "gtkwidgetprivate.h"
/**
* SECTION:gtkwidgetpaintable
* @Short_description: Drawing a widget elsewhere
* @Title: GtkWidgetPaintable
* @see_also: #GtkWidget, #GdkPaintable
*
* GtkWidgetPaintable is an implementation of the #GdkPaintable interface
* that allows displaying the contents of a #GtkWidget.
*
* GtkWidgetPaintable will also take care of the widget not being in a
* state where it can be drawn (like when it isn't shown) and just draw
* nothing or where it does not have a size (like when it is hidden) and
* report no size in that case.
*
* Of course, GtkWidgetPaintable allows you to monitor widgets for size
* changes by emitting the #GdkPaintable::invalidate-size signal whenever
* the size of the widget changes as well as for visual changes by
* emitting the #GdkPaintable::invalidate-contents signal whenever the
* widget changes.
*
* You can of course use a GtkWidgetPaintable everywhere a
* #GdkPaintable is allowed, including using it on a #GtkPicture (or one
* of its parents) that it was set on itself via gtk_picture_set_paintable().
* The paintable will take care of recursion when this happens. If you do
* this however, ensure the #GtkPicture:can-shrink property is set to
* %TRUE or you might end up with an infinitely growing widget.
*/
struct _GtkWidgetPaintable
{
GObject parent_instance;
GtkWidget *widget;
guint snapshot_count;
GdkPaintable *current_image; /* the image that we are presenting */
GdkPaintable *pending_image; /* the image that we should be presenting */
guint pending_update_cb; /* the idle source that updates the valid image to be the new current image */
};
struct _GtkWidgetPaintableClass
{
GObjectClass parent_class;
};
enum {
PROP_0,
PROP_WIDGET,
N_PROPS,
};
static GParamSpec *properties[N_PROPS] = { NULL, };
static void
gtk_widget_paintable_paintable_snapshot (GdkPaintable *paintable,
GdkSnapshot *snapshot,
double width,
double height)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (paintable);
if (self->snapshot_count > 4)
return;
else if (self->snapshot_count > 0)
{
graphene_rect_t bounds;
gtk_snapshot_push_clip (snapshot,
&GRAPHENE_RECT_INIT(0, 0, width, height));
if (gtk_widget_compute_bounds (self->widget, self->widget, &bounds))
{
gtk_snapshot_scale (snapshot, width / bounds.size.width, height / bounds.size.height);
gtk_snapshot_translate (snapshot, &bounds.origin);
}
gtk_widget_snapshot (self->widget, snapshot);
gtk_snapshot_pop (snapshot);
}
else
{
gdk_paintable_snapshot (self->current_image, snapshot, width, height);
}
}
static GdkPaintable *
gtk_widget_paintable_paintable_get_current_image (GdkPaintable *paintable)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (paintable);
return g_object_ref (self->current_image);
}
static int
gtk_widget_paintable_paintable_get_intrinsic_width (GdkPaintable *paintable)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (paintable);
return gdk_paintable_get_intrinsic_width (self->current_image);
}
static int
gtk_widget_paintable_paintable_get_intrinsic_height (GdkPaintable *paintable)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (paintable);
return gdk_paintable_get_intrinsic_height (self->current_image);
}
static void
gtk_widget_paintable_paintable_init (GdkPaintableInterface *iface)
{
iface->snapshot = gtk_widget_paintable_paintable_snapshot;
iface->get_current_image = gtk_widget_paintable_paintable_get_current_image;
iface->get_intrinsic_width = gtk_widget_paintable_paintable_get_intrinsic_width;
iface->get_intrinsic_height = gtk_widget_paintable_paintable_get_intrinsic_height;
}
G_DEFINE_TYPE_EXTENDED (GtkWidgetPaintable, gtk_widget_paintable, G_TYPE_OBJECT, 0,
G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
gtk_widget_paintable_paintable_init))
static void
gtk_widget_paintable_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (object);
switch (prop_id)
{
case PROP_WIDGET:
gtk_widget_paintable_set_widget (self, g_value_get_object (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_widget_paintable_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (object);
switch (prop_id)
{
case PROP_WIDGET:
g_value_set_object (value, self->widget);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_widget_paintable_dispose (GObject *object)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (object);
gtk_widget_paintable_set_widget (self, NULL);
G_OBJECT_CLASS (gtk_widget_paintable_parent_class)->dispose (object);
}
static void
gtk_widget_paintable_finalize (GObject *object)
{
GtkWidgetPaintable *self = GTK_WIDGET_PAINTABLE (object);
g_object_unref (self->current_image);
G_OBJECT_CLASS (gtk_widget_paintable_parent_class)->finalize (object);
}
static void
gtk_widget_paintable_class_init (GtkWidgetPaintableClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->get_property = gtk_widget_paintable_get_property;
gobject_class->set_property = gtk_widget_paintable_set_property;
gobject_class->dispose = gtk_widget_paintable_dispose;
gobject_class->finalize = gtk_widget_paintable_finalize;
/**
* GtkWidgetPaintable:widget
*
* The observed widget or %NULL if none.
*/
properties[PROP_WIDGET] =
g_param_spec_object ("widget",
P_("Widget"),
P_("Observed widget"),
GTK_TYPE_WIDGET,
G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (gobject_class, N_PROPS, properties);
}
static void
gtk_widget_paintable_init (GtkWidgetPaintable *self)
{
self->current_image = gdk_paintable_new_empty (0, 0);
}
/**
* gtk_widget_paintable_new:
* @widget: (allow-none) (transfer none): a #GtkWidget or %NULL
*
* Creates a new widget paintable observing the given widget.
*
2018-04-06 14:20:48 +00:00
* Returns: (transfer full) (type GtkWidgetPaintable): a new #GtkWidgetPaintable
**/
GdkPaintable *
gtk_widget_paintable_new (GtkWidget *widget)
{
g_return_val_if_fail (widget == NULL || GTK_IS_WIDGET (widget), NULL);
return g_object_new (GTK_TYPE_WIDGET_PAINTABLE,
"widget", widget,
NULL);
}
static GdkPaintable *
gtk_widget_paintable_snapshot_widget (GtkWidgetPaintable *self)
{
graphene_rect_t bounds;
if (self->widget == NULL)
return gdk_paintable_new_empty (0, 0);
if (!gtk_widget_compute_bounds (self->widget, self->widget, &bounds))
return gdk_paintable_new_empty (0, 0);
if (self->widget->priv->render_node == NULL)
return gdk_paintable_new_empty (bounds.size.width, bounds.size.height);
return gtk_render_node_paintable_new (self->widget->priv->render_node, &bounds);
}
/**
* gtk_widget_paintable_get_widget:
* @self: a #GtkWidgetPaintable
*
* Returns the widget that is observed or %NULL
* if none.
*
* Returns: (transfer none) (nullable): the observed widget.
**/
GtkWidget *
gtk_widget_paintable_get_widget (GtkWidgetPaintable *self)
{
g_return_val_if_fail (GTK_IS_WIDGET_PAINTABLE (self), NULL);
return self->widget;
}
/**
* gtk_widget_paintable_set_widget:
* @self: a #GtkWidgetPaintable
* @widget: (allow-none): the widget to observe or %NULL
*
* Sets the widget that should be observed.
**/
void
gtk_widget_paintable_set_widget (GtkWidgetPaintable *self,
GtkWidget *widget)
{
g_return_if_fail (GTK_IS_WIDGET_PAINTABLE (self));
g_return_if_fail (widget == NULL || GTK_IS_WIDGET (widget));
if (self->widget == widget)
return;
if (self->widget)
{
self->widget->priv->paintables = g_slist_remove (self->widget->priv->paintables,
self);
}
/* We do not ref the widget to not cause ref cycles when a widget
* is told to observe itself or one of its parent.
*/
self->widget = widget;
if (widget)
{
widget->priv->paintables = g_slist_prepend (widget->priv->paintables,
self);
}
g_object_unref (self->current_image);
self->current_image = gtk_widget_paintable_snapshot_widget (self);
g_clear_object (&self->pending_image);
if (self->pending_update_cb)
{
g_source_remove (self->pending_update_cb);
self->pending_update_cb = 0;
}
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_WIDGET]);
gdk_paintable_invalidate_size (GDK_PAINTABLE (self));
gdk_paintable_invalidate_contents (GDK_PAINTABLE (self));
}
static gboolean
gtk_widget_paintable_update_func (gpointer data)
{
GtkWidgetPaintable *self = data;
GdkPaintable *old_image;
if (self->current_image != self->pending_image)
{
old_image = self->current_image;
self->current_image = self->pending_image;
self->pending_image = NULL;
self->pending_update_cb = 0;
if (gdk_paintable_get_intrinsic_width (self->current_image) != gdk_paintable_get_intrinsic_width (old_image) ||
gdk_paintable_get_intrinsic_height (self->current_image) != gdk_paintable_get_intrinsic_height (old_image))
gdk_paintable_invalidate_size (GDK_PAINTABLE (self));
g_object_unref (old_image);
gdk_paintable_invalidate_contents (GDK_PAINTABLE (self));
}
else
{
g_clear_object (&self->pending_image);
self->pending_update_cb = 0;
}
return G_SOURCE_REMOVE;
}
void
gtk_widget_paintable_update_image (GtkWidgetPaintable *self)
{
GdkPaintable *pending_image;
if (self->pending_update_cb == 0)
{
self->pending_update_cb = g_idle_add_full (G_PRIORITY_HIGH,
gtk_widget_paintable_update_func,
self,
NULL);
}
pending_image = gtk_widget_paintable_snapshot_widget (self);
g_set_object (&self->pending_image, pending_image);
g_object_unref (pending_image);
}
void
gtk_widget_paintable_push_snapshot_count (GtkWidgetPaintable *self)
{
self->snapshot_count++;
}
void
gtk_widget_paintable_pop_snapshot_count (GtkWidgetPaintable *self)
{
self->snapshot_count--;
}