264c67c2aa
Currently, clutter_canvas_set_size() causes invalidation of the canvas
contents only if the newly set size is different. There are cases when
we want to invalidate the content regardless of the size set, but we
cannot do that right now without possibly causing two invalidations,
for instance:
clutter_canvas_set_size (canvas, new_width, new_height);
clutter_content_invalidate (canvas);
will cause two invalidations if the newly set size is different than
the existing one. One way to work around it is to check the current
size of the canvas and either call set_size() or invalidate() depending
on whether the size differs or not, respectively:
g_object_get (canvas, "width", &width, "height", &height, NULL);
if (width != new_width || height != new_height)
clutter_canvas_set_size (canvas, new_width, new_height);
else
clutter_content_invalidate (canvas);
this, howevere, implies knowledge of the internals of ClutterCanvas,
and of its optimizations — and encodes a certain behaviour in third
party code, which makes changes further down the line harder.
We could remove the optimization, and just issue an invalidation
regardless of the surface size, but it's not something I'd be happy to
do. Instead, we can add a new function specifically for ClutterCanvas
that causes a forced invalidation regardless of the size change. If we
ever decide to remove the optimization further down the road, we can
simply deprecate the function, and make it an alias of invalidate()
or set_size().
105 lines
3.4 KiB
C
105 lines
3.4 KiB
C
/*
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* Clutter.
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*
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* An OpenGL based 'interactive canvas' library.
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*
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* Copyright (C) 2012 Intel Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library. If not, see <http://www.gnu.org/licenses/>.
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*
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* Author:
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* Emmanuele Bassi <ebassi@linux.intel.com>
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*/
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#if !defined(__CLUTTER_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
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#error "Only <clutter/clutter.h> can be included directly."
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#endif
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#ifndef __CLUTTER_CANVAS_H__
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#define __CLUTTER_CANVAS_H__
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#include <clutter/clutter-types.h>
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G_BEGIN_DECLS
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#define CLUTTER_TYPE_CANVAS (clutter_canvas_get_type ())
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#define CLUTTER_CANVAS(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), CLUTTER_TYPE_CANVAS, ClutterCanvas))
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#define CLUTTER_IS_CANVAS(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), CLUTTER_TYPE_CANVAS))
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#define CLUTTER_CANVAS_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), CLUTTER_TYPE_CANVAS, ClutterCanvasClass))
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#define CLUTTER_IS_CANVAS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), CLUTTER_TYPE_CANVAS))
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#define CLUTTER_CANVAS_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), CLUTTER_TYPE_CANVAS, ClutterCanvasClass))
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typedef struct _ClutterCanvas ClutterCanvas;
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typedef struct _ClutterCanvasPrivate ClutterCanvasPrivate;
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typedef struct _ClutterCanvasClass ClutterCanvasClass;
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/**
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* ClutterCanvas:
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*
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* The <structname>ClutterCanvas</structname> structure contains
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* private data and should only be accessed using the provided
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* API.
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*
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* Since: 1.10
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*/
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struct _ClutterCanvas
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{
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/*< private >*/
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GObject parent_instance;
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ClutterCanvasPrivate *priv;
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};
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/**
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* ClutterCanvasClass:
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* @draw: class handler for the #ClutterCanvas::draw signal
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*
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* The <structname>ClutterCanvasClass</structname> structure contains
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* private data.
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*
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* Since: 1.10
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*/
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struct _ClutterCanvasClass
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{
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/*< private >*/
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GObjectClass parent_class;
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/*< public >*/
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gboolean (* draw) (ClutterCanvas *canvas,
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cairo_t *cr,
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int width,
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int height);
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/*< private >*/
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gpointer _padding[16];
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};
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CLUTTER_AVAILABLE_IN_1_10
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GType clutter_canvas_get_type (void) G_GNUC_CONST;
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CLUTTER_AVAILABLE_IN_1_10
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ClutterContent * clutter_canvas_new (void);
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CLUTTER_AVAILABLE_IN_1_10
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void clutter_canvas_set_size (ClutterCanvas *canvas,
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int width,
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int height);
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CLUTTER_AVAILABLE_IN_1_16
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void clutter_canvas_invalidate_with_size (ClutterCanvas *canvas,
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int width,
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int height);
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G_END_DECLS
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#endif /* __CLUTTER_CANVAS_H__ */
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