mutter/clutter/clutter-canvas.c
Emmanuele Bassi 0eeb61f3a8 canvas: Add canvas size to the ::draw signal
Instead of requiring a call to clutter_content_get_preferred_size(), we
can simply pass the canvas size to the Canvas::draw signal.
2012-03-16 12:33:37 +00:00

514 lines
14 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2012 Intel Corporation.
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
/**
* SECTION:clutter-canvas
* @Title: ClutterCanvas
* @Short_Description: Content for 2D painting
* @See_Also: #ClutterContent
*
* The #ClutterCanvas class is a #ClutterContent implementation that allows
* drawing using the Cairo API on a 2D surface.
*
* In order to draw on a #ClutterCanvas, you should connect a handler to the
* #ClutterCanvas::draw signal; the signal will receive a #cairo_t context
* that can be used to draw. #ClutterCanvas will emit the #ClutterCanvas::draw
* signal when invalidated using clutter_content_invalidate().
*
* <informalexample id="canvas-example">
* <programlisting>
* <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" parse="text" href="../../../../tests/interactive/test-canvas.c">
* <xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback>
* </xi:include>
* </programlisting>
* </informalexample>
*
* #ClutterCanvas is available since Clutter 1.10.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <cogl/cogl.h>
#include <cairo-gobject.h>
#include "clutter-canvas.h"
#define CLUTTER_ENABLE_EXPERIMENTAL_API
#include "clutter-backend.h"
#include "clutter-color.h"
#include "clutter-content-private.h"
#include "clutter-marshal.h"
#include "clutter-paint-node.h"
#include "clutter-paint-nodes.h"
#include "clutter-private.h"
struct _ClutterCanvasPrivate
{
cairo_t *cr;
int width;
int height;
CoglBitmap *buffer;
};
enum
{
PROP_0,
PROP_WIDTH,
PROP_HEIGHT,
LAST_PROP
};
static GParamSpec *obj_props[LAST_PROP] = { NULL, };
enum
{
DRAW,
LAST_SIGNAL
};
static guint canvas_signals[LAST_SIGNAL] = { 0, };
static void clutter_content_iface_init (ClutterContentIface *iface);
G_DEFINE_TYPE_WITH_CODE (ClutterCanvas, clutter_canvas, G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (CLUTTER_TYPE_CONTENT,
clutter_content_iface_init))
static void
clutter_cairo_context_draw_marshaller (GClosure *closure,
GValue *return_value,
guint n_param_values,
const GValue *param_values,
gpointer invocation_hint,
gpointer marshal_data)
{
cairo_t *cr = g_value_get_boxed (&param_values[1]);
cairo_save (cr);
_clutter_marshal_BOOLEAN__BOXED_INT_INT (closure,
return_value,
n_param_values,
param_values,
invocation_hint,
marshal_data);
cairo_restore (cr);
}
static void
clutter_canvas_finalize (GObject *gobject)
{
ClutterCanvasPrivate *priv = CLUTTER_CANVAS (gobject)->priv;
if (priv->buffer != NULL)
{
cogl_object_unref (priv->buffer);
priv->buffer = NULL;
}
G_OBJECT_CLASS (clutter_canvas_parent_class)->finalize (gobject);
}
static void
clutter_canvas_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterCanvasPrivate *priv = CLUTTER_CANVAS (gobject)->priv;
switch (prop_id)
{
case PROP_WIDTH:
if (priv->width != g_value_get_int (value))
{
priv->width = g_value_get_int (value);
clutter_content_invalidate (CLUTTER_CONTENT (gobject));
}
break;
case PROP_HEIGHT:
if (priv->height != g_value_get_int (value))
{
priv->height = g_value_get_int (value);
clutter_content_invalidate (CLUTTER_CONTENT (gobject));
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_canvas_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterCanvasPrivate *priv = CLUTTER_CANVAS (gobject)->priv;
switch (prop_id)
{
case PROP_WIDTH:
g_value_set_int (value, priv->width);
break;
case PROP_HEIGHT:
g_value_set_int (value, priv->height);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_canvas_class_init (ClutterCanvasClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
g_type_class_add_private (klass, sizeof (ClutterCanvasPrivate));
/**
* ClutterCanvas:width:
*
* The width of the canvas.
*
* Since: 1.10
*/
obj_props[PROP_WIDTH] =
g_param_spec_int ("width",
P_("Width"),
P_("The width of the canvas"),
-1, G_MAXINT,
-1,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS);
/**
* ClutterCanvas:height:
*
* The height of the canvas.
*
* Since: 1.10
*/
obj_props[PROP_HEIGHT] =
g_param_spec_int ("height",
P_("Height"),
P_("The height of the canvas"),
-1, G_MAXINT,
-1,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS);
/**
* ClutterCanvas::draw:
* @canvas: the #ClutterCanvas that emitted the signal
* @cr: the Cairo context used to draw
* @width: the width of the @canvas
* @height: the height of the @canvas
*
* The #ClutterCanvas::draw signal is emitted each time a canvas is
* invalidated.
*
* It is safe to connect multiple handlers to this signal: each
* handler invocation will be automatically protected by cairo_save()
* and cairo_restore() pairs.
*
* Return value: %TRUE if the signal emission should stop, and
* %FALSE otherwise
*
* Since: 1.10
*/
canvas_signals[DRAW] =
g_signal_new (I_("draw"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_NO_RECURSE,
G_STRUCT_OFFSET (ClutterCanvasClass, draw),
_clutter_boolean_handled_accumulator, NULL,
clutter_cairo_context_draw_marshaller,
G_TYPE_BOOLEAN, 3,
CAIRO_GOBJECT_TYPE_CONTEXT,
G_TYPE_INT,
G_TYPE_INT);
gobject_class->set_property = clutter_canvas_set_property;
gobject_class->get_property = clutter_canvas_get_property;
gobject_class->finalize = clutter_canvas_finalize;
g_object_class_install_properties (gobject_class, LAST_PROP, obj_props);
}
static void
clutter_canvas_init (ClutterCanvas *self)
{
self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self, CLUTTER_TYPE_CANVAS,
ClutterCanvasPrivate);
self->priv->width = -1;
self->priv->height = -1;
}
static void
clutter_canvas_paint_content (ClutterContent *content,
ClutterActor *actor,
ClutterPaintNode *root)
{
ClutterCanvas *self = CLUTTER_CANVAS (content);
ClutterPaintNode *node;
CoglTexture *texture;
ClutterActorBox box;
ClutterColor color;
guint8 paint_opacity;
if (self->priv->buffer == NULL)
return;
texture = cogl_texture_new_from_bitmap (self->priv->buffer,
COGL_TEXTURE_NO_SLICING,
CLUTTER_CAIRO_FORMAT_ARGB32);
if (texture == NULL)
return;
clutter_actor_get_content_box (actor, &box);
paint_opacity = clutter_actor_get_paint_opacity (actor);
color.red = paint_opacity;
color.green = paint_opacity;
color.blue = paint_opacity;
color.alpha = paint_opacity;
node = clutter_texture_node_new (texture, &color);
cogl_object_unref (texture);
clutter_paint_node_set_name (node, "Canvas");
clutter_paint_node_add_rectangle (node, &box);
clutter_paint_node_add_child (root, node);
clutter_paint_node_unref (node);
}
static void
clutter_canvas_emit_draw (ClutterCanvas *self)
{
ClutterCanvasPrivate *priv = self->priv;
cairo_surface_t *surface;
gboolean mapped_buffer;
unsigned char *data;
CoglBuffer *buffer;
gboolean res;
cairo_t *cr;
g_assert (priv->width >= 0 && priv->width >= 0);
if (priv->buffer == NULL)
{
CoglContext *ctx;
ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
priv->buffer = cogl_bitmap_new_with_size (ctx,
priv->width,
priv->height,
CLUTTER_CAIRO_FORMAT_ARGB32);
}
buffer = COGL_BUFFER (cogl_bitmap_get_buffer (priv->buffer));
if (buffer == NULL)
return;
cogl_buffer_set_update_hint (buffer, COGL_BUFFER_UPDATE_HINT_DYNAMIC);
data = cogl_buffer_map (buffer,
COGL_BUFFER_ACCESS_READ_WRITE,
COGL_BUFFER_MAP_HINT_DISCARD);
if (data != NULL)
{
int bitmap_stride = cogl_bitmap_get_rowstride (priv->buffer);
surface = cairo_image_surface_create_for_data (data,
CAIRO_FORMAT_ARGB32,
priv->width,
priv->height,
bitmap_stride);
mapped_buffer = TRUE;
}
else
{
surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
priv->width,
priv->height);
mapped_buffer = FALSE;
}
self->priv->cr = cr = cairo_create (surface);
g_signal_emit (self, canvas_signals[DRAW], 0,
cr, priv->width, priv->height,
&res);
self->priv->cr = NULL;
cairo_destroy (cr);
if (mapped_buffer)
cogl_buffer_unmap (buffer);
else
{
int size = cairo_image_surface_get_stride (surface) * priv->height;
cogl_buffer_set_data (buffer,
0,
cairo_image_surface_get_data (surface),
size);
}
cairo_surface_destroy (surface);
}
static void
clutter_canvas_invalidate (ClutterContent *content)
{
ClutterCanvas *self = CLUTTER_CANVAS (content);
ClutterCanvasPrivate *priv = self->priv;
if (priv->buffer != NULL)
{
cogl_object_unref (priv->buffer);
priv->buffer = NULL;
}
if (priv->width < 0 || priv->height < 0)
return;
clutter_canvas_emit_draw (self);
}
static gboolean
clutter_canvas_get_preferred_size (ClutterContent *content,
gfloat *width,
gfloat *height)
{
ClutterCanvasPrivate *priv = CLUTTER_CANVAS (content)->priv;
if (priv->width < 0 || priv->height < 0)
return FALSE;
if (width != NULL)
*width = priv->width;
if (height != NULL)
*height = priv->height;
return TRUE;
}
static void
clutter_content_iface_init (ClutterContentIface *iface)
{
iface->invalidate = clutter_canvas_invalidate;
iface->paint_content = clutter_canvas_paint_content;
iface->get_preferred_size = clutter_canvas_get_preferred_size;
}
/**
* clutter_canvas_new:
*
* Creates a new instance of #ClutterCanvas.
*
* You should call clutter_canvas_set_size() to set the size of the canvas.
*
* You should call clutter_content_invalidate() every time you wish to
* draw the contents of the canvas.
*
* Return value: (transfer full): The newly allocated instance of
* #ClutterCanvas. Use g_object_unref() when done.
*
* Since: 1.10
*/
ClutterContent *
clutter_canvas_new (void)
{
return g_object_new (CLUTTER_TYPE_CANVAS, NULL);
}
/**
* clutter_canvas_set_size:
* @canvas: a #ClutterCanvas
* @width: the width of the canvas, in pixels
* @height: the height of the canvas, in pixels
*
* Sets the size of the @canvas.
*
* This function will cause the @canvas to be invalidated.
*
* Since: 1.10
*/
void
clutter_canvas_set_size (ClutterCanvas *canvas,
int width,
int height)
{
GObject *obj;
gboolean width_changed = FALSE, height_changed = FALSE;
g_return_if_fail (CLUTTER_IS_CANVAS (canvas));
g_return_if_fail (width >= -1 && height >= -1);
obj = G_OBJECT (canvas);
g_object_freeze_notify (obj);
if (canvas->priv->width != width)
{
canvas->priv->width = width;
width_changed = TRUE;
g_object_notify_by_pspec (obj, obj_props[PROP_WIDTH]);
}
if (canvas->priv->height != height)
{
canvas->priv->height = height;
height_changed = TRUE;
g_object_notify_by_pspec (obj, obj_props[PROP_HEIGHT]);
}
if (width_changed || height_changed)
clutter_content_invalidate (CLUTTER_CONTENT (canvas));
g_object_thaw_notify (obj);
}