gtk/gdk/gdkdrawingcontext.c
Benjamin Otte ca78f5d3cb gdk: Make gdk_window_begin_draw_frame() take a draw context
... instead of a gl context.

This requires some refactoring in the way we mark the shared context as
drawing: We now call begin_frame/end_frame() on it and ignore the call
on the main context.
Unfortunately we need to do this check in all vfuncs, which sucks. But I
haven't found a better way.
2016-12-05 15:02:47 +01:00

383 lines
10 KiB
C

/* GDK - The GIMP Drawing Kit
* Copyright 2016 Endless
*
* 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/>.
*/
/**
* SECTION:gdkdrawingcontext
* @Title: GdkDrawingContext
* @Short_description: Drawing context for GDK windows
*
* #GdkDrawingContext is an object that represents the current drawing
* state of a #GdkWindow.
*
* It's possible to use a #GdkDrawingContext to draw on a #GdkWindow
* via rendering API like Cairo or OpenGL.
*
* A #GdkDrawingContext can only be created by calling gdk_window_begin_draw_frame()
* and will be valid until a call to gdk_window_end_draw_frame().
*
* #GdkDrawingContext is available since GDK 3.22
*/
#include "config.h"
#include <cairo-gobject.h>
#include "gdkdrawingcontextprivate.h"
#include "gdkrectangle.h"
#include "gdkinternals.h"
#include "gdkintl.h"
#include "gdkframeclockidle.h"
#include "gdkwindowimpl.h"
#include "gdkglcontextprivate.h"
#include "gdk-private.h"
typedef struct _GdkDrawingContextPrivate GdkDrawingContextPrivate;
struct _GdkDrawingContextPrivate {
GdkWindow *window;
GdkDrawContext *paint_context;
cairo_region_t *clip;
cairo_t *cr;
};
G_DEFINE_TYPE_WITH_PRIVATE (GdkDrawingContext, gdk_drawing_context, G_TYPE_OBJECT)
enum {
PROP_0,
PROP_WINDOW,
PROP_CLIP,
PROP_PAINT_CONTEXT,
N_PROPS
};
static GParamSpec *obj_property[N_PROPS];
static void
gdk_drawing_context_dispose (GObject *gobject)
{
GdkDrawingContext *self = GDK_DRAWING_CONTEXT (gobject);
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (self);
/* Unset the drawing context, in case somebody is holding
* onto the Cairo context
*/
if (priv->cr != NULL)
gdk_cairo_set_drawing_context (priv->cr, NULL);
g_clear_object (&priv->window);
g_clear_object (&priv->paint_context);
g_clear_pointer (&priv->clip, cairo_region_destroy);
g_clear_pointer (&priv->cr, cairo_destroy);
G_OBJECT_CLASS (gdk_drawing_context_parent_class)->dispose (gobject);
}
static void
gdk_drawing_context_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GdkDrawingContext *self = GDK_DRAWING_CONTEXT (gobject);
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (self);
switch (prop_id)
{
case PROP_WINDOW:
priv->window = g_value_dup_object (value);
if (priv->window == NULL)
{
g_critical ("The drawing context of type %s does not have a window "
"associated to it. Drawing contexts can only be created "
"using gdk_window_begin_draw_frame().",
G_OBJECT_TYPE_NAME (gobject));
return;
}
case PROP_PAINT_CONTEXT:
priv->paint_context = g_value_dup_object (value);
break;
case PROP_CLIP:
priv->clip = g_value_dup_boxed (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
gdk_drawing_context_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GdkDrawingContext *self = GDK_DRAWING_CONTEXT (gobject);
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (self);
switch (prop_id)
{
case PROP_WINDOW:
g_value_set_object (value, priv->window);
break;
case PROP_CLIP:
g_value_set_boxed (value, priv->clip);
break;
case PROP_PAINT_CONTEXT:
g_value_set_object (value, priv->paint_context);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
gdk_drawing_context_class_init (GdkDrawingContextClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->set_property = gdk_drawing_context_set_property;
gobject_class->get_property = gdk_drawing_context_get_property;
gobject_class->dispose = gdk_drawing_context_dispose;
/**
* GdkDrawingContext:window:
*
* The #GdkWindow that created the drawing context.
*
* Since: 3.22
*/
obj_property[PROP_WINDOW] =
g_param_spec_object ("window", "Window", "The window that created the context",
GDK_TYPE_WINDOW,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS);
/**
* GdkDrawingContext:clip:
*
* The clip region applied to the drawing context.
*
* Since: 3.22
*/
obj_property[PROP_CLIP] =
g_param_spec_boxed ("clip", "Clip", "The clip region of the context",
CAIRO_GOBJECT_TYPE_REGION,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS);
/**
* GdkDrawingContext:paint-context:
*
* The #GdkDrawContext used to draw or %NULL if Cairo is used.
*
* Since: 3.90
*/
obj_property[PROP_PAINT_CONTEXT] =
g_param_spec_object ("paint-context", "Paint context", "The context used to draw",
GDK_TYPE_DRAW_CONTEXT,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (gobject_class, N_PROPS, obj_property);
}
static void
gdk_drawing_context_init (GdkDrawingContext *self)
{
}
static const cairo_user_data_key_t draw_context_key;
void
gdk_cairo_set_drawing_context (cairo_t *cr,
GdkDrawingContext *context)
{
cairo_set_user_data (cr, &draw_context_key, context, NULL);
}
/**
* gdk_cairo_get_drawing_context:
* @cr: a Cairo context
*
* Retrieves the #GdkDrawingContext that created the Cairo
* context @cr.
*
* Returns: (transfer none) (nullable): a #GdkDrawingContext, if any is set
*
* Since: 3.22
*/
GdkDrawingContext *
gdk_cairo_get_drawing_context (cairo_t *cr)
{
g_return_val_if_fail (cr != NULL, NULL);
return cairo_get_user_data (cr, &draw_context_key);
}
/**
* gdk_drawing_context_get_cairo_context:
* @context: a #GdkDrawingContext created with a %NULL paint context
*
* Retrieves a Cairo context to be used to draw on the #GdkWindow
* that created the #GdkDrawingContext. The @context must have been
* created without a #GdkDrawContext for this function to work. If
* gdk_drawing_context_get_paint_context() does not return %NULL,
* then this function will.
*
* The returned context is guaranteed to be valid as long as the
* #GdkDrawingContext is valid, that is between a call to
* gdk_window_begin_draw_frame() and gdk_window_end_draw_frame().
*
* Returns: (transfer none): a Cairo context to be used to draw
* the contents of the #GdkWindow. The context is owned by the
* #GdkDrawingContext and should not be destroyed. %NULL is
* returned when a paint context is in used.
*
* Since: 3.22
*/
cairo_t *
gdk_drawing_context_get_cairo_context (GdkDrawingContext *context)
{
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_DRAWING_CONTEXT (context), NULL);
g_return_val_if_fail (GDK_IS_WINDOW (priv->window), NULL);
if (priv->paint_context != NULL)
return NULL;
if (priv->cr == NULL)
{
cairo_region_t *region;
cairo_surface_t *surface;
surface = _gdk_window_ref_cairo_surface (priv->window);
priv->cr = cairo_create (surface);
gdk_cairo_set_drawing_context (priv->cr, context);
region = gdk_window_get_current_paint_region (priv->window);
cairo_region_union (region, priv->clip);
gdk_cairo_region (priv->cr, region);
cairo_clip (priv->cr);
cairo_region_destroy (region);
cairo_surface_destroy (surface);
}
return priv->cr;
}
/**
* gdk_drawing_context_get_window:
* @context: a #GdkDrawingContext
*
* Retrieves the window that created the drawing @context.
*
* Returns: (transfer none): a #GdkWindow
*
* Since: 3.22
*/
GdkWindow *
gdk_drawing_context_get_window (GdkDrawingContext *context)
{
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_DRAWING_CONTEXT (context), NULL);
return priv->window;
}
/**
* gdk_drawing_context_get_paint_context:
* @context: a #GdkDrawingContext
*
* Retrieves the paint context used to draw with.
*
* Returns: (transfer none): a #GdkDrawContext or %NULL
*
* Since: 3.90
*/
GdkDrawContext *
gdk_drawing_context_get_paint_context (GdkDrawingContext *context)
{
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_DRAWING_CONTEXT (context), NULL);
return priv->paint_context;
}
/**
* gdk_drawing_context_get_clip:
* @context: a #GdkDrawingContext
*
* Retrieves a copy of the clip region used when creating the @context.
*
* Returns: (transfer full) (nullable): a Cairo region
*
* Since: 3.22
*/
cairo_region_t *
gdk_drawing_context_get_clip (GdkDrawingContext *context)
{
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_DRAWING_CONTEXT (context), NULL);
if (priv->clip == NULL)
return NULL;
return cairo_region_copy (priv->clip);
}
/**
* gdk_drawing_context_is_valid:
* @context: a #GdkDrawingContext
*
* Checks whether the given #GdkDrawingContext is valid.
*
* Returns: %TRUE if the context is valid
*
* Since: 3.22
*/
gboolean
gdk_drawing_context_is_valid (GdkDrawingContext *context)
{
GdkDrawingContextPrivate *priv = gdk_drawing_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_DRAWING_CONTEXT (context), FALSE);
if (priv->window == NULL)
return FALSE;
if (gdk_window_get_drawing_context (priv->window) != context)
return FALSE;
return TRUE;
}