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gdk: Add GdkPaintable

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Benjamin Otte 2018-02-16 05:32:32 +01:00
parent a721d8b78f
commit 8f43d7e188
5 changed files with 551 additions and 0 deletions
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14
docs/reference/gdk/gdk4-sections.txt
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@ -714,6 +714,20 @@ GDK_IS_EVENT
gdk_event_get_type
</SECTION>
<SECTION>
<TITLE>Paintable</TITLE>
<FILE>paintable</FILE>
GdkPaintable
gdk_paintable_snapshot
gdk_paintable_get_current_image
gdk_paintable_get_flags
gdk_paintable_get_intrinsic_width
gdk_paintable_get_intrinsic_height
gdk_paintable_get_intrinsic_aspect_ratio
gdk_paintable_invalidate_contents
gdk_paintable_invalidate_size
<SECTION>
<SECTION>
<TITLE>Textures</TITLE>
<FILE>textures</FILE>

1
gdk/gdk.h
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@ -56,6 +56,7 @@
#include <gdk/gdkkeysyms.h>
#include <gdk/gdkmemorytexture.h>
#include <gdk/gdkmonitor.h>
#include <gdk/gdkpaintable.h>
#include <gdk/gdkpango.h>
#include <gdk/gdkpixbuf.h>
#include <gdk/gdkproperty.h>

396
gdk/gdkpaintable.c Normal file
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@ -0,0 +1,396 @@
/*
* 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 "gdkpaintable.h"
/**
* SECTION:paintable
* @Title: GdkPaintable
* @Short_description: An interface for a paintable region
* @See_also: #ClutterContent, #GtkImage, #GdkTexture, #GtkSnapshot
*
* #GdkPaintable is a simple interface used by GDK and GDK to represent
* objects that can be painted anywhere at any size without requiring any
* sort of layout. The interface is inspired by similar concepts elsewhere,
* such as #ClutterContent, <ulink
* linkend="https://www.w3.org/TR/css-images-4/#paint-source">HTML/CSS Paint
* Sources</ulink> or <ulink linkend="https://www.w3.org/TR/SVG2/pservers.html">
* SVG Paint Servers</ulink>.
*
* A #GdkPaintable can be snapshot at any time and size using
* gdk_paintable_snapshot(). How the paintable interprets that size and if it
* scales or centers itself into the given rectangle is implementation defined,
* though if you are implementing a #GdkPaintable and don't know what to do, it
* is suggested that you scale your paintable ignoring any potential aspect ratio.
*
* The contents that a #GdkPaintable produces may depend on the #GdkSnapshot passed
* to it. For example, paintables may decide to use more detailed images on higher
* resolution screens or when OpenGL is available. A #GdkPaintable will however
* always produce the same output for the same snapshot.
*
* A #GdkPaintable may change its contents, meaning that it will now produce a
* different output with the same snpashot. Once that happens, it will call
* gdk_paintable_invalidate_contents() which will emit the
* #GdkPaintable::invalidate-contents signal.
* If a paintable is known to never change its contents, it will set the
* %GDK_PAINTABLE_STATIC_CONTENT flag. If a consumer cannot deal with changing
* contents, it may call gdk_paintable_get_static_image() which will return a
* static paintable and use that.
*
* A paintable can report an intrinsic (or preferred) size or aspect ratio it
* wishes to be rendered at, though it doesn't have to. Consumers of the interface
* can use this information to layout thepaintable appropriately.
* Just like the contents, the size of a paintable can change. A paintable will
* indicate this by calling gdk_paintable_invalidate_size() which will emit the
* #GdkPaintable::invalidate-size signal.
* And just like for contents, if a paintable is known to never change its size,
* it will set the %GDK_PAINTABLE_STATIC_SIZE flag.
*/
G_DEFINE_INTERFACE (GdkPaintable, gdk_paintable, G_TYPE_OBJECT)
enum {
INVALIDATE_CONTENTS,
INVALIDATE_SIZE,
LAST_SIGNAL
};
static guint signals[LAST_SIGNAL] = { 0 };
static void
gdk_paintable_default_snapshot (GdkPaintable *paintable,
GdkSnapshot *snapshot,
double width,
double height)
{
g_critical ("Paintable of type '%s' does not implement GdkPaintable::snapshot", G_OBJECT_TYPE_NAME (paintable));
}
static GdkPaintable *
gdk_paintable_default_get_current_image (GdkPaintable *paintable)
{
g_warning ("FIXME: implement by snapshotting at default size and returning a GskRendererNodePaintable");
return paintable;
}
static GdkPaintableFlags
gdk_paintable_default_get_flags (GdkPaintable *paintable)
{
return 0;
}
static int
gdk_paintable_default_get_intrinsic_width (GdkPaintable *paintable)
{
return 0;
}
static int
gdk_paintable_default_get_intrinsic_height (GdkPaintable *paintable)
{
return 0;
}
static double gdk_paintable_default_get_intrinsic_aspect_ratio (GdkPaintable *paintable)
{
int width, height;
width = gdk_paintable_get_intrinsic_width (paintable);
height = gdk_paintable_get_intrinsic_height (paintable);
if (width <= 0 || height <= 0)
return 0.0;
return (double) width / height;
};
static void
gdk_paintable_default_init (GdkPaintableInterface *iface)
{
iface->snapshot = gdk_paintable_default_snapshot;
iface->get_current_image = gdk_paintable_default_get_current_image;
iface->get_flags = gdk_paintable_default_get_flags;
iface->get_intrinsic_width = gdk_paintable_default_get_intrinsic_width;
iface->get_intrinsic_height = gdk_paintable_default_get_intrinsic_height;
iface->get_intrinsic_aspect_ratio = gdk_paintable_default_get_intrinsic_aspect_ratio;
/**
* GdkPaintable::invalidate-contents
* @paintable: a #GdkPaintable
*
* Emitted when the contents of the @paintable change.
*
* Examples for such an event would be videos changing to the next frame or
* the icon theme for an icon changing.
*
* Since: 4.0
*/
signals[INVALIDATE_CONTENTS] =
g_signal_new ("invalidate-contents",
GDK_TYPE_PAINTABLE,
G_SIGNAL_RUN_LAST,
0,
NULL, NULL,
g_cclosure_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* GdkPaintable::invalidate-size
* @paintable: a #GdkPaintable
*
* Emitted when the intrinsic size of the @paintable changes. This means the values
* reported by at least one of gdk_paintable_get_intrinsic_width(),
* gdk_paintable_get_intrinsic_height() or gdk_paintable_get_intrinsic_aspect_ratio()
* has changed.
*
* Examples for such an event would be a paintable displaying the contents of a toplevel
* window being resized.
*
* Since: 4.0
*/
signals[INVALIDATE_SIZE] =
g_signal_new ("invalidate-size",
GDK_TYPE_PAINTABLE,
G_SIGNAL_RUN_LAST,
0,
NULL, NULL,
g_cclosure_marshal_VOID__VOID,
G_TYPE_NONE, 0);
}
/**
* gdk_paintable_snapshot:
* @paintable: a #GdkPaintable
* @snapshot: a #GdkSnapshot to snapshot to
* @width: width to snapshot in
* @height: height to snapshot in
*
* Snapshots the given paintable with the given @width and @height at the
* current (0,0) offset of the @snapshot. If @width and @height are not larger
* than zero, this function will do nothing.
*
* Since: 4.0
**/
void
gdk_paintable_snapshot (GdkPaintable *paintable,
GdkSnapshot *snapshot,
double width,
double height)
{
GdkPaintableInterface *iface;
g_return_if_fail (GDK_IS_PAINTABLE (paintable));
g_return_if_fail (snapshot != NULL);
if (width <= 0.0 || height <= 0.0)
return;
iface = GDK_PAINTABLE_GET_IFACE (paintable);
iface->snapshot (paintable, snapshot, width, height);
}
#define GDK_PAINTABLE_IMMUTABLE (GDK_PAINTABLE_STATIC_SIZE | GDK_PAINTABLE_STATIC_CONTENTS)
static inline gboolean
gdk_paintable_is_immutable (GdkPaintable *paintable)
{
return (gdk_paintable_get_flags (paintable) & GDK_PAINTABLE_IMMUTABLE) == GDK_PAINTABLE_IMMUTABLE;
}
/**
* gdk_paintable_get_current_image:
* @paintable: a #GdkPaintable
*
* Gets an immutable paintable for the current contents displayed by @paintable.
*
* This is useful when you want to retain the current state of an animation, for
* example to take a screenshot of a running animation.
*
* If the @paintable is already immutable, it will return itself.
*
* Returns: (transfer full): An immutable paintable for the current
* contents of @paintable.
**/
GdkPaintable *
gdk_paintable_get_current_image (GdkPaintable *paintable)
{
GdkPaintableInterface *iface;
g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), NULL);
if (gdk_paintable_is_immutable (paintable))
return g_object_ref (paintable);
iface = GDK_PAINTABLE_GET_IFACE (paintable);
return iface->get_current_image (paintable);
}
/**
* gdk_paintable_get_flags:
* @paintable: a #GdkPaintable
*
* Get flags for the paintable. This is oftentimes useful for optimizations.
*
* See #GdkPaintableFlags for the flags and what they mean.
*
* Returns: The #GdkPaintableFlags for this paintable.
**/
GdkPaintableFlags
gdk_paintable_get_flags (GdkPaintable *paintable)
{
GdkPaintableInterface *iface;
g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0);
iface = GDK_PAINTABLE_GET_IFACE (paintable);
return iface->get_flags (paintable);
}
/**
* gdk_paintable_get_intrinsic_width:
* @paintable: a #GdkPaintable
*
* Gets the preferred width the @paintable would like to be displayed at.
* Consumers of this interface can use this to reserve enough space to draw
* the paintable.
*
* This is a purely informational value and does not in any way limit the values
* that may be passed to gdk_paintable_snapshot().
*
* If the @paintable does not have a preferred width, it returns 0. Negative
* values are never returned.
*
* Returns: the intrinsic width of @paintable or 0 if none.
**/
int
gdk_paintable_get_intrinsic_width (GdkPaintable *paintable)
{
GdkPaintableInterface *iface;
g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0);
iface = GDK_PAINTABLE_GET_IFACE (paintable);
return iface->get_intrinsic_width (paintable);
}
/**
* gdk_paintable_get_intrinsic_height:
* @paintable: a #GdkPaintable
*
* Gets the preferred height the @paintable would like to be displayed at.
* Consumers of this interface can use this to reserve enough space to draw
* the paintable.
*
* This is a purely informational value and does not in any way limit the values
* that may be passed to gdk_paintable_snapshot().
*
* If the @paintable does not have a preferred height, it returns 0. Negative
* values are never returned.
*
* Returns: the intrinsic height of @paintable or 0 if none.
**/
int
gdk_paintable_get_intrinsic_height (GdkPaintable *paintable)
{
GdkPaintableInterface *iface;
g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0);
iface = GDK_PAINTABLE_GET_IFACE (paintable);
return iface->get_intrinsic_height (paintable);
}
/**
* gdk_paintable_get_intrinsic_aspect_ratio:
* @paintable: a #GdkPaintable
*
* Gets the preferred aspect ratio the @paintable would like to be displayed at.
* The aspect ration is the width divided by the height, so a value of 0.5 means
* that the @paintable prefers to be displayed twice as high as it is wide.
* Consumers of this interface can use this to preserve aspect ratio when displaying
* this paintable.
*
* This is a purely informational value and does not in any way limit the values
* that may be passed to gdk_paintable_snapshot().
*
* Usually when a @paintable returns non-0 values from
* gdk_paintable_get_intrinsic_width() and gdk_paintable_get_intrinsic_height()
* the aspect ratio should conform to those values, though that is not required.
*
* If the @paintable does not have a preferred aspect ratio, it returns 0.0.
* Negative values are never returned.
*
* Returns: the intrinsic aspect ratio of @paintable or 0.0 if none.
**/
double
gdk_paintable_get_intrinsic_aspect_ratio (GdkPaintable *paintable)
{
GdkPaintableInterface *iface;
g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0);
iface = GDK_PAINTABLE_GET_IFACE (paintable);
return iface->get_intrinsic_aspect_ratio (paintable);
}
/**
* gdk_paintable_invalidate_contents:
* @paintable: a #GdkPaintable
*
* Called by implementations of #GdkPaintable to invalidate their contents.
* Unless the contents are invalidated, implementations must guarantee that
* multiple calls to GdkPaintable::snapshot produce the same output.
*
* This function will emit the GdkPaintable::invalidate-contents signal.
*
* If a @paintable reports the %GDK_PAINTABLE_STATIC_CONTENTS flag,
* it must not call this function.
**/
void
gdk_paintable_invalidate_contents (GdkPaintable *paintable)
{
g_return_if_fail (GDK_IS_PAINTABLE (paintable));
g_return_if_fail (!(gdk_paintable_get_flags (paintable) & GDK_PAINTABLE_STATIC_CONTENTS));
g_signal_emit (paintable, signals[INVALIDATE_CONTENTS], 0);
}
/**
* gdk_paintable_invalidate_size:
* @paintable: a #GdkPaintable
*
* Called by implementations of #GdkPaintable to invalidate their size.
* As long as the size is not invalidated, @paintable must return the same values
* for its width, height and intrinsic height.
*
* This function will emit the GdkPaintable::invalidate-size signal.
*
* If a @paintable reports the %GDK_PAINTABLE_STATIC_SIZE flag,
* it must not call this function.
**/
void
gdk_paintable_invalidate_size (GdkPaintable *paintable)
{
g_return_if_fail (GDK_IS_PAINTABLE (paintable));
g_return_if_fail (!(gdk_paintable_get_flags (paintable) & GDK_PAINTABLE_STATIC_SIZE));
g_signal_emit (paintable, signals[INVALIDATE_SIZE], 0);
}

138
gdk/gdkpaintable.h Normal file
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@ -0,0 +1,138 @@
/*
* 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>
*/
#ifndef __GDK_PAINTABLE_H__
#define __GDK_PAINTABLE_H__
#if !defined (__GDK_H_INSIDE__) && !defined (GDK_COMPILATION)
#error "Only <gdk/gdk.h> can be included directly."
#endif
#include <cairo.h>
#include <glib-object.h>
#include <gdk/gdkversionmacros.h>
G_BEGIN_DECLS
#define GDK_TYPE_PAINTABLE (gdk_paintable_get_type ())
typedef struct _GdkSnapshot GdkSnapshot; /* Forward declaration */
GDK_AVAILABLE_IN_ALL
G_DECLARE_INTERFACE (GdkPaintable, gdk_paintable, GDK, PAINTABLE, GObject)
/**
* GdkPaintableFlags:
* @GDK_PAINTABLE_STATIC_SIZE: The size is immutable.
* The GdkPaintable::invalidate-size signal will never be
* emitted.
* @GDK_PAINTABLE_STATIC_CONTENTS: The content is immutable.
* The GdkPaintable::invalidate-content signal will never be
* emitted.
*
* Flags about this object. Implementations use these for optimizations
* such as caching.
*/
typedef enum {
GDK_PAINTABLE_STATIC_SIZE = 1 << 0,
GDK_PAINTABLE_STATIC_CONTENTS = 1 << 1
} GdkPaintableFlags;
/**
* GdkPaintableIface:
* @snapshot: Snapshot the paintable. The given @width and @height are
* guaranteed to be larger than 0.0. The resulting snapshot must modify
* only the area in the rectangle from (0,0) to (width, height).
* This is the only function that must be implemented for this interface.
* @get_current_image: return a #GdkPaintable that does not change over
* time. This means the GDK_PAINTABLE_STATIC_SIZE and
* %GDK_PAINTABLE_STATIC_CONTENTS flag are set.
* @get_flags: Get the flags for this instance. See #GdkPaintableFlags
* for details.
* @get_intrinsic_width: The preferred width for this object to be
* snapshot at or 0 if none. This is purely a hint. The object must still
* be able to render at any size.
* @get_intrinsic_height: The preferred height for this object to be
* snapshot at or 0 if none. This is purely a hint. The object must still
* be able to render at any size.
* @get_intrinsic_aspect_ratio: The preferred aspect ratio for this object
* or 0 if none. If both GdkPaintable:get_intrinsic_width() and
* GdkPaintable:get_intrinsic_height() return non-zero values, this function
* should return the aspect ratio computed from those.
*
* The list of functions that can be implemented for the #GdkPaintable interface.
* Note that apart from the first function, no function is mandatory to implement,
* though it is a good idea to implement GdkPaintable:get_current_image() for
* non-static paintables and GdkPaintable:get_flags() if the image is not dynamic
* as the default implementation returns no flags and that will make the
* implementation likely quite slow.
*/
struct _GdkPaintableInterface
{
/*< private >*/
GTypeInterface g_iface;
/*< public >*/
/* draw to 0,0 with the given width and height */
void (* snapshot) (GdkPaintable *paintable,
GdkSnapshot *snapshot,
double width,
double height);
/* get the current contents in an immutable form (optional) */
GdkPaintable * (* get_current_image) (GdkPaintable *paintable);
/* get flags for potential optimizations (optional) */
GdkPaintableFlags (* get_flags) (GdkPaintable *paintable);
/* preferred width of paintable or 0 if it has no width (optional) */
int (* get_intrinsic_width) (GdkPaintable *paintable);
/* preferred height of paintable or 0 if it has no height (optional) */
int (* get_intrinsic_height) (GdkPaintable *paintable);
/* aspect ratio (width / height) of paintable or 0 if it has no aspect ratio (optional) */
double (* get_intrinsic_aspect_ratio) (GdkPaintable *paintable);
};
GDK_AVAILABLE_IN_ALL
void gdk_paintable_snapshot (GdkPaintable *paintable,
GdkSnapshot *snapshot,
double width,
double height);
GDK_AVAILABLE_IN_ALL
GdkPaintable * gdk_paintable_get_current_image (GdkPaintable *paintable);
GDK_AVAILABLE_IN_ALL
GdkPaintableFlags
gdk_paintable_get_flags (GdkPaintable *paintable);
GDK_AVAILABLE_IN_ALL
int gdk_paintable_get_intrinsic_width (GdkPaintable *paintable);
GDK_AVAILABLE_IN_ALL
int gdk_paintable_get_intrinsic_height (GdkPaintable *paintable);
GDK_AVAILABLE_IN_ALL
double gdk_paintable_get_intrinsic_aspect_ratio(GdkPaintable *paintable);
/* for implementations only */
GDK_AVAILABLE_IN_ALL
void gdk_paintable_invalidate_contents (GdkPaintable *paintable);
GDK_AVAILABLE_IN_ALL
void gdk_paintable_invalidate_size (GdkPaintable *paintable);
G_END_DECLS
#endif /* __GDK_PAINTABLE_H__ */

2
gdk/meson.build
View File

@ -29,6 +29,7 @@ gdk_public_sources = files([
'gdkkeyuni.c',
'gdkmemorytexture.c',
'gdkmonitor.c',
'gdkpaintable.c',
'gdkpango.c',
'gdkpixbuf-drawable.c',
'gdkpipeiostream.c',
@ -73,6 +74,7 @@ gdk_public_headers = files([
'gdkkeysyms.h',
'gdkmemorytexture.h',
'gdkmonitor.h',
'gdkpaintable.h',
'gdkpango.h',
'gdkpixbuf.h',
'gdkproperty.h',