gtk/gdk/gdkpaintable.h
2024-03-29 13:31:36 +00:00

147 lines
6.7 KiB
C

/*
* 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>
*/
#pragma once
#if !defined (__GDK_H_INSIDE__) && !defined (GTK_COMPILATION)
#error "Only <gdk/gdk.h> can be included directly."
#endif
#include <gdk/gdktypes.h>
G_BEGIN_DECLS
#define GDK_TYPE_PAINTABLE (gdk_paintable_get_type ())
GDK_AVAILABLE_IN_ALL
G_DECLARE_INTERFACE (GdkPaintable, gdk_paintable, GDK, PAINTABLE, GObject)
/**
* GdkPaintableFlags:
* @GDK_PAINTABLE_STATIC_SIZE: The size is immutable.
* The [signal@Gdk.Paintable::invalidate-size] signal will never be
* emitted.
* @GDK_PAINTABLE_STATIC_CONTENTS: The content is immutable.
* The [signal@Gdk.Paintable::invalidate-contents] signal will never be
* emitted.
*
* Flags about a paintable object.
*
* Implementations use these for optimizations such as caching.
*/
typedef enum {
GDK_PAINTABLE_STATIC_SIZE = 1 << 0,
GDK_PAINTABLE_STATIC_CONTENTS = 1 << 1
} GdkPaintableFlags;
/**
* GdkPaintableInterface:
* @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 [flags@Gdk.PaintableFlags]
* 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 [vfunc@Gdk.Paintable.get_intrinsic_width]
* and [vfunc@Gdk.Paintable.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 [vfunc@Gdk.Paintable.snapshot] function,
* no virtual function of this interface is mandatory to implement, though it
* is a good idea to implement [vfunc@Gdk.Paintable.get_current_image]
* for non-static paintables and [vfunc@Gdk.Paintable.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);
GDK_AVAILABLE_IN_ALL
void gdk_paintable_compute_concrete_size (GdkPaintable *paintable,
double specified_width,
double specified_height,
double default_width,
double default_height,
double *concrete_width,
double *concrete_height);
/* 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);
GDK_AVAILABLE_IN_ALL
GdkPaintable * gdk_paintable_new_empty (int intrinsic_width,
int intrinsic_height);
G_END_DECLS