1 | /* |
2 | * Copyright © 2018 Benjamin Otte |
3 | * |
4 | * This library is free software; you can redistribute it and/or |
5 | * modify it under the terms of the GNU Lesser General Public |
6 | * License as published by the Free Software Foundation; either |
7 | * version 2.1 of the License, or (at your option) any later version. |
8 | * |
9 | * This library is distributed in the hope that it will be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | * Lesser General Public License for more details. |
13 | * |
14 | * You should have received a copy of the GNU Lesser General Public |
15 | * License along with this library. If not, see <http://www.gnu.org/licenses/>. |
16 | * |
17 | * Authors: Benjamin Otte <otte@gnome.org> |
18 | */ |
19 | |
20 | #include "config.h" |
21 | |
22 | #include "gdkpaintable.h" |
23 | |
24 | #include "gdksnapshotprivate.h" |
25 | |
26 | /* HACK: So we don't need to include any (not-yet-created) GSK or GTK headers */ |
27 | void gtk_snapshot_push_debug (GdkSnapshot *snapshot, |
28 | const char *message, |
29 | ...) G_GNUC_PRINTF (2, 3); |
30 | void gtk_snapshot_pop (GdkSnapshot *snapshot); |
31 | |
32 | /** |
33 | * GdkPaintable: |
34 | * |
35 | * `GdkPaintable` is a simple interface used by GTK to represent content that |
36 | * can be painted. |
37 | * |
38 | * The content of a `GdkPaintable` can be painted anywhere at any size |
39 | * without requiring any sort of layout. The interface is inspired by |
40 | * similar concepts elsewhere, such as |
41 | * [ClutterContent](https://developer.gnome.org/clutter/stable/ClutterContent.html), |
42 | * [HTML/CSS Paint Sources](https://www.w3.org/TR/css-images-4/#paint-source), |
43 | * or [SVG Paint Servers](https://www.w3.org/TR/SVG2/pservers.html). |
44 | * |
45 | * A `GdkPaintable` can be snapshot at any time and size using |
46 | * [method@Gdk.Paintable.snapshot]. How the paintable interprets that size and |
47 | * if it scales or centers itself into the given rectangle is implementation |
48 | * defined, though if you are implementing a `GdkPaintable` and don't know what |
49 | * to do, it is suggested that you scale your paintable ignoring any potential |
50 | * aspect ratio. |
51 | * |
52 | * The contents that a `GdkPaintable` produces may depend on the [class@GdkSnapshot] |
53 | * passed to it. For example, paintables may decide to use more detailed images |
54 | * on higher resolution screens or when OpenGL is available. A `GdkPaintable` |
55 | * will however always produce the same output for the same snapshot. |
56 | * |
57 | * A `GdkPaintable` may change its contents, meaning that it will now produce |
58 | * a different output with the same snapshot. Once that happens, it will call |
59 | * [method@Gdk.Paintable.invalidate_contents] which will emit the |
60 | * [signal@GdkPaintable::invalidate-contents] signal. If a paintable is known |
61 | * to never change its contents, it will set the %GDK_PAINTABLE_STATIC_CONTENTS |
62 | * flag. If a consumer cannot deal with changing contents, it may call |
63 | * [method@Gdk.Paintable.get_current_image] which will return a static |
64 | * paintable and use that. |
65 | * |
66 | * A paintable can report an intrinsic (or preferred) size or aspect ratio it |
67 | * wishes to be rendered at, though it doesn't have to. Consumers of the interface |
68 | * can use this information to layout thepaintable appropriately. Just like the |
69 | * contents, the size of a paintable can change. A paintable will indicate this |
70 | * by calling [method@Gdk.Paintable.invalidate_size] which will emit the |
71 | * [signal@GdkPaintable::invalidate-size] signal. And just like for contents, |
72 | * if a paintable is known to never change its size, it will set the |
73 | * %GDK_PAINTABLE_STATIC_SIZE flag. |
74 | * |
75 | * Besides API for applications, there are some functions that are only |
76 | * useful for implementing subclasses and should not be used by applications: |
77 | * [method@Gdk.Paintable.invalidate_contents], |
78 | * [method@Gdk.Paintable.invalidate_size], |
79 | * [func@Gdk.Paintable.new_empty]. |
80 | */ |
81 | |
82 | G_DEFINE_INTERFACE (GdkPaintable, gdk_paintable, G_TYPE_OBJECT) |
83 | |
84 | enum { |
85 | INVALIDATE_CONTENTS, |
86 | INVALIDATE_SIZE, |
87 | LAST_SIGNAL |
88 | }; |
89 | |
90 | static guint signals[LAST_SIGNAL] = { 0 }; |
91 | |
92 | static void |
93 | gdk_paintable_default_snapshot (GdkPaintable *paintable, |
94 | GdkSnapshot *snapshot, |
95 | double width, |
96 | double height) |
97 | { |
98 | g_critical ("Paintable of type '%s' does not implement GdkPaintable::snapshot" , G_OBJECT_TYPE_NAME (paintable)); |
99 | } |
100 | |
101 | static GdkPaintable * |
102 | gdk_paintable_default_get_current_image (GdkPaintable *paintable) |
103 | { |
104 | g_warning ("FIXME: implement by snapshotting at default size and returning a GskRendererNodePaintable" ); |
105 | |
106 | return paintable; |
107 | } |
108 | |
109 | static GdkPaintableFlags |
110 | gdk_paintable_default_get_flags (GdkPaintable *paintable) |
111 | { |
112 | return 0; |
113 | } |
114 | |
115 | static int |
116 | gdk_paintable_default_get_intrinsic_width (GdkPaintable *paintable) |
117 | { |
118 | return 0; |
119 | } |
120 | |
121 | static int |
122 | gdk_paintable_default_get_intrinsic_height (GdkPaintable *paintable) |
123 | { |
124 | return 0; |
125 | } |
126 | |
127 | static double gdk_paintable_default_get_intrinsic_aspect_ratio (GdkPaintable *paintable) |
128 | { |
129 | int width, height; |
130 | |
131 | width = gdk_paintable_get_intrinsic_width (paintable); |
132 | height = gdk_paintable_get_intrinsic_height (paintable); |
133 | |
134 | if (width <= 0 || height <= 0) |
135 | return 0.0; |
136 | |
137 | return (double) width / height; |
138 | }; |
139 | |
140 | static void |
141 | g_value_object_transform_value (const GValue *src_value, |
142 | GValue *dest_value) |
143 | { |
144 | if (src_value->data[0].v_pointer && g_type_is_a (G_OBJECT_TYPE (src_value->data[0].v_pointer), G_VALUE_TYPE (dest_value))) |
145 | dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer); |
146 | else |
147 | dest_value->data[0].v_pointer = NULL; |
148 | } |
149 | |
150 | static void |
151 | gdk_paintable_default_init (GdkPaintableInterface *iface) |
152 | { |
153 | iface->snapshot = gdk_paintable_default_snapshot; |
154 | iface->get_current_image = gdk_paintable_default_get_current_image; |
155 | iface->get_flags = gdk_paintable_default_get_flags; |
156 | iface->get_intrinsic_width = gdk_paintable_default_get_intrinsic_width; |
157 | iface->get_intrinsic_height = gdk_paintable_default_get_intrinsic_height; |
158 | iface->get_intrinsic_aspect_ratio = gdk_paintable_default_get_intrinsic_aspect_ratio; |
159 | |
160 | g_value_register_transform_func (G_TYPE_OBJECT, GDK_TYPE_PAINTABLE, transform_func: g_value_object_transform_value); |
161 | g_value_register_transform_func (GDK_TYPE_PAINTABLE, G_TYPE_OBJECT, transform_func: g_value_object_transform_value); |
162 | |
163 | /** |
164 | * GdkPaintable::invalidate-contents |
165 | * @paintable: a `GdkPaintable` |
166 | * |
167 | * Emitted when the contents of the @paintable change. |
168 | * |
169 | * Examples for such an event would be videos changing to the next frame or |
170 | * the icon theme for an icon changing. |
171 | */ |
172 | signals[INVALIDATE_CONTENTS] = |
173 | g_signal_new (signal_name: "invalidate-contents" , |
174 | GDK_TYPE_PAINTABLE, |
175 | signal_flags: G_SIGNAL_RUN_LAST, |
176 | class_offset: 0, |
177 | NULL, NULL, |
178 | NULL, |
179 | G_TYPE_NONE, n_params: 0); |
180 | |
181 | /** |
182 | * GdkPaintable::invalidate-size |
183 | * @paintable: a `GdkPaintable` |
184 | * |
185 | * Emitted when the intrinsic size of the @paintable changes. |
186 | * |
187 | * This means the values reported by at least one of |
188 | * [method@Gdk.Paintable.get_intrinsic_width], |
189 | * [method@Gdk.Paintable.get_intrinsic_height] or |
190 | * [method@Gdk.Paintable.get_intrinsic_aspect_ratio] |
191 | * has changed. |
192 | * |
193 | * Examples for such an event would be a paintable displaying |
194 | * the contents of a toplevel surface being resized. |
195 | */ |
196 | signals[INVALIDATE_SIZE] = |
197 | g_signal_new (signal_name: "invalidate-size" , |
198 | GDK_TYPE_PAINTABLE, |
199 | signal_flags: G_SIGNAL_RUN_LAST, |
200 | class_offset: 0, |
201 | NULL, NULL, |
202 | NULL, |
203 | G_TYPE_NONE, n_params: 0); |
204 | } |
205 | |
206 | /** |
207 | * gdk_paintable_snapshot: |
208 | * @paintable: a `GdkPaintable` |
209 | * @snapshot: a `GdkSnapshot` to snapshot to |
210 | * @width: width to snapshot in |
211 | * @height: height to snapshot in |
212 | * |
213 | * Snapshots the given paintable with the given @width and @height. |
214 | * |
215 | * The paintable is drawn at the current (0,0) offset of the @snapshot. |
216 | * If @width and @height are not larger than zero, this function will |
217 | * do nothing. |
218 | */ |
219 | void |
220 | gdk_paintable_snapshot (GdkPaintable *paintable, |
221 | GdkSnapshot *snapshot, |
222 | double width, |
223 | double height) |
224 | { |
225 | GdkPaintableInterface *iface; |
226 | |
227 | g_return_if_fail (GDK_IS_PAINTABLE (paintable)); |
228 | g_return_if_fail (snapshot != NULL); |
229 | |
230 | if (width <= 0.0 || height <= 0.0) |
231 | return; |
232 | |
233 | gtk_snapshot_push_debug (snapshot, message: "%s %p @ %gx%g" , G_OBJECT_TYPE_NAME (paintable), paintable, width, height); |
234 | |
235 | iface = GDK_PAINTABLE_GET_IFACE (ptr: paintable); |
236 | iface->snapshot (paintable, snapshot, width, height); |
237 | |
238 | gtk_snapshot_pop (snapshot); |
239 | } |
240 | |
241 | #define GDK_PAINTABLE_IMMUTABLE (GDK_PAINTABLE_STATIC_SIZE | GDK_PAINTABLE_STATIC_CONTENTS) |
242 | static inline gboolean |
243 | gdk_paintable_is_immutable (GdkPaintable *paintable) |
244 | { |
245 | return (gdk_paintable_get_flags (paintable) & GDK_PAINTABLE_IMMUTABLE) == GDK_PAINTABLE_IMMUTABLE; |
246 | } |
247 | |
248 | /** |
249 | * gdk_paintable_get_current_image: |
250 | * @paintable: a `GdkPaintable` |
251 | * |
252 | * Gets an immutable paintable for the current contents displayed by @paintable. |
253 | * |
254 | * This is useful when you want to retain the current state of an animation, |
255 | * for example to take a screenshot of a running animation. |
256 | * |
257 | * If the @paintable is already immutable, it will return itself. |
258 | * |
259 | * Returns: (transfer full): An immutable paintable for the current |
260 | * contents of @paintable |
261 | */ |
262 | GdkPaintable * |
263 | gdk_paintable_get_current_image (GdkPaintable *paintable) |
264 | { |
265 | GdkPaintableInterface *iface; |
266 | |
267 | g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), NULL); |
268 | |
269 | if (gdk_paintable_is_immutable (paintable)) |
270 | return g_object_ref (paintable); |
271 | |
272 | iface = GDK_PAINTABLE_GET_IFACE (ptr: paintable); |
273 | return iface->get_current_image (paintable); |
274 | } |
275 | |
276 | /** |
277 | * gdk_paintable_get_flags: |
278 | * @paintable: a `GdkPaintable` |
279 | * |
280 | * Get flags for the paintable. |
281 | * |
282 | * This is oftentimes useful for optimizations. |
283 | * |
284 | * See [flags@Gdk.PaintableFlags] for the flags and what they mean. |
285 | * |
286 | * Returns: The `GdkPaintableFlags` for this paintable |
287 | */ |
288 | GdkPaintableFlags |
289 | gdk_paintable_get_flags (GdkPaintable *paintable) |
290 | { |
291 | GdkPaintableInterface *iface; |
292 | |
293 | g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0); |
294 | |
295 | iface = GDK_PAINTABLE_GET_IFACE (ptr: paintable); |
296 | return iface->get_flags (paintable); |
297 | } |
298 | |
299 | /** |
300 | * gdk_paintable_get_intrinsic_width: |
301 | * @paintable: a `GdkPaintable` |
302 | * |
303 | * Gets the preferred width the @paintable would like to be displayed at. |
304 | * |
305 | * Consumers of this interface can use this to reserve enough space to draw |
306 | * the paintable. |
307 | * |
308 | * This is a purely informational value and does not in any way limit the |
309 | * values that may be passed to [method@Gdk.Paintable.snapshot]. |
310 | * |
311 | * If the @paintable does not have a preferred width, it returns 0. |
312 | * Negative values are never returned. |
313 | * |
314 | * Returns: the intrinsic width of @paintable or 0 if none. |
315 | */ |
316 | int |
317 | gdk_paintable_get_intrinsic_width (GdkPaintable *paintable) |
318 | { |
319 | GdkPaintableInterface *iface; |
320 | |
321 | g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0); |
322 | |
323 | iface = GDK_PAINTABLE_GET_IFACE (ptr: paintable); |
324 | return iface->get_intrinsic_width (paintable); |
325 | } |
326 | |
327 | /** |
328 | * gdk_paintable_get_intrinsic_height: |
329 | * @paintable: a `GdkPaintable` |
330 | * |
331 | * Gets the preferred height the @paintable would like to be displayed at. |
332 | * |
333 | * Consumers of this interface can use this to reserve enough space to draw |
334 | * the paintable. |
335 | * |
336 | * This is a purely informational value and does not in any way limit the |
337 | * values that may be passed to [method@Gdk.Paintable.snapshot]. |
338 | * |
339 | * If the @paintable does not have a preferred height, it returns 0. |
340 | * Negative values are never returned. |
341 | * |
342 | * Returns: the intrinsic height of @paintable or 0 if none. |
343 | */ |
344 | int |
345 | gdk_paintable_get_intrinsic_height (GdkPaintable *paintable) |
346 | { |
347 | GdkPaintableInterface *iface; |
348 | |
349 | g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0); |
350 | |
351 | iface = GDK_PAINTABLE_GET_IFACE (ptr: paintable); |
352 | return iface->get_intrinsic_height (paintable); |
353 | } |
354 | |
355 | /** |
356 | * gdk_paintable_get_intrinsic_aspect_ratio: |
357 | * @paintable: a `GdkPaintable` |
358 | * |
359 | * Gets the preferred aspect ratio the @paintable would like to be displayed at. |
360 | * |
361 | * The aspect ratio is the width divided by the height, so a value of 0.5 |
362 | * means that the @paintable prefers to be displayed twice as high as it |
363 | * is wide. Consumers of this interface can use this to preserve aspect |
364 | * ratio when displaying the paintable. |
365 | * |
366 | * This is a purely informational value and does not in any way limit the |
367 | * values that may be passed to [method@Gdk.Paintable.snapshot]. |
368 | * |
369 | * Usually when a @paintable returns nonzero values from |
370 | * [method@Gdk.Paintable.get_intrinsic_width] and |
371 | * [method@Gdk.Paintable.get_intrinsic_height] the aspect ratio |
372 | * should conform to those values, though that is not required. |
373 | * |
374 | * If the @paintable does not have a preferred aspect ratio, |
375 | * it returns 0. Negative values are never returned. |
376 | * |
377 | * Returns: the intrinsic aspect ratio of @paintable or 0 if none. |
378 | */ |
379 | double |
380 | gdk_paintable_get_intrinsic_aspect_ratio (GdkPaintable *paintable) |
381 | { |
382 | GdkPaintableInterface *iface; |
383 | |
384 | g_return_val_if_fail (GDK_IS_PAINTABLE (paintable), 0); |
385 | |
386 | iface = GDK_PAINTABLE_GET_IFACE (ptr: paintable); |
387 | return iface->get_intrinsic_aspect_ratio (paintable); |
388 | } |
389 | |
390 | /** |
391 | * gdk_paintable_invalidate_contents: |
392 | * @paintable: a `GdkPaintable` |
393 | * |
394 | * Called by implementations of `GdkPaintable` to invalidate their contents. |
395 | * |
396 | * Unless the contents are invalidated, implementations must guarantee that |
397 | * multiple calls of [method@Gdk.Paintable.snapshot] produce the same output. |
398 | * |
399 | * This function will emit the [signal@Gdk.Paintable::invalidate-contents] |
400 | * signal. |
401 | * |
402 | * If a @paintable reports the %GDK_PAINTABLE_STATIC_CONTENTS flag, |
403 | * it must not call this function. |
404 | */ |
405 | void |
406 | gdk_paintable_invalidate_contents (GdkPaintable *paintable) |
407 | { |
408 | g_return_if_fail (GDK_IS_PAINTABLE (paintable)); |
409 | g_return_if_fail (!(gdk_paintable_get_flags (paintable) & GDK_PAINTABLE_STATIC_CONTENTS)); |
410 | |
411 | g_signal_emit (instance: paintable, signal_id: signals[INVALIDATE_CONTENTS], detail: 0); |
412 | } |
413 | |
414 | /** |
415 | * gdk_paintable_invalidate_size: |
416 | * @paintable: a `GdkPaintable` |
417 | * |
418 | * Called by implementations of `GdkPaintable` to invalidate their size. |
419 | * |
420 | * As long as the size is not invalidated, @paintable must return the same |
421 | * values for its intrinsic width, height and aspect ratio. |
422 | * |
423 | * This function will emit the [signal@Gdk.Paintable::invalidate-size] |
424 | * signal. |
425 | * |
426 | * If a @paintable reports the %GDK_PAINTABLE_STATIC_SIZE flag, |
427 | * it must not call this function. |
428 | */ |
429 | void |
430 | gdk_paintable_invalidate_size (GdkPaintable *paintable) |
431 | { |
432 | g_return_if_fail (GDK_IS_PAINTABLE (paintable)); |
433 | g_return_if_fail (!(gdk_paintable_get_flags (paintable) & GDK_PAINTABLE_STATIC_SIZE)); |
434 | |
435 | g_signal_emit (instance: paintable, signal_id: signals[INVALIDATE_SIZE], detail: 0); |
436 | } |
437 | |
438 | /** |
439 | * gdk_paintable_compute_concrete_size: |
440 | * @paintable: a `GdkPaintable` |
441 | * @specified_width: the width @paintable could be drawn into or |
442 | * 0.0 if unknown |
443 | * @specified_height: the height @paintable could be drawn into or |
444 | * 0.0 if unknown |
445 | * @default_width: the width @paintable would be drawn into if |
446 | * no other constraints were given |
447 | * @default_height: the height @paintable would be drawn into if |
448 | * no other constraints were given |
449 | * @concrete_width: (out): will be set to the concrete width computed |
450 | * @concrete_height: (out): will be set to the concrete height computed |
451 | * |
452 | * Compute a concrete size for the `GdkPaintable`. |
453 | * |
454 | * Applies the sizing algorithm outlined in the |
455 | * [CSS Image spec](https://drafts.csswg.org/css-images-3/#default-sizing) |
456 | * to the given @paintable. See that link for more details. |
457 | * |
458 | * It is not necessary to call this function when both @specified_width |
459 | * and @specified_height are known, but it is useful to call this |
460 | * function in GtkWidget:measure implementations to compute the |
461 | * other dimension when only one dimension is given. |
462 | */ |
463 | void |
464 | gdk_paintable_compute_concrete_size (GdkPaintable *paintable, |
465 | double specified_width, |
466 | double specified_height, |
467 | double default_width, |
468 | double default_height, |
469 | double *concrete_width, |
470 | double *concrete_height) |
471 | { |
472 | double image_width, image_height, image_aspect; |
473 | |
474 | g_return_if_fail (GDK_IS_PAINTABLE (paintable)); |
475 | g_return_if_fail (specified_width >= 0); |
476 | g_return_if_fail (specified_height >= 0); |
477 | g_return_if_fail (default_width > 0); |
478 | g_return_if_fail (default_height > 0); |
479 | g_return_if_fail (concrete_width != NULL); |
480 | g_return_if_fail (concrete_height != NULL); |
481 | |
482 | /* If the specified size is a definite width and height, |
483 | * the concrete object size is given that width and height. |
484 | */ |
485 | if (specified_width && specified_height) |
486 | { |
487 | *concrete_width = specified_width; |
488 | *concrete_height = specified_height; |
489 | return; |
490 | } |
491 | |
492 | image_width = gdk_paintable_get_intrinsic_width (paintable); |
493 | image_height = gdk_paintable_get_intrinsic_height (paintable); |
494 | image_aspect = gdk_paintable_get_intrinsic_aspect_ratio (paintable); |
495 | |
496 | /* If the specified size has neither a definite width nor height, |
497 | * and has no additional constraints, the dimensions of the concrete |
498 | * object size are calculated as follows: |
499 | */ |
500 | if (specified_width == 0.0 && specified_height == 0.0) |
501 | { |
502 | /* If the object has only an intrinsic aspect ratio, |
503 | * the concrete object size must have that aspect ratio, |
504 | * and additionally be as large as possible without either |
505 | * its height or width exceeding the height or width of the |
506 | * default object size. |
507 | */ |
508 | if (image_aspect > 0 && image_width == 0 && image_height == 0) |
509 | { |
510 | if (image_aspect * default_height > default_width) |
511 | { |
512 | *concrete_width = default_width; |
513 | *concrete_height = default_width / image_aspect; |
514 | } |
515 | else |
516 | { |
517 | *concrete_width = default_height * image_aspect; |
518 | *concrete_height = default_height; |
519 | } |
520 | } |
521 | else |
522 | { |
523 | /* Otherwise, the width and height of the concrete object |
524 | * size is the same as the object's intrinsic width and |
525 | * intrinsic height, if they exist. |
526 | * If the concrete object size is still missing a width or |
527 | * height, and the object has an intrinsic aspect ratio, |
528 | * the missing dimension is calculated from the present |
529 | * dimension and the intrinsic aspect ratio. |
530 | * Otherwise, the missing dimension is taken from the default |
531 | * object size. |
532 | */ |
533 | if (image_width) |
534 | *concrete_width = image_width; |
535 | else if (image_aspect) |
536 | *concrete_width = image_height * image_aspect; |
537 | else |
538 | *concrete_width = default_width; |
539 | |
540 | if (image_height) |
541 | *concrete_height = image_height; |
542 | else if (image_aspect) |
543 | *concrete_height = image_width / image_aspect; |
544 | else |
545 | *concrete_height = default_height; |
546 | } |
547 | |
548 | return; |
549 | } |
550 | |
551 | /* If the specified size has only a width or height, but not both, |
552 | * then the concrete object size is given that specified width or height. |
553 | * The other dimension is calculated as follows: |
554 | * If the object has an intrinsic aspect ratio, the missing dimension of |
555 | * the concrete object size is calculated using the intrinsic aspect-ratio |
556 | * and the present dimension. |
557 | * Otherwise, if the missing dimension is present in the object's intrinsic |
558 | * dimensions, the missing dimension is taken from the object's intrinsic |
559 | * dimensions. |
560 | * Otherwise, the missing dimension of the concrete object size is taken |
561 | * from the default object size. |
562 | */ |
563 | if (specified_width) |
564 | { |
565 | *concrete_width = specified_width; |
566 | if (image_aspect) |
567 | *concrete_height = specified_width / image_aspect; |
568 | else if (image_height) |
569 | *concrete_height = image_height; |
570 | else |
571 | *concrete_height = default_height; |
572 | } |
573 | else |
574 | { |
575 | *concrete_height = specified_height; |
576 | if (image_aspect) |
577 | *concrete_width = specified_height * image_aspect; |
578 | else if (image_width) |
579 | *concrete_width = image_width; |
580 | else |
581 | *concrete_width = default_width; |
582 | } |
583 | } |
584 | |
585 | #define GDK_TYPE_EMPTY_PAINTABLE (gdk_empty_paintable_get_type()) |
586 | static |
587 | G_DECLARE_FINAL_TYPE(GdkEmptyPaintable, gdk_empty_paintable, GDK, EMPTY_PAINTABLE, GObject) |
588 | |
589 | struct _GdkEmptyPaintable |
590 | { |
591 | GObject parent_instance; |
592 | |
593 | int width; |
594 | int height; |
595 | }; |
596 | |
597 | struct _GdkEmptyPaintableClass |
598 | { |
599 | GObjectClass parent_class; |
600 | }; |
601 | |
602 | static void |
603 | gdk_empty_paintable_snapshot (GdkPaintable *paintable, |
604 | GdkSnapshot *snapshot, |
605 | double width, |
606 | double height) |
607 | { |
608 | } |
609 | |
610 | static GdkPaintableFlags |
611 | gdk_empty_paintable_get_flags (GdkPaintable *paintable) |
612 | { |
613 | return GDK_PAINTABLE_STATIC_SIZE |
614 | | GDK_PAINTABLE_STATIC_CONTENTS; |
615 | } |
616 | |
617 | static int |
618 | gdk_empty_paintable_get_intrinsic_width (GdkPaintable *paintable) |
619 | { |
620 | GdkEmptyPaintable *self = GDK_EMPTY_PAINTABLE (ptr: paintable); |
621 | |
622 | return self->width; |
623 | } |
624 | |
625 | static int |
626 | gdk_empty_paintable_get_intrinsic_height (GdkPaintable *paintable) |
627 | { |
628 | GdkEmptyPaintable *self = GDK_EMPTY_PAINTABLE (ptr: paintable); |
629 | |
630 | return self->height; |
631 | } |
632 | |
633 | static void |
634 | gdk_empty_paintable_paintable_init (GdkPaintableInterface *iface) |
635 | { |
636 | iface->snapshot = gdk_empty_paintable_snapshot; |
637 | iface->get_flags = gdk_empty_paintable_get_flags; |
638 | iface->get_intrinsic_width = gdk_empty_paintable_get_intrinsic_width; |
639 | iface->get_intrinsic_height = gdk_empty_paintable_get_intrinsic_height; |
640 | } |
641 | |
642 | G_DEFINE_TYPE_WITH_CODE (GdkEmptyPaintable, gdk_empty_paintable, G_TYPE_OBJECT, |
643 | G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE, |
644 | gdk_empty_paintable_paintable_init)) |
645 | |
646 | static void |
647 | gdk_empty_paintable_class_init (GdkEmptyPaintableClass *klass) |
648 | { |
649 | } |
650 | |
651 | static void |
652 | gdk_empty_paintable_init (GdkEmptyPaintable *self) |
653 | { |
654 | } |
655 | |
656 | /** |
657 | * gdk_paintable_new_empty: |
658 | * @intrinsic_width: The intrinsic width to report. Can be 0 for no width. |
659 | * @intrinsic_height: The intrinsic height to report. Can be 0 for no height. |
660 | * |
661 | * Returns a paintable that has the given intrinsic size and draws nothing. |
662 | * |
663 | * This is often useful for implementing the |
664 | * [vfunc@Gdk.Paintable.get_current_image] virtual function |
665 | * when the paintable is in an incomplete state (like a |
666 | * [class@Gtk.MediaStream] before receiving the first frame). |
667 | * |
668 | * Returns: (transfer full): a `GdkPaintable` |
669 | */ |
670 | GdkPaintable * |
671 | gdk_paintable_new_empty (int intrinsic_width, |
672 | int intrinsic_height) |
673 | { |
674 | GdkEmptyPaintable *result; |
675 | |
676 | g_return_val_if_fail (intrinsic_width >= 0, NULL); |
677 | g_return_val_if_fail (intrinsic_height >= 0, NULL); |
678 | |
679 | result = g_object_new (GDK_TYPE_EMPTY_PAINTABLE, NULL); |
680 | |
681 | result->width = intrinsic_width; |
682 | result->height = intrinsic_height; |
683 | |
684 | return GDK_PAINTABLE (ptr: result); |
685 | } |
686 | |