1 /* GTK - The GIMP Toolkit
2 * Copyright (C) 2010 Carlos Garnacho <carlosg@gnome.org>
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 of the License, or (at your option) any later version.
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.
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/>.
20 #define GDK_DISABLE_DEPRECATION_WARNINGS
22 #include "gtkgradientprivate.h"
24 #include "gtkcsscolorvalueprivate.h"
25 #include "gtkcssrgbavalueprivate.h"
26 #include "gtkstylecontextprivate.h"
27 #include "gtkstyleproperties.h"
28 #include "gtksymboliccolorprivate.h"
32 * @Short_description: Gradients
35 * GtkGradient is a boxed type that represents a gradient.
36 * It is the result of parsing a
37 * <link linkend="gtkcssprovider-gradients">gradient expression</link>.
38 * To obtain the gradient represented by a GtkGradient, it has to
39 * be resolved with gtk_gradient_resolve(), which replaces all
40 * symbolic color references by the colors they refer to (in a given
41 * context) and constructs a #cairo_pattern_t value.
43 * It is not normally necessary to deal directly with #GtkGradients,
44 * since they are mostly used behind the scenes by #GtkStyleContext and
47 * #GtkGradient is deprecated. It was used internally by GTK's CSS engine
48 * to represent gradients. As its handling is not conforming to modern
49 * web standards, it is not used anymore. If you want to use gradients in
50 * your own code, please use Cairo directly.
53 G_DEFINE_BOXED_TYPE (GtkGradient, gtk_gradient,
54 gtk_gradient_ref, gtk_gradient_unref)
56 typedef struct ColorStop ColorStop;
61 GtkSymbolicColor *color;
79 * gtk_gradient_new_linear:
80 * @x0: X coordinate of the starting point
81 * @y0: Y coordinate of the starting point
82 * @x1: X coordinate of the end point
83 * @y1: Y coordinate of the end point
85 * Creates a new linear gradient along the line defined by (x0, y0) and (x1, y1). Before using the gradient
86 * a number of stop colors must be added through gtk_gradient_add_color_stop().
88 * Returns: A newly created #GtkGradient
92 * Deprecated: 3.8: #GtkGradient is deprecated.
95 gtk_gradient_new_linear (gdouble x0,
100 GtkGradient *gradient;
102 gradient = g_slice_new (GtkGradient);
103 gradient->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
109 gradient->radius0 = 0;
110 gradient->radius1 = 0;
112 gradient->ref_count = 1;
118 * gtk_gradient_new_radial:
119 * @x0: X coordinate of the start circle
120 * @y0: Y coordinate of the start circle
121 * @radius0: radius of the start circle
122 * @x1: X coordinate of the end circle
123 * @y1: Y coordinate of the end circle
124 * @radius1: radius of the end circle
126 * Creates a new radial gradient along the two circles defined by (x0, y0, radius0) and
127 * (x1, y1, radius1). Before using the gradient a number of stop colors must be added
128 * through gtk_gradient_add_color_stop().
130 * Returns: A newly created #GtkGradient
134 * Deprecated: 3.8: #GtkGradient is deprecated.
137 gtk_gradient_new_radial (gdouble x0,
144 GtkGradient *gradient;
146 gradient = g_slice_new (GtkGradient);
147 gradient->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
153 gradient->radius0 = radius0;
154 gradient->radius1 = radius1;
156 gradient->ref_count = 1;
162 * gtk_gradient_add_color_stop:
163 * @gradient: a #GtkGradient
164 * @offset: offset for the color stop
165 * @color: color to use
167 * Adds a stop color to @gradient.
171 * Deprecated: 3.8: #GtkGradient is deprecated.
174 gtk_gradient_add_color_stop (GtkGradient *gradient,
176 GtkSymbolicColor *color)
180 g_return_if_fail (gradient != NULL);
182 stop.offset = offset;
183 stop.color = gtk_symbolic_color_ref (color);
185 g_array_append_val (gradient->stops, stop);
190 * @gradient: a #GtkGradient
192 * Increases the reference count of @gradient.
194 * Returns: The same @gradient
198 * Deprecated: 3.8: #GtkGradient is deprecated.
201 gtk_gradient_ref (GtkGradient *gradient)
203 g_return_val_if_fail (gradient != NULL, NULL);
205 gradient->ref_count++;
211 * gtk_gradient_unref:
212 * @gradient: a #GtkGradient
214 * Decreases the reference count of @gradient, freeing its memory
215 * if the reference count reaches 0.
219 * Deprecated: 3.8: #GtkGradient is deprecated.
222 gtk_gradient_unref (GtkGradient *gradient)
224 g_return_if_fail (gradient != NULL);
226 gradient->ref_count--;
228 if (gradient->ref_count == 0)
232 for (i = 0; i < gradient->stops->len; i++)
236 stop = &g_array_index (gradient->stops, ColorStop, i);
237 gtk_symbolic_color_unref (stop->color);
240 g_array_free (gradient->stops, TRUE);
241 g_slice_free (GtkGradient, gradient);
246 * gtk_gradient_resolve:
247 * @gradient: a #GtkGradient
248 * @props: #GtkStyleProperties to use when resolving named colors
249 * @resolved_gradient: (out): return location for the resolved pattern
251 * If @gradient is resolvable, @resolved_gradient will be filled in
252 * with the resolved gradient as a cairo_pattern_t, and %TRUE will
253 * be returned. Generally, if @gradient can't be resolved, it is
254 * due to it being defined on top of a named color that doesn't
257 * Returns: %TRUE if the gradient has been resolved
261 * Deprecated: 3.8: #GtkGradient is deprecated.
264 gtk_gradient_resolve (GtkGradient *gradient,
265 GtkStyleProperties *props,
266 cairo_pattern_t **resolved_gradient)
268 cairo_pattern_t *pattern;
271 g_return_val_if_fail (gradient != NULL, FALSE);
272 g_return_val_if_fail (GTK_IS_STYLE_PROPERTIES (props), FALSE);
273 g_return_val_if_fail (resolved_gradient != NULL, FALSE);
275 if (gradient->radius0 == 0 && gradient->radius1 == 0)
276 pattern = cairo_pattern_create_linear (gradient->x0, gradient->y0,
277 gradient->x1, gradient->y1);
279 pattern = cairo_pattern_create_radial (gradient->x0, gradient->y0,
281 gradient->x1, gradient->y1,
284 for (i = 0; i < gradient->stops->len; i++)
289 stop = &g_array_index (gradient->stops, ColorStop, i);
291 if (!gtk_symbolic_color_resolve (stop->color, props, &color))
293 cairo_pattern_destroy (pattern);
297 cairo_pattern_add_color_stop_rgba (pattern, stop->offset,
298 color.red, color.green,
299 color.blue, color.alpha);
302 *resolved_gradient = pattern;
307 _gtk_gradient_resolve_full (GtkGradient *gradient,
308 GtkStyleProviderPrivate *provider,
309 GtkCssComputedValues *values,
310 GtkCssComputedValues *parent_values,
311 GtkCssDependencies *dependencies)
313 cairo_pattern_t *pattern;
316 g_return_val_if_fail (gradient != NULL, NULL);
317 g_return_val_if_fail (GTK_IS_STYLE_PROVIDER (provider), NULL);
318 g_return_val_if_fail (GTK_IS_CSS_COMPUTED_VALUES (values), NULL);
319 g_return_val_if_fail (parent_values == NULL || GTK_IS_CSS_COMPUTED_VALUES (parent_values), NULL);
320 g_return_val_if_fail (*dependencies == 0, NULL);
322 if (gradient->radius0 == 0 && gradient->radius1 == 0)
323 pattern = cairo_pattern_create_linear (gradient->x0, gradient->y0,
324 gradient->x1, gradient->y1);
326 pattern = cairo_pattern_create_radial (gradient->x0, gradient->y0,
328 gradient->x1, gradient->y1,
331 for (i = 0; i < gradient->stops->len; i++)
336 GtkCssDependencies stop_deps;
338 stop = &g_array_index (gradient->stops, ColorStop, i);
340 /* if color resolving fails, assume transparency */
341 val = _gtk_css_color_value_resolve (_gtk_symbolic_color_get_css_value (stop->color),
343 _gtk_css_computed_values_get_value (values, GTK_CSS_PROPERTY_COLOR),
344 GTK_CSS_DEPENDS_ON_COLOR,
348 rgba = *_gtk_css_rgba_value_get_rgba (val);
349 *dependencies = _gtk_css_dependencies_union (*dependencies, stop_deps);
350 _gtk_css_value_unref (val);
354 rgba.red = rgba.green = rgba.blue = rgba.alpha = 0.0;
357 cairo_pattern_add_color_stop_rgba (pattern, stop->offset,
358 rgba.red, rgba.green,
359 rgba.blue, rgba.alpha);
366 append_number (GString *str,
372 if (zero && d == 0.0)
373 g_string_append (str, zero);
374 else if (half && d == 0.5)
375 g_string_append (str, half);
376 else if (one && d == 1.0)
377 g_string_append (str, one);
380 char buf[G_ASCII_DTOSTR_BUF_SIZE];
382 g_ascii_dtostr (buf, sizeof (buf), d);
383 g_string_append (str, buf);
388 * gtk_gradient_to_string:
389 * @gradient: the gradient to print
391 * Creates a string representation for @gradient that is suitable
392 * for using in GTK CSS files.
394 * Returns: A string representation for @gradient
396 * Deprecated: 3.8: #GtkGradient is deprecated.
399 gtk_gradient_to_string (GtkGradient *gradient)
404 g_return_val_if_fail (gradient != NULL, NULL);
406 str = g_string_new ("-gtk-gradient (");
408 if (gradient->radius0 == 0 && gradient->radius1 == 0)
410 g_string_append (str, "linear, ");
411 append_number (str, gradient->x0, "left", "center", "right");
412 g_string_append_c (str, ' ');
413 append_number (str, gradient->y0, "top", "center", "bottom");
414 g_string_append (str, ", ");
415 append_number (str, gradient->x1, "left", "center", "right");
416 g_string_append_c (str, ' ');
417 append_number (str, gradient->y1, "top", "center", "bottom");
421 g_string_append (str, "radial, ");
422 append_number (str, gradient->x0, "left", "center", "right");
423 g_string_append_c (str, ' ');
424 append_number (str, gradient->y0, "top", "center", "bottom");
425 g_string_append (str, ", ");
426 append_number (str, gradient->radius0, NULL, NULL, NULL);
427 g_string_append (str, ", ");
428 append_number (str, gradient->x1, "left", "center", "right");
429 g_string_append_c (str, ' ');
430 append_number (str, gradient->y1, "top", "center", "bottom");
431 g_string_append (str, ", ");
432 append_number (str, gradient->radius1, NULL, NULL, NULL);
435 for (i = 0; i < gradient->stops->len; i++)
440 stop = &g_array_index (gradient->stops, ColorStop, i);
442 g_string_append (str, ", ");
444 if (stop->offset == 0.0)
445 g_string_append (str, "from (");
446 else if (stop->offset == 1.0)
447 g_string_append (str, "to (");
450 g_string_append (str, "color-stop (");
451 append_number (str, stop->offset, NULL, NULL, NULL);
452 g_string_append (str, ", ");
455 s = gtk_symbolic_color_to_string (stop->color);
456 g_string_append (str, s);
459 g_string_append (str, ")");
462 g_string_append (str, ")");
464 return g_string_free (str, FALSE);
468 gtk_gradient_fade (GtkGradient *gradient,
474 faded = g_slice_new (GtkGradient);
475 faded->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
477 faded->x0 = gradient->x0;
478 faded->y0 = gradient->y0;
479 faded->x1 = gradient->x1;
480 faded->y1 = gradient->y1;
481 faded->radius0 = gradient->radius0;
482 faded->radius1 = gradient->radius1;
484 faded->ref_count = 1;
486 for (i = 0; i < gradient->stops->len; i++)
488 GtkSymbolicColor *color;
491 stop = &g_array_index (gradient->stops, ColorStop, i);
492 color = gtk_symbolic_color_new_alpha (stop->color, opacity);
493 gtk_gradient_add_color_stop (faded, stop->offset, color);
494 gtk_symbolic_color_unref (color);
501 _gtk_gradient_transition (GtkGradient *start,
506 GtkGradient *gradient;
509 g_return_val_if_fail (start != NULL, NULL);
512 return gtk_gradient_fade (start, 1.0 - CLAMP (progress, 0.0, 1.0));
514 if (start->stops->len != end->stops->len)
517 /* check both are radial/linear */
518 if ((start->radius0 == 0 && start->radius1 == 0) != (end->radius0 == 0 && end->radius1 == 0))
521 gradient = g_slice_new (GtkGradient);
522 gradient->stops = g_array_new (FALSE, FALSE, sizeof (ColorStop));
524 gradient->x0 = (1 - progress) * start->x0 + progress * end->x0;
525 gradient->y0 = (1 - progress) * start->y0 + progress * end->y0;
526 gradient->x1 = (1 - progress) * start->x1 + progress * end->x1;
527 gradient->y1 = (1 - progress) * start->y1 + progress * end->y1;
528 gradient->radius0 = (1 - progress) * start->radius0 + progress * end->radius0;
529 gradient->radius1 = (1 - progress) * start->radius1 + progress * end->radius1;
531 gradient->ref_count = 1;
533 for (i = 0; i < start->stops->len; i++)
535 ColorStop *start_stop, *end_stop;
536 GtkSymbolicColor *color;
539 start_stop = &g_array_index (start->stops, ColorStop, i);
540 end_stop = &g_array_index (end->stops, ColorStop, i);
542 offset = (1 - progress) * start_stop->offset + progress * end_stop->offset;
543 color = gtk_symbolic_color_new_mix (start_stop->color,
546 gtk_gradient_add_color_stop (gradient, offset, color);
547 gtk_symbolic_color_unref (color);