animation: Add CSS transition object

This is an implementation of GtkStyleAnimation for CSS transitions.

Again, this doesn't do anything but store the data needed to do the
transition.

1 files changed, 131 insertions, 0 deletions

diff --git a/gtk/gtkcsstransition.c b/gtk/gtkcsstransition.c
new file mode 100644
index 0000000000..79b803d93d
--- /dev/null
+++ b/gtk/gtkcsstransition.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright © 2012 Red Hat Inc.
+ *
+ * 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 "gtkcsstransitionprivate.h"
+
+#include "gtkcsseasevalueprivate.h"
+
+G_DEFINE_TYPE (GtkCssTransition, _gtk_css_transition, GTK_TYPE_STYLE_ANIMATION)
+
+static GtkBitmask *
+gtk_css_transition_set_values (GtkStyleAnimation    *animation,
+                               GtkBitmask           *changed,
+                               gint64                for_time_us,
+                               GtkCssComputedValues *values)
+{
+  GtkCssTransition *transition = GTK_CSS_TRANSITION (animation);
+  GtkCssValue *value;
+  double progress;
+
+  if (transition->start_time >= for_time_us)
+    value = _gtk_css_value_ref (transition->start);
+  else if (transition->end_time <= for_time_us)
+    value = _gtk_css_value_ref (transition->end);
+  else
+    {
+      progress = (double) (for_time_us - transition->start_time) / (transition->end_time - transition->start_time);
+      progress = _gtk_css_ease_value_transform (transition->ease, progress);
+
+      value = _gtk_css_value_transition (transition->start,
+                                         transition->end,
+                                         progress);
+      if (value == NULL)
+        value = _gtk_css_value_ref (transition->end);
+    }
+
+  _gtk_css_computed_values_set_value (values, transition->property, value, NULL);
+  _gtk_css_value_unref (value);
+
+  return _gtk_bitmask_set (changed, transition->property, TRUE);
+}
+
+static gboolean
+gtk_css_transition_is_finished (GtkStyleAnimation *animation,
+                                gint64             at_time_us)
+{
+  GtkCssTransition *transition = GTK_CSS_TRANSITION (animation);
+
+  return at_time_us >= transition->end_time;
+}
+
+static void
+gtk_css_transition_finalize (GObject *object)
+{
+  GtkCssTransition *transition = GTK_CSS_TRANSITION (object);
+
+  _gtk_css_value_unref (transition->start);
+  _gtk_css_value_unref (transition->end);
+  _gtk_css_value_unref (transition->ease);
+
+  G_OBJECT_CLASS (_gtk_css_transition_parent_class)->finalize (object);
+}
+
+static void
+_gtk_css_transition_class_init (GtkCssTransitionClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GtkStyleAnimationClass *animation_class = GTK_STYLE_ANIMATION_CLASS (klass);
+
+  object_class->finalize = gtk_css_transition_finalize;
+
+  animation_class->set_values = gtk_css_transition_set_values;
+  animation_class->is_finished = gtk_css_transition_is_finished;
+}
+
+static void
+_gtk_css_transition_init (GtkCssTransition *transition)
+{
+}
+
+GtkStyleAnimation *
+_gtk_css_transition_new (guint        property,
+                         GtkCssValue *start,
+                         GtkCssValue *end,
+                         GtkCssValue *ease,
+                         gint64       start_time_us,
+                         gint64       end_time_us)
+{
+  GtkCssTransition *transition;
+
+  g_return_val_if_fail (start != NULL, NULL);
+  g_return_val_if_fail (end != NULL, NULL);
+  g_return_val_if_fail (ease != NULL, NULL);
+  g_return_val_if_fail (start_time_us <= end_time_us, NULL);
+
+  transition = g_object_new (GTK_TYPE_CSS_TRANSITION, NULL);
+
+  transition->property = property;
+  transition->start = _gtk_css_value_ref (start);
+  transition->end = _gtk_css_value_ref (end);
+  transition->ease = _gtk_css_value_ref (ease);
+  transition->start_time = start_time_us;
+  transition->end_time = end_time_us;
+
+  return GTK_STYLE_ANIMATION (transition);
+}
+
+guint
+_gtk_css_transition_get_property (GtkCssTransition *transition)
+{
+  g_return_val_if_fail (GTK_IS_CSS_TRANSITION (transition), 0);
+
+  return transition->property;
+}