[gtk+] cssanimation: Implement pausing the animation

[Benjamin Otte <otte src gnome org>]

commit 0cecf315fd766748d2510a9f0af4820c260c9aca
Author: Benjamin Otte <otte redhat com>
Date:   Mon Sep 17 17:00:02 2012 +0200

    cssanimation: Implement pausing the animation

 gtk/gtkcssanimation.c        |   53 ++++++++++++++++++++++++++++++++++-------
 gtk/gtkcssanimationprivate.h |    7 ++++-
 gtk/gtkcsscomputedvalues.c   |   44 +++++++++++++++++++++++------------
 3 files changed, 79 insertions(+), 25 deletions(-)
---
diff --git a/gtk/gtkcssanimation.c b/gtk/gtkcssanimation.c
index e4c692a..2ebf585 100644
--- a/gtk/gtkcssanimation.c
+++ b/gtk/gtkcssanimation.c
@@ -27,18 +27,22 @@
 
 G_DEFINE_TYPE (GtkCssAnimation, _gtk_css_animation, GTK_TYPE_STYLE_ANIMATION)
 
+/* NB: Return value can be negative (if animation hasn't started yet) */
+static gint64
+gtk_css_animation_get_elapsed (GtkCssAnimation *animation,
+                               gint64           for_time_us)
+{
+  if (animation->play_state == GTK_CSS_PLAY_STATE_PAUSED)
+    return animation->timestamp;
+  else
+    return for_time_us - animation->timestamp;
+}
 /* NB: Return value can be negative and +-Inf */
 static double
 gtk_css_animation_get_iteration (GtkCssAnimation *animation,
                                  gint64           for_time_us)
 {
-  gint64 elapsed;
-  double iterations;
-
-  elapsed = for_time_us - animation->timestamp;
-  iterations = (double) elapsed / animation->duration;
-
-  return iterations;
+  return (double) gtk_css_animation_get_elapsed (animation, for_time_us) / animation->duration;
 }
 
 static gboolean
@@ -144,6 +148,9 @@ gtk_css_animation_is_static (GtkStyleAnimation *style_animation,
   GtkCssAnimation *animation = GTK_CSS_ANIMATION (style_animation);
   double iteration;
 
+  if (animation->play_state == GTK_CSS_PLAY_STATE_PAUSED)
+    return TRUE;
+
   iteration = gtk_css_animation_get_iteration (animation, at_time_us);
 
   return iteration >= animation->iteration_count;
@@ -182,7 +189,8 @@ _gtk_css_animation_init (GtkCssAnimation *animation)
 GtkStyleAnimation *
 _gtk_css_animation_new (const char      *name,
                         GtkCssKeyframes *keyframes,
-                        gint64           start_time_us,
+                        gint64           timestamp,
+                        gint64           delay_us,
                         gint64           duration_us,
                         GtkCssValue     *ease,
                         GtkCssDirection  direction,
@@ -201,7 +209,11 @@ _gtk_css_animation_new (const char      *name,
 
   animation->name = g_strdup (name);
   animation->keyframes = _gtk_css_keyframes_ref (keyframes);
-  animation->timestamp = start_time_us;
+  if (play_state == GTK_CSS_PLAY_STATE_PAUSED)
+    animation->timestamp = - delay_us;
+  else
+    animation->timestamp = timestamp + delay_us;
+
   animation->duration = duration_us;
   animation->ease = _gtk_css_value_ref (ease);
   animation->direction = direction;
@@ -219,3 +231,26 @@ _gtk_css_animation_get_name (GtkCssAnimation *animation)
 
   return animation->name;
 }
+
+GtkStyleAnimation *
+_gtk_css_animation_copy (GtkCssAnimation *animation,
+                         gint64           at_time_us,
+                         GtkCssPlayState  play_state)
+{
+  g_return_val_if_fail (GTK_IS_CSS_ANIMATION (animation), NULL);
+
+  if (animation->play_state == play_state)
+    return g_object_ref (animation);
+
+  return _gtk_css_animation_new (animation->name,
+                                 animation->keyframes,
+                                 at_time_us,
+                                 - gtk_css_animation_get_elapsed (animation, at_time_us),
+                                 animation->duration,
+                                 animation->ease,
+                                 animation->direction,
+                                 play_state,
+                                 animation->fill_mode,
+                                 animation->iteration_count);
+}
+
diff --git a/gtk/gtkcssanimationprivate.h b/gtk/gtkcssanimationprivate.h
index f992605..08dc663 100644
--- a/gtk/gtkcssanimationprivate.h
+++ b/gtk/gtkcssanimationprivate.h
@@ -60,7 +60,8 @@ GType                   _gtk_css_animation_get_type        (void) G_GNUC_CONST;
 
 GtkStyleAnimation *     _gtk_css_animation_new             (const char         *name,
                                                             GtkCssKeyframes    *keyframes,
-                                                            gint64              start_time_us,
+                                                            gint64              timestamp,
+                                                            gint64              delay_us,
                                                             gint64              duration_us,
                                                             GtkCssValue        *ease,
                                                             GtkCssDirection     direction,
@@ -68,6 +69,10 @@ GtkStyleAnimation *     _gtk_css_animation_new             (const char         *
                                                             GtkCssFillMode      fill_mode,
                                                             double              iteration_count);
 
+GtkStyleAnimation *     _gtk_css_animation_copy            (GtkCssAnimation   *animation,
+                                                            gint64             at_time_us,
+                                                            GtkCssPlayState    play_state);
+
 const char *            _gtk_css_animation_get_name        (GtkCssAnimation   *animation);
 
 G_END_DECLS
diff --git a/gtk/gtkcsscomputedvalues.c b/gtk/gtkcsscomputedvalues.c
index cd2f66b..250b0b0 100644
--- a/gtk/gtkcsscomputedvalues.c
+++ b/gtk/gtkcsscomputedvalues.c
@@ -434,6 +434,7 @@ gtk_css_computed_values_find_animation (GtkCssComputedValues *values,
 static void
 gtk_css_computed_values_create_css_animations (GtkCssComputedValues *values,
                                                gint64                timestamp,
+                                               GtkCssComputedValues *source,
                                                GtkStyleContext      *context)
 {
   GtkStyleProviderPrivate *provider;
@@ -465,21 +466,34 @@ gtk_css_computed_values_create_css_animations (GtkCssComputedValues *values,
       if (animation)
         continue;
 
-      keyframes = _gtk_style_provider_private_get_keyframes (provider, name);
-      if (keyframes == NULL)
-        continue;
+      if (source)
+        animation = gtk_css_computed_values_find_animation (source, name);
 
-      keyframes = _gtk_css_keyframes_compute (keyframes, context);
-
-      animation = _gtk_css_animation_new (name,
-                                          keyframes,
-                                          timestamp + _gtk_css_number_value_get (_gtk_css_array_value_get_nth (delays, i), 100) * G_USEC_PER_SEC,
-                                          _gtk_css_number_value_get (_gtk_css_array_value_get_nth (durations, i), 100) * G_USEC_PER_SEC,
-                                          _gtk_css_array_value_get_nth (timing_functions, i),
-                                          _gtk_css_direction_value_get (_gtk_css_array_value_get_nth (directions, i)),
-                                          _gtk_css_play_state_value_get (_gtk_css_array_value_get_nth (play_states, i)),
-                                          _gtk_css_fill_mode_value_get (_gtk_css_array_value_get_nth (fill_modes, i)),
-                                          _gtk_css_number_value_get (_gtk_css_array_value_get_nth (iteration_counts, i), 100));
+      if (animation)
+        {
+          animation = _gtk_css_animation_copy (GTK_CSS_ANIMATION (animation),
+                                               timestamp,
+                                               _gtk_css_play_state_value_get (_gtk_css_array_value_get_nth (play_states, i)));
+        }
+      else
+        {
+          keyframes = _gtk_style_provider_private_get_keyframes (provider, name);
+          if (keyframes == NULL)
+            continue;
+
+          keyframes = _gtk_css_keyframes_compute (keyframes, context);
+
+          animation = _gtk_css_animation_new (name,
+                                              keyframes,
+                                              timestamp,
+                                              _gtk_css_number_value_get (_gtk_css_array_value_get_nth (delays, i), 100) * G_USEC_PER_SEC,
+                                              _gtk_css_number_value_get (_gtk_css_array_value_get_nth (durations, i), 100) * G_USEC_PER_SEC,
+                                              _gtk_css_array_value_get_nth (timing_functions, i),
+                                              _gtk_css_direction_value_get (_gtk_css_array_value_get_nth (directions, i)),
+                                              _gtk_css_play_state_value_get (_gtk_css_array_value_get_nth (play_states, i)),
+                                              _gtk_css_fill_mode_value_get (_gtk_css_array_value_get_nth (fill_modes, i)),
+                                              _gtk_css_number_value_get (_gtk_css_array_value_get_nth (iteration_counts, i), 100));
+        }
       values->animations = g_slist_prepend (values->animations, animation);
     }
 }
@@ -494,7 +508,7 @@ _gtk_css_computed_values_create_animations (GtkCssComputedValues *values,
 {
   if (source != NULL)
     gtk_css_computed_values_create_css_transitions (values, timestamp, source);
-  gtk_css_computed_values_create_css_animations (values, timestamp, context);
+  gtk_css_computed_values_create_css_animations (values, timestamp, source, context);
 }
 
 GtkBitmask *