Explicit animation support

ui/base/animation/tween.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/base/animation/tween.h"
 
 #include <math.h>
 
 #if defined(OS_WIN)
 #include <float.h>
 #endif
 
 #include "base/logging.h"
 #include "ui/gfx/rect.h"
+#include "ui/gfx/interpolated_transform.h"
 
 namespace ui {
 
 // static
 double Tween::CalculateValue(Tween::Type type, double state) {
   DCHECK_GE(state, 0);
   DCHECK_LE(state, 1);
 
   switch (type) {
     case EASE_IN:
@@ skipping 51 matching lines @@
                               const gfx::Rect& start_bounds,
                               const gfx::Rect& target_bounds) {
   return gfx::Rect(ValueBetween(value, start_bounds.x(), target_bounds.x()),
                    ValueBetween(value, start_bounds.y(), target_bounds.y()),
                    ValueBetween(value, start_bounds.width(),
                                 target_bounds.width()),
                    ValueBetween(value, start_bounds.height(),
                                 target_bounds.height()));
 }
 
+// static
+Transform Tween::ValueBetween(double value,
+                              const Transform& start_transform,
+                              const Transform& end_transform) {
+  Transform to_return;
+  gfx::Point start_translation, end_translation;
+  float start_rotation, end_rotation;
+  gfx::Point3f start_scale, end_scale;
+  if (InterpolatedTransform::FactorTRS(start_transform,
+                                       &start_translation,
+                                       &start_rotation,
+                                       &start_scale) &&
+      InterpolatedTransform::FactorTRS(end_transform,
+                                       &end_translation,
+                                       &end_rotation,
+                                       &end_scale)) {
+    to_return.SetScale(ValueBetween(value, start_scale.x(), end_scale.x()),
+                       ValueBetween(value, start_scale.y(), end_scale.y()));
+    to_return.ConcatRotate(ValueBetween(value, start_rotation, end_rotation));
+    to_return.ConcatTranslate(
+        ValueBetween(value, start_translation.x(), end_translation.x()),
+        ValueBetween(value, start_translation.y(), end_translation.y()));
+  } else {
+    for (int row = 0; row < 4; ++row) {
+      for (int col = 0; col < 4; ++col) {
+        to_return.matrix().set(row, col,
+            ValueBetween(value,
+                         start_transform.matrix().get(row, col),
+                         end_transform.matrix().get(row, col)));
+      }
+    }
+  }
+
+  return to_return;
+}
+
 }  // namespace ui