Basic support for animating window properties in Mus.

components/mus/public/interfaces/animations.mojom

Index: components/mus/public/interfaces/animations.mojom
diff --git a/components/mus/public/interfaces/animations.mojom b/components/mus/public/interfaces/animations.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..e7bd0afa8c8a77fbe23ca017944eb05918b1a0c4
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+++ b/components/mus/public/interfaces/animations.mojom
@@ -0,0 +1,62 @@
+// Copyright 2016 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.
+
+module mus.mojom;
+
+import "ui/gfx/mojo/transform.mojom";
+
+enum AnimationTweenType {
+  LINEAR,
+  EASE_IN,
+  EASE_OUT,
+  EASE_IN_OUT,
+};
+//import "ui/gfx/geometry/mojo/geometry.mojom";

[sky, 2016/06/16 16:36:33]

?

[mfomitchev, 2016/06/22 21:59:35]

Done.

+
+enum AnimationProperty {
+  // Used for pausing.
+  NONE,
+  OPACITY,
+  TRANSFORM,
+};
+
+struct AnimationValue {
+  float float_value;
+  gfx.mojom.Transform transform;

[sky, 2016/06/16 16:36:33]

Shouldn't this be a ? as it isn't applicable to all properties?

[mfomitchev, 2016/06/22 21:59:35]

Done. Note that we still always return true for transforms in
IsAnimationValueValid() - we can't differentiate between the true Identity
transform and the transform that wasn't specified (and was thus initialized to
Identity). I think it's ok for now, but I am not sure if that's what we want
longer term. On one hand it's marginally less "correct". OTOH not having to pass
Identity transforms over IPC lets us save on IPC traffic, so it might be
actually be a good thing.

+};
+
+// Identifies how a particular property should be animated between a start and
+// target value.
+struct AnimationElement {
+  AnimationProperty property;
+
+  // Duration is in microseconds.
+  int64 duration;
+
+  AnimationTweenType tween_type;
+
+  // If not specified the start value is taken from either the current value
+  // (for the first element) or the target_value of the previous element.
+  AnimationValue? start_value;
+
+  // target_value may be null when property is NONE.
+  AnimationValue? target_value;
+};
+
+// An AnimationSequence consists of a number of AnimationElements to animate.
+// Each element is animated serially.
+struct AnimationSequence {
+  // Number of times to run the sequence. Value of 0 means run until
+  // explicitly stopped.
+  uint32 cycle_count;
+
+  array<AnimationElement> elements;
+};
+
+// AnimationGroup identifies a window and a set of AnimationSequences to apply
+// to the window. Each sequence is run in parallel.
+struct AnimationGroup {
+  uint32 window_id;
+  array<AnimationSequence> sequences;
+};