Move *Animation to app/

http://crbug.com/11387

Review URL: http://codereview.chromium.org/109001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@15275 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 125 insertions, 0 deletions

diff --git a/app/slide_animation.cc b/app/slide_animation.cc
new file mode 100644
index 0000000..ca468d2
--- /dev/null
+++ b/app/slide_animation.cc
@@ -0,0 +1,125 @@
+// Copyright (c) 2006-2008 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 "app/slide_animation.h"
+
+#include <math.h>
+
+// How many frames per second to target.
+static const int kDefaultFramerateHz = 50;
+
+// How long animations should take by default.
+static const int kDefaultDurationMs = 120;
+
+SlideAnimation::SlideAnimation(AnimationDelegate* target)
+    : Animation(kDefaultFramerateHz, target),
+      target_(target),
+      tween_type_(EASE_OUT),
+      showing_(false),
+      value_start_(0),
+      value_end_(0),
+      value_current_(0),
+      slide_duration_(kDefaultDurationMs) {
+}
+
+SlideAnimation::~SlideAnimation() {
+}
+
+void SlideAnimation::Reset() {
+  Reset(0);
+}
+
+void SlideAnimation::Reset(double value) {
+  Stop();
+  showing_ = static_cast<bool>(value == 1);
+  value_current_ = value;
+}
+
+void SlideAnimation::Show() {
+  // If we're already showing (or fully shown), we have nothing to do.
+  if (showing_)
+    return;
+
+  showing_ = true;
+  value_start_ = value_current_;
+  value_end_ = 1.0;
+
+  // Make sure we actually have something to do.
+  if (slide_duration_ == 0) {
+    AnimateToState(1.0);  // Skip to the end of the animation.
+    return;
+  } else if (value_current_ == value_end_)  {
+    return;
+  }
+
+  // This will also reset the currently-occuring animation.
+  SetDuration(static_cast<int>(slide_duration_ * (1 - value_current_)));
+  Start();
+}
+
+void SlideAnimation::Hide() {
+  // If we're already hiding (or hidden), we have nothing to do.
+  if (!showing_)
+    return;
+
+  showing_ = false;
+  value_start_ = value_current_;
+  value_end_ = 0.0;
+
+  // Make sure we actually have something to do.
+  if (slide_duration_ == 0) {
+    AnimateToState(0.0);  // Skip to the end of the animation.
+    return;
+  } else if (value_current_ == value_end_) {
+    return;
+  }
+
+  // This will also reset the currently-occuring animation.
+  SetDuration(static_cast<int>(slide_duration_ * value_current_));
+  Start();
+}
+
+void SlideAnimation::AnimateToState(double state) {
+  if (state > 1.0)
+    state = 1.0;
+
+  // Make our animation ease-out.
+  switch (tween_type_) {
+    case EASE_IN:
+      state = pow(state, 2);
+      break;
+    case EASE_IN_OUT:
+      if (state < 0.5)
+        state = pow(state * 2, 2) / 2.0;
+      else
+        state = 1.0 - (pow((state - 1.0) * 2, 2) / 2.0);
+      break;
+    case FAST_IN_OUT:
+      state = (pow(state - 0.5, 3) + 0.125) / 0.25;
+      break;
+    case NONE:
+      // state remains linear.
+      break;
+    case EASE_OUT_SNAP:
+      state = 0.95 * (1.0 - pow(1.0 - state, 2));
+      break;
+    case EASE_OUT:
+    default:
+      state = 1.0 - pow(1.0 - state, 2);
+      break;
+  }
+
+  value_current_ = value_start_ + (value_end_ - value_start_) * state;
+
+  // Implement snapping.
+  if (tween_type_ == EASE_OUT_SNAP && fabs(value_current_ - value_end_) <= 0.06)
+    value_current_ = value_end_;
+
+  // Correct for any overshoot (while state may be capped at 1.0, let's not
+  // take any rounding error chances.
+  if ((value_end_ >= value_start_ && value_current_ > value_end_) ||
+      (value_end_ < value_start_ && value_current_ < value_end_)) {
+    value_current_ = value_end_;
+  }
+}