Consistent animations & up button behavior in Gallery

Bug: 7302857
Bug: 7295464
This CL makes all of the transition animations throughout
the Gallery app consistent. The animation is the previous
view shrinking and fading out while the new view starts out
bigger than the view port and is coming in to the viewport
size as it fades in. Having consistent animations allows us
to not keep PhotoPage/AlbumPage instances around in certain
cases, making it possible to have consistent up button
behavior when switching between the grid and filmstrip.
Finally, this also makes the transitions in the camera app
filmstrip/grid switching consistent with those in the
gallery app.
Change-Id: I77bac6a0cde1e439738c78f9e16ab15ed5910cfb

1 files changed, 77 insertions, 0 deletions

diff --git a/src/com/android/gallery3d/anim/StateTransitionAnimation.java b/src/com/android/gallery3d/anim/StateTransitionAnimation.java
new file mode 100644
index 000000000..ffe753db7
--- /dev/null
+++ b/src/com/android/gallery3d/anim/StateTransitionAnimation.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.gallery3d.anim;
+
+import android.view.animation.DecelerateInterpolator;
+
+import com.android.gallery3d.ui.GLCanvas;
+import com.android.gallery3d.ui.GLView;
+import com.android.gallery3d.ui.RawTexture;
+
+public class StateTransitionAnimation extends Animation {
+    private static final float BACKGROUND_ALPHA_FROM = 1f;
+    private static final float BACKGROUND_ALPHA_TO = 0f;
+    private static final float BACKGROUND_SCALE_FROM = 1f;
+    private static final float BACKGROUND_SCALE_TO = 0f;
+    private static final float FOREGROUND_ALPHA_FROM = 0.9f;
+    private static final float FOREGROUND_ALPHA_TO = 1f;
+    private static final float FOREGROUND_SCALE_FROM = 3f;
+    private static final float FOREGROUND_SCALE_TO = 1f;
+
+    private float mCurrentForegroundScale;
+    private float mCurrentBackgroundScale;
+    private float mCurrentBackgroundAlpha;
+    private float mCurrentForegroundAlpha;
+
+    public StateTransitionAnimation(int duration) {
+        setDuration(duration);
+        setInterpolator(new DecelerateInterpolator());
+    }
+
+    @Override
+    protected void onCalculate(float progress) {
+        mCurrentForegroundScale = FOREGROUND_SCALE_FROM
+                + (FOREGROUND_SCALE_TO - FOREGROUND_SCALE_FROM) * progress;
+        mCurrentForegroundAlpha = FOREGROUND_ALPHA_FROM
+                + (FOREGROUND_ALPHA_TO - FOREGROUND_ALPHA_FROM) * progress;
+        mCurrentBackgroundAlpha = BACKGROUND_ALPHA_FROM
+                + (BACKGROUND_ALPHA_TO - BACKGROUND_ALPHA_FROM) * progress;
+        mCurrentBackgroundScale = BACKGROUND_SCALE_FROM
+                + (BACKGROUND_SCALE_TO - BACKGROUND_SCALE_FROM) * progress;
+    }
+
+    public void applyBackground(GLView view, GLCanvas canvas, RawTexture fadeTexture) {
+        canvas.clearBuffer(view.getBackgroundColor());
+        canvas.save();
+        canvas.setAlpha(mCurrentBackgroundAlpha);
+        int xOffset = view.getWidth() / 2;
+        int yOffset = view.getHeight() / 2;
+        canvas.translate(xOffset, yOffset);
+        canvas.scale(mCurrentBackgroundScale, mCurrentBackgroundScale, 1);
+        fadeTexture.draw(canvas, -xOffset, -yOffset);
+        canvas.restore();
+    }
+
+    public void applyForegroundTransformation(GLView view, GLCanvas canvas) {
+        int xOffset = view.getWidth() / 2;
+        int yOffset = view.getHeight() / 2;
+        canvas.translate(xOffset, yOffset);
+        canvas.scale(mCurrentForegroundScale, mCurrentForegroundScale, 1);
+        canvas.translate(-xOffset, -yOffset);
+        canvas.setAlpha(mCurrentForegroundAlpha);
+    }
+}