1 files changed, 48 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/anim/AlphaAnimation.java b/src/com/android/gallery3d/anim/AlphaAnimation.java
new file mode 100644
index 000000000..cb17527b8
--- /dev/null
+++ b/src/com/android/gallery3d/anim/AlphaAnimation.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2010 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 com.android.gallery3d.common.Utils;
+import com.android.gallery3d.ui.GLCanvas;
+
+public class AlphaAnimation extends CanvasAnimation {
+    private final float mStartAlpha;
+    private final float mEndAlpha;
+    private float mCurrentAlpha;
+
+    public AlphaAnimation(float from, float to) {
+        mStartAlpha = from;
+        mEndAlpha = to;
+        mCurrentAlpha = from;
+    }
+
+    @Override
+    public void apply(GLCanvas canvas) {
+        canvas.multiplyAlpha(mCurrentAlpha);
+    }
+
+    @Override
+    public int getCanvasSaveFlags() {
+        return GLCanvas.SAVE_FLAG_ALPHA;
+    }
+
+    @Override
+    protected void onCalculate(float progress) {
+        mCurrentAlpha = Utils.clamp(mStartAlpha
+                + (mEndAlpha - mStartAlpha) * progress, 0f, 1f);
+    }
+}