1 files changed, 141 insertions, 0 deletions
diff --git a/core/java/android/animation/RevealAnimator.java b/core/java/android/animation/RevealAnimator.java
new file mode 100644
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+++ b/core/java/android/animation/RevealAnimator.java
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+/*
+ * Copyright (C) 2014 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 android.animation;
+
+import android.view.View;
+
+import java.util.ArrayList;
+
+/**
+ * Reveals a View with an animated clipping circle.
+ * The clipping is implemented efficiently by talking to a private reveal API on View.
+ * This hidden class currently only accessed by the {@link android.view.View}.
+ *
+ * @hide
+ */
+public class RevealAnimator extends ValueAnimator {
+    private final static String LOGTAG = "RevealAnimator";
+    private ValueAnimator.AnimatorListener mListener;
+    private ValueAnimator.AnimatorUpdateListener mUpdateListener;
+    private RevealCircle mReuseRevealCircle = new RevealCircle(0);
+    private RevealAnimator(final View clipView, final int x, final int y,
+            float startRadius, float endRadius, final boolean inverseClip) {
+
+        setObjectValues(new RevealCircle(startRadius), new RevealCircle(endRadius));
+        setEvaluator(new RevealCircleEvaluator(mReuseRevealCircle));
+
+        mUpdateListener = new ValueAnimator.AnimatorUpdateListener() {
+                @Override
+            public void onAnimationUpdate(ValueAnimator animation) {
+                RevealCircle circle = (RevealCircle) animation.getAnimatedValue();
+                float radius = circle.getRadius();
+                clipView.setRevealClip(true, inverseClip, x, y, radius);
+            }
+        };
+        mListener = new AnimatorListenerAdapter() {
+                @Override
+            public void onAnimationCancel(Animator animation) {
+                clipView.setRevealClip(false, false, 0, 0, 0);
+            }
+
+                @Override
+            public void onAnimationEnd(Animator animation) {
+                clipView.setRevealClip(false, false, 0, 0, 0);
+            }
+        };
+        addUpdateListener(mUpdateListener);
+        addListener(mListener);
+    }
+
+    public static RevealAnimator ofRevealCircle(View clipView, int x, int y,
+            float startRadius, float endRadius, boolean inverseClip) {
+        RevealAnimator anim = new RevealAnimator(clipView, x, y,
+                startRadius, endRadius, inverseClip);
+        return anim;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void removeAllUpdateListeners() {
+        super.removeAllUpdateListeners();
+        addUpdateListener(mUpdateListener);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void removeAllListeners() {
+        super.removeAllListeners();
+        addListener(mListener);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public ArrayList<AnimatorListener> getListeners() {
+        ArrayList<AnimatorListener> allListeners =
+                (ArrayList<AnimatorListener>) super.getListeners().clone();
+        allListeners.remove(mListener);
+        return allListeners;
+    }
+
+    private class RevealCircle {
+        float mRadius;
+
+        public RevealCircle(float radius) {
+            mRadius = radius;
+        }
+
+        public void setRadius(float radius) {
+            mRadius = radius;
+        }
+
+        public float getRadius() {
+            return mRadius;
+        }
+    }
+
+    private class RevealCircleEvaluator implements TypeEvaluator<RevealCircle> {
+
+        private RevealCircle mRevealCircle;
+
+        public RevealCircleEvaluator() {
+        }
+
+        public RevealCircleEvaluator(RevealCircle reuseCircle) {
+            mRevealCircle = reuseCircle;
+        }
+
+        @Override
+        public RevealCircle evaluate(float fraction, RevealCircle startValue,
+                RevealCircle endValue) {
+            float currentRadius = startValue.mRadius
+                    + ((endValue.mRadius - startValue.mRadius) * fraction);
+            if (mRevealCircle == null) {
+                return new RevealCircle(currentRadius);
+            } else {
+                mRevealCircle.setRadius(currentRadius);
+                return mRevealCircle;
+            }
+        }
+    }
+}