change package name to uiuios

src/com/android/uiuios/FirstFrameAnimatorHelper.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2013 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.uiuios;
+
+import static com.android.uiuios.Utilities.SINGLE_FRAME_MS;
+
+import android.animation.ValueAnimator;
+import android.animation.ValueAnimator.AnimatorUpdateListener;
+import android.util.Log;
+import android.view.View;
+import android.view.View.OnAttachStateChangeListener;
+import android.view.ViewTreeObserver.OnDrawListener;
+
+/*
+ *  This is a helper class that listens to updates from the corresponding animation.
+ *  For the first two frames, it adjusts the current play time of the animation to
+ *  prevent jank at the beginning of the animation
+ */
+public class FirstFrameAnimatorHelper implements OnDrawListener, OnAttachStateChangeListener {
+
+    private static final String TAG = "FirstFrameAnimatorHlpr";
+    private static final boolean DEBUG = false;
+    private static final int MAX_DELAY = 1000;
+
+    private View mRootView;
+    private long mGlobalFrameCount;
+
+    public FirstFrameAnimatorHelper(View target) {
+        target.addOnAttachStateChangeListener(this);
+        if (target.isAttachedToWindow()) {
+            onViewAttachedToWindow(target);
+        }
+    }
+
+    public <T extends ValueAnimator> T addTo(T anim) {
+        anim.addUpdateListener(new MyListener());
+        return anim;
+    }
+
+    @Override
+    public void onDraw() {
+        mGlobalFrameCount ++;
+    }
+
+    @Override
+    public void onViewAttachedToWindow(View view) {
+        mRootView = view.getRootView();
+        mRootView.getViewTreeObserver().addOnDrawListener(this);
+    }
+
+    @Override
+    public void onViewDetachedFromWindow(View view) {
+        if (mRootView != null) {
+            mRootView.getViewTreeObserver().removeOnDrawListener(this);
+            mRootView = null;
+        }
+    }
+
+    private class MyListener implements AnimatorUpdateListener {
+
+        private long mStartFrame;
+        private long mStartTime = -1;
+        private boolean mHandlingOnAnimationUpdate;
+        private boolean mAdjustedSecondFrameTime;
+
+        @Override
+        public void onAnimationUpdate(final ValueAnimator animation) {
+            final long currentTime = System.currentTimeMillis();
+            if (mStartTime == -1) {
+                mStartFrame = mGlobalFrameCount;
+                mStartTime = currentTime;
+            }
+
+            final long currentPlayTime = animation.getCurrentPlayTime();
+            boolean isFinalFrame = Float.compare(1f, animation.getAnimatedFraction()) == 0;
+
+            if (!mHandlingOnAnimationUpdate &&
+                    mRootView != null &&
+                    mRootView.getWindowVisibility() == View.VISIBLE &&
+                    // If the current play time exceeds the duration, or the animated fraction is 1,
+                    // the animation will get finished, even if we call setCurrentPlayTime --
+                    // therefore don't adjust the animation in that case
+                    currentPlayTime < animation.getDuration() && !isFinalFrame) {
+                mHandlingOnAnimationUpdate = true;
+                long frameNum = mGlobalFrameCount - mStartFrame;
+
+                // If we haven't drawn our first frame, reset the time to t = 0
+                // (give up after MAX_DELAY ms of waiting though - might happen, for example, if we
+                // are no longer in the foreground and no frames are being rendered ever)
+                if (frameNum == 0 && currentTime < mStartTime + MAX_DELAY && currentPlayTime > 0) {
+                    // The first frame on animations doesn't always trigger an invalidate...
+                    // force an invalidate here to make sure the animation continues to advance
+                    mRootView.invalidate();
+                    animation.setCurrentPlayTime(0);
+                    // For the second frame, if the first frame took more than 16ms,
+                    // adjust the start time and pretend it took only 16ms anyway. This
+                    // prevents a large jump in the animation due to an expensive first frame
+                } else if (frameNum == 1 && currentTime < mStartTime + MAX_DELAY &&
+                        !mAdjustedSecondFrameTime &&
+                        currentTime > mStartTime + SINGLE_FRAME_MS &&
+                        currentPlayTime > SINGLE_FRAME_MS) {
+                    animation.setCurrentPlayTime(SINGLE_FRAME_MS);
+                    mAdjustedSecondFrameTime = true;
+                } else {
+                    if (frameNum > 1) {
+                        mRootView.post(() -> animation.removeUpdateListener(this));
+                    }
+                    if (DEBUG) print(animation);
+                }
+                mHandlingOnAnimationUpdate = false;
+            } else {
+                if (DEBUG) print(animation);
+            }
+        }
+
+        public void print(ValueAnimator animation) {
+            float flatFraction = animation.getCurrentPlayTime() / (float) animation.getDuration();
+            Log.d(TAG, mGlobalFrameCount +
+                    "(" + (mGlobalFrameCount - mStartFrame) + ") " + mRootView + " dirty? " +
+                    mRootView.isDirty() + " " + flatFraction + " " + this + " " + animation);
+        }
+    }
+}