| /* |
| * Copyright (C) 2011 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.view; |
| |
| import com.android.internal.util.ArrayUtils; |
| |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.os.Message; |
| import android.os.SystemClock; |
| import android.os.SystemProperties; |
| import android.util.Log; |
| |
| /** |
| * Coodinates animations and drawing for UI on a particular thread. |
| * @hide |
| */ |
| public final class Choreographer extends Handler { |
| private static final String TAG = "Choreographer"; |
| private static final boolean DEBUG = false; |
| |
| // The default amount of time in ms between animation frames. |
| // When vsync is not enabled, we want to have some idea of how long we should |
| // wait before posting the next animation message. It is important that the |
| // default value be less than the true inter-frame delay on all devices to avoid |
| // situations where we might skip frames by waiting too long (we must compensate |
| // for jitter and hardware variations). Regardless of this value, the animation |
| // and display loop is ultimately rate-limited by how fast new graphics buffers can |
| // be dequeued. |
| private static final long DEFAULT_FRAME_DELAY = 10; |
| |
| // The number of milliseconds between animation frames. |
| private static long sFrameDelay = DEFAULT_FRAME_DELAY; |
| |
| // Thread local storage for the choreographer. |
| private static final ThreadLocal<Choreographer> sThreadInstance = |
| new ThreadLocal<Choreographer>() { |
| @Override |
| protected Choreographer initialValue() { |
| Looper looper = Looper.myLooper(); |
| if (looper == null) { |
| throw new IllegalStateException("The current thread must have a looper!"); |
| } |
| return new Choreographer(looper); |
| } |
| }; |
| |
| // System property to enable/disable vsync for animations and drawing. |
| // Enabled by default. |
| private static final boolean USE_VSYNC = SystemProperties.getBoolean( |
| "debug.choreographer.vsync", true); |
| |
| // System property to enable/disable the use of the vsync / animation timer |
| // for drawing rather than drawing immediately. |
| // Temporarily disabled by default because postponing performTraversals() violates |
| // assumptions about traversals happening in-order relative to other posted messages. |
| // Bug: 5721047 |
| private static final boolean USE_ANIMATION_TIMER_FOR_DRAW = SystemProperties.getBoolean( |
| "debug.choreographer.animdraw", false); |
| |
| private static final int MSG_DO_ANIMATION = 0; |
| private static final int MSG_DO_DRAW = 1; |
| |
| private final Looper mLooper; |
| |
| private OnAnimateListener[] mOnAnimateListeners; |
| private OnDrawListener[] mOnDrawListeners; |
| |
| private boolean mAnimationScheduled; |
| private boolean mDrawScheduled; |
| private FrameDisplayEventReceiver mFrameDisplayEventReceiver; |
| private long mLastAnimationTime; |
| private long mLastDrawTime; |
| |
| private Choreographer(Looper looper) { |
| super(looper); |
| mLooper = looper; |
| mLastAnimationTime = Long.MIN_VALUE; |
| mLastDrawTime = Long.MIN_VALUE; |
| } |
| |
| /** |
| * Gets the choreographer for this thread. |
| * Must be called on the UI thread. |
| * |
| * @return The choreographer for this thread. |
| * @throws IllegalStateException if the thread does not have a looper. |
| */ |
| public static Choreographer getInstance() { |
| return sThreadInstance.get(); |
| } |
| |
| /** |
| * The amount of time, in milliseconds, between each frame of the animation. This is a |
| * requested time that the animation will attempt to honor, but the actual delay between |
| * frames may be different, depending on system load and capabilities. This is a static |
| * function because the same delay will be applied to all animations, since they are all |
| * run off of a single timing loop. |
| * |
| * The frame delay may be ignored when the animation system uses an external timing |
| * source, such as the display refresh rate (vsync), to govern animations. |
| * |
| * @return the requested time between frames, in milliseconds |
| */ |
| public static long getFrameDelay() { |
| return sFrameDelay; |
| } |
| |
| /** |
| * The amount of time, in milliseconds, between each frame of the animation. This is a |
| * requested time that the animation will attempt to honor, but the actual delay between |
| * frames may be different, depending on system load and capabilities. This is a static |
| * function because the same delay will be applied to all animations, since they are all |
| * run off of a single timing loop. |
| * |
| * The frame delay may be ignored when the animation system uses an external timing |
| * source, such as the display refresh rate (vsync), to govern animations. |
| * |
| * @param frameDelay the requested time between frames, in milliseconds |
| */ |
| public static void setFrameDelay(long frameDelay) { |
| sFrameDelay = frameDelay; |
| } |
| |
| /** |
| * Schedules animation (and drawing) to occur on the next frame synchronization boundary. |
| * Must be called on the UI thread. |
| */ |
| public void scheduleAnimation() { |
| if (!mAnimationScheduled) { |
| mAnimationScheduled = true; |
| if (USE_VSYNC) { |
| if (DEBUG) { |
| Log.d(TAG, "Scheduling vsync for animation."); |
| } |
| if (mFrameDisplayEventReceiver == null) { |
| mFrameDisplayEventReceiver = new FrameDisplayEventReceiver(mLooper); |
| } |
| mFrameDisplayEventReceiver.scheduleVsync(); |
| } else { |
| final long now = SystemClock.uptimeMillis(); |
| final long nextAnimationTime = Math.max(mLastAnimationTime + sFrameDelay, now); |
| if (DEBUG) { |
| Log.d(TAG, "Scheduling animation in " + (nextAnimationTime - now) + " ms."); |
| } |
| sendEmptyMessageAtTime(MSG_DO_ANIMATION, nextAnimationTime); |
| } |
| } |
| } |
| |
| /** |
| * Schedules drawing to occur on the next frame synchronization boundary. |
| * Must be called on the UI thread. |
| */ |
| public void scheduleDraw() { |
| if (!mDrawScheduled) { |
| mDrawScheduled = true; |
| if (USE_ANIMATION_TIMER_FOR_DRAW) { |
| scheduleAnimation(); |
| } else { |
| if (DEBUG) { |
| Log.d(TAG, "Scheduling draw immediately."); |
| } |
| sendEmptyMessage(MSG_DO_DRAW); |
| } |
| } |
| } |
| |
| @Override |
| public void handleMessage(Message msg) { |
| switch (msg.what) { |
| case MSG_DO_ANIMATION: |
| doAnimation(); |
| break; |
| case MSG_DO_DRAW: |
| doDraw(); |
| break; |
| } |
| } |
| |
| private void doAnimation() { |
| if (mAnimationScheduled) { |
| mAnimationScheduled = false; |
| |
| final long start = SystemClock.uptimeMillis(); |
| if (DEBUG) { |
| Log.d(TAG, "Performing animation: " + Math.max(0, start - mLastAnimationTime) |
| + " ms have elapsed since previous animation."); |
| } |
| mLastAnimationTime = start; |
| |
| final OnAnimateListener[] listeners = mOnAnimateListeners; |
| if (listeners != null) { |
| for (int i = 0; i < listeners.length; i++) { |
| listeners[i].onAnimate(); |
| } |
| } |
| |
| if (DEBUG) { |
| Log.d(TAG, "Animation took " + (SystemClock.uptimeMillis() - start) + " ms."); |
| } |
| } |
| |
| if (USE_ANIMATION_TIMER_FOR_DRAW) { |
| doDraw(); |
| } |
| } |
| |
| private void doDraw() { |
| if (mDrawScheduled) { |
| mDrawScheduled = false; |
| |
| final long start = SystemClock.uptimeMillis(); |
| if (DEBUG) { |
| Log.d(TAG, "Performing draw: " + Math.max(0, start - mLastDrawTime) |
| + " ms have elapsed since previous draw."); |
| } |
| mLastDrawTime = start; |
| |
| final OnDrawListener[] listeners = mOnDrawListeners; |
| if (listeners != null) { |
| for (int i = 0; i < listeners.length; i++) { |
| listeners[i].onDraw(); |
| } |
| } |
| |
| if (DEBUG) { |
| Log.d(TAG, "Draw took " + (SystemClock.uptimeMillis() - start) + " ms."); |
| } |
| } |
| } |
| |
| /** |
| * Adds an animation listener. |
| * Must be called on the UI thread. |
| * |
| * @param listener The listener to add. |
| */ |
| public void addOnAnimateListener(OnAnimateListener listener) { |
| if (listener == null) { |
| throw new IllegalArgumentException("listener must not be null"); |
| } |
| |
| if (DEBUG) { |
| Log.d(TAG, "Adding onAnimate listener: " + listener); |
| } |
| |
| mOnAnimateListeners = ArrayUtils.appendElement(OnAnimateListener.class, |
| mOnAnimateListeners, listener); |
| } |
| |
| /** |
| * Removes an animation listener. |
| * Must be called on the UI thread. |
| * |
| * @param listener The listener to remove. |
| */ |
| public void removeOnAnimateListener(OnAnimateListener listener) { |
| if (listener == null) { |
| throw new IllegalArgumentException("listener must not be null"); |
| } |
| |
| if (DEBUG) { |
| Log.d(TAG, "Removing onAnimate listener: " + listener); |
| } |
| |
| mOnAnimateListeners = ArrayUtils.removeElement(OnAnimateListener.class, |
| mOnAnimateListeners, listener); |
| stopTimingLoopIfNoListeners(); |
| } |
| |
| /** |
| * Adds a draw listener. |
| * Must be called on the UI thread. |
| * |
| * @param listener The listener to add. |
| */ |
| public void addOnDrawListener(OnDrawListener listener) { |
| if (listener == null) { |
| throw new IllegalArgumentException("listener must not be null"); |
| } |
| |
| if (DEBUG) { |
| Log.d(TAG, "Adding onDraw listener: " + listener); |
| } |
| |
| mOnDrawListeners = ArrayUtils.appendElement(OnDrawListener.class, |
| mOnDrawListeners, listener); |
| } |
| |
| /** |
| * Removes a draw listener. |
| * Must be called on the UI thread. |
| * |
| * @param listener The listener to remove. |
| */ |
| public void removeOnDrawListener(OnDrawListener listener) { |
| if (listener == null) { |
| throw new IllegalArgumentException("listener must not be null"); |
| } |
| |
| if (DEBUG) { |
| Log.d(TAG, "Removing onDraw listener: " + listener); |
| } |
| |
| mOnDrawListeners = ArrayUtils.removeElement(OnDrawListener.class, |
| mOnDrawListeners, listener); |
| stopTimingLoopIfNoListeners(); |
| } |
| |
| private void stopTimingLoopIfNoListeners() { |
| if (mOnDrawListeners == null && mOnAnimateListeners == null) { |
| if (DEBUG) { |
| Log.d(TAG, "Stopping timing loop."); |
| } |
| |
| if (mAnimationScheduled) { |
| mAnimationScheduled = false; |
| if (!USE_VSYNC) { |
| removeMessages(MSG_DO_ANIMATION); |
| } |
| } |
| |
| if (mDrawScheduled) { |
| mDrawScheduled = false; |
| if (!USE_ANIMATION_TIMER_FOR_DRAW) { |
| removeMessages(MSG_DO_DRAW); |
| } |
| } |
| |
| if (mFrameDisplayEventReceiver != null) { |
| mFrameDisplayEventReceiver.dispose(); |
| mFrameDisplayEventReceiver = null; |
| } |
| } |
| } |
| |
| /** |
| * Listens for animation frame timing events. |
| */ |
| public static interface OnAnimateListener { |
| /** |
| * Called to animate properties before drawing the frame. |
| */ |
| public void onAnimate(); |
| } |
| |
| /** |
| * Listens for draw frame timing events. |
| */ |
| public static interface OnDrawListener { |
| /** |
| * Called to draw the frame. |
| */ |
| public void onDraw(); |
| } |
| |
| private final class FrameDisplayEventReceiver extends DisplayEventReceiver { |
| public FrameDisplayEventReceiver(Looper looper) { |
| super(looper); |
| } |
| |
| @Override |
| public void onVsync(long timestampNanos, int frame) { |
| doAnimation(); |
| } |
| } |
| } |