package com.nineoldandroids.animation;
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/**
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* This class provides a simple callback mechanism to listeners that is synchronized with other
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* animators in the system. There is no duration, interpolation, or object value-setting
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* with this Animator. Instead, it is simply started and proceeds to send out events on every
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* animation frame to its TimeListener (if set), with information about this animator,
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* the total elapsed time, and the time since the last animation frame.
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*
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* @hide
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*/
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public class TimeAnimator extends ValueAnimator {
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private TimeListener mListener;
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private long mPreviousTime = -1;
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@Override
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boolean animationFrame(long currentTime) {
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if (mPlayingState == STOPPED) {
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mPlayingState = RUNNING;
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if (mSeekTime < 0) {
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mStartTime = currentTime;
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} else {
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mStartTime = currentTime - mSeekTime;
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// Now that we're playing, reset the seek time
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mSeekTime = -1;
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}
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}
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if (mListener != null) {
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long totalTime = currentTime - mStartTime;
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long deltaTime = (mPreviousTime < 0) ? 0 : (currentTime - mPreviousTime);
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mPreviousTime = currentTime;
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mListener.onTimeUpdate(this, totalTime, deltaTime);
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}
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return false;
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}
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/**
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* Sets a listener that is sent update events throughout the life of
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* an animation.
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*
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* @param listener the listener to be set.
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*/
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public void setTimeListener(TimeListener listener) {
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mListener = listener;
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}
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@Override
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void animateValue(float fraction) {
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// Noop
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}
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@Override
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void initAnimation() {
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// noop
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}
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/**
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* Implementors of this interface can set themselves as update listeners
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* to a <code>TimeAnimator</code> instance to receive callbacks on every animation
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* frame to receive the total time since the animator started and the delta time
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* since the last frame. The first time the listener is called, totalTime and
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* deltaTime should both be zero.
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*
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* @hide
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*/
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public static interface TimeListener {
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/**
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* <p>Notifies listeners of the occurrence of another frame of the animation,
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* along with information about the elapsed time.</p>
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*
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* @param animation The animator sending out the notification.
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* @param totalTime The
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*/
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void onTimeUpdate(TimeAnimator animation, long totalTime, long deltaTime);
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}
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}
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