Android源碼解析之屬性動(dòng)畫(huà)詳解

ObjectAnimator
 .ofInt(mView,"width",100,500)
 .setDuration(1000)
 .start();

public static ObjectAnimator ofInt(Object target, String propertyName, int... values) {
 ObjectAnimator anim = new ObjectAnimator(target, propertyName);
 anim.setIntValues(values);
 return anim;
}

public void setIntValues(int... values) {
 if (mValues == null || mValues.length == 0) {
 // No values yet - this animator is being constructed piecemeal. Init the values with
 // whatever the current propertyName is
 if (mProperty != null) {
 setValues(PropertyValuesHolder.ofInt(mProperty, values));
 } else {
 setValues(PropertyValuesHolder.ofInt(mPropertyName, values));
 }
 } else {
 super.setIntValues(values);
 }
}

public static PropertyValuesHolder ofInt(String propertyName, int... values) {
 return new IntPropertyValuesHolder(propertyName, values);
}

public IntPropertyValuesHolder(String propertyName, int... values) {
 super(propertyName);
 setIntValues(values);
}

public void setIntValues(int... values) {
 super.setIntValues(values);
 mIntKeyframes = (Keyframes.IntKeyframes) mKeyframes;
}

public static KeyframeSet ofInt(int... values) {
 int numKeyframes = values.length;
 IntKeyframe keyframes[] = new IntKeyframe[Math.max(numKeyframes,2)];
 if (numKeyframes == 1) {
 keyframes[0] = (IntKeyframe) Keyframe.ofInt(0f);
 keyframes[1] = (IntKeyframe) Keyframe.ofInt(1f, values[0]);
 } else {
 keyframes[0] = (IntKeyframe) Keyframe.ofInt(0f, values[0]);
 for (int i = 1; i < numKeyframes; ++i) {
 keyframes[i] =
  (IntKeyframe) Keyframe.ofInt((float) i / (numKeyframes - 1), values[i]);
 }
 }
 return new IntKeyframeSet(keyframes);
}

public void setValues(PropertyValuesHolder... values) {
 int numValues = values.length;
 mValues = values;
 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues);
 for (int i = 0; i < numValues; ++i) {
 PropertyValuesHolder valuesHolder = values[i];
 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder);
 }
 // New property/values/target should cause re-initialization prior to starting
 mInitialized = false;
}

public void start() {
 // See if any of the current active/pending animators need to be canceled
 AnimationHandler handler = sAnimationHandler.get();
 if (handler != null) {
 int numAnims = handler.mAnimations.size();
 for (int i = numAnims - 1; i >= 0; i--) {
 if (handler.mAnimations.get(i) instanceof ObjectAnimator) {
 ObjectAnimator anim = (ObjectAnimator) handler.mAnimations.get(i);
 if (anim.mAutoCancel && hasSameTargetAndProperties(anim)) {
  anim.cancel();
 }
 }
 }
 numAnims = handler.mPendingAnimations.size();
 for (int i = numAnims - 1; i >= 0; i--) {
 if (handler.mPendingAnimations.get(i) instanceof ObjectAnimator) {
 ObjectAnimator anim = (ObjectAnimator) handler.mPendingAnimations.get(i);
 if (anim.mAutoCancel && hasSameTargetAndProperties(anim)) {
  anim.cancel();
 }
 }
 }
 numAnims = handler.mDelayedAnims.size();
 for (int i = numAnims - 1; i >= 0; i--) {
 if (handler.mDelayedAnims.get(i) instanceof ObjectAnimator) {
 ObjectAnimator anim = (ObjectAnimator) handler.mDelayedAnims.get(i);
 if (anim.mAutoCancel && hasSameTargetAndProperties(anim)) {
  anim.cancel();
 }
 }
 }
 }
 if (DBG) {
 Log.d(LOG_TAG, "Anim target, duration: " + getTarget() + ", " + getDuration());
 for (int i = 0; i < mValues.length; ++i) {
 PropertyValuesHolder pvh = mValues[i];
 Log.d(LOG_TAG, " Values[" + i + "]: " +
 pvh.getPropertyName() + ", " + pvh.mKeyframes.getValue(0) + ", " +
 pvh.mKeyframes.getValue(1));
 }
 }
 super.start();
}

private void start(boolean playBackwards) {
 if (Looper.myLooper() == null) {
 throw new AndroidRuntimeException("Animators may only be run on Looper threads");
 }
 mReversing = playBackwards;
 mPlayingBackwards = playBackwards;
 if (playBackwards && mSeekFraction != -1) {
 if (mSeekFraction == 0 && mCurrentIteration == 0) {
 // special case: reversing from seek-to-0 should act as if not seeked at all
 mSeekFraction = 0;
 } else if (mRepeatCount == INFINITE) {
 mSeekFraction = 1 - (mSeekFraction % 1);
 } else {
 mSeekFraction = 1 + mRepeatCount - (mCurrentIteration + mSeekFraction);
 }
 mCurrentIteration = (int) mSeekFraction;
 mSeekFraction = mSeekFraction % 1;
 }
 if (mCurrentIteration > 0 && mRepeatMode == REVERSE &&
 (mCurrentIteration < (mRepeatCount + 1) || mRepeatCount == INFINITE)) {
 // if we were seeked to some other iteration in a reversing animator,
 // figure out the correct direction to start playing based on the iteration
 if (playBackwards) {
 mPlayingBackwards = (mCurrentIteration % 2) == 0;
 } else {
 mPlayingBackwards = (mCurrentIteration % 2) != 0;
 }
 }
 int prevPlayingState = mPlayingState;
 mPlayingState = STOPPED;
 mStarted = true;
 mStartedDelay = false;
 mPaused = false;
 updateScaledDuration(); // in case the scale factor has changed since creation time
 AnimationHandler animationHandler = getOrCreateAnimationHandler();
 animationHandler.mPendingAnimations.add(this);
 if (mStartDelay == 0) {
 // This sets the initial value of the animation, prior to actually starting it running
 if (prevPlayingState != SEEKED) {
 setCurrentPlayTime(0);
 }
 mPlayingState = STOPPED;
 mRunning = true;
 notifyStartListeners();
 }
 animationHandler.start();
}

doAnimationFrame(mChoreographer.getFrameTime());

void doAnimationFrame(long frameTime) {
 mLastFrameTime = frameTime;
 // mPendingAnimations holds any animations that have requested to be started
 // We're going to clear mPendingAnimations, but starting animation may
 // cause more to be added to the pending list (for example, if one animation
 // starting triggers another starting). So we loop until mPendingAnimations
 // is empty.
 while (mPendingAnimations.size() > 0) {
 ArrayList<ValueAnimator> pendingCopy =
 (ArrayList<ValueAnimator>) mPendingAnimations.clone();
 mPendingAnimations.clear();
 int count = pendingCopy.size();
 for (int i = 0; i < count; ++i) {
 ValueAnimator anim = pendingCopy.get(i);
 // If the animation has a startDelay, place it on the delayed list
 if (anim.mStartDelay == 0) {
 anim.startAnimation(this);
 } else {
 mDelayedAnims.add(anim);
 }
 }
 }
 // Next, process animations currently sitting on the delayed queue, adding
 // them to the active animations if they are ready
 int numDelayedAnims = mDelayedAnims.size();
 for (int i = 0; i < numDelayedAnims; ++i) {
 ValueAnimator anim = mDelayedAnims.get(i);
 if (anim.delayedAnimationFrame(frameTime)) {
 mReadyAnims.add(anim);
 }
 }
 int numReadyAnims = mReadyAnims.size();
 if (numReadyAnims > 0) {
 for (int i = 0; i < numReadyAnims; ++i) {
 ValueAnimator anim = mReadyAnims.get(i);
 anim.startAnimation(this);
 anim.mRunning = true;
 mDelayedAnims.remove(anim);
 }
 mReadyAnims.clear();
 }
 // Now process all active animations. The return value from animationFrame()
 // tells the handler whether it should now be ended
 int numAnims = mAnimations.size();
 for (int i = 0; i < numAnims; ++i) {
 mTmpAnimations.add(mAnimations.get(i));
 }
 for (int i = 0; i < numAnims; ++i) {
 ValueAnimator anim = mTmpAnimations.get(i);
 if (mAnimations.contains(anim) && anim.doAnimationFrame(frameTime)) {
 mEndingAnims.add(anim);
 }
 }
 mTmpAnimations.clear();
 if (mEndingAnims.size() > 0) {
 for (int i = 0; i < mEndingAnims.size(); ++i) {
 mEndingAnims.get(i).endAnimation(this);
 }
 mEndingAnims.clear();
 }
 // Schedule final commit for the frame.
 mChoreographer.postCallback(Choreographer.CALLBACK_COMMIT, mCommit, null);
 // If there are still active or delayed animations, schedule a future call to
 // onAnimate to process the next frame of the animations.
 if (!mAnimations.isEmpty() || !mDelayedAnims.isEmpty()) {
 scheduleAnimation();
 }
}

boolean animationFrame(long currentTime) {
 boolean done = false;
 switch (mPlayingState) {
 case RUNNING:
 case SEEKED:
 float fraction = mDuration > 0 ? (float)(currentTime - mStartTime) / mDuration : 1f;
 if (mDuration == 0 && mRepeatCount != INFINITE) {
 // Skip to the end
 mCurrentIteration = mRepeatCount;
 if (!mReversing) {
  mPlayingBackwards = false;
 }
 }
 if (fraction >= 1f) {
 if (mCurrentIteration < mRepeatCount || mRepeatCount == INFINITE) {
  // Time to repeat
  if (mListeners != null) {
  int numListeners = mListeners.size();
  for (int i = 0; i < numListeners; ++i) {
  mListeners.get(i).onAnimationRepeat(this);
  }
  }
  if (mRepeatMode == REVERSE) {
  mPlayingBackwards = !mPlayingBackwards;
  }
  mCurrentIteration += (int) fraction;
  fraction = fraction % 1f;
  mStartTime += mDuration;
  // Note: We do not need to update the value of mStartTimeCommitted here
  // since we just added a duration offset.
 } else {
  done = true;
  fraction = Math.min(fraction, 1.0f);
 }
 }
 if (mPlayingBackwards) {
 fraction = 1f - fraction;
 }
 animateValue(fraction);
 break;
 }
 return done;
 }

void animateValue(float fraction) {
 final Object target = getTarget();
 if (mTarget != null && target == null) {
 // We lost the target reference, cancel and clean up.
 cancel();
 return;
 }
 super.animateValue(fraction);
 int numValues = mValues.length;
 for (int i = 0; i < numValues; ++i) {
 mValues[i].setAnimatedValue(target);
 }
}

void animateValue(float fraction) {
 fraction = mInterpolator.getInterpolation(fraction);
 mCurrentFraction = fraction;
 int numValues = mValues.length;
 for (int i = 0; i < numValues; ++i) {
 mValues[i].calculateValue(fraction);
 }
 if (mUpdateListeners != null) {
 int numListeners = mUpdateListeners.size();
 for (int i = 0; i < numListeners; ++i) {
 mUpdateListeners.get(i).onAnimationUpdate(this);
 }
 }
}

void calculateValue(float fraction) {
 mIntAnimatedValue = mIntKeyframes.getIntValue(fraction);
}

void setAnimatedValue(Object target) {
 if (mIntProperty != null) {
 mIntProperty.setValue(target, mIntAnimatedValue);
 return;
 }
 if (mProperty != null) {
 mProperty.set(target, mIntAnimatedValue);
 return;
 }
 if (mJniSetter != 0) {
 nCallIntMethod(target, mJniSetter, mIntAnimatedValue);
 return;
 }
 if (mSetter != null) {
 try {
 mTmpValueArray[0] = mIntAnimatedValue;
 mSetter.invoke(target, mTmpValueArray);
 } catch (InvocationTargetException e) {
 Log.e("PropertyValuesHolder", e.toString());
 } catch (IllegalAccessException e) {
 Log.e("PropertyValuesHolder", e.toString());
 }
 }
}