/*
* Copyright 2013 Niek Haarman
*
* 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.haarman.listviewanimations.swinginadapters;
import junit.framework.Assert;
import android.util.SparseArray;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import com.haarman.listviewanimations.BaseAdapterDecorator;
import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.AnimatorSet;
import com.nineoldandroids.animation.ObjectAnimator;
/**
* A BaseAdapterDecorator class which applies multiple Animators at once to
* views when they are first shown. The Animators applied include the animations
* specified in getAnimators(ViewGroup, View), plus an alpha transition.
*/
public abstract class AnimationAdapter extends BaseAdapterDecorator {
protected static final long DEFAULTANIMATIONDELAYMILLIS = 100;
protected static final long DEFAULTANIMATIONDURATIONMILLIS = 300;
private static final long INITIALDELAYMILLIS = 150;
private SparseArray<Animator> mAnimators;
private long mAnimationStartMillis;
private int mLastAnimatedPosition;
private boolean mHasParentAnimationAdapter;
public AnimationAdapter(BaseAdapter baseAdapter) {
super(baseAdapter);
mAnimators = new SparseArray<Animator>();
mAnimationStartMillis = -1;
mLastAnimatedPosition = -1;
if (baseAdapter instanceof AnimationAdapter) {
((AnimationAdapter) baseAdapter).setHasParentAnimationAdapter(true);
}
}
@Override
public final View getView(int position, View convertView, ViewGroup parent) {
if (!mHasParentAnimationAdapter) {
Assert.assertNotNull("Call setListView() on this AnimationAdapter before setAdapter()!", getListView());
if (convertView != null) {
int hashCode = convertView.hashCode();
Animator animator = mAnimators.get(hashCode);
if (animator != null) {
animator.end();
}
mAnimators.remove(hashCode);
}
}
View itemView = super.getView(position, convertView, parent);
if (!mHasParentAnimationAdapter) {
animateViewIfNecessary(position, itemView, parent);
}
return itemView;
}
private void animateViewIfNecessary(int position, View view, ViewGroup parent) {
if (position > mLastAnimatedPosition && !mHasParentAnimationAdapter) {
animateView(parent, view);
mLastAnimatedPosition = position;
}
}
private void animateView(ViewGroup parent, View view) {
if (mAnimationStartMillis == -1) {
mAnimationStartMillis = System.currentTimeMillis();
}
hideView(view);
Animator[] childAnimators;
if (mDecoratedBaseAdapter instanceof AnimationAdapter) {
childAnimators = ((AnimationAdapter) mDecoratedBaseAdapter).getAnimators(parent, view);
} else {
childAnimators = new Animator[0];
}
Animator[] animators = getAnimators(parent, view);
Animator alphaAnimator = ObjectAnimator.ofFloat(view, "alpha", 0, 1);
AnimatorSet set = new AnimatorSet();
set.playTogether(concatAnimators(childAnimators, animators, alphaAnimator));
set.setStartDelay(calculateAnimationDelay());
set.setDuration(getAnimationDurationMillis());
set.start();
mAnimators.put(view.hashCode(), set);
}
private void hideView(View view) {
ObjectAnimator animator = ObjectAnimator.ofFloat(view, "alpha", 0);
AnimatorSet set = new AnimatorSet();
set.play(animator);
set.setDuration(0);
set.start();
}
private Animator[] concatAnimators(Animator[] childAnimators, Animator[] animators, Animator alphaAnimator) {
Animator[] allAnimators = new Animator[childAnimators.length + animators.length + 1];
int i;
for (i = 0; i < animators.length; ++i) {
allAnimators[i] = animators[i];
}
for (int j = 0; j < childAnimators.length; ++j) {
allAnimators[i] = childAnimators[j];
++i;
}
allAnimators[allAnimators.length - 1] = alphaAnimator;
return allAnimators;
}
private long calculateAnimationDelay() {
long delay;
int numberOfItems = getListView().getLastVisiblePosition() - getListView().getFirstVisiblePosition();
if (numberOfItems + 1 < mLastAnimatedPosition) {
delay = getAnimationDelayMillis();
} else {
long delaySinceStart = (mLastAnimatedPosition + 1) * getAnimationDelayMillis();
delay = mAnimationStartMillis + INITIALDELAYMILLIS + delaySinceStart - System.currentTimeMillis();
}
return Math.max(0, delay);
}
/**
* Set whether this AnimationAdapter is encapsulated by another
* AnimationAdapter. When this is set to true, this AnimationAdapter does
* not apply any animations to the views. Should not be set explicitly, the
* AnimationAdapter class manages this by itself.
*/
public void setHasParentAnimationAdapter(boolean hasParentAnimationAdapter) {
mHasParentAnimationAdapter = hasParentAnimationAdapter;
}
/**
* Get the delay in milliseconds before an animation of a view should start.
*/
protected abstract long getAnimationDelayMillis();
/**
* Get the duration of the animation in milliseconds.
*/
protected abstract long getAnimationDurationMillis();
/**
* Get the Animators to apply to the views. In addition to the returned
* Animators, an alpha transition will be applied to the view.
*
* @param parent
* The parent of the view
* @param view
* The view that will be animated, as retrieved by getView()
*/
public abstract Animator[] getAnimators(ViewGroup parent, View view);
}