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GitHub地址：https://github.com/motianhuo/wechat
微信从6.0版本开始推出小视频功能，随着4G网络的出现，视频将会是一个趋势，他能表达出文字所不能表现的东西，增加了微信的黏性。还记得微信小视频这个功能一推出，如同病毒一样席卷朋友圈。
作为爱美的我们，怎么能把我们的窘态暴露给朋友圈的小伙伴呢，必须正能量！美好的！必须美化！ So，录制小视频后，加各种滤镜，炫酷MV主题，妈妈再也不担心我的猪窝了…
“小视频”对于微信如此之重要。那么，如何实现呢?
先看下咱们的实现效果：
PS：gif 图片比较大，如果等不及的童鞋，可以点击这里查看视频
OK，先看下，消息列表页面的 下滑显示眼睛动画效果的实现方式：
自定义ListView：PullDownListView.java
PullDownListView来自guojunyi的分享, GitHub项目地址:点击这里
package com.example.wechat01.widght;
import android.content.Context;
import android.graphics.Color;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;
import android.widget.RelativeLayout;
import com.example.wechat01.R;
import com.nineoldandroids.animation.ValueAnimator;
import com.nineoldandroids.animation.ValueAnimator.AnimatorUpdateListener;
public class PullDownListView extends RelativeLayout implements
OnScrollListener {
static int MAX_PULL_TOP_HEIGHT;
static int MAX_PULL_BOTTOM_HEIGHT;
static int REFRESHING_TOP_HEIGHT;
static int REFRESHING_BOTTOM_HEIGHT;
private boolean isTop;
private boolean isBottom;
private boolean isRefreshing;
private boolean isAnimation;
RelativeLayout layoutHeader;
RelativeLayout layoutFooter;
private int mCurrentY = 0;
boolean pullTag = false;
OnScrollListener mOnScrollListener;
OnPullHeightChangeListener mOnPullHeightChangeListener;
public void setOnPullHeightChangeListener(
OnPullHeightChangeListener listener) {
this.mOnPullHeightChangeListener = listener;
}
public void setOnScrollListener(OnScrollListener listener) {
mOnScrollListener = listener;
}
public PullDownListView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}
public boolean isRefreshing() {
return this.isRefreshing;
}
private ListView mListView = new ListView(getContext()) {
int lastY = 0;
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (isAnimation || isRefreshing) {
return super.onTouchEvent(ev);
}
RelativeLayout parent = (RelativeLayout) mListView.getParent();
int currentY = (int) ev.getRawY();
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
lastY = (int) ev.getRawY();
break;
case MotionEvent.ACTION_MOVE: {
boolean isToBottom = currentY - lastY >= 0 ? true : false;
int step = Math.abs(currentY - lastY);
lastY = currentY;
if (isTop && mListView.getTop() >= 0) {
if (isToBottom && mListView.getTop() <= MAX_PULL_TOP_HEIGHT) {
MotionEvent event = MotionEvent.obtain(ev);
ev.setAction(MotionEvent.ACTION_UP);
super.onTouchEvent(ev);
pullTag = true;
if (mListView.getTop() > layoutHeader.getHeight()) {
step = step / 2;
}
if ((mListView.getTop() + step) > MAX_PULL_TOP_HEIGHT) {
mCurrentY = MAX_PULL_TOP_HEIGHT;
scrollTopTo(mCurrentY);
} else {
mCurrentY += step;
scrollTopTo(mCurrentY);
}
} else if (!isToBottom && mListView.getTop() > 0) {
MotionEvent event = MotionEvent.obtain(ev);
ev.setAction(MotionEvent.ACTION_UP);
super.onTouchEvent(ev);
if ((mListView.getTop() - step) < 0) {
mCurrentY = 0;
scrollTopTo(mCurrentY);
} else {
mCurrentY -= step;
scrollTopTo(mCurrentY);
}
} else if (!isToBottom && mListView.getTop() == 0) {
if (!pullTag) {
return super.onTouchEvent(ev);
}
}
return true;
} else if (isBottom
&& mListView.getBottom() <= parent.getHeight()) {
if (!isToBottom
&& (parent.getHeight() - mListView.getBottom()) <= MAX_PULL_BOTTOM_HEIGHT) {
MotionEvent event = MotionEvent.obtain(ev);
ev.setAction(MotionEvent.ACTION_UP);
super.onTouchEvent(ev);
pullTag = true;
if (parent.getHeight() - mListView.getBottom() > layoutFooter
.getHeight()) {
step = step / 2;
}
if ((mListView.getBottom() - step) < (parent
.getHeight() - MAX_PULL_BOTTOM_HEIGHT)) {
mCurrentY = -MAX_PULL_BOTTOM_HEIGHT;
scrollBottomTo(mCurrentY);
} else {
mCurrentY -= step;
scrollBottomTo(mCurrentY);
}
} else if (isToBottom
&& (mListView.getBottom() < parent.getHeight())) {
if ((mListView.getBottom() + step) > parent.getHeight()) {
mCurrentY = 0;
scrollBottomTo(mCurrentY);
} else {
mCurrentY += step;
scrollBottomTo(mCurrentY);
}
} else if (isToBottom
&& mListView.getBottom() == parent.getHeight()) {
if (!pullTag) {
return super.onTouchEvent(ev);
}
}
return true;
}
break;
}
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
pullTag = false;
if (mListView.getTop() > 0) {
if (mListView.getTop() > REFRESHING_TOP_HEIGHT) {
animateTopTo(layoutHeader.getMeasuredHeight());
isRefreshing = true;
if (null != mOnPullHeightChangeListener) {
mOnPullHeightChangeListener.onRefreshing(true);
}
} else {
animateTopTo(0);
}
} else if (mListView.getBottom() < parent.getHeight()) {
if ((parent.getHeight() - mListView.getBottom()) > REFRESHING_BOTTOM_HEIGHT) {
animateBottomTo(-layoutFooter.getMeasuredHeight());
isRefreshing = true;
if (null != mOnPullHeightChangeListener) {
mOnPullHeightChangeListener.onRefreshing(false);
}
} else {
animateBottomTo(0);
}
}
}
return super.onTouchEvent(ev);
}
};
public void scrollBottomTo(int y) {
mListView.layout(mListView.getLeft(), y, mListView.getRight(),
this.getMeasuredHeight() + y);
if (null != mOnPullHeightChangeListener) {
mOnPullHeightChangeListener.onBottomHeightChange(
layoutHeader.getHeight(), -y);
}
}
public void animateBottomTo(final int y) {
ValueAnimator animator = ValueAnimator.ofInt(mListView.getBottom()
- this.getMeasuredHeight(), y);
animator.setDuration(300);
animator.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
// TODO Auto-generated method stub
int frameValue = (Integer) animation.getAnimatedValue();
mCurrentY = frameValue;
scrollBottomTo(frameValue);
if (frameValue == y) {
isAnimation = false;
}
}
});
isAnimation = true;
animator.start();
}
public void scrollTopTo(int y) {
mListView.layout(mListView.getLeft(), y, mListView.getRight(),
this.getMeasuredHeight() + y);
if (null != mOnPullHeightChangeListener) {
mOnPullHeightChangeListener.onTopHeightChange(
layoutHeader.getHeight(), y);
}
}
public void animateTopTo(final int y) {
ValueAnimator animator = ValueAnimator.ofInt(mListView.getTop(), y);
animator.setDuration(300);
animator.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
// TODO Auto-generated method stub
int frameValue = (Integer) animation.getAnimatedValue();
mCurrentY = frameValue;
scrollTopTo(frameValue);
if (frameValue == y) {
isAnimation = false;
}
}
});
isAnimation = true;
animator.start();
}
@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
REFRESHING_TOP_HEIGHT = layoutHeader.getMeasuredHeight();
REFRESHING_BOTTOM_HEIGHT = layoutFooter.getMeasuredHeight();
MAX_PULL_TOP_HEIGHT = this.getMeasuredHeight();
MAX_PULL_BOTTOM_HEIGHT = this.getMeasuredHeight();
}
@Override
public void onFinishInflate() {
mListView.setBackgroundColor(0xffffffff);
mListView.setCacheColorHint(Color.TRANSPARENT);
mListView.setVerticalScrollBarEnabled(false);
mListView.setLayoutParams(new RelativeLayout.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
mListView.setOnScrollListener(this);
mListView.setDividerHeight(0);
this.addView(mListView);
layoutHeader = (RelativeLayout) this.findViewById(R.id.layoutHeader);
layoutFooter = (RelativeLayout) this.findViewById(R.id.layoutFooter);
super.onFinishInflate();
}
public ListView getListView() {
return this.mListView;
}
public void pullUp() {
isRefreshing = false;
if (mListView.getTop() > 0) {
animateTopTo(0);
} else if (mListView.getBottom() < this.getHeight()) {
animateBottomTo(0);
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {