google 提供的API中,有个类,大家都很熟悉,GestureDetector。使用它,我们可以识别用户通常会用的手势。但是,这个类不支持多点触摸(可能 google认为没有人会在几个手指都在屏幕上的时候,使用手势吧~),不过,最近和朋友们一起做的一个App,的确用到了多点手势(主要是 onScroll和onFling两个手势),所以,我就把这个类拓展了一下,来实现让多个控件各自跟着一跟手指实现拖动和滑动的效果。
顺便说一下,大家应该都知道,在Android3.0以后,Android的触摸事件的分配机制和以前的版本是有区别的。从3.0开始,用户在不同控件
上操作产生的touch消息不会相互干扰,touch消息会被分派到不同控件上的touchListener中处理。而
在以前的版本中,所有的touch消息,都会被分排到第一个碰到屏幕的手指所操作的控件的touchListener中处理,也就是说,会出现这样一个矛盾的现象:
在界面上有A,B,C三个控件,然后,当你先用食指按住A,跟着又用中指和无名指(嘛,别的手指也行,不用在意中指还是无名指)按住B,C。当中指和无
名指移动的时候,B和C都无法接收到这个ACTION_MOVE消息,而接收到消息的却是A。而在3.0以上版本中,并不存在这个问题。
使用以下的这个类,可以实现从2.2到3.2平台上手势识别的兼容。
代码区:
packagecom.finger.utils;
importjava.util.ArrayList;
importjava.util.List;
importandroid.content.Context;
importandroid.os.Handler;
importandroid.os.Message;
importandroid.view.MotionEvent;
importandroid.view.VelocityTracker;
importandroid.view.ViewConfiguration;
publicclassMultiTouchGestureDetector {
@SuppressWarnings("unused")
privatestaticfinalString MYTAG ="Ray";
publicstaticfinalString CLASS_NAME ="MultiTouchGestureDetector";
/**
* 事件信息类 <br/>
* 用来记录一个手势
*/
privateclassEventInfo {
privateMultiMotionEvent mCurrentDownEvent; //当前的down事件
privateMultiMotionEvent mPreviousUpEvent; //上一次up事件
privatebooleanmStillDown; //当前手指是否还在屏幕上
privatebooleanmInLongPress; //当前事件是否属于长按手势
privatebooleanmAlwaysInTapRegion; //是否当前手指仅在小范围内移动,当手指仅在小范围内移动时,视为手指未曾移动过,不会触发onScroll手势
privatebooleanmAlwaysInBiggerTapRegion; //是否当前手指在较大范围内移动,仅当此值为true时,双击手势才能成立
privatebooleanmIsDoubleTapping; //当前手势,是否为双击手势
privatefloatmLastMotionY; //最后一次事件的X坐标
privatefloatmLastMotionX; //最后一次事件的Y坐标
privateEventInfo(MotionEvent e) {
this(newMultiMotionEvent(e));
}
privateEventInfo(MultiMotionEvent me) {
mCurrentDownEvent = me;
mStillDown =true;
mInLongPress =false;
mAlwaysInTapRegion =true;
mAlwaysInBiggerTapRegion =true;
mIsDoubleTapping =false;
}
//释放MotionEven对象,使系统能够继续使用它们
publicvoidrecycle() {
if(mCurrentDownEvent !=null) {
mCurrentDownEvent.recycle();
mCurrentDownEvent =null;
}
if(mPreviousUpEvent !=null) {
mPreviousUpEvent.recycle();
mPreviousUpEvent =null;
}
}
@Override
publicvoidfinalize() {
this.recycle();
}
}
/**
* 多点事件类 <br/>
* 将一个多点事件拆分为多个单点事件,并方便获得事件的绝对坐标
* <br/> 绝对坐标用以在界面中找到触点所在的控件
* @author ray-ni
*/
publicclassMultiMotionEvent {
privateMotionEvent mEvent;
privateintmIndex;
privateMultiMotionEvent(MotionEvent e) {
mEvent = e;
mIndex = (e.getAction() &
MotionEvent.ACTION_POINTER_ID_MASK) >>
MotionEvent.ACTION_POINTER_ID_SHIFT; //等效于 mEvent.getActionIndex();
}
privateMultiMotionEvent(MotionEvent e,intidx) {
mEvent = e;
mIndex = idx;
}
// 行为
publicintgetAction() {
intaction = mEvent.getAction() & MotionEvent.ACTION_MASK; //等效于 mEvent.getActionMasked();
switch(action) {
caseMotionEvent.ACTION_POINTER_DOWN:
action = MotionEvent.ACTION_DOWN;
break;
caseMotionEvent.ACTION_POINTER_UP:
action = MotionEvent.ACTION_UP;
break;
}
returnaction;
}
// 返回X的绝对坐标
publicfloatgetX() {
returnmEvent.getX(mIndex) + mEvent.getRawX() - mEvent.getX();
}
// 返回Y的绝对坐标
publicfloatgetY() {
returnmEvent.getY(mIndex) + mEvent.getRawY() - mEvent.getY();
}
// 事件发生的时间
publiclonggetEventTime() {
returnmEvent.getEventTime();
}
// 事件序号
publicintgetIndex() {
returnmIndex;
}
// 事件ID
publicintgetId() {
returnmEvent.getPointerId(mIndex);
}
// 释放事件对象,使系统能够继续使用
publicvoidrecycle() {
if(mEvent !=null) {
mEvent.recycle();
mEvent =null;
}
}
}
// 多点手势监听器
publicinterfaceMultiTouchGestureListener {
// 手指触碰到屏幕,由一个 ACTION_DOWN触发
booleanonDown(MultiMotionEvent e);
// 确定一个press事件,强调手指按下的一段时间(TAP_TIMEOUT)内,手指未曾移动或抬起
voidonShowPress(MultiMotionEvent e);
// 手指点击屏幕后离开,由 ACTION_UP引发,可以简单的理解为单击事件,即手指点击时间不长(未构成长按事件),也不曾移动过
booleanonSingleTapUp(MultiMotionEvent e);
// 长按,手指点下后一段时间(DOUBLE_TAP_TIMEOUT)内,不曾抬起或移动
voidonLongPress(MultiMotionEvent e);
// 拖动,由ACTION_MOVE触发,手指地按下后,在屏幕上移动
booleanonScroll(MultiMotionEvent e1, MultiMotionEvent e2,floatdistanceX,floatdistanceY);
// 滑动,由ACTION_UP触发,手指按下并移动一段距离后,抬起时触发
booleanonFling(MultiMotionEvent e1, MultiMotionEvent e2,floatvelocityX,floatvelocityY);
}
// 多点双击监听器
publicinterfaceMultiTouchDoubleTapListener {
// 单击事件确认,强调第一个单击事件发生后,一段时间内,未发生第二次单击事件,即确定不会触发双击事件
booleanonSingleTapConfirmed(MultiMotionEvent e);
// 双击事件, 由ACTION_DOWN触发,从第一次单击事件的DOWN事件开始的一段时间(DOUBLE_TAP_TIMEOUT)内结束(即手指),
// 并且在第一次单击事件的UP时间开始后的一段时间内(DOUBLE_TAP_TIMEOUT)发生第二次单击事件,
// 除此之外两者坐标间距小于定值(DOUBLE_TAP_SLAP)时,则触发双击事件
booleanonDoubleTap(MultiMotionEvent e);
// 双击事件,与onDoubleTap事件不同之处在于,构成双击的第二次点击的ACTION_DOWN,ACTION_MOVE和ACTION_UP都会触发该事件
booleanonDoubleTapEvent(MultiMotionEvent e);
}
// 事件信息队列,队列的下标与MotionEvent的pointId对应
privatestaticList<EventInfo> sEventInfos =newArrayList<EventInfo>(10);
// 双击判断队列,这个队列中的元素等待双击超时的判断结果
privatestaticList<EventInfo> sEventForDoubleTap =newArrayList<EventInfo>(5);
// 指定大点击区域的大小(这个比较拗口),这个值主要用于帮助判断双击是否成立
privateintmBiggerTouchSlopSquare =20*20;
// 判断是否构成onScroll手势,当手指在这个范围内移动时,不触发onScroll手势
privateintmTouchSlopSquare;
// 判断是否构成双击,只有两次点击的距离小于该值,才能构成双击手势
privateintmDoubleTapSlopSquare;
// 最小滑动速度
privateintmMinimumFlingVelocity;
// 最大滑动速度
privateintmMaximumFlingVelocity;
// 长按阀值,当手指按下后,在该阀值的时间内,未移动超过mTouchSlopSquare的距离并未抬起,则长按手势触发
privatestaticfinalintLONGPRESS_TIMEOUT = ViewConfiguration.getLongPressTimeout();
// showPress手势的触发阀值,当手指按下后,在该阀值的时间内,未移动超过mTouchSlopSquare的距离并未抬起,则showPress手势触发
privatestaticfinalintTAP_TIMEOUT = ViewConfiguration.getTapTimeout();
// 双击超时阀值,仅在两次双击事件的间隔(第一次单击的UP事件和第二次单击的DOWN事件)小于此阀值,双击事件才能成立
privatestaticfinalintDOUBLE_TAP_TIMEOUT = ViewConfiguration.getDoubleTapTimeout();
// 双击区域阀值,仅在两次双击事件的距离小于此阀值,双击事件才能成立
privatestaticfinalintDOUBLE_TAP_SLAP =64;
// GestureHandler所处理的Message的what属性可能为以下 常量:
// showPress手势
privatestaticfinalintSHOW_PRESS =1;
// 长按手势
privatestaticfinalintLONG_PRESS =2;
// SingleTapConfirmed手势
privatestaticfinalintTAP_SINGLE =3;
// 双击手势
privatestaticfinalintTAP_DOUBLE =4;
// 手势处理器
privatefinalGestureHandler mHandler;
// 手势监听器
privatefinalMultiTouchGestureListener mListener;
// 双击监听器
privateMultiTouchDoubleTapListener mDoubleTapListener;
// 长按允许阀值
privatebooleanmIsLongpressEnabled;
// 速度追踪器
privateVelocityTracker mVelocityTracker;
privateclassGestureHandlerextendsHandler {
GestureHandler() {
super();
}
GestureHandler(Handler handler) {
super(handler.getLooper());
}
@Override
publicvoidhandleMessage(Message msg) {
intidx = (Integer) msg.obj;
switch(msg.what) {
caseSHOW_PRESS: {
if(idx >= sEventInfos.size()) {
// Log.w(MYTAG, CLASS_NAME + ":handleMessage,
msg.what = SHOW_PRESS, idx=" + idx + ", while sEventInfos.size()="
// + sEventInfos.size());
break;
}
EventInfo info = sEventInfos.get(idx);
if(info ==null) {
// Log.e(MYTAG, CLASS_NAME + ":handleMessage, msg.what = SHOW_PRESS, idx=" + idx + ", Info = null");
break;
}
// 触发手势监听器的onShowPress事件
mListener.onShowPress(info.mCurrentDownEvent);
break;
}
caseLONG_PRESS: {
// Log.d(MYTAG, CLASS_NAME + ":trigger LONG_PRESS");
if(idx >= sEventInfos.size()) {
// Log.w(MYTAG, CLASS_NAME + ":handleMessage,
msg.what = LONG_PRESS, idx=" + idx + ", while sEventInfos.size()="
// + sEventInfos.size());
break;
}
EventInfo info = sEventInfos.get(idx);
if(info ==null) {
// Log.e(MYTAG, CLASS_NAME + ":handleMessage, msg.what = LONG_PRESS, idx=" + idx + ", Info = null");
break;
}
dispatchLongPress(info, idx);
break;
}
caseTAP_SINGLE: {
// Log.d(MYTAG, CLASS_NAME + ":trriger TAP_SINGLE");
// If the user's finger is still down, do not count it as a tap
if(idx >= sEventInfos.size()) {
// Log.e(MYTAG, CLASS_NAME + ":handleMessage,
msg.what = TAP_SINGLE, idx=" + idx + ", while sEventInfos.size()="
// + sEventInfos.size());
break;
}
EventInfo info = sEventInfos.get(idx);
if(info ==null) {
// Log.e(MYTAG, CLASS_NAME + ":handleMessage, msg.what = TAP_SINGLE, idx=" + idx + ", Info = null");
break;
}
if(mDoubleTapListener !=null&& !info.mStillDown) {//手指在双击超时的阀值内未离开屏幕进行第二次单击事件,则确定单击事件成立(不再触发双击事件)
mDoubleTapListener.onSingleTapConfirmed(info.mCurrentDownEvent);
}
break;
}
caseTAP_DOUBLE: {
if(idx >= sEventForDoubleTap.size()) {
// Log.w(MYTAG, CLASS_NAME + ":handleMessage,
msg.what = TAP_DOUBLE, idx=" + idx + ", while
sEventForDoubleTap.size()="
// + sEventForDoubleTap.size());
break;
}
EventInfo info = sEventForDoubleTap.get(idx);
if(info ==null) {
// Log.w(MYTAG, CLASS_NAME + ":handleMessage, msg.what = TAP_DOUBLE, idx=" + idx + ", Info = null");
break;
}
sEventForDoubleTap.set(idx,null);// 这个没什么好做的,就是把队列中对应的元素清除而已
break;
}
default:
thrownewRuntimeException("Unknown message "+ msg);// never
}
}
}
/**
* 触发长按事件
* @param info
* @param idx
*/
privatevoiddispatchLongPress(EventInfo info,intidx) {
mHandler.removeMessages(TAP_SINGLE, idx);//移除单击事件确认
info.mInLongPress =true;
mListener.onLongPress(info.mCurrentDownEvent);
}
/**
* 构造器1
* @param context
* @param listener
*/
publicMultiTouchGestureDetector(Context context, MultiTouchGestureListener listener) {
this(context, listener,null);
}
/**
* 构造器2
* @param context
* @param listener
* @param handler
*/
publicMultiTouchGestureDetector(Context context, MultiTouchGestureListener listener, Handler handler) {
if(handler !=null) {
mHandler =newGestureHandler(handler);
}else{
mHandler =newGestureHandler();
}
mListener = listener;
if(listenerinstanceofMultiTouchDoubleTapListener) {
setOnDoubleTapListener((MultiTouchDoubleTapListener) listener);
}
init(context);
}
/**
* 初始化识别器
* @param context
*/
privatevoidinit(Context context) {
if(mListener ==null) {
thrownewNullPointerException("OnGestureListener must not be null");
}
mIsLongpressEnabled =true;
inttouchSlop, doubleTapSlop;
if(context ==null) {
touchSlop = ViewConfiguration.getTouchSlop();
doubleTapSlop = DOUBLE_TAP_SLAP;
mMinimumFlingVelocity = ViewConfiguration.getMinimumFlingVelocity();
mMaximumFlingVelocity = ViewConfiguration.getMaximumFlingVelocity();
}else{//允许识别器在App中,使用偏好的设定
finalViewConfiguration configuration = ViewConfiguration.get(context);
touchSlop = configuration.getScaledTouchSlop();
doubleTapSlop = configuration.getScaledDoubleTapSlop();
mMinimumFlingVelocity = configuration.getScaledMinimumFlingVelocity();
mMaximumFlingVelocity = configuration.getScaledMaximumFlingVelocity();
}
mTouchSlopSquare = touchSlop * touchSlop /16;
mDoubleTapSlopSquare = doubleTapSlop * doubleTapSlop;
}
/**
* 设置双击监听器
* @param onDoubleTapListener
*/
publicvoidsetOnDoubleTapListener(MultiTouchDoubleTapListener onDoubleTapListener) {
mDoubleTapListener = onDoubleTapListener;
}
/**
* 设置是否允许长按
* @param isLongpressEnabled
*/
publicvoidsetIsLongpressEnabled(booleanisLongpressEnabled) {
mIsLongpressEnabled = isLongpressEnabled;
}
/**
* 判断是否允许长按
* @return
*/
publicbooleanisLongpressEnabled() {
returnmIsLongpressEnabled;
}
/**
* 判断当前事件是否为双击事件
* <br/> 通过遍历sEventForDoubleTap来匹配是否存在能够构成双击事件的单击事件
* @param e
* @return
*/
privateEventInfo checkForDoubleTap(MultiMotionEvent e) {
if(sEventForDoubleTap.isEmpty()) {
// Log.e(MYTAG, CLASS_NAME + ":checkForDoubleTap(), sEventForDoubleTap is empty !");
returnnull;
}
for(inti =0; i < sEventForDoubleTap.size(); i++) {
EventInfo info = sEventForDoubleTap.get(i);
if(info !=null&& isConsideredDoubleTap(info, e)) {
sEventForDoubleTap.set(i,null);// 这个单击事件已经被消耗了,所以置为null
mHandler.removeMessages(TAP_DOUBLE, i);// 移除Handler内的为处理消息
returninfo;
}
}
returnnull;
}
/**
* 判断当前按下事件是否能和指定的单击事件构成双击事件
*
* @param info
* @param secondDown
* @return
*/
privatebooleanisConsideredDoubleTap(EventInfo info, MultiMotionEvent secondDown) {
if(!info.mAlwaysInBiggerTapRegion) {//如多第一次单击事件有过较大距离的移动,则无法构成双击事件
returnfalse;
}
if(secondDown.getEventTime() - info.mPreviousUpEvent.getEventTime() > DOUBLE_TAP_TIMEOUT) {
//如果第一次单击的UP时间和第二次单击的down时间时间间隔大于DOUBLE_TAP_TIMEOUT,也无法构成双击事件
returnfalse;
}
intdeltaX = (int) info.mCurrentDownEvent.getX() - (int) secondDown.getX();
intdeltaY = (int) info.mCurrentDownEvent.getY() - (int) secondDown.getY();
return(deltaX * deltaX + deltaY * deltaY < mDoubleTapSlopSquare);//最后判断两次单击事件的距离
}
/**
* 将事件信息放入双击判断队列,并返回序号
*
* @param info
* @return
*/
privateintaddIntoTheMinIndex(EventInfo info) {
for(inti =0; i < sEventForDoubleTap.size(); i++) {
if(sEventForDoubleTap.get(i) ==null) {
sEventForDoubleTap.set(i, info);
returni;
}
}
sEventForDoubleTap.add(info);
returnsEventForDoubleTap.size() -1;
}
/**
* 从事件信息队列中移除指定序号的事件
*
* @param idx
*/
privatevoidremoveEventFromList(intid) {
if(id > sEventInfos.size() || id <0) {
// Log.e(MYTAG, CLASS_NAME + ".removeEventFromList(), id=" +
id + ", while sEventInfos.size() =" + sEventInfos.size());
return;
}
sEventInfos.set(id,null);
}
/**
* 向事件队列中添加新信息
*
* @param e
*/
privatevoidaddEventIntoList(EventInfo info) {
intid = info.mCurrentDownEvent.getId();
if(id < sEventInfos.size()) {
// if (sEventInfos.get(id) != null)
// Log.e(MYTAG, CLASS_NAME + ".addEventIntoList, info(" + id + ") has not set to null !");
sEventInfos.set(info.mCurrentDownEvent.getId(), info);
}elseif(id == sEventInfos.size()) {
sEventInfos.add(info);
}else{
// Log.e(MYTAG, CLASS_NAME + ".addEventIntoList, invalidata id !");
}
}
publicbooleanonTouchEvent(MotionEvent ev) {
if(mVelocityTracker ==null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);//把所有事件都添加到速度追踪器,为计算速度做准备
booleanhandled =false;
finalintaction = ev.getAction();//获取Action
// int idx = (action & MotionEvent.ACTION_POINTER_INDEX_MASK)
>> MotionEvent.ACTION_POINTER_INDEX_SHIFT;//获取触摸事件的序号
intidx = ev.getPointerId(ev.getActionIndex());//获取触摸事件的id
switch(action & MotionEvent.ACTION_MASK) {
caseMotionEvent.ACTION_DOWN:
caseMotionEvent.ACTION_POINTER_DOWN: {
EventInfo info =newEventInfo(MotionEvent.obtain(ev));
this.addEventIntoList(info);//将手势信息保存到队列中
if(mDoubleTapListener !=null) {//如果双击监听器不为null
if(mHandler.hasMessages(TAP_DOUBLE)) {
MultiMotionEvent e =newMultiMotionEvent(ev);
EventInfo origInfo = checkForDoubleTap(e);//检查是否构成双击事件
if(origInfo !=null) {
info.mIsDoubleTapping =true;
handled |= mDoubleTapListener.onDoubleTap(origInfo.mCurrentDownEvent);
handled |= mDoubleTapListener.onDoubleTapEvent(e);
}
}
if(!info.mIsDoubleTapping) {//当前事件不构成双击事件,那么发送延迟消息以判断onSingleTapConfirmed事件
mHandler.sendMessageDelayed(mHandler.obtainMessage(TAP_SINGLE, idx), DOUBLE_TAP_TIMEOUT);
// Log.d(MYTAG, CLASS_NAME + ": add TAP_SINGLE");
}
}
// 记录X坐标和Y坐标
info.mLastMotionX = info.mCurrentDownEvent.getX();
info.mLastMotionY = info.mCurrentDownEvent.getY();
if(mIsLongpressEnabled) {//允许长按
mHandler.removeMessages(LONG_PRESS, idx);
mHandler.sendMessageAtTime(mHandler.obtainMessage(LONG_PRESS, idx),
info.mCurrentDownEvent.getEventTime() + TAP_TIMEOUT
+ LONGPRESS_TIMEOUT);//延时消息以触发长按手势
// Log.d(MYTAG, CLASS_NAME +
// ":add LONG_PRESS to handler for idx " + idx);
}
mHandler.sendMessageAtTime(mHandler.obtainMessage(SHOW_PRESS, idx),
info.mCurrentDownEvent.getEventTime() + TAP_TIMEOUT);//
延时消息,触发showPress手势
handled |= mListener.onDown(info.mCurrentDownEvent);//触发onDown()
break;
}
caseMotionEvent.ACTION_UP:
caseMotionEvent.ACTION_POINTER_UP: {
MultiMotionEvent currentUpEvent =newMultiMotionEvent(ev);
if(idx >= sEventInfos.size()) {
// Log.e(MYTAG, CLASS_NAME + ":ACTION_POINTER_UP, idx=" +
idx + ", while sEventInfos.size()=" + sEventInfos.size());
break;
}
EventInfo info = sEventInfos.get(currentUpEvent.getId());
if(info ==null) {
// Log.e(MYTAG, CLASS_NAME + ":ACTION_POINTER_UP, idx=" + idx + ", Info = null");
break;
}
info.mStillDown =false;
if(info.mIsDoubleTapping) {//处于双击状态,则触发onDoubleTapEvent事件
handled |= mDoubleTapListener.onDoubleTapEvent(currentUpEvent);
}elseif(info.mInLongPress) {//处于长按状态
mHandler.removeMessages(TAP_SINGLE, idx);//可以无视这行代码
info.mInLongPress =false;
}elseif(info.mAlwaysInTapRegion) {//尚未移动过
if(mHandler.hasMessages(TAP_SINGLE, idx)) {//还在双击的时间阀值内,所以要为双击判断做额外处理
mHandler.removeMessages(TAP_SINGLE, idx);
info.mPreviousUpEvent =newMultiMotionEvent(MotionEvent.obtain(ev));
intindex =this.addIntoTheMinIndex(info);// 把当前事件放入队列,等待双击的判断
mHandler.sendMessageAtTime(mHandler.obtainMessage(TAP_DOUBLE, index), info.mCurrentDownEvent.getEventTime()
+ DOUBLE_TAP_TIMEOUT);// 将双击超时判断添加到Handler
// Log.d(MYTAG, CLASS_NAME + ": add TAP_DOUBLE");
}
handled = mListener.onSingleTapUp(currentUpEvent);//触发onSingleTapUp事件
}else{
// A fling must travel the minimum tap distance
finalVelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumFlingVelocity);//计算1秒钟内的滑动速度
//获取X和Y方向的速度
finalfloatvelocityX = velocityTracker.getXVelocity(idx);
finalfloatvelocityY = velocityTracker.getYVelocity(idx);
// Log.i(MYTAG, CLASS_NAME + ":ACTION_POINTER_UP, idx=" + idx +
// ", vx=" + velocityX + ", vy=" + velocityY);
// 触发滑动事件
if((Math.abs(velocityY) > mMinimumFlingVelocity) || (Math.abs(velocityX) > mMinimumFlingVelocity)) {
handled = mListener.onFling(info.mCurrentDownEvent, currentUpEvent, velocityX, velocityY);
}
}
// Hold the event we obtained above - listeners may have changed the
// original.
if(action == MotionEvent.ACTION_UP) { //释放速度追踪器
mVelocityTracker.recycle();
mVelocityTracker =null;
// Log.w(MYTAG, CLASS_NAME +
// ":ACTION_POINTER_UP, mVelocityTracker.recycle()");
}
info.mIsDoubleTapping =false;
// Log.d(MYTAG, CLASS_NAME + "remove LONG_PRESS");
// 移除showPress和长按消息
mHandler.removeMessages(SHOW_PRESS, idx);
mHandler.removeMessages(LONG_PRESS, idx);
removeEventFromList(currentUpEvent.getId());//手指离开,则从队列中删除手势信息
break;
}
caseMotionEvent.ACTION_MOVE:
for(intrIdx =0; rIdx < ev.getPointerCount(); rIdx++) {//因为无法确定当前发生移动的是哪个手指,所以遍历处理所有手指
MultiMotionEvent e =newMultiMotionEvent(ev, rIdx);
if(e.getId() >= sEventInfos.size()) {
// Log.e(MYTAG, CLASS_NAME + ":ACTION_MOVE, idx=" +
rIdx + ", while sEventInfos.size()=" + sEventInfos.size());
break;
}
EventInfo info = sEventInfos.get(e.getId());
if(info ==null) {
// Log.e(MYTAG, CLASS_NAME + ":ACTION_MOVE, idx=" + rIdx + ", Info = null");
break;
}
if(info.mInLongPress) { //长按,则不处理move事件
break;
}
//当前坐标
floatx = e.getX();
floaty = e.getY();
//距离上次事件移动的位置
finalfloatscrollX = x - info.mLastMotionX;
finalfloatscrollY = y - info.mLastMotionY;
if(info.mIsDoubleTapping) {//双击事件
handled |= mDoubleTapListener.onDoubleTapEvent(e);
}elseif(info.mAlwaysInTapRegion) {//该手势尚未移动过(移动的距离小于mTouchSlopSquare,视为未移动过)
// 计算从落下到当前事件,移动的距离
finalintdeltaX = (int) (x - info.mCurrentDownEvent.getX());
finalintdeltaY = (int) (y - info.mCurrentDownEvent.getY());
// Log.d(MYTAG, CLASS_NAME + "deltaX="+deltaX+";deltaY=" +
// deltaX +"mTouchSlopSquare=" + mTouchSlopSquare);
intdistance = (deltaX * deltaX) + (deltaY * deltaY);
if(distance > mTouchSlopSquare) { // 移动距离超过mTouchSlopSquare
handled = mListener.onScroll(info.mCurrentDownEvent, e, scrollX, scrollY);
info.mLastMotionX = e.getX();
info.mLastMotionY = e.getY();
info.mAlwaysInTapRegion =false;
// Log.d(MYTAG, CLASS_NAME +
// ":remove LONG_PRESS for idx" + rIdx +
// ",mTouchSlopSquare("+mTouchSlopSquare+"), distance("+distance+")");
// 清除onSingleTapConform,showPress,longPress三种消息
intid = e.getId();
mHandler.removeMessages(TAP_SINGLE, id);
mHandler.removeMessages(SHOW_PRESS, id);
mHandler.removeMessages(LONG_PRESS, id);
}
if(distance > mBiggerTouchSlopSquare) {//移动距离大于mBiggerTouchSlopSquare,则无法构成双击事件
info.mAlwaysInBiggerTapRegion =false;
}
}elseif((Math.abs(scrollX) >=1) || (Math.abs(scrollY) >=1)) {//之前已经移动过了
handled = mListener.onScroll(info.mCurrentDownEvent, e, scrollX, scrollY);
info.mLastMotionX = x;
info.mLastMotionY = y;
}
}
break;
caseMotionEvent.ACTION_CANCEL:
cancel();//清理
}
returnhandled;
}
// 清理所有队列
privatevoidcancel() {
mHandler.removeMessages(SHOW_PRESS);
mHandler.removeMessages(LONG_PRESS);
mHandler.removeMessages(TAP_SINGLE);
mVelocityTracker.recycle();
mVelocityTracker =null;
sEventInfos.clear();
sEventForDoubleTap.clear();
}
}