关于android的触摸事件这个知识点，一直感觉掌握不牢固，趁着前几天有空，就仔细了看了一遍源码，顺便写了一下笔记，本来不想发成博客，但考虑到有些可能分析的不对，所以发出来，希望大家多多指出问题，如果对你有少许的帮助，那就太好了。
本篇文章是基于android sdk 25的分析。
github
ACTION_DOWN或ACTION_POINTER_DOWN和ACTION_HOVER_MOVE 这三个事件称为初始事件，因为只有在分发这三个事件时候，才会处理触摸目标。
ACTION_POINTER_DOWN和ACTION_HOVER_MOVE这两个称为多指初始事件。
触摸目标指消费了初始事件的子视图，数据结构为链表。新增加的子视图为存放在头部。
viewFlags & CLICKABLE == CLICKABLE || viewFlags & LONG_CLICKABLE == LONG_CLICKABLE || viewFlags & CONTEXT_CLICKABLE == CONTEXT_CLICKABLE 表示该视图是 "可点击的"。
- Android的Touch事件由Activity->ViewGroup-View按顺序分发(这里只关心到Activity)
- 父视图可以通过
onInterceptTouchEvent来拦截事件分发到子视图 - 子视图可以调用
requestDisallowInterceptTouchEvent来禁止父视图拦截事件，但在ACTION_DOWN时，会清除该标记，即只在ACTION_DOWN时，调用该方法没有效果。 - 如果子视图没有调用
requestDisallowInterceptTouchEvent，那么父视图任何时候都可以拦截事件，即使子视图已经消费了ACTION_DOWN，拦截事件后，会向子视图分发一个ACTION_CANCEL事件 - 父视图分发事件时，只会在初始事件时候，来设置触摸目标。即如果子视图没消费这三个事件，也不会接收到后续的事件。
- 当分发多指初始事件时，没有新的子视图来消费该事件时，会将该事件的指针赋予触摸目标的尾部。
- 当没有子视图来消费事件时，会将事件分发给父视图。(super.dispatchTouchEvent)
- View的事件分发，OnTouchListener.onTouch -> onTouchEvent -> TouchDelegate.onTouchEvent -> onClick/onLongClick等等
- 只要视图是可点击的就默认会消费事件，即使该视图是不启用的(setEnabled(false))，只是不做点击处理反应。
Activity中
public boolean dispatchTouchEvent(MotionEvent ev) {
if (ev.getAction() == MotionEvent.ACTION_DOWN) {
//用户交互回调
onUserInteraction();
}
if (getWindow().superDispatchTouchEvent(ev)) {
//window是否消费该事件,touch事件分发从这里开始
return true;
}
//当前view没有消费事件，则由activity处理
return onTouchEvent(ev);
}
//当前没有任何view去消费事件时
public boolean onTouchEvent(MotionEvent event) {
//window是否消费该事件，来关闭当前window
if (mWindow.shouldCloseOnTouch(this, event)) {
finish();
return true;
}
return false;
}
PhoneWindow中
@Override
public boolean superDispatchTouchEvent(MotionEvent event) {
//window将事件委托给DecorView分发
return mDecor.superDispatchTouchEvent(event);
}
DecorView中
public boolean superDispatchTouchEvent(MotionEvent event) {
//调用父类的dispatchTouchEvent进行分发
return super.dispatchTouchEvent(event);
}
ViewGroup中
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
//输入事件一致性验证者
if (mInputEventConsistencyVerifier != null) {
mInputEventConsistencyVerifier.onTouchEvent(ev, 1);
}
// If the event targets the accessibility focused view and this is it, start
// normal event dispatch. Maybe a descendant is what will handle the click.
//辅助功能处理
if (ev.isTargetAccessibilityFocus() && isAccessibilityFocusedViewOrHost()) {
ev.setTargetAccessibilityFocus(false);
}
//从这里开始事件分发
boolean handled = false;
//安全策略过滤
if (onFilterTouchEventForSecurity(ev)) {
final int action = ev.getAction();
//多指处理
//多指情况下，POINTER:指针。(可以理解为单个手指)
final int actionMasked = action & MotionEvent.ACTION_MASK;
// Handle an initial down.
//处理一个初始按下事件ACTION_DOWN
if (actionMasked == MotionEvent.ACTION_DOWN) {
//丢弃之前的状态
// Throw away all previous state when starting a new touch gesture.
// The framework may have dropped the up or cancel event for the previous gesture
// due to an app switch, ANR, or some other state change.
//取消，清除所有的触摸目标
cancelAndClearTouchTargets(ev);
//重置触摸状态，这里会将使用requestDisallowInterceptTouchEvent设置的状态清除
//这个状态可以阻止父视图(通过onInterceptTouchEvent)拦截子视图Touch事件
resetTouchState();
}
// Check for interception.
//检查是否拦截
final boolean intercepted;
//当为ACTION_DEON事件或触摸目标为不为null
//即使已经有子视图消费了事件，依然会执行判断
if (actionMasked == MotionEvent.ACTION_DOWN
|| mFirstTouchTarget != null) {
//检查子视图是否调用了requestDisallowInterceptTouchEvent来禁止父视图拦截
//这个标记为ACTION_DOWN处理中被清除，即子视图在ACTION_DOWN中调用是不起作用
final boolean disallowIntercept = (mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0;
if (!disallowIntercept) {
//检查当前父视图是否拦截该事件
intercepted = onInterceptTouchEvent(ev);
//恢复action，以防止在onInterceptTouchEvent被改变
ev.setAction(action); // restore action in case it was changed
} else {
intercepted = false;
}
} else {
// There are no touch targets and this action is not an initial down
// so this view group continues to intercept touches.
//当前不是ACTION_DOWN事件，且没有触摸目标
//即子视图如果不消费ACTION_DOWN，那么后续事件也不会分发到。
intercepted = true;
}
// If intercepted, start normal event dispatch. Also if there is already
// a view that is handling the gesture, do normal event dispatch.
//辅助功能
if (intercepted || mFirstTouchTarget != null) {
ev.setTargetAccessibilityFocus(false);
}
// Check for cancelation.
//检查是否为ACTION_CANCEL事件
final boolean canceled = resetCancelNextUpFlag(this)
|| actionMasked == MotionEvent.ACTION_CANCEL;
// Update list of touch targets for pointer down, if needed.
//检查是否把事件分发给多个子视图
//通过setMotionEventSplittingEnabled设置，Android3.0以上默认开启
final boolean split = (mGroupFlags & FLAG_SPLIT_MOTION_EVENTS) != 0;
TouchTarget newTouchTarget = null;
boolean alreadyDispatchedToNewTouchTarget = false;
//当事件不取消而且不拦截
if (!canceled && !intercepted) {
// If the event is targeting accessiiblity focus we give it to the
// view that has accessibility focus and if it does not handle it
// we clear the flag and dispatch the event to all children as usual.
// We are looking up the accessibility focused host to avoid keeping
// state since these events are very rare.
//辅助功能
View childWithAccessibilityFocus = ev.isTargetAccessibilityFocus()
? findChildWithAccessibilityFocus() : null;
//1.当ACTION_DOWN事件(第一次按下)
//2.或事件可以分发给多个子视图且ACTION+POINTER_DOWN(多指处理，当主指针还没结束，又按下一个指针)
//3.或多指情况下，指针移动
//这里的判断表示，只有在ACTION_DOWN或者当前事件分发还没结束，出现新的指针事件才会进行分发。但这里的前提依然是，事件未取消和父视图不拦截，和至少接收了ACTION_DOWN事件(即触摸目标链表不为空，ACTION_DOWN事件除外)
if (actionMasked == MotionEvent.ACTION_DOWN
|| (split && actionMasked == MotionEvent.ACTION_POINTER_DOWN)
|| actionMasked == MotionEvent.ACTION_HOVER_MOVE) {
//获取事件的指针索引
final int actionIndex = ev.getActionIndex(); // always 0 for down
//指针id的位掩码(用于获取触摸目标捕获的指针)
//TouchTarget.pointerIdBis 指针id的组合位掩码，用于目标捕获的所有指针
final int idBitsToAssign = split ? 1 << ev.getPointerId(actionIndex)
: TouchTarget.ALL_POINTER_IDS;
// Clean up earlier touch targets for this pointer id in case they
// have become out of sync.
//清除这个指针作用的早先的触摸目标
removePointersFromTouchTargets(idBitsToAssign);
final int childrenCount = mChildrenCount;
//扫描可以接收事件的子视图
if (newTouchTarget == null && childrenCount != 0) {
final float x = ev.getX(actionIndex);
final float y = ev.getY(actionIndex);
// Find a child that can receive the event.
// Scan children from front to back.
//获取子视图的事件分发列表
//这里考虑了自定义的子视图绘制顺序
final ArrayList preorderedList = buildTouchDispatchChildList();
//TODO:按buildTouchDispatchChildList()的返回 != null，即customOrder永远为false，即自定义了绘制顺序也不会改变事件分发顺序
final boolean customOrder = preorderedList == null
&& isChildrenDrawingOrderEnabled();
final View[] children = mChildren;
for (int i = childrenCount - 1; i >= 0; i--) {
final int childIndex = getAndVerifyPreorderedIndex(
childrenCount, i, customOrder);
final View child = getAndVerifyPreorderedView(
preorderedList, children, childIndex);
// If there is a view that has accessibility focus we want it
// to get the event first and if not handled we will perform a
// normal dispatch. We may do a double iteration but this is
// safer given the timeframe.
//辅助功能
if (childWithAccessibilityFocus != null) {
if (childWithAccessibilityFocus != child) {
continue;
}
childWithAccessibilityFocus = null;
i = childrenCount - 1;
}
//检查子视图是否可以接受事件和触摸事件是否作用在子视图上
if (!canViewReceivePointerEvents(child)
|| !isTransformedTouchPointInView(x, y, child, null)) {
ev.setTargetAccessibilityFocus(false);
continue;
}
//检查当前子视图是否已经存在触摸目标链表中
newTouchTarget = getTouchTarget(child);
if (newTouchTarget != null) {
// Child is already receiving touch within its bounds.
// Give it the new pointer in addition to the ones it is handling.
//如果已经存在，则将新指针id赋值给它，并退出循环
newTouchTarget.pointerIdBits |= idBitsToAssign;
break;
}
//检查是否设置了取消标记
//TODO:但这里没对结果进行处理
resetCancelNextUpFlag(child);
//在这里将事件交予子视图进行分发
//一般能执行到这里的:
//1.ACTION_DOWN
//2.多指情况下，指针作用于"新"视图上
if (dispatchTransformedTouchEvent(ev, false, child, idBitsToAssign)) {
//如果子视图消费了事件
// Child wants to receive touch within its bounds.
//保存一些值
mLastTouchDownTime = ev.getDownTime();
if (preorderedList != null) {
// childIndex points into presorted list, find original index
for (int j = 0; j < childrenCount; j++) {
if (children[childIndex] == mChildren[j]) {
mLastTouchDownIndex = j;
break;
}
}
} else {
mLastTouchDownIndex = childIndex;
}
mLastTouchDownX = ev.getX();
mLastTouchDownY = ev.getY();
//设置接收事件的子视图为新的触摸目标，并设置为触摸目标链表的头
newTouchTarget = addTouchTarget(child, idBitsToAssign);
alreadyDispatchedToNewTouchTarget = true;
break;
}
// The accessibility focus didn't handle the event, so clear
// the flag and do a normal dispatch to all children.
ev.setTargetAccessibilityFocus(false);
}
if (preorderedList != null) preorderedList.clear();
}
if (newTouchTarget == null && mFirstTouchTarget != null) {
// Did not find a child to receive the event.
// Assign the pointer to the least recently added target.
//当触摸目标链表不为空，且当前事件没有产生新的触摸目标(包含已有的触摸目标)来接收
newTouchTarget = mFirstTouchTarget;
while (newTouchTarget.next != null) {
newTouchTarget = newTouchTarget.next;
}
//找到触摸目标链表的尾部，将指针作用于它
newTouchTarget.pointerIdBits |= idBitsToAssign;
}
}
}
// Dispatch to touch targets.
//除了ACTION_DOWN，ACTION_POINTER_DOWN,ACTION_HOVER_MOVE
//其他的事件的分发都从这里
if (mFirstTouchTarget == null) {
// No touch targets so treat this as an ordinary view.
//没有子视图接收事件，将事件分发给当前视图
handled = dispatchTransformedTouchEvent(ev, canceled, null,
TouchTarget.ALL_POINTER_IDS);
} else {
// Dispatch to touch targets, excluding the new touch target if we already
// dispatched to it. Cancel touch targets if necessary.
//将事件分发给触摸目标，除了新的触摸目标，因为在之前已经分发了
TouchTarget predecessor = null;
TouchTarget target = mFirstTouchTarget;
while (target != null) {
final TouchTarget next = target.next;
if (alreadyDispatchedToNewTouchTarget && target == newTouchTarget) {
//新的触摸目标，直接跳过
handled = true;
} else {
//检查事件是否被取消或者被拦截
//即使子视图在ACTION_DOWN中接收了事件，如果没禁止拦截，父视图依然可以拦截事件
final boolean cancelChild = resetCancelNextUpFlag(target.child)
|| intercepted;
//分发到触摸目标
//当cancelChild=true,会分发ACTION_CANCEL事件
//dispatchTransformedTouchEvent中会判断当前触摸目标是否包含指针id
if (dispatchTransformedTouchEvent(ev, cancelChild,
target.child, target.pointerIdBits)) {
handled = true;
}
//当事件被取消，清除触摸目标链表
if (cancelChild) {
if (predecessor == null) {
mFirstTouchTarget = next;
} else {
predecessor.next = next;
}
target.recycle();
target = next;
continue;
}
}
predecessor = target;
target = next;
}
}
// Update list of touch targets for pointer up or cancel, if needed.
if (canceled
|| actionMasked == MotionEvent.ACTION_UP
|| actionMasked == MotionEvent.ACTION_HOVER_MOVE) {
resetTouchState();
} else if (split && actionMasked == MotionEvent.ACTION_POINTER_UP) {
final int actionIndex = ev.getActionIndex();
final int idBitsToRemove = 1 << ev.getPointerId(actionIndex);
removePointersFromTouchTargets(idBitsToRemove);
}
}
if (!handled && mInputEventConsistencyVerifier != null) {
mInputEventConsistencyVerifier.onUnhandledEvent(ev, 1);
}
return handled;
}
//取消和清除所有触摸目标
private void cancelAndClearTouchTargets(MotionEvent event) {
if (mFirstTouchTarget != null) {
boolean syntheticEvent = false;
if (event == null) {
final long now = SystemClock.uptimeMillis();
//获取一个ACTION_CANCEL事件
event = MotionEvent.obtain(now, now,
MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0);
event.setSource(InputDevice.SOURCE_TOUCHSCREEN);
syntheticEvent = true;
}
for (TouchTarget target = mFirstTouchTarget; target != null; target = target.next) {
resetCancelNextUpFlag(target.child);
//分发ACTION_CANCEL事件
dispatchTransformedTouchEvent(event, true, target.child, target.pointerIdBits);
}
clearTouchTargets();
if (syntheticEvent) {
event.recycle();
}
}
}
//清除所有触摸目标
private void clearTouchTargets() {
TouchTarget target = mFirstTouchTarget;
if (target != null) {
do {
TouchTarget next = target.next;
target.recycle();
target = next;
} while (target != null);
mFirstTouchTarget = null;
}
}
//将事件分发到相应的目标
private boolean dispatchTransformedTouchEvent(MotionEvent event, boolean cancel,
View child, int desiredPointerIdBits) {
final boolean handled;
// Canceling motions is a special case. We don't need to perform any transformations
// or filtering. The important part is the action, not the contents.
//当事件取消时，会根据是否有触摸目标，向当前视图或子视图分发一个ACTION_CANCEL事件
final int oldAction = event.getAction();
if (cancel || oldAction == MotionEvent.ACTION_CANCEL) {
event.setAction(MotionEvent.ACTION_CANCEL);
if (child == null) {
handled = super.dispatchTouchEvent(event);
} else {
handled = child.dispatchTouchEvent(event);
}
event.setAction(oldAction);
return handled;
}
// Calculate the number of pointers to deliver.
//计算要传递的指针
final int oldPointerIdBits = event.getPointerIdBits();
final int newPointerIdBits = oldPointerIdBits & desiredPointerIdBits;
// If for some reason we ended up in an inconsistent state where it looks like we
// might produce a motion event with no pointers in it, then drop the event.
//该触摸目标不包含该指针,不分发
if (newPointerIdBits == 0) {
return false;
}
// If the number of pointers is the same and we don't need to perform any fancy
// irreversible transformations, then we can reuse the motion event for this
// dispatch as long as we are careful to revert any changes we make.
// Otherwise we need to make a copy.
//将事件进行分发，根据是否有触摸目标
final MotionEvent transformedEvent;
if (newPointerIdBits == oldPointerIdBits) {
if (child == null || child.hasIdentityMatrix()) {
if (child == null) {
handled = super.dispatchTouchEvent(event);
} else {
final float offsetX = mScrollX - child.mLeft;
final float offsetY = mScrollY - child.mTop;
event.offsetLocation(offsetX, offsetY);
handled = child.dispatchTouchEvent(event);
event.offsetLocation(-offsetX, -offsetY);
}
return handled;
}
transformedEvent = MotionEvent.obtain(event);
} else {
transformedEvent = event.split(newPointerIdBits);
}
// Perform any necessary transformations and dispatch.
if (child == null) {
handled = super.dispatchTouchEvent(transformedEvent);
} else {
final float offsetX = mScrollX - child.mLeft;
final float offsetY = mScrollY - child.mTop;
transformedEvent.offsetLocation(offsetX, offsetY);
if (! child.hasIdentityMatrix()) {
transformedEvent.transform(child.getInverseMatrix());
}
handled = child.dispatchTouchEvent(transformedEvent);
}
// Done.
transformedEvent.recycle();
return handled;
}
View中
public boolean dispatchTouchEvent(MotionEvent event) {
//辅助功能
// If the event should be handled by accessibility focus first.
if (event.isTargetAccessibilityFocus()) {
// We don't have focus or no virtual descendant has it, do not handle the event.
if (!isAccessibilityFocusedViewOrHost()) {
return false;
}
// We have focus and got the event, then use normal event dispatch.
event.setTargetAccessibilityFocus(false);
}
boolean result = false;
//调试作用
if (mInputEventConsistencyVerifier != null) {
mInputEventConsistencyVerifier.onTouchEvent(event, 0);
}
final int actionMasked = event.getActionMasked();
if (actionMasked == MotionEvent.ACTION_DOWN) {
// Defensive cleanup for new gesture
//停止嵌套滚动
stopNestedScroll();
}
if (onFilterTouchEventForSecurity(event)) {
//安全策略过滤
//处理拖动滚动条
if ((mViewFlags & ENABLED_MASK) == ENABLED && handleScrollBarDragging(event)) {
result = true;
}
//noinspection SimplifiableIfStatement
//先调用OnTouchListener回调
ListenerInfo li = mListenerInfo;
if (li != null && li.mOnTouchListener != null
&& (mViewFlags & ENABLED_MASK) == ENABLED
&& li.mOnTouchListener.onTouch(this, event)) {
result = true;
}
//如果没有OnTouchListener或者没有消费，则调用onTouchEvent
if (!result && onTouchEvent(event)) {
result = true;
}
}
//调试
if (!result && mInputEventConsistencyVerifier != null) {
mInputEventConsistencyVerifier.onUnhandledEvent(event, 0);
}
// Clean up after nested scrolls if this is the end of a gesture;
// also cancel it if we tried an ACTION_DOWN but we didn't want the rest
// of the gesture.
//当ACTION_UP，ACTION_CANCEL或ACTION_DOWN且不消费，停止嵌套滚动
if (actionMasked == MotionEvent.ACTION_UP ||
actionMasked == MotionEvent.ACTION_CANCEL ||
(actionMasked == MotionEvent.ACTION_DOWN && !result)) {
stopNestedScroll();
}
return result;
}
public boolean onTouchEvent(MotionEvent event) {
final float x = event.getX();
final float y = event.getY();
final int viewFlags = mViewFlags;
final int action = event.getAction();
if ((viewFlags & ENABLED_MASK) == DISABLED) {
//当该视图不启用时(setEnabled(false))
if (action == MotionEvent.ACTION_UP && (mPrivateFlags & PFLAG_PRESSED) != 0) {
setPressed(false);
}
// A disabled view that is clickable still consumes the touch
// events, it just doesn't respond to them.
//不启用的视图依然可以消费事件，只是没有反应而已。
//只要该视图是 "可点击的"
return (((viewFlags & CLICKABLE) == CLICKABLE
|| (viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)
|| (viewFlags & CONTEXT_CLICKABLE) == CONTEXT_CLICKABLE);
}
//调用TouchDelegate
if (mTouchDelegate != null) {
if (mTouchDelegate.onTouchEvent(event)) {
return true;
}
}
if (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE) ||
(viewFlags & CONTEXT_CLICKABLE) == CONTEXT_CLICKABLE) {
//该视图是 "可点击的"
switch (action) {
case MotionEvent.ACTION_UP:
boolean prepressed = (mPrivateFlags & PFLAG_PREPRESSED) != 0;
if ((mPrivateFlags & PFLAG_PRESSED) != 0 || prepressed) {
//当我们设置 "按下" 状态或 "延时按下" 状态
// take focus if we don't have it already and we should in
// touch mode.
//获取焦点
boolean focusTaken = false;
if (isFocusable() && isFocusableInTouchMode() && !isFocused()) {
focusTaken = requestFocus();
}
if (prepressed) {
// The button is being released before we actually
// showed it as pressed. Make it show the pressed
// state now (before scheduling the click) to ensure
// the user sees it.
//如果设置了 "延时按下" 状态，那在实际释放之前设置为 "按下" 状态
setPressed(true, x, y);
}
if (!mHasPerformedLongPress && !mIgnoreNextUpEvent) {
//如果没有调用长按动作而且不忽略下一个抬起的事件，清除长按回调，不回调长按事件
// This is a tap, so remove the longpress check
removeLongPressCallback();
// Only perform take click actions if we were in the pressed state
if (!focusTaken) {
//获取不了焦点，表示正在按下状态，才处理点击事件
// Use a Runnable and post this rather than calling
// performClick directly. This lets other visual state
// of the view update before click actions start.
if (mPerformClick == null) {
mPerformClick = new PerformClick();
}
if (!post(mPerformClick)) {
performClick();
}
}
}
if (mUnsetPressedState == null) {
mUnsetPressedState = new UnsetPressedState();
}
//清除 "按下" 状态
if (prepressed) {
postDelayed(mUnsetPressedState,
ViewConfiguration.getPressedStateDuration());
} else if (!post(mUnsetPressedState)) {
// If the post failed, unpress right now
mUnsetPressedState.run();
}
//取消点击检测计时器。即 "延时按下" 状态
removeTapCallback();
}
mIgnoreNextUpEvent = false;
break;
case MotionEvent.ACTION_DOWN:
mHasPerformedLongPress = false;
//执行按钮的相关操作
//比如菜单栏点击
if (performButtonActionOnTouchDown(event)) {
break;
}
// Walk up the hierarchy to determine if we're inside a scrolling container.
//检查当前是否位于滚动容器中
boolean isInScrollingContainer = isInScrollingContainer();
// For views inside a scrolling container, delay the pressed feedback for
// a short period in case this is a scroll.
//当父视图处于滚动中，则延时处理 "按下" 状态
if (isInScrollingContainer) {
mPrivateFlags |= PFLAG_PREPRESSED;
if (mPendingCheckForTap == null) {
mPendingCheckForTap = new CheckForTap();
}
mPendingCheckForTap.x = event.getX();
mPendingCheckForTap.y = event.getY();
postDelayed(mPendingCheckForTap, ViewConfiguration.getTapTimeout());
} else {
// Not inside a scrolling container, so show the feedback right away
setPressed(true, x, y);
checkForLongClick(0, x, y);
}
break;
case MotionEvent.ACTION_CANCEL:
//当事件取消时候，清理
setPressed(false);
removeTapCallback();
removeLongPressCallback();
mInContextButtonPress = false;
mHasPerformedLongPress = false;
mIgnoreNextUpEvent = false;
break;
case MotionEvent.ACTION_MOVE:
drawableHotspotChanged(x, y);
// Be lenient about moving outside of buttons
//当手指移动时候，不再处于当前视图范围，取消事件
if (!pointInView(x, y, mTouchSlop)) {
// Outside button
removeTapCallback();
if ((mPrivateFlags & PFLAG_PRESSED) != 0) {
// Remove any future long press/tap checks
removeLongPressCallback();
setPressed(false);
}
}
break;
}
//不管有没有处理，只要该视图具有 "可点击" ，就会默认消费掉该事件
//即使该视图不启用，依然会消费事件，只是不执行 "点击" 事件。
return true;
}
return false;
}