重写OnTouchEvent() 然后在方法内部写触摸算法
返回true,表示消费事件,所有触摸反馈不再生效,返回事件所有权
if (event.actionMasked == MotionEvent.ACTION_UP){
performClick()//抬起事件 执行performClick 触发点击
}
override fun onTouchEvent(event: MotionEvent): Boolean {
//event 触摸事件
}
//所有的触摸事件都是一个序列,如Down-Up,Down-Up-Cancel,Down-Move
//实例1
View TouchEvnet ->ViewGroup TouchEvent
//实例2
View1 TouchEvnet ->View2 TouchEvnet ->ViewGroup TouchEvent
event.action 和ActionMarked区别
ActionMarked属性:
ACTION_MASK
ACTION_DOWN
ACTION_UP
ACTION_MOVE
ACTION_CANCEL
ACTION_OUTSIDE
ACTION_POINTER_DOWN
ACTION_POINTER_UP
ACTION_HOVER_MOVE
ACTION_SCROLL
ACTION_HOVER_ENTER
ACTION_HOVER_EXIT
ACTION_BUTTON_PRESS
ACTION_BUTTON_RELEASE
ACTION_POINTER_INDEX_MASK
ACTION_POINTER_INDEX_SHIFT
....
ActionMarked相比Action,适用于多点触控 //ACTION_POINTER_UP 非第一根手指抬起
新版会根据事件和Pointer
event.Action会拿到多个事件 如down 可能会action-down - action-pointer-down,会融合多个事件
onTouchEvent
public boolean onTouchEvent(MotionEvent event) {
final float x = event.getX(); //x坐标
final float y = event.getY(); //y坐标
final int viewFlags = mViewFlags;
final int action = event.getAction(); //Action
final boolean clickable = ((viewFlags & CLICKABLE) == CLICKABLE
|| (viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)
|| (viewFlags & CONTEXT_CLICKABLE) == CONTEXT_CLICKABLE;
//符合点击 长按 上下文 都属于点击事件
if ((viewFlags & ENABLED_MASK) == DISABLED) {
if (action == MotionEvent.ACTION_UP && (mPrivateFlags & PFLAG_PRESSED) != 0) {
setPressed(false); //抬起 标记未点击
}
mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;
// A disabled view that is clickable still consumes the touch
// events, it just doesn't respond to them.
return clickable; //如果可点击但禁用 返回clickable 标记消费
}
if (mTouchDelegate != null) {
if (mTouchDelegate.onTouchEvent(event)) {
return true;
//mTouchDelegate 增加点击区域
}
}
if (clickable || (viewFlags & TOOLTIP) == TOOLTIP) {
//TOOLTIP API26以上新特性 解释工具 辅助工具
//可点击或者有辅助工具解释描述
switch (action) {
case MotionEvent.ACTION_UP:
mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;
if ((viewFlags & TOOLTIP) == TOOLTIP) {
//辅助提示 松开手指消失 1500ms
handleTooltipUp();
}
if (!clickable) {
//不可点击 取消所有事件
removeTapCallback();
removeLongPressCallback();
mInContextButtonPress = false;
mHasPerformedLongPress = false;
mIgnoreNextUpEvent = false;
break;
}
boolean prepressed = (mPrivateFlags & PFLAG_PREPRESSED) != 0;
//按下或者预准备按下
if ((mPrivateFlags & PFLAG_PRESSED) != 0 || prepressed) {
boolean focusTaken = false;
//如果可以获取焦点并且触摸模式可以获取焦点
if (isFocusable() && isFocusableInTouchMode() && !isFocused()) {
focusTaken = requestFocus();
}
//预准备按下
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.
setPressed(true, x, y); //按下状态为true
}
if (!mHasPerformedLongPress && !mIgnoreNextUpEvent) {
// This is a tap, so remove the longpress check
removeLongPressCallback(); //移除长按操作
// Only perform take click actions if we were in the pressed state
if (!focusTaken) {
//不是预准备按下
// 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)) {
//抬起 触发点击
performClickInternal();
}
}
}
if (mUnsetPressedState == null) {
mUnsetPressedState = new UnsetPressedState();
}
//延迟操作置空 64ms 自动抬起
if (prepressed) {
postDelayed(mUnsetPressedState,
ViewConfiguration.getPressedStateDuration());
} else if (!post(mUnsetPressedState)) {
// If the post failed, unpress right now
mUnsetPressedState.run();
}
removeTapCallback();
}
mIgnoreNextUpEvent = false;
break;
case MotionEvent.ACTION_DOWN:
if (event.getSource() == InputDevice.SOURCE_TOUCHSCREEN) {
mPrivateFlags3 |= PFLAG3_FINGER_DOWN;
//是否触摸到View
}
mHasPerformedLongPress = false;
if (!clickable) {
//不可点击则检查长按 会有延迟执行
checkForLongClick(
ViewConfiguration.getLongPressTimeout(), x, y,
TOUCH_GESTURE_CLASSIFIED__CLASSIFICATION__LONG_PRESS);
break;
}
if (performButtonActionOnTouchDown(event)) {
//鼠标右键点击 显示上下文菜单
break;
}
/*
如果在滑动控件 不停递归 返回状态
public boolean isInScrollingContainer() {
ViewParent p = getParent();
while (p != null && p instanceof ViewGroup) {
if (((ViewGroup) p).shouldDelayChildPressedState()) {
//shouldDelayChildPressedState 是否延迟子View延迟状态
return true;
}
p = p.getParent();
}
return false;
}
*/
boolean isInScrollingContainer = isInScrollingContainer();
//预按下 是否滑动或者按下 进行延迟判断
if (isInScrollingContainer) {
mPrivateFlags |= PFLAG_PREPRESSED;
if (mPendingCheckForTap == null) {
mPendingCheckForTap = new CheckForTap();
/*
private final class CheckForTap implements Runnable {
public float x;
public float y;
@Override
public void run() {
mPrivateFlags &= ~PFLAG_PREPRESSED; //置空预点击
setPressed(true, x, y);
final long delay = //检查长按
ViewConfiguration.getLongPressTimeout() - ViewConfiguration.getTapTimeout();
checkForLongClick(delay, x, y, TOUCH_GESTURE_CLASSIFIED__CLASSIFICATION__LONG_PRESS);
}
}
*/
}
mPendingCheckForTap.x = event.getX();
mPendingCheckForTap.y = event.getY();
postDelayed(mPendingCheckForTap, ViewConfiguration.getTapTimeout() ); //100ms
} else {
// Not inside a scrolling container, so show the feedback right away
setPressed(true, x, y); //不在滑动控件 设为按下状态
checkForLongClick( //检查是否要长按,设置等待器
ViewConfiguration.getLongPressTimeout(), //500ms
x,
y,
TOUCH_GESTURE_CLASSIFIED__CLASSIFICATION__LONG_PRESS);
//预按下 需要等待 getLongPressTimeout 500 - getTapTimeout 100ms
}
break;
case MotionEvent.ACTION_CANCEL:
//移除所有事件
if (clickable) {
setPressed(false);
}
removeTapCallback();
removeLongPressCallback();
mInContextButtonPress = false;
mHasPerformedLongPress = false;
mIgnoreNextUpEvent = false;
mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;
break;
case MotionEvent.ACTION_MOVE:
if (clickable) {
//可点击 5.0后波纹效果
drawableHotspotChanged(x, y);
}
final int motionClassification = event.getClassification();
final boolean ambiguousGesture =
//未规定手势 增加长按事件
motionClassification == MotionEvent.CLASSIFICATION_AMBIGUOUS_GESTURE;
int touchSlop = mTouchSlop;
if (ambiguousGesture && hasPendingLongPressCallback()) {
final float ambiguousMultiplier =
ViewConfiguration.getAmbiguousGestureMultiplier();
if (!pointInView(x, y, touchSlop)) {
//如果手指出界限 ,touchSlop 触摸边界 增加延长长按
// The default action here is to cancel long press. But instead, we
// just extend the timeout here, in case the classification
// stays ambiguous.
removeLongPressCallback();
// 长按事件的两倍ms
long delay = (long) (ViewConfiguration.getLongPressTimeout()
* ambiguousMultiplier);
// Subtract the time already spent
delay -= event.getEventTime() - event.getDownTime();
//检查长按
checkForLongClick(
delay,
x,
y,
TOUCH_GESTURE_CLASSIFIED__CLASSIFICATION__LONG_PRESS);
}
touchSlop *= ambiguousMultiplier;
}
// Be lenient about moving outside of buttons
if (!pointInView(x, y, touchSlop)) {
//取消事件
removeTapCallback();
removeLongPressCallback();
if ((mPrivateFlags & PFLAG_PRESSED) != 0) {
setPressed(false);
}
mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;
}
//Android 10 用力点击 触发长按
final boolean deepPress =
motionClassification == MotionEvent.CLASSIFICATION_DEEP_PRESS;
if (deepPress && hasPendingLongPressCallback()) {
// process the long click action immediately
removeLongPressCallback();
checkForLongClick(
0 /* send immediately */,
x,
y,
TOUCH_GESTURE_CLASSIFIED__CLASSIFICATION__DEEP_PRESS);
}
break;
}
}如果不是滑动Layout 可以重写sholdDelayChildPressedState false 关闭延迟点击事件
ViewGroup:
onIntercerceptTouchEvent
onTouchEvent
onIntercerceptTouchEvent 判断是否拦截
1.
ViewGroup onIntercerceptTouchEvent false ->View -> onTouchEvent false ->... ->ViewGroup ->onTouchEvent
2.
ViewGroup onIntercerceptTouchEvent false -> ViewGroup onIntercerceptTouchEvent false -> View -> onTouchEvent false ->... ->ViewGroup ->onTouchEvent ->ViewGroup ->onTouchEvent
3.
ViewGroup onIntercerceptTouchEven true -> ViewGroup -> onTouchEvent true
ViewGroup onInterceptTouchEvent 建议先返回false 放行,然后记录 事件/数据做准备
disparchTouchEvent 管理ViewGroup的onIntercerceptTouchEvent / onTouchEvent
disparchTouchEvent 管理有View的 onTouchEvent
子View dispatchTouchEvent 返回true 消费事件不再传递
ViewGroup dispatchTouchEvent调用super.dispatchTouchEvent
View dispatchTouchEvnet:
if (onFilterTouchEventForSecurity(event)) {
if ((mViewFlags & ENABLED_MASK) == ENABLED && handleScrollBarDragging(event)) {
result = true;
}
//noinspection SimplifiableIfStatement
ListenerInfo li = mListenerInfo;
//mOnTouchListener touch事件监听 有则不调用onTouchEvnet
if (li != null && li.mOnTouchListener != null
&& (mViewFlags & ENABLED_MASK) == ENABLED
&& li.mOnTouchListener.onTouch(this, event)) {
result = true;
}
if (!result && onTouchEvent(event)) {
result = true;
}
return TouchEvent
}ViewGroup.dispatchTouchEvent -> 核心
if(intercptTouchEvent)
{onTouchEvent}
else{子View.dispatchTouchEvent}
@Override
public boolean dispatchTouchEvent(MotionEvent ev){
if (mInputEventConsistencyVerifier != null) {
mInputEventConsistencyVerifier.onTouchEvent(ev, 1);
}
//障碍相关
// 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.
if (ev.isTargetAccessibilityFocus() && isAccessibilityFocusedViewOrHost()) {
ev.setTargetAccessibilityFocus(false);
}
boolean handled = false;
if (onFilterTouchEventForSecurity(ev)) {
final int action = ev.getAction();
final int actionMasked = action & MotionEvent.ACTION_MASK;
// Handle an initial down.
if (actionMasked == MotionEvent.ACTION_DOWN) {
// 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.
cancelAndClearTouchTargets(ev); //清空状态,确保view没有按下, 是全新的一个序列 down
resetTouchState();//拦截子View
}
// Check for interception.
final boolean intercepted;
if (actionMasked == MotionEvent.ACTION_DOWN // 按下事件判断子View的是否拦截
|| mFirstTouchTarget != null) {
//mFirstTouchTarget 有子View被按下
final boolean disallowIntercept = (mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0;
if (!disallowIntercept) {
intercepted = onInterceptTouchEvent(ev);
ev.setAction(action); // restore action in case it was changed
} else {
//不拦截
intercepted = false;
}
} else {
// There are no touch targets and this action is not an initial down
// so this view group continues to intercept touches.
//拦截
intercepted = true;
}
// If intercepted, start normal event dispatch. Also if there is already
// a view that is handling the gesture, do normal event dispatch.
if (intercepted || mFirstTouchTarget != null) {
ev.setTargetAccessibilityFocus(false);
}
// Check for cancelation.
final boolean canceled = resetCancelNextUpFlag(this)
|| actionMasked == MotionEvent.ACTION_CANCEL;
// Update list of touch targets for pointer down, if needed.
final boolean split = (mGroupFlags & FLAG_SPLIT_MOTION_EVENTS) != 0;
TouchTarget newTouchTarget = null;
boolean alreadyDispatchedToNewTouchTarget = false;
//非取消和拦截状态
if (!canceled && !intercepted) {
// If the event is targeting accessibility 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.
View childWithAccessibilityFocus = ev.isTargetAccessibilityFocus()
? findChildWithAccessibilityFocus() : null;
//split 多点触控,
if (actionMasked == MotionEvent.ACTION_DOWN
|| (split && actionMasked == MotionEvent.ACTION_POINTER_DOWN)
|| actionMasked == MotionEvent.ACTION_HOVER_MOVE) {
final int actionIndex = ev.getActionIndex(); // always 0 for down
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.
removePointersFromTouchTargets(idBitsToAssign);
final int childrenCount = mChildrenCount;
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.
final ArrayList<View> preorderedList = buildTouchDispatchChildList();
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.
if (childWithAccessibilityFocus != null) {
if (childWithAccessibilityFocus != child) {
continue;
}
childWithAccessibilityFocus = null;
i = childrenCount - 1;
}
if (!child.canReceivePointerEvents()
|| !isTransformedTouchPointInView(x, y, child, null)) {
ev.setTargetAccessibilityFocus(false);
continue;
}
//获取有没有在触摸的子View可以接收
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.
//pointerIdBits 添加进去
newTouchTarget.pointerIdBits |= idBitsToAssign;
break;
}
resetCancelNextUpFlag(child);
//没有在触摸的子View可以接收,尝试能都找到新的子View接收事件
if (dispatchTransformedTouchEvent(ev, false, child, idBitsToAssign)) {
// Child wants to receive touch within its bounds.
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();
//添加
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.
newTouchTarget = mFirstTouchTarget;
while (newTouchTarget.next != null) {
newTouchTarget = newTouchTarget.next;
}
newTouchTarget.pointerIdBits |= idBitsToAssign;
}
}
}
// Dispatch to touch targets.
//子View不接收事件
if (mFirstTouchTarget == null) {
// No touch targets so treat this as an ordinary view.
//调用自己的TouchEvent
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.
TouchTarget predecessor = null;
TouchTarget target = mFirstTouchTarget; //内部被触摸到的子View
while (target != null) {
final TouchTarget next = target.next;
if (alreadyDispatchedToNewTouchTarget && target == newTouchTarget) {
handled = true;
} else {
final boolean cancelChild = resetCancelNextUpFlag(target.child)
|| intercepted;
//处理子View偏移
if (dispatchTransformedTouchEvent(ev, cancelChild,
target.child, target.pointerIdBits)) {
handled = true;
}
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;
}
@Override
public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
//在down之后 和 up之前 ,在父View ViewGroup 调用,同一事件不拦截
if (disallowIntercept == ((mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0)) {
// We're already in this state, assume our ancestors are too
return;
}
if (disallowIntercept) {
mGroupFlags |= FLAG_DISALLOW_INTERCEPT;
} else {
mGroupFlags &= ~FLAG_DISALLOW_INTERCEPT;
}
// Pass it up to our parent
if (mParent != null) {
mParent.requestDisallowInterceptTouchEvent(disallowIntercept);
}
}
dispatchTransformedTouchEvent () ViewGroup 偏移计算 处理子View 进行转换
