Android View 事件分发机制 源码解析 （上）
2016-11-25 17:22
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版权声明：本文为博主原创文章，未经博主允许不得转载。
目录(?)[+]
案例
dispatchTouchEvent
3View的onTouchEvent
MotionEventACTION_DOWN
MotionEventACTION_MOVE
MotionEventACTION_UP
总结
一直想写事件分发机制的文章，不管咋样，也得自己研究下事件分发的源码，写出心得~
首先我们先写个简单的例子来测试View的事件转发的流程~
MyButton
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package com.example.zhy_event03;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.Button;
public class MyButton extends Button
{
private static final String TAG = MyButton.class.getSimpleName();
public MyButton(Context context, AttributeSet attrs)
{
super(context, attrs);
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouchEvent ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouchEvent ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouchEvent ACTION_UP");
break;
default:
break;
}
return super.onTouchEvent(event);
}
@Override
public boolean dispatchTouchEvent(MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "dispatchTouchEvent ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "dispatchTouchEvent ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "dispatchTouchEvent ACTION_UP");
break;
default:
break;
}
return super.dispatchTouchEvent(event);
}
}
在onTouchEvent和dispatchTouchEvent中打印了日志~
然后把我们自定义的按钮加到主布局文件中；
布局文件：
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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<com.example.zhy_event03.MyButton
android:id="@+id/id_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="click me" />
</LinearLayout>
最后看一眼MainActivity的代码
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package com.example.zhy_event03;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;
public class MainActivity extends Activity
{
protected static final String TAG = "MyButton";
private Button mButton ;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButton = (Button) findViewById(R.id.id_btn);
mButton.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouch ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouch ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouch ACTION_UP");
break;
default:
break;
}
return false;
}
});
}
}
在MainActivity中，我们还给MyButton设置了OnTouchListener这个监听~
好了，跟View事件相关一般就这三个地方了，一个onTouchEvent，一个dispatchTouchEvent，一个setOnTouchListener;
下面我们运行，然后点击按钮，查看日志输出：
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08-31 06:09:39.030: E/MyButton(879): dispatchTouchEvent ACTION_DOWN
08-31 06:09:39.030: E/MyButton(879): onTouch ACTION_DOWN
08-31 06:09:39.049: E/MyButton(879): onTouchEvent ACTION_DOWN
08-31 06:09:39.138: E/MyButton(879): dispatchTouchEvent ACTION_MOVE
08-31 06:09:39.138: E/MyButton(879): onTouch ACTION_MOVE
08-31 06:09:39.147: E/MyButton(879): onTouchEvent ACTION_MOVE
08-31 06:09:39.232: E/MyButton(879): dispatchTouchEvent ACTION_UP
08-31 06:09:39.248: E/MyButton(879): onTouch ACTION_UP
08-31 06:09:39.248: E/MyButton(879): onTouchEvent ACTION_UP
我有意点击的时候蹭了一下，不然不会触发MOVE，手抖可能会打印一堆MOVE的日志~~~
好了，可以看到，不管是DOWN，MOVE，UP都会按照下面的顺序执行：
1、dispatchTouchEvent
2、 setOnTouchListener的onTouch
3、onTouchEvent
下面就跟随日志的脚步开始源码的探索~
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/**
* Pass the touch screen motion event down to the target view, or this
* view if it is the target.
*
* @param event The motion event to be dispatched.
* @return True if the event was handled by the view, false otherwise.
*/
public boolean dispatchTouchEvent(MotionEvent event) {
if (!onFilterTouchEventForSecurity(event)) {
return false;
}
if (mOnTouchListener != null && (mViewFlags & ENABLED_MASK) == ENABLED &&
mOnTouchListener.onTouch(this, event)) {
return true;
}
return onTouchEvent(event);
}
直接看13行：首先判断mOnTouchListener不为null，并且view是enable的状态，然后 mOnTouchListener.onTouch(this, event)返回true，这三个条件如果都满足，直接return true ; 也就是下面的onTouchEvent(event）不会被执行了；
那么mOnTouchListener是和方神圣，我们来看看：
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/**
* Register a callback to be invoked when a touch event is sent to this view.
* @param l the touch listener to attach to this view
*/
public void setOnTouchListener(OnTouchListener l) {
mOnTouchListener = l;
}
也就是说：如果我们设置了setOnTouchListener，并且return true，那么View自己的onTouchEvent就不会被执行了，当然了，本例我们return false，我们还得往下探索 ;
已经解决一个常见的问题：View的onTouchListener和onTouchEvent的调用关系，相信大家应该已经明白了~let's
Go；继续往下。
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/**
* Implement this method to handle touch screen motion events.
*
* @param event The motion event.
* @return True if the event was handled, false otherwise.
*/
public boolean onTouchEvent(MotionEvent event) {
final int viewFlags = mViewFlags;
if ((viewFlags & ENABLED_MASK) == DISABLED) {
// A disabled view that is clickable still consumes the touch
// events, it just doesn't respond to them.
return (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE));
}
if (mTouchDelegate != null) {
if (mTouchDelegate.onTouchEvent(event)) {
return true;
}
}
if (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)) {
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
boolean prepressed = (mPrivateFlags & PREPRESSED) != 0;
if ((mPrivateFlags & PRESSED) != 0 || prepressed) {
// take focus if we don't have it already and we should in
// touch mode.
boolean focusTaken = false;
if (isFocusable() && isFocusableInTouchMode() && !isFocused()) {
focusTaken = requestFocus();
}
if (!mHasPerformedLongPress) {
// This is a tap, so remove the longpress check
removeLongPressCallback();
// Only perform take click actions if we were in the pressed state
if (!focusTaken) {
// 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();
}
if (prepressed) {
mPrivateFlags |= PRESSED;
refreshDrawableState();
postDelayed(mUnsetPressedState,
ViewConfiguration.getPressedStateDuration());
} else if (!post(mUnsetPressedState)) {
// If the post failed, unpress right now
mUnsetPressedState.run();
}
removeTapCallback();
}
break;
case MotionEvent.ACTION_DOWN:
if (mPendingCheckForTap == null) {
mPendingCheckForTap = new CheckForTap();
}
mPrivateFlags |= PREPRESSED;
mHasPerformedLongPress = false;
postDelayed(mPendingCheckForTap, ViewConfiguration.getTapTimeout());
break;
case MotionEvent.ACTION_CANCEL:
mPrivateFlags &= ~PRESSED;
refreshDrawableState();
removeTapCallback();
break;
case MotionEvent.ACTION_MOVE:
final int x = (int) event.getX();
final int y = (int) event.getY();
// Be lenient about moving outside of buttons
int slop = mTouchSlop;
if ((x < 0 - slop) || (x >= getWidth() + slop) ||
(y < 0 - slop) || (y >= getHeight() + slop)) {
// Outside button
removeTapCallback();
if ((mPrivateFlags & PRESSED) != 0) {
// Remove any future long press/tap checks
removeLongPressCallback();
// Need to switch from pressed to not pressed
mPrivateFlags &= ~PRESSED;
refreshDrawableState();
}
}
break;
}
return true;
}
return false;
}
代码还是比较长的，
10-15行，如果当前View是Disabled状态且是可点击则会消费掉事件（return true);可以忽略，不是我们的重点；
17-21行，如果设置了mTouchDelegate，则会将事件交给代理者处理，直接return true，如果大家希望自己的View增加它的touch范围，可以尝试使用TouchDelegate，这里也不是重点，可以忽略；
接下来到我们的重点了：
23行的判断：如果我们的View可以点击或者可以长按，则，注意IF的范围，最终一定return true ;
if (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)) {
//...
return true;
}
接下来就是 switch (event.getAction())了，判断事件类型，DOWN,MOVE,UP等；
我们按照例子执行的顺序，先看 case MotionEvent.ACTION_DOWN （71-78行）:
76行：设置mHasPerformedLongPress=false；表示长按事件还未触发；
77行：发送一个延迟为ViewConfiguration.getTapTimeout()的延迟消息，到达延时时间后会执行CheckForTap()里面的run方法：
1、ViewConfiguration.getTapTimeout()为115毫秒；
2、CheckForTap
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private final class CheckForTap implements Runnable {
public void run() {
mPrivateFlags &= ~PREPRESSED;
mPrivateFlags |= PRESSED;
refreshDrawableState();
if ((mViewFlags & LONG_CLICKABLE) == LONG_CLICKABLE) {
postCheckForLongClick(ViewConfiguration.getTapTimeout());
}
}
}
在run方法里面取消mPrivateFlags的PREPRESSED，然后设置PRESSED标识，刷新背景，如果View支持长按事件，则再发一个延时消息，检测长按；
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private void postCheckForLongClick(int delayOffset) {
mHasPerformedLongPress = false;
if (mPendingCheckForLongPress == null) {
mPendingCheckForLongPress = new CheckForLongPress();
}
mPendingCheckForLongPress.rememberWindowAttachCount();
postDelayed(mPendingCheckForLongPress,
ViewConfiguration.getLongPressTimeout() - delayOffset);
}
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class CheckForLongPress implements Runnable {
private int mOriginalWindowAttachCount;
public void run() {
if (isPressed() && (mParent != null)
&& mOriginalWindowAttachCount == mWindowAttachCount) {
if (performLongClick()) {
mHasPerformedLongPress = true;
}
}
}
可以看到，当用户按下，首先会设置标识为PREPRESSED
如果115后，没有抬起，会将View的标识设置为PRESSED且去掉PREPRESSED标识，然后发出一个检测长按的延迟任务，延时为：ViewConfiguration.getLongPressTimeout() - delayOffset（500ms -115ms），这个115ms刚好时检测额PREPRESSED时间；也就是用户从DOWN触发开始算起，如果500ms内没有抬起则认为触发了长按事件：
1、如果此时设置了长按的回调，则执行长按时的回调，且如果长按的回调返回true;才把mHasPerformedLongPress置为ture；
2、否则，如果没有设置长按回调或者长按回调返回的是false；则mHasPerformedLongPress依然是false;
好了DOWN就分析完成了；大家回个神，下面回到VIEW的onTouchEvent中的ACTION_MOVE:
87-88行：拿到当前触摸的x,y坐标；
91行判断当然触摸点有没有移出我们的View，如果移出了：
1、执行removeTapCallback();
2、然后判断是否包含PRESSED标识，如果包含，移除长按的检查：removeLongPressCallback();
3、最后把mPrivateFlags中PRESSED标识去除，刷新背景；
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private void removeTapCallback() {
if (mPendingCheckForTap != null) {
mPrivateFlags &= ~PREPRESSED;
removeCallbacks(mPendingCheckForTap);
}
}
如果115ms后，你才移出控件外，则你的当前mPrivateFlags一定为PRESSED且发送了长按的检测；
就会走上面的2和3；首先移除removeLongPressCallback（）
private void removeLongPressCallback() {
if (mPendingCheckForLongPress != null) {
removeCallbacks(mPendingCheckForLongPress);
}
}
然后把mPrivateFlags中PRESSED标识去除，刷新背景；
好了，MOVE我们也分析完成了，总结一下：只要用户移出了我们的控件：则将mPrivateFlags取出PRESSED标识，且移除所有在DOWN中设置的检测，长按等；
下面再回个神，回到View的onTouchEvent的ACTION_UP：
27行：判断mPrivateFlags是否包含PREPRESSED
28行：如果包含PRESSED或者PREPRESSED则进入执行体，也就是无论是115ms内或者之后抬起都会进入执行体。
36行：如果mHasPerformedLongPress没有被执行，进入IF
38行：removeLongPressCallback（）；移除长按的检测
45-50行：如果mPerformClick如果mPerformClick为null，初始化一个实例，然后立即通过handler添加到消息队列尾部，如果添加失败则直接执行 performClick();添加成功，在mPerformClick的run方法中就是执行performClick（）；
终于执行了我们的click事件了，下面看一下performClick()方法：
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public boolean performClick() {
sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);
if (mOnClickListener != null) {
playSoundEffect(SoundEffectConstants.CLICK);
mOnClickListener.onClick(this);
return true;
}
return false;
}
if (mOnClickListener != null) {
mOnClickListener.onClick(this);
return true;
}
久违了~我们的mOnClickListener ；
别激动，还没结束，回到ACTION_UP，
58行：如果prepressed为true，进入IF体：
为mPrivateFlags设置表示为PRESSED，刷新背景，125毫秒后执行mUnsetPressedState
否则：mUnsetPressedState.run();立即执行；也就是不管咋样，最后mUnsetPressedState.run()都会执行；
看看这个UnsetPressedState主要干什么:
private final class UnsetPressedState implements Runnable {
public void run() {
setPressed(false);
}
}
public void setPressed(boolean pressed) {
if (pressed) {
mPrivateFlags |= PRESSED;
} else {
mPrivateFlags &= ~PRESSED;
}
refreshDrawableState();
dispatchSetPressed(pressed);
}
把我们的mPrivateFlags中的PRESSED取消，然后刷新背景，把setPress转发下去。
ACTION_UP的最后一行：removeTapCallback()，如果mPendingCheckForTap不为null，移除;
1、整个View的事件转发流程是：
View.dispatchEvent->View.setOnTouchListener->View.onTouchEvent
在dispatchTouchEvent中会进行OnTouchListener的判断，如果OnTouchListener不为null且返回true，则表示事件被消费，onTouchEvent不会被执行；否则执行onTouchEvent。
2、onTouchEvent中的DOWN,MOVE,UP
DOWN时：
a、首先设置标志为PREPRESSED，设置mHasPerformedLongPress=false ;然后发出一个115ms后的mPendingCheckForTap；
b、如果115ms内没有触发UP，则将标志置为PRESSED，清除PREPRESSED标志，同时发出一个延时为500-115ms的，检测长按任务消息；
c、如果500ms内（从DOWN触发开始算），则会触发LongClickListener:
此时如果LongClickListener不为null，则会执行回调，同时如果LongClickListener.onClick返回true，才把mHasPerformedLongPress设置为true;否则mHasPerformedLongPress依然为false;
MOVE时：
主要就是检测用户是否划出控件，如果划出了：
115ms内，直接移除mPendingCheckForTap；
115ms后，则将标志中的PRESSED去除，同时移除长按的检查：removeLongPressCallback();
UP时：
a、如果115ms内，触发UP，此时标志为PREPRESSED，则执行UnsetPressedState，setPressed(false);会把setPress转发下去，可以在View中复写dispatchSetPressed方法接收；
b、如果是115ms-500ms间，即长按还未发生，则首先移除长按检测，执行onClick回调；
c、如果是500ms以后，那么有两种情况：
i.设置了onLongClickListener，且onLongClickListener.onClick返回true，则点击事件OnClick事件无法触发；
ii.没有设置onLongClickListener或者onLongClickListener.onClick返回false，则点击事件OnClick事件依然可以触发；
d、最后执行mUnsetPressedState.run()，将setPressed传递下去，然后将PRESSED标识去除；
最后问个问题，然后再运行个例子结束：
1、setOnLongClickListener和setOnClickListener是否只能执行一个
不是的，只要setOnLongClickListener中的onClick返回false，则两个都会执行；返回true则会屏幕setOnClickListener
最后我们给MyButton同时设置setOnClickListener和setOnLongClickListener，运行看看：
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package com.example.zhy_event03;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity
{
protected static final String TAG = "MyButton";
private Button mButton ;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButton = (Button) findViewById(R.id.id_btn);
mButton.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouch ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouch ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouch ACTION_UP");
break;
default:
break;
}
return false;
}
});
mButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Toast.makeText(getApplicationContext(), "onclick",Toast.LENGTH_SHORT).show();
}
});
mButton.setOnLongClickListener(new OnLongClickListener()
{
@Override
public boolean onLongClick(View v)
{
Toast.makeText(getApplicationContext(), "setOnLongClickListener",Toast.LENGTH_SHORT).show();
return false;
}
});
}
}
可以看到LongClickListener已经ClickListener都触发了~
最后，本篇博文完成了对View的事件分发机制的整个流程的说明，并且对源码进行了分析；
当然了，View结束，肯定到我们的ViewGroup了，请点击：Android ViewGroup事件分发机制
目录(?)[+]
案例
dispatchTouchEvent
3View的onTouchEvent
MotionEventACTION_DOWN
MotionEventACTION_MOVE
MotionEventACTION_UP
总结
一直想写事件分发机制的文章，不管咋样，也得自己研究下事件分发的源码，写出心得~
首先我们先写个简单的例子来测试View的事件转发的流程~
1、案例
为了更好的研究View的事件转发，我们自定以一个MyButton继承Button，然后把跟事件传播有关的方法进行复写，然后添加上日志~MyButton
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package com.example.zhy_event03;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.Button;
public class MyButton extends Button
{
private static final String TAG = MyButton.class.getSimpleName();
public MyButton(Context context, AttributeSet attrs)
{
super(context, attrs);
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouchEvent ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouchEvent ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouchEvent ACTION_UP");
break;
default:
break;
}
return super.onTouchEvent(event);
}
@Override
public boolean dispatchTouchEvent(MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "dispatchTouchEvent ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "dispatchTouchEvent ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "dispatchTouchEvent ACTION_UP");
break;
default:
break;
}
return super.dispatchTouchEvent(event);
}
}
package com.example.zhy_event03;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.Button;
public class MyButton extends Button
{
private static final String TAG = MyButton.class.getSimpleName();
public MyButton(Context context, AttributeSet attrs)
{
super(context, attrs);
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouchEvent ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouchEvent ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouchEvent ACTION_UP");
break;
default:
break;
}
return super.onTouchEvent(event);
}
@Override
public boolean dispatchTouchEvent(MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "dispatchTouchEvent ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "dispatchTouchEvent ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "dispatchTouchEvent ACTION_UP");
break;
default:
break;
}
return super.dispatchTouchEvent(event);
}
}在onTouchEvent和dispatchTouchEvent中打印了日志~
然后把我们自定义的按钮加到主布局文件中；
布局文件：
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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<com.example.zhy_event03.MyButton
android:id="@+id/id_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="click me" />
</LinearLayout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" > <com.example.zhy_event03.MyButton android:id="@+id/id_btn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="click me" /> </LinearLayout>
最后看一眼MainActivity的代码
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package com.example.zhy_event03;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;
public class MainActivity extends Activity
{
protected static final String TAG = "MyButton";
private Button mButton ;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButton = (Button) findViewById(R.id.id_btn);
mButton.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouch ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouch ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouch ACTION_UP");
break;
default:
break;
}
return false;
}
});
}
}
package com.example.zhy_event03;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;
public class MainActivity extends Activity
{
protected static final String TAG = "MyButton";
private Button mButton ;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButton = (Button) findViewById(R.id.id_btn);
mButton.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouch ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouch ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouch ACTION_UP");
break;
default:
break;
}
return false;
}
});
}
}在MainActivity中，我们还给MyButton设置了OnTouchListener这个监听~
好了，跟View事件相关一般就这三个地方了，一个onTouchEvent，一个dispatchTouchEvent，一个setOnTouchListener;
下面我们运行，然后点击按钮，查看日志输出：
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08-31 06:09:39.030: E/MyButton(879): dispatchTouchEvent ACTION_DOWN
08-31 06:09:39.030: E/MyButton(879): onTouch ACTION_DOWN
08-31 06:09:39.049: E/MyButton(879): onTouchEvent ACTION_DOWN
08-31 06:09:39.138: E/MyButton(879): dispatchTouchEvent ACTION_MOVE
08-31 06:09:39.138: E/MyButton(879): onTouch ACTION_MOVE
08-31 06:09:39.147: E/MyButton(879): onTouchEvent ACTION_MOVE
08-31 06:09:39.232: E/MyButton(879): dispatchTouchEvent ACTION_UP
08-31 06:09:39.248: E/MyButton(879): onTouch ACTION_UP
08-31 06:09:39.248: E/MyButton(879): onTouchEvent ACTION_UP
08-31 06:09:39.030: E/MyButton(879): dispatchTouchEvent ACTION_DOWN 08-31 06:09:39.030: E/MyButton(879): onTouch ACTION_DOWN 08-31 06:09:39.049: E/MyButton(879): onTouchEvent ACTION_DOWN 08-31 06:09:39.138: E/MyButton(879): dispatchTouchEvent ACTION_MOVE 08-31 06:09:39.138: E/MyButton(879): onTouch ACTION_MOVE 08-31 06:09:39.147: E/MyButton(879): onTouchEvent ACTION_MOVE 08-31 06:09:39.232: E/MyButton(879): dispatchTouchEvent ACTION_UP 08-31 06:09:39.248: E/MyButton(879): onTouch ACTION_UP 08-31 06:09:39.248: E/MyButton(879): onTouchEvent ACTION_UP
我有意点击的时候蹭了一下，不然不会触发MOVE，手抖可能会打印一堆MOVE的日志~~~
好了，可以看到，不管是DOWN，MOVE，UP都会按照下面的顺序执行：
1、dispatchTouchEvent
2、 setOnTouchListener的onTouch
3、onTouchEvent
下面就跟随日志的脚步开始源码的探索~
2、dispatchTouchEvent
首先进入View的dispatchTouchEvent[java]
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/**
* Pass the touch screen motion event down to the target view, or this
* view if it is the target.
*
* @param event The motion event to be dispatched.
* @return True if the event was handled by the view, false otherwise.
*/
public boolean dispatchTouchEvent(MotionEvent event) {
if (!onFilterTouchEventForSecurity(event)) {
return false;
}
if (mOnTouchListener != null && (mViewFlags & ENABLED_MASK) == ENABLED &&
mOnTouchListener.onTouch(this, event)) {
return true;
}
return onTouchEvent(event);
}
/**
* Pass the touch screen motion event down to the target view, or this
* view if it is the target.
*
* @param event The motion event to be dispatched.
* @return True if the event was handled by the view, false otherwise.
*/
public boolean dispatchTouchEvent(MotionEvent event) {
if (!onFilterTouchEventForSecurity(event)) {
return false;
}
if (mOnTouchListener != null && (mViewFlags & ENABLED_MASK) == ENABLED &&
mOnTouchListener.onTouch(this, event)) {
return true;
}
return onTouchEvent(event);
}直接看13行：首先判断mOnTouchListener不为null，并且view是enable的状态，然后 mOnTouchListener.onTouch(this, event)返回true，这三个条件如果都满足，直接return true ; 也就是下面的onTouchEvent(event）不会被执行了；
那么mOnTouchListener是和方神圣，我们来看看：
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/**
* Register a callback to be invoked when a touch event is sent to this view.
* @param l the touch listener to attach to this view
*/
public void setOnTouchListener(OnTouchListener l) {
mOnTouchListener = l;
}
/**
* Register a callback to be invoked when a touch event is sent to this view.
* @param l the touch listener to attach to this view
*/
public void setOnTouchListener(OnTouchListener l) {
mOnTouchListener = l;
}其实就是我们在Activity中设置的setOnTouchListener。也就是说：如果我们设置了setOnTouchListener，并且return true，那么View自己的onTouchEvent就不会被执行了，当然了，本例我们return false，我们还得往下探索 ;
已经解决一个常见的问题：View的onTouchListener和onTouchEvent的调用关系，相信大家应该已经明白了~let's
Go；继续往下。
3、View的onTouchEvent:
接下来是View的onTouchEvent:[java]
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/**
* Implement this method to handle touch screen motion events.
*
* @param event The motion event.
* @return True if the event was handled, false otherwise.
*/
public boolean onTouchEvent(MotionEvent event) {
final int viewFlags = mViewFlags;
if ((viewFlags & ENABLED_MASK) == DISABLED) {
// A disabled view that is clickable still consumes the touch
// events, it just doesn't respond to them.
return (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE));
}
if (mTouchDelegate != null) {
if (mTouchDelegate.onTouchEvent(event)) {
return true;
}
}
if (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)) {
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
boolean prepressed = (mPrivateFlags & PREPRESSED) != 0;
if ((mPrivateFlags & PRESSED) != 0 || prepressed) {
// take focus if we don't have it already and we should in
// touch mode.
boolean focusTaken = false;
if (isFocusable() && isFocusableInTouchMode() && !isFocused()) {
focusTaken = requestFocus();
}
if (!mHasPerformedLongPress) {
// This is a tap, so remove the longpress check
removeLongPressCallback();
// Only perform take click actions if we were in the pressed state
if (!focusTaken) {
// 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();
}
if (prepressed) {
mPrivateFlags |= PRESSED;
refreshDrawableState();
postDelayed(mUnsetPressedState,
ViewConfiguration.getPressedStateDuration());
} else if (!post(mUnsetPressedState)) {
// If the post failed, unpress right now
mUnsetPressedState.run();
}
removeTapCallback();
}
break;
case MotionEvent.ACTION_DOWN:
if (mPendingCheckForTap == null) {
mPendingCheckForTap = new CheckForTap();
}
mPrivateFlags |= PREPRESSED;
mHasPerformedLongPress = false;
postDelayed(mPendingCheckForTap, ViewConfiguration.getTapTimeout());
break;
case MotionEvent.ACTION_CANCEL:
mPrivateFlags &= ~PRESSED;
refreshDrawableState();
removeTapCallback();
break;
case MotionEvent.ACTION_MOVE:
final int x = (int) event.getX();
final int y = (int) event.getY();
// Be lenient about moving outside of buttons
int slop = mTouchSlop;
if ((x < 0 - slop) || (x >= getWidth() + slop) ||
(y < 0 - slop) || (y >= getHeight() + slop)) {
// Outside button
removeTapCallback();
if ((mPrivateFlags & PRESSED) != 0) {
// Remove any future long press/tap checks
removeLongPressCallback();
// Need to switch from pressed to not pressed
mPrivateFlags &= ~PRESSED;
refreshDrawableState();
}
}
break;
}
return true;
}
return false;
}
/**
* Implement this method to handle touch screen motion events.
*
* @param event The motion event.
* @return True if the event was handled, false otherwise.
*/
public boolean onTouchEvent(MotionEvent event) {
final int viewFlags = mViewFlags;
if ((viewFlags & ENABLED_MASK) == DISABLED) {
// A disabled view that is clickable still consumes the touch
// events, it just doesn't respond to them.
return (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE));
}
if (mTouchDelegate != null) {
if (mTouchDelegate.onTouchEvent(event)) {
return true;
}
}
if (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)) {
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
boolean prepressed = (mPrivateFlags & PREPRESSED) != 0;
if ((mPrivateFlags & PRESSED) != 0 || prepressed) {
// take focus if we don't have it already and we should in
// touch mode.
boolean focusTaken = false;
if (isFocusable() && isFocusableInTouchMode() && !isFocused()) {
focusTaken = requestFocus();
}
if (!mHasPerformedLongPress) {
// This is a tap, so remove the longpress check
removeLongPressCallback();
// Only perform take click actions if we were in the pressed state
if (!focusTaken) {
// 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();
}
if (prepressed) {
mPrivateFlags |= PRESSED;
refreshDrawableState();
postDelayed(mUnsetPressedState,
ViewConfiguration.getPressedStateDuration());
} else if (!post(mUnsetPressedState)) {
// If the post failed, unpress right now
mUnsetPressedState.run();
}
removeTapCallback();
}
break;
case MotionEvent.ACTION_DOWN:
if (mPendingCheckForTap == null) {
mPendingCheckForTap = new CheckForTap();
}
mPrivateFlags |= PREPRESSED;
mHasPerformedLongPress = false;
postDelayed(mPendingCheckForTap, ViewConfiguration.getTapTimeout());
break;
case MotionEvent.ACTION_CANCEL:
mPrivateFlags &= ~PRESSED;
refreshDrawableState();
removeTapCallback();
break;
case MotionEvent.ACTION_MOVE:
final int x = (int) event.getX();
final int y = (int) event.getY();
// Be lenient about moving outside of buttons
int slop = mTouchSlop;
if ((x < 0 - slop) || (x >= getWidth() + slop) ||
(y < 0 - slop) || (y >= getHeight() + slop)) {
// Outside button
removeTapCallback();
if ((mPrivateFlags & PRESSED) != 0) {
// Remove any future long press/tap checks
removeLongPressCallback();
// Need to switch from pressed to not pressed
mPrivateFlags &= ~PRESSED;
refreshDrawableState();
}
}
break;
}
return true;
}
return false;
}代码还是比较长的，
10-15行，如果当前View是Disabled状态且是可点击则会消费掉事件（return true);可以忽略，不是我们的重点；
17-21行，如果设置了mTouchDelegate，则会将事件交给代理者处理，直接return true，如果大家希望自己的View增加它的touch范围，可以尝试使用TouchDelegate，这里也不是重点，可以忽略；
接下来到我们的重点了：
23行的判断：如果我们的View可以点击或者可以长按，则，注意IF的范围，最终一定return true ;
if (((viewFlags & CLICKABLE) == CLICKABLE ||
(viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)) {
//...
return true;
}
接下来就是 switch (event.getAction())了，判断事件类型，DOWN,MOVE,UP等；
我们按照例子执行的顺序，先看 case MotionEvent.ACTION_DOWN （71-78行）:
1、MotionEvent.ACTION_DOWN
75行：给mPrivateFlags设置一个PREPRESSED的标识76行：设置mHasPerformedLongPress=false；表示长按事件还未触发；
77行：发送一个延迟为ViewConfiguration.getTapTimeout()的延迟消息，到达延时时间后会执行CheckForTap()里面的run方法：
1、ViewConfiguration.getTapTimeout()为115毫秒；
2、CheckForTap
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private final class CheckForTap implements Runnable {
public void run() {
mPrivateFlags &= ~PREPRESSED;
mPrivateFlags |= PRESSED;
refreshDrawableState();
if ((mViewFlags & LONG_CLICKABLE) == LONG_CLICKABLE) {
postCheckForLongClick(ViewConfiguration.getTapTimeout());
}
}
}
private final class CheckForTap implements Runnable {
public void run() {
mPrivateFlags &= ~PREPRESSED;
mPrivateFlags |= PRESSED;
refreshDrawableState();
if ((mViewFlags & LONG_CLICKABLE) == LONG_CLICKABLE) {
postCheckForLongClick(ViewConfiguration.getTapTimeout());
}
}
}在run方法里面取消mPrivateFlags的PREPRESSED，然后设置PRESSED标识，刷新背景，如果View支持长按事件，则再发一个延时消息，检测长按；
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private void postCheckForLongClick(int delayOffset) {
mHasPerformedLongPress = false;
if (mPendingCheckForLongPress == null) {
mPendingCheckForLongPress = new CheckForLongPress();
}
mPendingCheckForLongPress.rememberWindowAttachCount();
postDelayed(mPendingCheckForLongPress,
ViewConfiguration.getLongPressTimeout() - delayOffset);
}
private void postCheckForLongClick(int delayOffset) {
mHasPerformedLongPress = false;
if (mPendingCheckForLongPress == null) {
mPendingCheckForLongPress = new CheckForLongPress();
}
mPendingCheckForLongPress.rememberWindowAttachCount();
postDelayed(mPendingCheckForLongPress,
ViewConfiguration.getLongPressTimeout() - delayOffset);
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class CheckForLongPress implements Runnable {
private int mOriginalWindowAttachCount;
public void run() {
if (isPressed() && (mParent != null)
&& mOriginalWindowAttachCount == mWindowAttachCount) {
if (performLongClick()) {
mHasPerformedLongPress = true;
}
}
}
class CheckForLongPress implements Runnable {
private int mOriginalWindowAttachCount;
public void run() {
if (isPressed() && (mParent != null)
&& mOriginalWindowAttachCount == mWindowAttachCount) {
if (performLongClick()) {
mHasPerformedLongPress = true;
}
}
}可以看到，当用户按下，首先会设置标识为PREPRESSED
如果115后，没有抬起，会将View的标识设置为PRESSED且去掉PREPRESSED标识，然后发出一个检测长按的延迟任务，延时为：ViewConfiguration.getLongPressTimeout() - delayOffset（500ms -115ms），这个115ms刚好时检测额PREPRESSED时间；也就是用户从DOWN触发开始算起，如果500ms内没有抬起则认为触发了长按事件：
1、如果此时设置了长按的回调，则执行长按时的回调，且如果长按的回调返回true;才把mHasPerformedLongPress置为ture；
2、否则，如果没有设置长按回调或者长按回调返回的是false；则mHasPerformedLongPress依然是false;
好了DOWN就分析完成了；大家回个神，下面回到VIEW的onTouchEvent中的ACTION_MOVE:
2、MotionEvent.ACTION_MOVE
86到105行：87-88行：拿到当前触摸的x,y坐标；
91行判断当然触摸点有没有移出我们的View，如果移出了：
1、执行removeTapCallback();
2、然后判断是否包含PRESSED标识，如果包含，移除长按的检查：removeLongPressCallback();
3、最后把mPrivateFlags中PRESSED标识去除，刷新背景；
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private void removeTapCallback() {
if (mPendingCheckForTap != null) {
mPrivateFlags &= ~PREPRESSED;
removeCallbacks(mPendingCheckForTap);
}
}
private void removeTapCallback() {
if (mPendingCheckForTap != null) {
mPrivateFlags &= ~PREPRESSED;
removeCallbacks(mPendingCheckForTap);
}
}这个是移除，DOWN触发时设置的PREPRESSED的检测；即当前触发时机在DOWN触发不到115ms时，你就已经移出控件外了；如果115ms后，你才移出控件外，则你的当前mPrivateFlags一定为PRESSED且发送了长按的检测；
就会走上面的2和3；首先移除removeLongPressCallback（）
private void removeLongPressCallback() {
if (mPendingCheckForLongPress != null) {
removeCallbacks(mPendingCheckForLongPress);
}
}
然后把mPrivateFlags中PRESSED标识去除，刷新背景；
好了，MOVE我们也分析完成了，总结一下：只要用户移出了我们的控件：则将mPrivateFlags取出PRESSED标识，且移除所有在DOWN中设置的检测，长按等；
下面再回个神，回到View的onTouchEvent的ACTION_UP：
3、MotionEvent.ACTION_UP
26到69行：27行：判断mPrivateFlags是否包含PREPRESSED
28行：如果包含PRESSED或者PREPRESSED则进入执行体，也就是无论是115ms内或者之后抬起都会进入执行体。
36行：如果mHasPerformedLongPress没有被执行，进入IF
38行：removeLongPressCallback（）；移除长按的检测
45-50行：如果mPerformClick如果mPerformClick为null，初始化一个实例，然后立即通过handler添加到消息队列尾部，如果添加失败则直接执行 performClick();添加成功，在mPerformClick的run方法中就是执行performClick（）；
终于执行了我们的click事件了，下面看一下performClick()方法：
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public boolean performClick() {
sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);
if (mOnClickListener != null) {
playSoundEffect(SoundEffectConstants.CLICK);
mOnClickListener.onClick(this);
return true;
}
return false;
}
public boolean performClick() {
sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);
if (mOnClickListener != null) {
playSoundEffect(SoundEffectConstants.CLICK);
mOnClickListener.onClick(this);
return true;
}
return false;
}if (mOnClickListener != null) {
mOnClickListener.onClick(this);
return true;
}
久违了~我们的mOnClickListener ；
别激动，还没结束，回到ACTION_UP，
58行：如果prepressed为true，进入IF体：
为mPrivateFlags设置表示为PRESSED，刷新背景，125毫秒后执行mUnsetPressedState
否则：mUnsetPressedState.run();立即执行；也就是不管咋样，最后mUnsetPressedState.run()都会执行；
看看这个UnsetPressedState主要干什么:
private final class UnsetPressedState implements Runnable {
public void run() {
setPressed(false);
}
}
public void setPressed(boolean pressed) {
if (pressed) {
mPrivateFlags |= PRESSED;
} else {
mPrivateFlags &= ~PRESSED;
}
refreshDrawableState();
dispatchSetPressed(pressed);
}
把我们的mPrivateFlags中的PRESSED取消，然后刷新背景，把setPress转发下去。
ACTION_UP的最后一行：removeTapCallback()，如果mPendingCheckForTap不为null，移除;
4、总结
好了，代码跨度还是相当大的，下面需要总结下：1、整个View的事件转发流程是：
View.dispatchEvent->View.setOnTouchListener->View.onTouchEvent
在dispatchTouchEvent中会进行OnTouchListener的判断，如果OnTouchListener不为null且返回true，则表示事件被消费，onTouchEvent不会被执行；否则执行onTouchEvent。
2、onTouchEvent中的DOWN,MOVE,UP
DOWN时：
a、首先设置标志为PREPRESSED，设置mHasPerformedLongPress=false ;然后发出一个115ms后的mPendingCheckForTap；
b、如果115ms内没有触发UP，则将标志置为PRESSED，清除PREPRESSED标志，同时发出一个延时为500-115ms的，检测长按任务消息；
c、如果500ms内（从DOWN触发开始算），则会触发LongClickListener:
此时如果LongClickListener不为null，则会执行回调，同时如果LongClickListener.onClick返回true，才把mHasPerformedLongPress设置为true;否则mHasPerformedLongPress依然为false;
MOVE时：
主要就是检测用户是否划出控件，如果划出了：
115ms内，直接移除mPendingCheckForTap；
115ms后，则将标志中的PRESSED去除，同时移除长按的检查：removeLongPressCallback();
UP时：
a、如果115ms内，触发UP，此时标志为PREPRESSED，则执行UnsetPressedState，setPressed(false);会把setPress转发下去，可以在View中复写dispatchSetPressed方法接收；
b、如果是115ms-500ms间，即长按还未发生，则首先移除长按检测，执行onClick回调；
c、如果是500ms以后，那么有两种情况：
i.设置了onLongClickListener，且onLongClickListener.onClick返回true，则点击事件OnClick事件无法触发；
ii.没有设置onLongClickListener或者onLongClickListener.onClick返回false，则点击事件OnClick事件依然可以触发；
d、最后执行mUnsetPressedState.run()，将setPressed传递下去，然后将PRESSED标识去除；
最后问个问题，然后再运行个例子结束：
1、setOnLongClickListener和setOnClickListener是否只能执行一个
不是的，只要setOnLongClickListener中的onClick返回false，则两个都会执行；返回true则会屏幕setOnClickListener
最后我们给MyButton同时设置setOnClickListener和setOnLongClickListener，运行看看：
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package com.example.zhy_event03;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity
{
protected static final String TAG = "MyButton";
private Button mButton ;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButton = (Button) findViewById(R.id.id_btn);
mButton.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouch ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouch ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouch ACTION_UP");
break;
default:
break;
}
return false;
}
});
mButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Toast.makeText(getApplicationContext(), "onclick",Toast.LENGTH_SHORT).show();
}
});
mButton.setOnLongClickListener(new OnLongClickListener()
{
@Override
public boolean onLongClick(View v)
{
Toast.makeText(getApplicationContext(), "setOnLongClickListener",Toast.LENGTH_SHORT).show();
return false;
}
});
}
}
package com.example.zhy_event03;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity
{
protected static final String TAG = "MyButton";
private Button mButton ;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButton = (Button) findViewById(R.id.id_btn);
mButton.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
int action = event.getAction();
switch (action)
{
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "onTouch ACTION_DOWN");
break;
case MotionEvent.ACTION_MOVE:
Log.e(TAG, "onTouch ACTION_MOVE");
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "onTouch ACTION_UP");
break;
default:
break;
}
return false;
}
});
mButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Toast.makeText(getApplicationContext(), "onclick",Toast.LENGTH_SHORT).show();
}
});
mButton.setOnLongClickListener(new OnLongClickListener()
{
@Override
public boolean onLongClick(View v)
{
Toast.makeText(getApplicationContext(), "setOnLongClickListener",Toast.LENGTH_SHORT).show();
return false;
}
});
}
}效果图：可以看到LongClickListener已经ClickListener都触发了~
最后，本篇博文完成了对View的事件分发机制的整个流程的说明，并且对源码进行了分析；
当然了，View结束，肯定到我们的ViewGroup了，请点击：Android ViewGroup事件分发机制
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