android 事件分发机制

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;  
}  

package com.joyfulmath.frameworksample.viewdemo;

import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;

import com.joyfulmath.frameworksample.R;

/**
 * Created by Administrator on 2016/8/27 0027.
 */
public class TestViewAction extends Activity implements View.OnClickListener,View.OnTouchListener
{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.content_main);
        Button button = (Button) findViewById(R.id.button_id);
        button.setOnClickListener(this);
        button.setOnTouchListener(this);
        Button imageView = (Button) findViewById(R.id.imageId);
        imageView.setOnClickListener(this);
        imageView.setOnTouchListener(this);
        MyLayout myLayout = (MyLayout) findViewById(R.id.my_layout);
        myLayout.setOnTouchListener(this);
        myLayout.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId())
        {
            case R.id.button_id:
                TraceLog.i("button_id");
                break;
            case R.id.imageId:
                TraceLog.i("imageId");
                break;
            case R.id.my_layout:
                TraceLog.i("my_layout");
                break;
        }

    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (v.getId())
        {
            case R.id.button_id:
                TraceLog.i("button_id");
                break;
            case R.id.imageId:
                TraceLog.i("imageId");
                break;
            case R.id.my_layout:
                TraceLog.i("my_layout");
                break;
        }
        return false;
    }
}