/**
     * 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 (mInputEventConsistencyVerifier != null) {
            mInputEventConsistencyVerifier.onTouchEvent(event, 0);
        }

        if (onFilterTouchEventForSecurity(event)) {
            //noinspection SimplifiableIfStatement
            ListenerInfo li = mListenerInfo;
            if (li != null && li.mOnTouchListener != null && (mViewFlags & ENABLED_MASK) == ENABLED
                    && li.mOnTouchListener.onTouch(this, event)) {
                return true;
            }

            if (onTouchEvent(event)) {
                return true;
            }
        }

        if (mInputEventConsistencyVerifier != null) {
            mInputEventConsistencyVerifier.onUnhandledEvent(event, 0);
        }
        return false;
    }

找到这个判断:

            if (onTouchEvent(event)) {
                return true;
            }

onTouchEvent的源码比较多，贴最重要的:

                        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();
                                }
                            }
                        }

可以看到有个performClick(),它的源码里有这么一句 li.mOnClickListener.onClick(this);

    public boolean performClick() {
        sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);

        ListenerInfo li = mListenerInfo;
        if (li != null && li.mOnClickListener != null) {
            playSoundEffect(SoundEffectConstants.CLICK);
            li.mOnClickListener.onClick(this);
            return true;
        }

        return false;
    }

终于对上了，它执行了我们注册的onClick监听。当然执行前会经过一系列判断，是否注册了监听等。
总结:

package org.yanzi.ui;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.Button;

public class TestButton extends Button {
	private final static String tag = "yan";
	public TestButton(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
	}
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		// TODO Auto-generated method stub
		switch(event.getAction()){
		case MotionEvent.ACTION_DOWN:
			Log.i(tag, "TestButton-onTouchEvent-ACTION_DOWN...");
			break;
		case MotionEvent.ACTION_UP:
			Log.i(tag, "TestButton-onTouchEvent-ACTION_UP...");
			break;
		default:break;
		}
		return super.onTouchEvent(event);
	}

	@Override
	public boolean dispatchTouchEvent(MotionEvent event) {
		// TODO Auto-generated method stub
		switch(event.getAction()){
		case MotionEvent.ACTION_DOWN:
			Log.i(tag, "TestButton-dispatchTouchEvent-ACTION_DOWN...");
			break;
		case MotionEvent.ACTION_UP:
			Log.i(tag, "TestButton-dispatchTouchEvent-ACTION_UP...");
			break;
		default:break;
		}
		
		return super.dispatchTouchEvent(event);
	}

}

在Activity里注册两个监听:

		testBtn.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				Log.i(tag, "testBtn---onClick...");
			}
		});
		testBtn.setOnTouchListener(new View.OnTouchListener() {

			@Override
			public boolean onTouch(View v, MotionEvent event) {
				// TODO Auto-generated method stub
				switch(event.getAction()){
				case MotionEvent.ACTION_DOWN:
					Log.i(tag, "testBtn-onTouch-ACTION_DOWN...");
					break;
				case MotionEvent.ACTION_UP:
					Log.i(tag, "testBtn-onTouch-ACTION_UP...");
					break;
				default:break;

				}
				return false;
			}
		});

同时复写Activity的dispatch方法和onTouchEvent方法：

@Override
	public boolean dispatchTouchEvent(MotionEvent ev) {
		// TODO Auto-generated method stub
		switch(ev.getAction()){
		case MotionEvent.ACTION_DOWN:
			Log.i(tag, "MainActivity-dispatchTouchEvent-ACTION_DOWN...");
			break;
		case MotionEvent.ACTION_UP:
			Log.i(tag, "MainActivity-dispatchTouchEvent-ACTION_UP...");
			break;
		default:break;
		}
		return super.dispatchTouchEvent(ev);
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		// TODO Auto-generated method stub
		switch(event.getAction()){
		case MotionEvent.ACTION_DOWN:
			Log.i(tag, "MainActivity-onTouchEvent-ACTION_DOWN...");
			break;
		case MotionEvent.ACTION_UP:
			Log.i(tag, "MainActivity-onTouchEvent-ACTION_UP...");
			break;
		default:break;
		}
		return super.onTouchEvent(event);
	}

最终一次点击，打印信息如下:

testBtn.setOnTouchListener(new View.OnTouchListener() {

			@Override
			public boolean onTouch(View v, MotionEvent event) {
				// TODO Auto-generated method stub
				switch(event.getAction()){
				case MotionEvent.ACTION_DOWN:
					Log.i(tag, "testBtn-onTouch-ACTION_DOWN...");
					break;
				case MotionEvent.ACTION_UP:
					Log.i(tag, "testBtn-onTouch-ACTION_UP...");
					break;
				default:break;

				}
				return true;
			}
		});

事件流程为:

    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (mInputEventConsistencyVerifier != null) {
            mInputEventConsistencyVerifier.onTouchEvent(ev, 1);
        }

        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);
                resetTouchState();
            }

            // Check for interception.
            final boolean intercepted;
            if (actionMasked == MotionEvent.ACTION_DOWN
                    || mFirstTouchTarget != null) {
                final boolean disallowIntercept = (mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0;
                if (!disallowIntercept) {
                    intercepted = onInterceptTouchEvent(ev);
                    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.
                intercepted = true;
            }

            // 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;
            if (!canceled && !intercepted) {
                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 (childrenCount != 0) {
                        // Find a child that can receive the event.
                        // Scan children from front to back.
                        final View[] children = mChildren;
                        final float x = ev.getX(actionIndex);
                        final float y = ev.getY(actionIndex);

                        final boolean customOrder = isChildrenDrawingOrderEnabled();
                        for (int i = childrenCount - 1; i >= 0; i--) {
                            final int childIndex = customOrder ?
                                    getChildDrawingOrder(childrenCount, i) : i;
                            final View child = children[childIndex];
                            if (!canViewReceivePointerEvents(child)
                                    || !isTransformedTouchPointInView(x, y, child, null)) {
                                continue;
                            }

                            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.
                                newTouchTarget.pointerIdBits |= idBitsToAssign;
                                break;
                            }

                            resetCancelNextUpFlag(child);
                            if (dispatchTransformedTouchEvent(ev, false, child, idBitsToAssign)) {
                                // Child wants to receive touch within its bounds.
                                mLastTouchDownTime = ev.getDownTime();
                                mLastTouchDownIndex = childIndex;
                                mLastTouchDownX = ev.getX();
                                mLastTouchDownY = ev.getY();
                                newTouchTarget = addTouchTarget(child, idBitsToAssign);
                                alreadyDispatchedToNewTouchTarget = true;
                                break;
                            }
                        }
                    }

                    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.
            if (mFirstTouchTarget == null) {
                // No touch targets so treat this as an ordinary view.
                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;
                while (target != null) {
                    final TouchTarget next = target.next;
                    if (alreadyDispatchedToNewTouchTarget && target == newTouchTarget) {
                        handled = true;
                    } else {
                        final boolean cancelChild = resetCancelNextUpFlag(target.child)
                        || intercepted;
                        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;
    }

可以看到标红的有两句(intercepted = onInterceptTouchEvent(ev);    if (!canceled && !intercepted)  )，它会先调用 intercepted = onInterceptTouchEvent(ev);然后通过if判断。

  public boolean onInterceptTouchEvent(MotionEvent ev) {
        return false;
    }

它就一句话，默认false。也就是说这个谋士默认的意见是，永远不拦截！！！！只要有孩子，就交给孩子们处理吧。下面给出实例说明，新建TestLinearLayout继承自Linearlayout。

package org.yanzi.ui;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.LinearLayout;

public class TestLinearLayout extends LinearLayout{
	private final static String tag = "yan";
	public TestLinearLayout(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
	}

	@Override
	public boolean dispatchTouchEvent(MotionEvent ev) {
		// TODO Auto-generated method stub
		switch(ev.getAction()){
		case MotionEvent.ACTION_DOWN:
			Log.i(tag, "TestLinearLayout-dispatchTouchEvent-ACTION_DOWN...");
			break;
		case MotionEvent.ACTION_UP:
			Log.i(tag, "TestLinearLayout-dispatchTouchEvent-ACTION_UP...");
			break;
		default:break;
		}
		return super.dispatchTouchEvent(ev);
	}

	@Override
	public boolean onInterceptTouchEvent(MotionEvent ev) {
		// TODO Auto-generated method stub
		switch(ev.getAction()){
		case MotionEvent.ACTION_DOWN:
			Log.i(tag, "TestLinearLayout-onInterceptTouchEvent-ACTION_DOWN...");
			break;
		case MotionEvent.ACTION_UP:
			Log.i(tag, "TestLinearLayout-onInterceptTouchEvent-ACTION_UP...");
			break;
		default:break;
		}
		return super.onInterceptTouchEvent(ev);
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		// TODO Auto-generated method stub
		switch(event.getAction()){
		case MotionEvent.ACTION_DOWN:
			Log.i(tag, "TestLinearLayout-onTouchEvent-ACTION_DOWN...");
			break;
		case MotionEvent.ACTION_UP:
			Log.i(tag, "TestLinearLayout-onTouchEvent-ACTION_UP...");
			break;
		default:break;
		}
		return super.onTouchEvent(event);
	}
	

}

布局文件改成:

<RelativeLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <org.yanzi.ui.TestLinearLayout
        android:id="@+id/linearlayout_test"
        android:layout_width="200dip"
        android:layout_height="200dip" >

        <org.yanzi.ui.TestButton
            android:id="@+id/btn_test"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="测试按钮" />
    </org.yanzi.ui.TestLinearLayout>

</RelativeLayout>

在Activity里给这个自定义LinearLayout也注册上onClick监听、onTouch监听。

testLinelayout = (TestLinearLayout)findViewById(R.id.linearlayout_test);
		testLinelayout.setOnTouchListener(new View.OnTouchListener() {
			
			@Override
			public boolean onTouch(View v, MotionEvent event) {
				// TODO Auto-generated method stub
				switch(event.getAction()){
				case MotionEvent.ACTION_DOWN:
					Log.i(tag, "testLinelayout-onTouch-ACTION_DOWN...");
					break;
				case MotionEvent.ACTION_UP:
					Log.i(tag, "testLinelayout-onTouch-ACTION_UP...");
					break;
				default:break;

				}
				return false;
			}
		});
		
		testLinelayout.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				Log.i(tag, "testLinelayout---onClick...");
			}
		});

不复写事件传递里的 任何方法，流程如下:

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