安卓筆記俠

@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
      ...省略
           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;
           }

          ...省略
       return handled;
}

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

public boolean dispatchTouchEvent(MotionEvent ev) {
 ...省略
              final View[] children = mChildren;
              for (int i = childrenCount - 1; i >= 0; i--) {
                            final int childIndex = customOrder
                                    ? getChildDrawingOrder(childrenCount, i) : i;
                            final View child = (preorderedList == null)
                                    ? children[childIndex] : preorderedList.get(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 (!canViewReceivePointerEvents(child)
                                    || !isTransformedTouchPointInView(x, y, child, null)) {
                                ev.setTargetAccessibilityFocus(false);
                                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();
                                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();
                                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);
                        }

 ...省略

}

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.
       final int oldAction = event.getAction();
       if (cancel || oldAction == MotionEvent.ACTION_CANCEL) {
           event.setAction(MotionEvent.ACTION_CANCEL);
           if (child == null) {
               handled = dispatchTouchEvent(event);
           } else {
               handled = child.dispatchTouchEvent(event);
           }
           event.setAction(oldAction);
           return handled;
       }
 ...省略      
}

public boolean dispatchTouchEvent(MotionEvent event) {
      ...省略
       boolean result = false;
       if (onFilterTouchEventForSecurity(event)) {
           //noinspection SimplifiableIfStatement
           ListenerInfo li = mListenerInfo;
           if (li != null && li.mOnTouchListener != null
                   && (mViewFlags & ENABLED_MASK) == ENABLED
                   && li.mOnTouchListener.onTouch(this, event)) {
               result = true;
           }

           if (!result && onTouchEvent(event)) {
               result = true;
           }
       }
    ...省略
       return result;
   }

public boolean onTouchEvent(MotionEvent event) {
     ...省略
       final int action = event.getAction();
       if (((viewFlags & CLICKABLE) == CLICKABLE ||
               (viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE) ||
               (viewFlags & CONTEXT_CLICKABLE) == CONTEXT_CLICKABLE) {
           switch (action) {
               case MotionEvent.ACTION_UP:
                   boolean prepressed = (mPrivateFlags & PFLAG_PREPRESSED) != 0;
                   if ((mPrivateFlags & PFLAG_PRESSED) != 0 || prepressed) {
                       // take focus if we don't have it already and we should in
                       // touch mode.
                       boolean focusTaken = false;
                      
                       if (!mHasPerformedLongPress && !mIgnoreNextUpEvent) {
                           // 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();
                               }
                           }
                       }
      ...省略    
       }
       return true;
      }          
      return false;
   }

public boolean performClick() {
    final boolean result;
    final ListenerInfo li = mListenerInfo;
    if (li != null && li.mOnClickListener != null) {
        playSoundEffect(SoundEffectConstants.CLICK);
        li.mOnClickListener.onClick(this);
        result = true;
    } else {
        result = false;
    }

    sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);
    return result;
}

public boolean dispatchTouchEvent(MotionEvent ev) {
boolean result=false;
if(onInterceptTouchEvent(ev)){
      result=onTouchEvent(ev);

 }else{
      result=child.dispatchTouchEvent(ev);
}
return result;