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这里我还是统一给出答案吧。我们都知道假设我们不希望我们的ViewGroup阻拦我们的View获得MotionEvent。我们一般仅仅须要在onInterceptTouchEvent这个函数中return false(而且该函数默认return false)。或者,在特定的情况下,假设我们希望某些时候交给我们的我们ViewGroup来处理有些情况下我们又希望我们的View来处理MotionEvent。这样的情况下,我们应该怎么来处理呢。我想大家都知道,我们须要在onInterceptTouchEvent做一些处理,由于大家都知道onInterceptTouchEvent是用来做MotionEvent事件的处理对象推断的。
而是实实在在的重写了全部逻辑(至于View源代码的dispatchTouchEvent,各位看官去我的上一篇博文里面去看看吧)
@Override public boolean dispatchTouchEvent(MotionEvent ev) { if (mInputEventConsistencyVerifier != null) { mInputEventConsistencyVerifier.onTouchEvent(ev, 1); } if (DBG_MOTION || DBG_TOUCH) { Xlog.d(TAG, "(ViewGroup)dispatchTouchEvent 1: ev = " + ev + ",mFirstTouchTarget = " + mFirstTouchTarget + ",this = " + this); } boolean handled = false; if (onFilterTouchEventForSecurity(ev)) { //上一篇博文中提到的遮蔽推断事实上是错误的,这里指的应该是窗体被其它窗体遮挡。非常明显普通情况下是不会的 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);//这里開始推断 /// M : add log to help debugging if (intercepted == true) { if (DBG_TOUCH) { Xlog.d(TAG, "Touch event was intercepted event = " + ev + ",this = " + this); } } 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; if (DBG_MOTION) { Xlog.d(TAG, "(ViewGroup)dispatchTouchEvent 2: actionMasked = " + actionMasked + ",intercepted = " + intercepted + ",canceled = " + canceled + ",split = " + split + ",mChildrenCount = " + mChildrenCount + ",mFirstTouchTarget = " + mFirstTouchTarget + ",this = " + this); } TouchTarget newTouchTarget = null; boolean alreadyDispatchedToNewTouchTarget = false; if (!canceled && !intercepted) { //根据interceptd 分析转折点 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 View[] children = mChildren; 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)) { if (DBG_MOTION) { Xlog.d(TAG, "(ViewGroup)dispatchTouchEvent continue 6: i = " + i + ",count = " + childrenCount + ",child = " + child + ",this = " + this); } continue; } newTouchTarget = getTouchTarget(child); if (DBG_MOTION) { Xlog.d(TAG, "(ViewGroup)dispatchTouchEvent to child 3: child = " + child + ",childrenCount = " + childrenCount + ",i = " + i + ",newTouchTarget = " + newTouchTarget + ",idBitsToAssign = " + idBitsToAssign + ",mFirstTouchTarget = " + mFirstTouchTarget + ",this = " + this); } 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) { if (DBG_MOTION) { Xlog.d(TAG, "(ViewGroup)dispatchTouchEvent mFirstTouchTarget = null, canceled = " + canceled + ",this = " + this); } // 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 (DBG_MOTION) { Xlog.d(TAG, "dispatchTouchEvent middle 5: cancelChild = " + cancelChild + ",mFirstTouchTarget = " + mFirstTouchTarget + ",target = " + target + ",predecessor = " + predecessor + ",next = " + next + ",this = " + this); } 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 (DBG_MOTION) { Xlog.d(TAG, "(ViewGroup)dispatchTouchEvent end 4: handled = " + handled + ",mFirstTouchTarget = " + mFirstTouchTarget + ",this = " + this); } if (!handled && mInputEventConsistencyVerifier != null) { mInputEventConsistencyVerifier.onUnhandledEvent(ev, 1); } return handled; }
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 (DBG_MOTION) { Xlog.d(TAG, "dispatchTransformedTouchEvent 1: event = " + event + ",cancel = " + cancel + ",oldAction = " + oldAction + ",desiredPointerIdBits = " + desiredPointerIdBits + ",mFirstTouchTarget = " + mFirstTouchTarget + ",child = " + child + ",this = " + this); } if (cancel || oldAction == MotionEvent.ACTION_CANCEL) { event.setAction(MotionEvent.ACTION_CANCEL); if (child == null) { handled = super.dispatchTouchEvent(event); } else { handled = child.dispatchTouchEvent(event); } event.setAction(oldAction); if (DBG_MOTION) { Xlog.d(TAG, "Dispatch cancel action end: handled = " + handled + ",oldAction = " + oldAction + ",child = " + child + ",this = " + this); } return handled; } // Calculate the number of pointers to deliver. final int oldPointerIdBits = event.getPointerIdBits(); final int newPointerIdBits = oldPointerIdBits & desiredPointerIdBits; // If for some reason we ended up in an inconsistent state where it looks like we // might produce a motion event with no pointers in it, then drop the event. if (newPointerIdBits == 0) { Xlog.i(TAG, "Dispatch transformed touch event without pointers in " + this); return false; } // If the number of pointers is the same and we don't need to perform any fancy // irreversible transformations, then we can reuse the motion event for this // dispatch as long as we are careful to revert any changes we make. // Otherwise we need to make a copy. final MotionEvent transformedEvent; if (newPointerIdBits == oldPointerIdBits) { if (child == null || child.hasIdentityMatrix()) { if (child == null) { handled = super.dispatchTouchEvent(event); } else { final float offsetX = mScrollX - child.mLeft; final float offsetY = mScrollY - child.mTop; event.offsetLocation(offsetX, offsetY); handled = child.dispatchTouchEvent(event); event.offsetLocation(-offsetX, -offsetY); } if (DBG_MOTION) { Xlog.d(TAG, "dispatchTransformedTouchEvent 2 to child " + child + ",handled = " + handled + ",mScrollX = " + mScrollX + ",mScrollY = " + mScrollY + ",mFirstTouchTarget = " + mFirstTouchTarget + ",event = " + event + ",this = " + this); } return handled; } transformedEvent = MotionEvent.obtain(event); } else { transformedEvent = event.split(newPointerIdBits); } // Perform any necessary transformations and dispatch. if (child == null) { handled = super.dispatchTouchEvent(transformedEvent); } else { final float offsetX = mScrollX - child.mLeft; final float offsetY = mScrollY - child.mTop; transformedEvent.offsetLocation(offsetX, offsetY); if (! child.hasIdentityMatrix()) { transformedEvent.transform(child.getInverseMatrix()); } handled = child.dispatchTouchEvent(transformedEvent); } if (DBG_MOTION) { Xlog.d(TAG, "dispatchTransformedTouchEvent 3 to child " + child + ",handled = " + handled + ",mScrollX = " + mScrollX + ",mScrollY = " + mScrollY + ",mFirstTouchTarget = " + mFirstTouchTarget + ",transformedEvent = " + transformedEvent + ",this = " + this); } // Done. transformedEvent.recycle(); return handled; }
public boolean onInterceptTouchEvent(MotionEvent ev) { return false; }
handled = child.dispatchTouchEvent(transformedEvent);当然 由于我们的MyImageView 也设置了onTouchListener和onClickListener,所以他顺理成章的消费了本次MotionEvent
if (child == null) { handled = super.dispatchTouchEvent(transformedEvent); } else我们的MyFrameLayout 也还是终于享受到了MotionEvent
if (!canceled && !intercepted) { //根据interceptd 分析转折点</span>
if (mFirstTouchTarget == null) { if (DBG_MOTION) { Xlog.d(TAG, "(ViewGroup)dispatchTouchEvent mFirstTouchTarget = null, canceled = " + canceled + ",this = " + this); } // No touch targets so treat this as an ordinary view. handled = dispatchTransformedTouchEvent(ev, canceled, null, TouchTarget.ALL_POINTER_IDS);
@Override public boolean onInterceptTouchEvent(MotionEvent event) { switch(event.getAction()){ case MotionEvent.ACTION_DOWN:{ Log.d(TAG,"MyFrameLayout onInterceptTouchEvent ACTION_DOWN return true"); return true; } case MotionEvent.ACTION_MOVE:{ Log.d(TAG,"MyFrameLayout onInterceptTouchEvent ACTION_MOVE return true"); return true; } case MotionEvent.ACTION_UP:{ Log.d(TAG,"MyFrameLayout onInterceptTouchEvent ACTION_UP return true"); return true; } } return true; }
@Override public boolean onTouchEvent(MotionEvent event) { Log.d(TAG,"MyFrameLayout onTouchEvent"+event.getAction()); switch(event.getAction()){ case MotionEvent.ACTION_DOWN:{ Log.d(TAG,"MyFrameLayout onTouchEvent ACTION_DOWN return true"); break; } case MotionEvent.ACTION_MOVE:{ Log.d(TAG,"MyFrameLayout onTouchEvent ACTION_MOVE return true"); break; } case MotionEvent.ACTION_UP:{ Log.d(TAG,"MyFrameLayout onTouchEvent ACTION_UP return true"); break; } } return super.onTouchEvent(event); }
@Override public boolean onTouchEvent(MotionEvent event) { Log.d(TAG,"MyImageView onTouchEvent"+event.getAction()); switch(event.getAction()){ case MotionEvent.ACTION_DOWN:{ Log.d(TAG,"MyImageView onTouchEvent ACTION_DOWN return true"); break; } case MotionEvent.ACTION_MOVE:{ Log.d(TAG,"MyImageView onTouchEvent ACTION_MOVE return true"); break; } case MotionEvent.ACTION_UP:{ Log.d(TAG,"MyImageView onTouchEvent ACTION_UP return true"); break; } } return super.onTouchEvent(event); }
相同不会OnClickListener
onInterceptTouchEvent 与 onTouchEvent 分析与MotionEvent在ViewGroup与View中的分发
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原文地址:http://www.cnblogs.com/bhlsheji/p/5379100.html