触摸屏虚拟键盘 Android Touch事件传递机制全面解析（从WMS到View树）(8)

if (mFirstTouchTarget == null) { // 假设没有子view接受该事件，则直接把当前的ViewGroup当作普通的View看待，把事件传递给自己（详见dispatchTransformedTouchEvent方法，注意第三个参数传递的是null）。

handled = dispatchTransformedTouchEvent(ev, canceled, null, TouchTarget.ALL_POINTER_IDS); } else { // 假设之前的DOWN事件被子view消费掉了。就会直接找到该子View相应的Target，将MOVE或UP事件传递给它们。 TouchTarget predecessor = null; TouchTarget target = mFirstTouchTarget; while (target != null) { final TouchTarget next = target.next; if (alreadyDispatchedToNewTouchTarget && target == newTouchTarget) { //假设该事件已经被消费掉了，则不再进行分发（该分支主要针对DOWN事件） handled = true; } else { //否则。就直接将DOWN或UP事件分发给目标Target（之前消费DOWN事件的view相应的target，注意dispatchTransformedTouchEvent的第三个参数为target.child），这里要注意的是，假设intercepted为true，也就是MOVE或UP事件被拦截了，则cancelChild为true，则会分发一次CANCLE事件（注意dispatchTransformedTouchEvent的第二个参数）。 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; } } // 假设当前事件是CANCLE或UP。会调用resetTouchState方法。清空Touch状态，这里会清空mFirstTouchTarget链表，并将mFirstTouchTarget置为null 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; }

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