ViewGroup事件分发处理

来源：互联网发布：淘宝新店第一天刷几单编辑：程序博客网时间：2024/05/24 06:49

https://www.processon.com/diagraming/56cd741de4b08c023484cedf

public boolean dispatchTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
final float xf = ev.getX();
final float yf = ev.getY();
final float scrolledXFloat = xf + mScrollX;
final float scrolledYFloat = yf + mScrollY;
final Rect frame = mTempRect;
boolean disallowIntercept = (mGroupFlags & FLAG_DISALLOW_INTERCEPT) != 0;
if (action == MotionEvent.ACTION_DOWN) {
if (mMotionTarget != null) {
mMotionTarget = null;
}
if (disallowIntercept || !onInterceptTouchEvent(ev)) {
ev.setAction(MotionEvent.ACTION_DOWN);
final int scrolledXInt = (int) scrolledXFloat;
final int scrolledYInt = (int) scrolledYFloat;
final View[] children = mChildren;
final int count = mChildrenCount;
for (int i = count - 1; i >= 0; i--) {
final View child = children[i];
if ((child.mViewFlags & VISIBILITY_MASK) == VISIBLE
|| child.getAnimation() != null) {
child.getHitRect(frame);
if (frame.contains(scrolledXInt, scrolledYInt)) {
final float xc = scrolledXFloat - child.mLeft;
final float yc = scrolledYFloat - child.mTop;
ev.setLocation(xc, yc);
child.mPrivateFlags &= ~CANCEL_NEXT_UP_EVENT;
if (child.dispatchTouchEvent(ev)) {
mMotionTarget = child;
return true;
}
}
}
}
}
}
boolean isUpOrCancel = (action == MotionEvent.ACTION_UP) ||
(action == MotionEvent.ACTION_CANCEL);
if (isUpOrCancel) {
mGroupFlags &= ~FLAG_DISALLOW_INTERCEPT;
}
final View target = mMotionTarget;
if (target == null) {
ev.setLocation(xf, yf);
if ((mPrivateFlags & CANCEL_NEXT_UP_EVENT) != 0) {
ev.setAction(MotionEvent.ACTION_CANCEL);
mPrivateFlags &= ~CANCEL_NEXT_UP_EVENT;
}
return super.dispatchTouchEvent(ev);
}
if (!disallowIntercept && onInterceptTouchEvent(ev)) {
final float xc = scrolledXFloat - (float) target.mLeft;
final float yc = scrolledYFloat - (float) target.mTop;
mPrivateFlags &= ~CANCEL_NEXT_UP_EVENT;
ev.setAction(MotionEvent.ACTION_CANCEL);
ev.setLocation(xc, yc);
if (!target.dispatchTouchEvent(ev)) {
}
mMotionTarget = null;
return true;
}
if (isUpOrCancel) {
mMotionTarget = null;
}
final float xc = scrolledXFloat - (float) target.mLeft;
final float yc = scrolledYFloat - (float) target.mTop;
ev.setLocation(xc, yc);
if ((target.mPrivateFlags & CANCEL_NEXT_UP_EVENT) != 0) {
ev.setAction(MotionEvent.ACTION_CANCEL);
target.mPrivateFlags &= ~CANCEL_NEXT_UP_EVENT;
mMotionTarget = null;
}
return target.dispatchTouchEvent(ev);
}

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