寻找最近的公共父视图
- (instancetype)mas_closestCommonSuperview:(MAS_VIEW *)view {
MAS_VIEW *closestCommonSuperview = nil;
MAS_VIEW *secondViewSuperview = view;
// 先是用view和self及self的父视图们挨个的比较,然后是用view的父视图们和self及self的父视图们挨个的比较
// 这个while结束的条件是:1、内部while找到了closestCommonSuperview;2、找遍了传进来的view的所有父视图后secondViewSuperview变成了nil
while (!closestCommonSuperview && secondViewSuperview) {
MAS_VIEW *firstViewSuperview = self;
// 这个while结束的条件是:1、self或者self的父视图们中有一个 和传进来的view是同一个视图;2、找遍了所有的父视图后firstViewSuperview变成了nil
while (!closestCommonSuperview && firstViewSuperview) {
if (secondViewSuperview == firstViewSuperview) {
closestCommonSuperview = secondViewSuperview;
}
firstViewSuperview = firstViewSuperview.superview;
}
secondViewSuperview = secondViewSuperview.superview;
}
return closestCommonSuperview;
}