FunnySaltyFish

@leavesCZY 感谢Review 1. 是的，statusBar的隐藏应该在`AnimatedVisibility`内部，用于在查看图片时隐藏掉状态栏，已修正 2. 图片缩放在我写了一段时间后发现不那么容易，要实现流畅的效果，得考虑图片的大小与当前控件的大小，根据缩放比例判断拖动的边界。我已将有关`拖动`的代码删去，目前仅保留双击放大的效果。 3. 为`Activity`设置主题的原因是，在我引入项目时发现，如果整个`Application`没有设置主题，那么`MatisseActivity`默认会有个标题栏（也就是应用名字）与页面重叠，因此对`Activity`本身提前加入了`Theme`。至于`windowNoTitle`是否是必须的，我未做额外考量，只是加上了。

As far as I know, not yet. The library was just finished one week ago. One of my applications uses the library but the relevant codes are not open source...

Ok, it can help maintain the quality of the list, I agree. However, may I ask you to please keep this PR open for some time? Maybe passer-by can know...

Got it, I'll close the PR.