Flutter PIP 插件 ---- 为iOS 重构PipController, Demo界面，更好的体验

接上文 Flutter PIP 插件 ---- 新增PipActivity，Android 11以下支持自动进入PIP Mode

项目地址 PIP， pub.dev也已经同步发布 pip 0.0.3，你的加星和点赞，将是我继续改进最大的动力

在之前的界面设计中，还原动画等体验一直不太好，遂优化一下，现在体验效果看起来更好了，
唯一一个还没搞定的是应用内还原的动画，应用内还原的时候，有一个从小到达逐渐拉伸的效果，猜测可能是和图片的渲染有关？有大佬能指点一二不？

不再获取PipViewController

前面也讲到这个比较危险，虽然多方求证似乎也没什么，但还是怕，所以改成查找PipWindow，并在pictureInPictureControllerDidStartPictureInPicture通知中把自渲染View添加到rootView中去

- (void)pictureInPictureControllerDidStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {PIP_LOG(@"pictureInPictureControllerDidStartPictureInPicture");#if USE_PIP_VIEW_CONTROLLER// if you use the pipViewController, you must call this every time to bring// the content view to the front, otherwise the content view will not be// visible and covered by the pip host view.if (_pipViewController) {[_pipViewController.view bringSubviewToFront:_contentView];}
#else// TODO @sylar: check if this is the best way to do this, what will happen if// we have multiple windows? what if the root view controller is not a// UIViewController?UIWindow *window = [[UIApplication sharedApplication] windows].firstObject;if (window) {UIViewController *rootViewController = window.rootViewController;UIView *superview = rootViewController.view.superview;[self insertContentViewIfNeeded:superview];} else {PIP_LOG(@"pictureInPictureControllerDidStartPictureInPicture: window is nil");[_pipStateDelegate pipStateChanged:PipStateFailederror:@"Can not find the pip window"];return;}
#endif_isPipActived = YES;[_pipStateDelegate pipStateChanged:PipStateStarted error:nil];
}

遗留项是，这个查找PipWindow的方法靠不靠谱？有其他方法但是看起来也不靠谱

不再每次都将自渲染UIView从PipWindow移除

观察到一个现象是，如果是依赖PipViewController在 pictureInPictureControllerWillStartPictureInPicture 中添加UIView，还必须得在 pictureInPictureControllerDidStartPictureInPicture 中调用一次 bringSubviewToFront，否则的话你会比系统自动添加的View早添加，导致你的层级在下面；改用通过获取PipWindow方式后，就不用在bringSubviewToFront，因为不是一个parent了。

另外一些场景下可能会创建一个悬空的UIView用来做渲染，这样的话我们就没必要每次都把他从PipWindow上移除还原到父parent上，可以在PipWindow显示的一瞬间就立即看到渲染的内容

- (void)pictureInPictureControllerDidStopPictureInPicture:(AVPictureInPictureController *)pictureInPictureController {PIP_LOG(@"pictureInPictureControllerDidStopPictureInPicture");// restore the content view in// pictureInPictureControllerDidStopPictureInPicture will have the best user// experience.[self restoreContentViewIfNeeded];_isPipActived = NO;[_pipStateDelegate pipStateChanged:PipStateStopped error:nil];
}- (void)restoreContentViewIfNeeded {if (_contentView == nil) {PIP_LOG(@"restoreContentViewIfNeeded: contentView is nil");return;}// do not restore the content view if the original parent view is nil or// the content view is already in the original parent view.// keep the content view in the pip view controller will make the user// experience better, the pip content view will be visible immediately.if (_contentViewOriginalParentView == nil ||[_contentViewOriginalParentView.subviews containsObject:_contentView]) {PIP_LOG(@"restoreContentViewIfNeeded: _contentViewOriginalParentView is nil or "@"contentView is already in the original parent view");return;}[_contentView removeFromSuperview];PIP_LOG(@"restoreContentViewIfNeeded: contentView is removed from the original "@"parent view");if (_contentViewOriginalParentView != nil) {// in case that the subviews of _contentViewOriginalParentView has been// changed, we need to get the real index of the content view.NSUInteger trueIndex = MIN(_contentViewOriginalParentView.subviews.count,_contentViewOriginalIndex);[_contentViewOriginalParentView insertSubview:_contentViewatIndex:trueIndex];PIP_LOG(@"restoreContentViewIfNeeded: contentView is added to the original "@"parent view "@"at index: %lu",trueIndex);// restore the original frame_contentView.frame = _contentViewOriginalFrame;// restore the original constraints[_contentView removeConstraints:_contentView.constraints.copy];[_contentView addConstraints:_contentViewOriginalConstraints];// restore the original translatesAutoresizingMaskIntoConstraints_contentView.translatesAutoresizingMaskIntoConstraints =_contentViewOriginalTranslatesAutoresizingMaskIntoConstraints;// restore the original parent view[_contentViewOriginalParentViewremoveConstraints:_contentViewOriginalParentView.constraints.copy];[_contentViewOriginalParentViewaddConstraints:_contentViewOriginalParentViewConstraints];}
}

支持动态设置PipWindow窗口大小

这个没什么好说的，修改创建contentSource的时候的sampleBufferDisplayer的大小就可以动态修改PipWindow窗口大小，判断各种对象都已经有了的话就只修改大小而不用重新创建controller就行了

if (options.preferredContentSize.width > 0 &&options.preferredContentSize.height > 0) {[_pipViewupdateFrameSize:CGSizeMake(options.preferredContentSize.width,options.preferredContentSize.height)];
}

重要的事情说三遍

项目地址 PIP， pub.dev也已经同步发布 pip 0.0.3，你的加星和点赞，将是我继续改进最大的动力

项目地址 PIP， pub.dev也已经同步发布 pip 0.0.3，你的加星和点赞，将是我继续改进最大的动力

项目地址 PIP， pub.dev也已经同步发布 pip 0.0.3，你的加星和点赞，将是我继续改进最大的动力