Question

I am writing a UI library in which i would like to be able to have the alpha of the UIViews as if the UIViewGroupOpacity info.plist ket was set. See following links:

Make UIView and subviews translucent as one layer, not individually

iOS controlling UIView alpha behaviour for subviews

But, as I am writing a lib, I dont want the projects to have to set this global key, and effect the behaviour of the main project.

Is there any other way of achieving this? I dont want to cycle through all the subviews and set alpha of each subview, as the project that includes my lib might have this key enabled…

Answer 1

Yes there is, you can set shouldRasterize of the view’s layer.

containerView.layer.shouldRasterize = YES;
// Not setting rasterizationScale, will cause blurry images on retina displays:
containerView.layer.rasterizationScale = [[UIScreen mainScreen] scale];

This will have the same effect as UIViewGroupOpacity but only for containerView and it’s subviews.