In core animation or in App kit When we say layer-backed view or simply add a layer in the view,then actually what we mean by the layer.
+3
A:
The CALayer is the canvas upon which everything in Core Animation is painted. When you define movement, color changes, image effects, and so on, those are applied to CALayer objects. From a code perspective, CALayers are a lightweight representation similar to an NSView. In fact, NSView objects can be manipulated via their CALayer. This is referred to as being layer-backed.
Iamamac
2010-01-03 06:09:40
Zarra's description there isn't quite right. The "canvas on which everything is painted" is a GL surface, which is owned by the CALayer. It's rather like the relationship between an NSWindow instance and the actual Quartz 2D window that lives in the window server.
NSResponder
2010-01-03 14:36:40
+2
A:
A CALayer is an object which manages and draws upon a GL surface, and can manipulate that surface's location in three dimensions, without needing to redraw its contents.
NSResponder
2010-01-03 08:28:51