A Layer is a fundamental UI building block for defining visible UI elements of Frames. A Layer is an element of an Layers array defined in a Frame. Layer XML elements, as a part of Layers array, can be defined on any Frame, which includes elements like Buttons and CheckButtons.
- Texture ... - 0 or more Textures to be rendered in the Layer
- FontString ... - 0 or more FontStrings to be rendered in the Layer
- level (DRAWLAYER) - Layer level in 'Z order'. Default is 'ARTWORK'.
- textureSubLevel (int) - sub-level of 'level' for textures. Range of -8 .. 7. Default is '0'.
An Layer is a fundemental UI construct for defining visible renderable elements of Frames. An Layer is an element of an Layers array defined in a Frame. Layer XML elements, as a part of Layers array, can be defined on any Frame, which also includes Buttons and CheckButtons.
<Frame name="MyFrame"> <Layers> <Layer> <Texture> <Size x="100" y="100" /> <HitRectInsets> <AbsInset left="0" right="-100" top="0" bottom="0"/> </HitRectInsets> <Color a="1" r="1" g="1" b="1" /> </Texture> <Texture> <Size x="100" y="100" /> <Color a="1" r="1" g="1" b="1" /> </Texture> </Layer> </Layers> </Frame>
This example will show a frame with a single default layer, displaying two textures.
There are 3 main levels of layer: BACKGROUND is in the back, ARTWORK is in the middle, and OVERLAY is in front. If you want to be sure that a object is before another, you must specify the level where you want to place it.
- BACKGROUND - Level 0. Place the background of your frame here.
- BORDER - Level 1. Place the border of your frame here.
- ARTWORK - Level 2. Place the artwork of your frame here.
- OVERLAY - Level 3. Place your text, objects, and buttons in this level.
- HIGHLIGHT - Level 4. Special layer that only shows on mouseover.
Elements in the 'HIGHLIGHT' Layer are automatically shown or hidden when the mouse enters or leaves. For Highlighting to work you need 'enableMouse="true"' in your <Frame> attributes.
<Layers> <Layer level="BACKGROUND"> ... </Layer> <Layer level="ARTWORK"> ... </Layer> <Layer level="OVERLAY"> ... </Layer> </Layers>
This allows for fine tuning order of Textures in a Layer. FontStrings are always drawn on top of Textures at the same Level, so this only applies to Textures.
- wowInterface forums - discussion on Layer mechanics for patch 4.0 and newer