Layer terminology

Unpoly allows you to stack multiple pages on top of each other. Each stack element is called a layer.

The kind of layer (e.g. a modal dialog vs. a popup box) is called mode.

The initial page is called the root layer. An overlay is any layer that is not the root layer.

Available modes

Mode	Description	Overlay?
`root`	The initial page	no
`modal`	A modal dialog box	yes
`drawer`	A drawer sliding in from the side	yes
`popup`	A popup menu anchored to a link	yes
`cover`	An overlay covering the entire screen	yes

The default mode for new overlays is modal. You can change this in up.layer.config.mode.

You may configure default attributes for each layer mode in up.layer.config.