Display regions and layers

Coordinates and default region

A region uses pixel coordinates in the order [top, left, width, height, layer]. A larger layer value places content in front. Query the physical display geometry before setting positions. The initial region is a1; at least one region must remain.

Region names use letters and digits, must be unique, and cannot be default. Web and plugin commands without an area target the default region. Layout is stored on the device; query it when opening an editor.

{"screen":{"action":"display"}}
{"screen":{"action":"list"}}
{"screen":{"action":"add","area":"a2","position":[0,0,960,540,1]}}
{"screen":{"action":"update","area":"a2","position":[60,80,960,540,2]}}
{"screen":{"action":"default","area":"a2"}}

Window states

A window can be closed, open and visible, or open and hidden. Open a closed window; hide a visible one; show a hidden one. Invalid transitions return an error. Clear removes displayed content without deleting the region. Open, close, show and hide without an area apply to all regions.

{"screen":{"action":"hide","area":"a2"}}
{"screen":{"action":"show","area":"a2"}}
{"screen":{"action":"clear","area":"a2"}}

Desktop and Android behavior

Desktop regions use separate borderless windows. Android uses a single application window, so closing or hiding regions does not behave like separate desktop processes. Validate overlapping layouts and display orientation on the target device.