【collapseMode】

Important: this config is only effective for collapsible Panels which are direct child items of a border layout.

When not a direct child item of a border layout, then the Panel's header remains visible, and the body is collapsed to zero dimensions. If the Panel has no header, then a new header (orientated correctly depending on the collapseDirection) will be inserted to show a the title and a re- expand tool.

When a child item of a border layout, this config has three possible values:

• undefined - When collapsed, a placeholder Header is injected into the layout to represent the Panel and to provide a UI with a Tool to allow the user to re-expand the Panel.

• "header" - The Panel collapses to leave its header visible as when not inside a border layout.

• "mini" - The Panel collapses without a visible header.