The source of the information contained by this panel when the information transitions from another panel to this one. By default it is null, indicating the information does not transition from any other particular panel.
Dismisses the panel, triggering the end of its life. It will be removed from the frontend, causing onRemovedFromFrontend to be called and preventing it from being shown again. May not be called if the panel has not been added to a frontend.
Called when the panel is attached to the system UI. The panel may be detached and attached multiple times, for example on configuration changes. However, a panel will never be attached multiple times at once.
Called when the panel has been dismissed from the system UI, either through user interaction or other events. This triggers the end of the life of a panel; it will be removed from the frontend, causing onRemovedFromFrontend to be called and preventing it from being shown again in the system UI.