Get start (top-left) corner of the popup if drawAnchored is to be used.
Draw the popup using the assigned anchor position.
Give focus to whatever node had focus before this one.
Position the frame is "anchored" to. A corner of the frame will be chosen to match this position.
A child popup will keep this focus alive while focused. Typically, child popups are spawned as a result of actions within the popup itself, for example in context menus, an action can spawn a submenu. Use spawnChildPopup to spawn child popups.
Node that had focus before popupFrame took over. When the popup is closed using a keyboard shortcut, this node will take focus again.
Handle input. Called each frame when focused.
Set focus to this node.
Check if this node has focus. Recommended implementation: return tree.focus is this. Proxy nodes, such as FluidFilePicker might choose to return the value of the node they hold.
Run input actions for the node.
Mixin template to enable input actions in this class.
This is an override of Frame to simplify creating popups: if clicked outside of it, it will disappear from the node tree.