Which way the copies of a pasted array run. A fragment is arrayed across its short axis, so that the copies stack up beside each other rather than end to end: a row of gates laid out left to right becomes a vertical array, and a column of them a horizontal one. Prefixed because CommonTypes.Orientation is Horizontal | Vertical and is used unqualified all over the draw block - two of these cases named the same would shadow it.

Keeps track of the current action that the user is doing

For Keyboard messages. These name draw block *actions*, not keys - KeyTypes decides which chord reaches which. AltC, AltV, AltZ and AltShiftZ used to be here with no dispatcher, and CtrlS with a handler that added a square for a demo.

Used to keep track of what the mouse is on

Possible fields that may (or may not) be used in a dialog popup.

What a right-click has made draggable on one custom component. These used to be reached by holding Ctrl, which meant the affordance appeared on every custom component at once, vanished if the key was released or the window lost focus, and was undiscoverable. A mode entered from the component's own menu applies to that component alone and stays until the user clicks away.

Used to keep mouse movement (AKA velocity) info as well as position