Class for a bubble dragger. It moves things on the bubble canvas around the workspace when they are being dragged by a mouse or touch. These can be block comments, mutators, warnings, or workspace comments.
The item on the bubble canvas to drag.
The workspace to drag on.
Execute a step of bubble dragging, based on the given event. Update the display accordingly.
The most recent move event.
How far the pointer has moved from the position at the start of the drag, in pixel units.
Finish a bubble drag and put the bubble back on the workspace.
The mouseup/touchend event.
How far the pointer has moved from the position at the start of the drag, in pixel units.
Fake class which should be extended to avoid inheriting static properties