Input handling

  • Can define keyUp:, keyDown:, leftMouseDown: middleDoubleClick:, etc., for any morph.

  • Argument is a ui2Event. Encodes type, state at time of event, source hand, etc.,

  • Events are processed in order

Input handling

In general, we can make a morph sensitive to input events by defining these methods appropriately: 

	keyUp:, keyDown:
	leftMouseUp: leftMouseDown:, middleMouseUp, rightMouseUp,...
	leftDoubleClick:, middleDoubleClick, rightDoubleClick:
	mouseMove:

Morphic represents user actions such as pressing a key or mouse button using ui2Event objects. A ui2Event actually carries two kinds of information: its type, such as "leftMouseDown", and the state of the mouse buttons and certain keyboard keys when the event occurred. This allows a program to tell, for example, if the shift key was held down when the left mouse button was pressed. As events occur, they are placed into a buffer. Morphic removes and processes events from this buffer in order. Thus, even if a user occasionally gets ahead of the system, the system will eventually catch up.

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