Events in Morphic originate in a Hand, pass to a target morph, and are then dispatched by an EventHandler. EventHandlers support redirection of mouse and keyboard activity by specifying and independent recipient object and message selector for each of the possible events. In addition each eventHandler can supply an optional value parameter for distinguishing between, eg, events from a number of otherwise identical source morphs.

The basic protocol of an event handler is to receive a message of the form
mouseDown: event in: targetMorph
and redirect this as one of
mouseDownRecipient perform: mouseDownSelector0
mouseDownRecipient perform: mouseDownSelector1 with: event
mouseDownRecipient perform: mouseDownSelector2 with: event with: targetMorph
mouseDownRecipient perform: mouseDownSelector3 with: event with: targetMorph with: valueParameter
depending on the arity of the mouseDownSelector.

	copying
	veryDeepFixupWith: veryDeepInner:

	events
	click:fromMorph: doubleClick:fromMorph: doubleClickTimeout:fromMorph: gesture:fromMorph: keyStroke:fromMorph: mouseDown:fromMorph: mouseEnter:fromMorph: mouseEnterDragging:fromMorph: mouseLeave:fromMorph: mouseLeaveDragging:fromMorph: mouseMove:fromMorph: mouseStillDown:fromMorph: mouseUp:fromMorph: send:to:withEvent:fromMorph: startDrag:fromMorph:

	fixups
	fixAlansOldEventHandlers fixReversedValueMessages replaceSendsIn:with:

	initialization
	adaptToWorld: forgetDispatchesTo: on:send:to: on:send:to:withValue:

	object fileIn
	convertToCurrentVersion:refStream:

	testing
	handlesClickOrDrag: handlesGesture: handlesGestureStart: handlesKeyboard: handlesMouseDown: handlesMouseMove: handlesMouseOver: handlesMouseOverDragging: handlesMouseStillDown: hasGestureRecipient

	access	top
	allRecipients Answer a list, without duplication, of all the objects serving as recipients to any of the events I handle. Intended for debugging/documentation use only
	firstMouseSelector Answer the selector corresponding to the first mouse-handling selector fielded. Created in support of providing balloon-help for halo handles, triggered by the selector handled
	gestureRecipient
	gestureSelector
	messageList Return a list of 'Class selector' for each message I can send. tk 9/13/97
	methodRefList Return a MethodReference for each message I can send. tk 9/13/97, raa 5/29/01
	mouseDownSelector
	mouseStillDownRecipient
	mouseStillDownSelector
	mouseUpSelector
	printOn: Append to the argument, aStream, a sequence of characters that identifies the receiver.

	copying	top
	veryDeepFixupWith: ALL inst vars were weakly copied. If they were in the tree being copied, fix them up, otherwise point to the originals!!
	veryDeepInner: ALL fields are weakly copied! Can't duplicate an object by duplicating a button that activates it. See DeepCopier.

	events	top
	click:fromMorph: This message is sent only when double clicks are handled.
	doubleClick:fromMorph:
	doubleClickTimeout:fromMorph:
	gesture:fromMorph: Pass the gesture event to the target morph
	keyStroke:fromMorph:
	mouseDown:fromMorph: Take double-clicks into account.
	mouseEnter:fromMorph:
	mouseEnterDragging:fromMorph:
	mouseLeave:fromMorph:
	mouseLeaveDragging:fromMorph:
	mouseMove:fromMorph:
	mouseStillDown:fromMorph:
	mouseUp:fromMorph:
	send:to:withEvent:fromMorph:
	startDrag:fromMorph:

	fixups	top
	fixAlansOldEventHandlers
	fixReversedValueMessages ar 3/18/2001: Due to the change in the ordering of the value parameter old event handlers may have messages that need to be fixed up. Do this here.
	replaceSendsIn:with: Replace all the sends that occur in array1 with those in array2. Used for fixing old event handlers in files.

	initialization	top
	adaptToWorld: If any of my recipients refer to a world or a hand, make them now refer to the corresponding items in the new world. (instVarNamed: is slow, later use perform of two selectors.)
	forgetDispatchesTo: aSelector is no longer implemented by my corresponding Player, so don't call it any more
	on:send:to:
	on:send:to:withValue:

	object fileIn	top
	convertToCurrentVersion:refStream: 20 dec 2000 - only a few (old) conversion exists

	testing	top
	handlesClickOrDrag:
	handlesGesture: Does the associated morph want to handle gestures?
	handlesGestureStart: Does the associated morph want to handle gestures?
	handlesKeyboard:
	handlesMouseDown:
	handlesMouseMove:
	handlesMouseOver:
	handlesMouseOverDragging:
	handlesMouseStillDown:
	hasGestureRecipient

	fixups	top
	fixAlansOldEventHandlers EventHandler fixAlansOldEventHandlers