During recording, the EventRecorder subscribes to all events of the normal morphic hand, and saves them as they occur.

For replay, a second playback hand is created that reads events from the recorder and plays them back in the world.

The EventRecorder began with the work of Ted Kaehler and John Malone. This was then signifcantly expanded by Leandro Caniglia and Valeria Murgia as a tutorial aid for the Morphic Wrapper project.

Since that time, I have...
Changed to a simple inboard array for the tape (event storage).
Provided the ability to condense linear mouse movement with interpolation at replay.
Made simple provisions for wrap-around of the millisecond clock.
Eliminated step methods in favor of using the processEvents cycle in the playback hand.
Provided a pause/resume mechanism that is capable of surviving project changes.
Added the ability to spawn a simple 'play me' button that can be saved as a morph.
Caused the playback hand to display its cursor double size for visibility.
Integrated a voice recorder with on-the-fly compression.
This currently does NOT survive project changes, not is its data stored on the tape.
Right now it can only be saved by saving the entire recorder as a morph.
This will be fixed by adding a startSound event at each project change.
We will also convert read/write file to use saveOnFile.
Added a journal file facility for recording sequences that end in a crash.
The above two features can be engaged via the ER's morph menu.
- Dan Ingalls 3/6/99

	commands
	button condense play record setStatusLight: shrink step stepTime stop wantsSteps

	event handling
	handleListenEvent: nextEventToPlay synchronize

	fileIn/Out
	checkTape convertV0Tape: readFrom: readFromV0: readFromV1: readTape readTape: writeCheck writeFileNamed: writeTape writeTape:

	initialization
	addButtons addCustomMenuItems:hand: addJournalFile addVoiceControls buttonFor: caption:voiceRecorder:tape: initialize makeARowForButtons makeASpacer makeStatusLight

	object fileIn

	pause/resume
	pauseIn: resumeIn: resumePlayIn: resumeRecordIn:

	piano rolls
	addMorphsTo:pianoRoll:eventTime:betweenTime:and: encounteredAtTime:inScorePlayer:atIndex:inEventTrack:secsPerTick: justDroppedIntoPianoRoll:event: myDurationInMS

	accessing	top
	button:
	recTime

	commands	top
	button Make a simple button interface for replay only
	condense Shorten the tape by deleting mouseMove events that can just as well be interpolated later at playback time.
	play
	record
	setStatusLight:
	shrink Shorten the tape by deleting mouseMove events that can just as well be interpolated later at playback time.
	step Do some periodic activity. Use startStepping/stopStepping to start and stop getting sent this message. The time between steps is specified by this morph's answer to the stepTime message. The generic version dispatches control to the player, if any. The nasty circumlocation about owner's transformation is necessitated by the flexing problem that the player remains in the properties dictionary both of the flex and the real morph. In the current architecture, only the top renderer's pointer to the player should actually be honored for the purpose of firing.
	stepTime Answer the desired time between steps in milliseconds. This default implementation requests that the 'step' method be called once every second.
	stop Stop running my script. For ordinary morphs, this means stop stepping.
	wantsSteps Return true if the receiver overrides the default Morph step method.

	event handling	top
	handleListenEvent: Record the given event
	nextEventToPlay Return the next event when it is time to be replayed. If it is not yet time, then return an interpolated mouseMove. Return nil if nothing has happened. Return an EOF event if there are no more events to be played.
	synchronize

	fileIn/Out	top
	checkTape See if this tape was already converted to the new format
	convertV0Tape: Convert the tape into the new format
	readFrom: Private
	readFromV0:
	readFromV1:
	readTape
	readTape:
	writeCheck
	writeFileNamed:
	writeTape
	writeTape:

	initialization	top
	addButtons
	addCustomMenuItems:hand: Add morph-specific items to the given menu which was invoked by the given hand. This method provides is invoked both from the halo-menu and from the control-menu regimes.
	addJournalFile In case there is a chance of not regaining control to stop recording and save a file, the EventRecorder can write directly to file as it is recording. This is useful for capturing a sequence that results in a nasty crash.
	addVoiceControls
	buttonFor:
	caption:voiceRecorder:tape:
	initialize
	makeARowForButtons
	makeASpacer
	makeStatusLight

object fileIn

top

	pause/resume	top
	pauseIn: Suspend playing or recording, either as part of a stop command, or as part of a project switch, after which it will be resumed.
	resumeIn: Resume playing or recording after a project switch.
	resumePlayIn:
	resumeRecordIn:

	piano rolls	top
	addMorphsTo:pianoRoll:eventTime:betweenTime:and: a hack to allow for abitrary morphs to be dropped into piano roll
	encounteredAtTime:inScorePlayer:atIndex:inEventTrack:secsPerTick: a hack to allow for abitrary morphs to be dropped into piano roll
	justDroppedIntoPianoRoll:event:
	myDurationInMS

	instance creation	top
	descriptionForPartsBin Answer a description for use in a parts bin
	fromFileNamed:
	readFrom: Create an object based on the contents of aStream.