I display a graph of numbers, normalized so the full range of values just fits my height. I support a movable cursor that can be dragged with the mouse.

Implementation notes: Some operations on me may be done at sound sampling rates (e.g. 11-44 thousand times/second). To allow such high bandwidth application, certain operations that change my appearance do not immediately report a damage rectangle. Instead, a flag is set indicating that my display needs to refreshed and a step method reports the damage rectangle if that flag is set. Also, I cache a bitmap of my graph to allow the cursor to be moved without redrawing the graph.

	change reporting
	layoutChanged

	commands
	appendValue: centerCursor clear loadSineWave loadSound: loadSoundData: playOnce reverse

	drawing
	drawOn:

	events
	handlesMouseDown: mouseMove:

	initialization
	initialize

	menu
	addCustomMenuItems:hand: openWaveEditor readDataFromFile

	object fileIn
	convertToCurrentVersion:refStream:

	private
	drawCursorOn: drawDataOn: flushCachedForm keepIndexInView:

	script support

	stepping
	step

	scripting
	additionsToViewerCategories

	accessing	top
	color: Set the receiver's color. Directly set the color if appropriate, else go by way of fillStyle
	cursor vacuous backstop in case it gets sent to a morph that doesn't know what to do with it
	cursor: vacuous backstop in case it gets sent to a morph that doesn't know what to do with it
	cursorAtEnd
	cursorColor
	cursorColor:
	cursorColorAtZeroCrossing
	cursorColorAtZeroCrossings:
	cursorWrapped:
	data
	data:
	dataColor
	dataColor:
	interpolatedValueAtCursor
	lastValue
	lastValue:
	startIndex
	startIndex:
	valueAtCursor
	valueAtCursor:

	change reporting	top
	layoutChanged

	commands	top
	appendValue:
	centerCursor Scroll so that the cursor is as close as possible to the center of my window.
	clear
	loadSineWave
	loadSound:
	loadSoundData:
	playOnce
	reverse

	drawing	top
	drawOn:

	events	top
	handlesMouseDown: Do I want to receive mouseDown events (mouseDown:, mouseMove:, mouseUp:)?
	mouseMove: Handle a mouse move event. The default response is to let my eventHandler, if any, handle it.

	initialization	top
	initialize

	menu	top
	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.
	openWaveEditor
	readDataFromFile

	object fileIn	top
	convertToCurrentVersion:refStream: subclasses should implement if they wish to convert old instances to modern ones

	private	top
	drawCursorOn:
	drawDataOn:
	flushCachedForm
	keepIndexInView:

script support

top

	stepping	top
	step Make a deferred damage rectangle if I've changed. This allows applications to call methods that invalidate my display at high-bandwidth without paying the cost of doing the damage reporting on ever call; they can merely set hasChanged to true.

	parts bin	top
	descriptionForPartsBin If the receiver is a member of a class that would like to be represented in a parts bin, answer the name by which it should be known, and a documentation string to be provided, for example, as balloon help. When the 'nativitySelector' is sent to the 'globalReceiver', it is expected that some kind of Morph will result. The parameters used in the implementation below are for documentation purposes only!

	scripting	top
	additionsToViewerCategories Answer a list of (<categoryName> <list of category specs>) pairs that characterize the phrases this kind of morph wishes to add to various Viewer categories.