I represent an interface to the user input devices. There is at least one instance of me named Sensor in the system.

	cursor
	currentCursor currentCursor: cursorPoint cursorPoint: peekPosition

	initialize
	flushEvents shutDown startUp

	joystick
	joystickButtons: joystickOn: joystickXY: testJoystick:

	keyboard
	flushKeyboard kbdTest keyboard keyboardPeek keyboardPressed

	modifier keys
	anyModifierKeyPressed commandKeyPressed controlKeyPressed leftShiftDown macOptionKeyPressed rawMacOptionKeyPressed shiftPressed

	mouse
	anyButtonPressed blueButtonPressed mousePoint noButtonPressed peekButtons peekMousePt redButtonPressed waitButton waitButtonOrKeyboard waitClickButton waitNoButton yellowButtonPressed

	private
	buttons characterForKeycode: primCursorLocPut: primCursorLocPutAgain: primInterruptSemaphore: primKbdNext primKbdPeek primMouseButtons primMousePt primReadJoystick: primSetInterruptKey: primTabletGetParameters: primTabletRead:

	tablet
	hasTablet tabletExtent tabletPoint tabletPressure tabletTimestamp

	user interrupts
	inputProcess installInterruptWatcher interruptWatcherProcess setInterruptKey: userInterruptWatcher

	accessing	top
	eventQueue
	eventQueue:

	cursor	top
	currentCursor The current cursor is maintained in class Cursor.
	currentCursor: The current cursor is maintained in class Cursor.
	cursorPoint Answer a Point indicating the cursor location.
	cursorPoint: Set aPoint to be the current cursor location.
	peekPosition

	initialize	top
	flushEvents Do nothing
	shutDown
	startUp

	joystick	top
	joystickButtons:
	joystickOn:
	joystickXY:
	testJoystick: Sensor testJoystick: 3

	keyboard	top
	flushKeyboard Remove all characters from the keyboard buffer.
	kbdTest Sensor kbdTest
	keyboard Answer the next character from the keyboard.
	keyboardPeek Answer the next character in the keyboard buffer without removing it, or nil if it is empty.
	keyboardPressed Answer true if keystrokes are available.

	modifier keys	top
	anyModifierKeyPressed ignore, however, the shift keys 'cause that's not REALLY a command key
	commandKeyPressed Answer whether the command key on the keyboard is being held down.
	controlKeyPressed Answer whether the control key on the keyboard is being held down.
	leftShiftDown Answer whether the shift key on the keyboard is being held down. The name of this message is a throwback to the Alto, which had independent left and right shift keys.
	macOptionKeyPressed Answer whether the option key on the Macintosh keyboard is being held down. Macintosh specific.
	rawMacOptionKeyPressed Answer whether the option key on the Macintosh keyboard is being held down. Macintosh specific. Clients are discouraged from calling this directly, since it circumvents bert's attempt to eradicate option-key checks
	shiftPressed Answer whether the shift key on the keyboard is being held down.

	mouse	top
	anyButtonPressed Answer whether a mouse button is being pressed.
	blueButtonPressed Answer whether only the blue mouse button is being pressed. This is the third mouse button or cmd+click on the Mac.
	mousePoint Answer a Point indicating the coordinates of the current mouse location.
	noButtonPressed Answer whether any mouse button is not being pressed.
	peekButtons
	peekMousePt
	redButtonPressed Answer true if the red mouse button is being pressed. This is the first mouse button.
	waitButton Wait for the user to press any mouse button and then answer with the current location of the cursor.
	waitButtonOrKeyboard Wait for the user to press either any mouse button or any key. Answer the current cursor location or nil if a keypress occured.
	waitClickButton Wait for the user to click (press and then release) any mouse button and then answer with the current location of the cursor.
	waitNoButton Wait for the user to release any mouse button and then answer with the current location of the cursor.
	yellowButtonPressed Answer whether only the yellow mouse button is being pressed. This is the second mouse button or option+click on the Mac.

	private	top
	buttons
	characterForKeycode: Map the given keycode to a Smalltalk character object. Encoding: A keycode is 12 bits: <4 modifer bits><8 bit ISO character> Modifier bits are: <command><option><control><shift>
	primCursorLocPut: If the primitive fails, try again with a rounded point.
	primCursorLocPutAgain: Do nothing if primitive is not implemented.
	primInterruptSemaphore: Primitive. Install the argument as the semaphore to be signalled whenever the user presses the interrupt key. The semaphore will be signaled once each time the interrupt key is pressed.
	primKbdNext
	primKbdPeek
	primMouseButtons
	primMousePt Primitive. Poll the mouse to find out its position. Return a Point. Fail if event-driven tracking is used instead of polling. Optional. See Object documentation whatIsAPrimitive.
	primReadJoystick: Return the joystick input word for the joystick with the given index in the range [1..16]. Returns zero if the index does not correspond to a currently installed joystick.
	primSetInterruptKey: Primitive. Register the given keycode as the user interrupt key. The low byte of the keycode is the ISO character and its next four bits are the Smalltalk modifer bits <cmd><opt><ctrl><shift>.
	primTabletGetParameters: Answer the pen tablet parameters. For parameters that differ from cursor to cursor, answer those associated with the cursor having the given index. Answer nil if there is no pen tablet. The parameters are: 1. tablet width, in tablet units 2. tablet height, in tablet units 3. number of tablet units per inch 4. number of cursors (pens, pucks, etc; some tablets have more than one) 5. this cursor index 6. and 7. x scale and x offset for scaling tablet coordintes (e.g., to fit the screen) 8. and 9. y scale and y offset for scaling tablet coordintes (e.g., to fit the screen) 10. number of pressure levels 11. presure threshold needed close pen tip switch 12. number of pen tilt angles
	primTabletRead: Answer the pen tablet data for the cursor having the given index. Answer nil if there is no pen tablet. The data is: 1. index of the cursor to which this data applies 2. timestamp of the last state chance for this cursor 3., 4., and 5. x, y, and z coordinates of the cursor (z is typically 0) 6. and 7. xTilt and yTilt of the cursor; (signed) 8. type of cursor (0 = unknown, 1 = pen, 2 = puck, 3 = eraser) 9. cursor buttons 10. cursor pressure, downward 11. cursor pressure, tangential 12. flags

	tablet	top
	hasTablet Answer true if there is a pen tablet available on this computer.
	tabletExtent Answer the full tablet extent in tablet coordinates.
	tabletPoint Answer the current position of the first tablet pointing device (pen, puck, or eraser) in tablet coordinates.
	tabletPressure Answer the current pressure of the first tablet pointing device (pen, puck, or eraser), a number between 0.0 (no pressure) and 1.0 (max pressure)
	tabletTimestamp Answer the time (in tablet clock ticks) at which the tablet's primary pen last changed state. This can be used in polling loops; if this timestamp hasn't changed, then the pen state hasn't changed either.

	user interrupts	top
	inputProcess For non-event image compatibility
	installInterruptWatcher Initialize the interrupt watcher process. Terminate the old process if any.
	interruptWatcherProcess Answer my interrupt watcher process, if any
	setInterruptKey: Register the given keycode as the user interrupt key.
	userInterruptWatcher Wait for user interrupts and open a notifier on the active process when one occurs.

	public	top
	default Answer the default system InputSensor, Sensor.
	startUp This message is sent to registered classes when the system is coming up.