	CS 683 Emerging Technologies: Embracing Change Spring Semester, 2001 Morphic Intro
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Contents of Doc 20, Morphic Intro

Reference
Squeak: Object-Oriented Design with Multimedia Applications, Guzdial, Chapter 5


Doc 20, Morphic Intro Slide # 2

Morphic

New interface experiment from Self

Goals were:

Concreteness


Language supports Direct, copy & modify style of programming
Interface supports Immediate & direct access to all parts of application even when running

Uniformity


Language Merges state and behavior Uses objects & messages for everything
Interface Uses graphical objects down to the lowest level Removes the distinction between run and edit

Flexibility


Doc 20, Morphic Intro Slide # 3

Morphs

Live an a world

Can interact with

Its world
Other morphs in the world

Can be programmed with:

Smalltalk code
Tiles and scripts
Graphical wired together (Fabrik)


Doc 20, Morphic Intro Slide # 4

Basic Interaction
Simple Events
Keyboard
Mouse
Drag & Drop


Doc 20, Morphic Intro Slide # 5

Keyboard Events

Three types in order sent

Key down
Key stroke

Contains key pressed

Key up

To handle keyboard events Morph subclass must implement:

handlesKeyboard: anKeyboardEvent

The method must return true for the types of events of interest

Important KeyboardEvent Methods

isKeyDown	anyModifierKeyPressed
isKeyUp	commandKeyPressed
isKeyboard	controlKeyPressed
isKeystroke	macOptionKeyPressed
keyCharacter	shiftPressed
keyValue


Doc 20, Morphic Intro Slide # 6

To Actually handle Keyboard Events
Morph subclass must implement

keyDown: anEvent
keyStroke: anEvent
keyUp: anEvent


Doc 20, Morphic Intro Slide # 7

Handling Mouse Events

A Morph subclass must override one or more of the following methods to be notified of the event

Return true to handle the event

handlesKeyboard: aMouseButtonEvent
handlesMouseDown: aMouseButtonEvent
handlesMouseOver: aMouseButtonEvent
handlesMouseOverDragging: aMouseButtonEvent
handlesMouseStillDown: aMouseButtonEvent

To handle the event implement one of:

mouseDown: aMouseButtonEvent
mouseEnter:  aMouseButtonEvent
mouseEnterDragging:  aMouseButtonEvent
mouseLeave:  aMouseButtonEvent
mouseLeaveDragging:  aMouseButtonEvent
mouseMove:  aMouseButtonEvent
mouseStillDown:  aMouseButtonEvent
mouseStillDownThreshold  aMouseButtonEvent
mouseUp: aMouseButtonEvent


Doc 20, Morphic Intro Slide # 8

Important MouseButtonEvent Methods

isDraggingEvent	anyButtonPressed
isMouse	blueButtonPressed
isMouseDown	cursorPoint
isMouseEnter	redButtonPressed
isMouseLeave	targetPoint
isMouseMove	yellowButtonPressed
isMouseUp
isMove


Doc 20, Morphic Intro Slide # 9

Drawing

To change the image of the Morph subClass

Override the method

drawOn: aCanvas


Doc 20, Morphic Intro Slide # 10

Stepping

Morphs are active

Periodically they are sent the message step

This method can perform animation etc.

The time between sending step is determined by the method

stepTime

This method returns time in milliseconds

To start stepping send:

startStepping

To send stepping send:

endStepping


Doc 20, Morphic Intro Slide # 11

Example

Morph subclass: #TestMorphic
   instanceVariableNames: ''
   classVariableNames: ''
   poolDictionaries: ''
   category: 'Whitney-Morphic'!
   
step
   self world bounds bottom > self bottom
      ifTrue:[self bottom: (self bottom + 3)
   
stepTime
   ^500
   
handlesKeyboard: aKeyBoardEvent
   ^aKeyBoardEvent isKeystroke
   
keyStroke: anEvent
   Transcript 
      show: 'You pressed key ';
      show: anEvent keyCharacter;
      cr.
   
drawOn: aCanvas
   aCanvas
      fillOval: self bounds
      color: Color red

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