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Instance Variable Names

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INSTANCE VARIABLE ARE NAMES USED TO REFER TO COMPONENTS AND OTHER VALUES/OBJECTS WITHIN AN APPLET.

VARIABLES MUST BE "INTRODUCED" BY DECLARATIONS:

  • THAT APPEARS WITHIN THE APPLET BEFORE THE LIST OF METHOD DEFINITIONS,

  • THAT INCLUDES THE NAME TO BE USED AND THE CLASS OF COMPONENTS TO WHICH IT WILL REFER.
    public class VertSlider extends AppletTemplate
    {
    	Slider vertControl, horizControl;
    	
    	public void mouseDown() {
    		...	}
    	...
    }
    



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Williams College
Department of Computer Science
This page is part of a section of lecture slides related to " Variables " within the topic "Java -- Executable Web Content". Other slides within this section and other sections of slides for the topic "Java -- Executable Web Content" can be accessed using the links below.
  • Limitations of the Client/Server Model
  • THE CLIENT/SERVER MODEL LIMITS THE WEB
  • FORMS PROVIDE LIMITED INTERACTIVITY
  • How Applets Fit
  • ACTIVE DOCUMENTS
  • JAVA
  • Applet Structure
  • APPLET STRUCTURE
  • METHOD STRUCTURE
  • METHOD PARAMETERS
  • Event Handling
  • THE "EVENT" INTERFACE
  • Basics of Java Graphics
  • IDENTIFYING PIXELS
  • THE "Pen" INTERFACE
  • GRAPHIC PRIMITIVES
  • DRAWING TEXT
  • OPTIONAL PARAMETERS
  • LINE DRAWING
  • Shape Drawing Methods
  • SHAPE DRAWING
  • SHAPE DRAWING (cont.)
  • CLEAR METHODS
  • DRAWING + CLEARING = INVERSION
  • Specifying Colors
  • User Interface Components
  • User Interface Components
  • Component Constructors
  • The Slider Constructor Method
  • The Slider Constructor Method (cont.)
  • Variables
  • Naming Components
  • Instance Variable Names
  • Associating Names with Components
  • Component Layout Management
  • Adding Components to the Display
  • The Layout Manager
  • Event Handlers for Components
  • Component Event Handlers
  • THE scroll METHOD
  • COMPONENT ACCESS METHODS
  • THE SLIDER getValue METHOD
  • More on Methods
  • PUBLIC VS. PRIVATE
  • PRIVATE METHODS
  • VOID vs. NON-VOID METHODS
  • FUNCTIONS