Label Class Diagram

Ancestor class specifications:

java.lang.Object
java.awt.Component

Label Class Specification

Invariant

A Label object...

- is a string of text.

- should be added to a container object with its upper-left corner x pixels from the left and y pixels from the top. (The upper left corner of the container is (0, 0).)

- when it is contained within a proper GUI container the value of text is displayed in color foreColor in a rectangular region; this region has a background color of backColor.

Below is a Label with text == "message", a white backColor and a black foreColor.

Constructor Methods

public Label( String s )

post: A new Label object is created

and text == s

and foreColor == Color.black and backColor is transparent

(Note that Labels don't appear until added.)

Update Methods

public void setBackground( java.awt.Color c )

post: backColor == c

public void setForeground (java.awt.Color c )

post: foreColor == c

public void setBounds( int initX, int initY, int w, int h)

post: x == initX and y == initY

and width == w and height == h

public void setText( String s )

post: text == s

public void repaint( )

post: Causes the Java virtual machine to update the display of this object as soon as possible.

Query Methods

public java.awt.Color getBackground( )

post: result == backColor

public java.awt.Color getForeground( )

post: result == foreColor

public int getX( )

post: result == x

public int getY( )

post: result == y

public int getWidth( )

post: result == width

public int getHeight( )

post: result == height

publicString getText( )

post: result == text