JFrame Class Diagram

Ancestor class specifications:

java.lang.Object
java.awt.Component
java.awt.Container
java.awt.Window
java.awt.Frame

JFrame Class Specification

Invariant

A JFrame object...

- is a rectangular window.

- is placed on a computer screen with its upper-left corner x pixels from the left and y pixels from the top. (The upper left corner of the screen is (0, 0).)

- has usable dimension of width pixels from side to side and height pixels from top to bottom; this region has a background color of backColor.

- has title displayed in the window's title bar

Below is a JFrame with a gray backColor on a white screen.

Constructor Methods

public JFrame( String s )

post: A new JFrame (window) object is created

and title == s

(Note that this method needs to be followed by calls to setBounds and setVisible in order to make the object appear.)

Update Methods

public void add( java.awt.Component c, int j )

pre: j == 0 for best results

post: The pic graphical object will be drawn upon the content pane of this JFrame

public void remove( java.awt.Component c )

post: The pic graphical object will be removed from this JFrame

note: Nothing occurs if pic was not added to this JFrame at the time of the call.

public void repaint( )

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

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 setLayout( java.awt.LayoutManager m ) )

pre: m == null (for use in this book)

post: Objects added to the frame will be arranged via m

note: In this book an argument of null is suggested.

public void setVisible( boolean b )

post: b == true implies this JFrame is made visible and brought to the foreground (in front of other windows).

public void addKeyListener( java.awt.event.KeyListener lis )

post: Key listener events (keyPressed, keyReleased and keyTyped) have been redirected to the lis object

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