Image Class Diagram

Ancestor class specifications:

java.lang.Object
java.awt.Component
java.awt.Container
javax.swing.JComponent

Image Class Specification

Invariant

An Image object...

- can display a graphical (.gif, .jpeg, or .tiff type) image within a rectangular region.

- 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 rectangle has dimensions given by width and height. (Note that the image will be stretched as necessary to conform to these dimensions.)

- if necessary, the image is clipped to the boundaries of its GUI container.

Below is a castle Image added to My Window.

Constructor Methods

public Image( int initX, int initY, int w, int h )

post: A new Image object is created

and x == 0 and y == 0

and width == 0 and height == 0

(Note that Images don't appear until an image file has been assigned and the Image object has been added to a visible Container.)

public Image( int initX, int initY, int w, int h )

post: A new Image object is created

and x == initX and y == initY

and width == w and height == h

(Note that Images don't appear until an image file has been assigned and the Image object has been added to a visible Container.)

public Image( int initX, int initY, int w, int h, String f )

pre: f is the name of a valid, accessible image file (such as those of type .tiff, .gif or .jpeg)

post: A new Image object is created

and x == initX and y == initY

and width == w and height == h

and the image from file f has been assigned to this

(Note that Images don't appear until the Image object has been added to a visible Container.)

Update Methods

public void setImage( String f )

pre: f is the name of a valid, accessible image file (such as those of type .tiff, .gif or .jpeg)

post: the image from file f has been assigned to this

public void setLocation( int intX, int initY )

post: x == initX and y == initY

public void setSize( int w, int h )

post: width == w and height == h

public void repaint( )

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

Query Methods

public int getX( )

post: result == x

public int getY( )

post: result == y

public int getWidth( )

post: result == width

public int getHeight( )

post: result == height

public java.awt.Container getParent( )

post: this Rectangle is added to a Container

implies result == the Container to which this is added

and this Rectangle is not added implies result == null