acm.program
Class GraphicsProgram

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--java.awt.Panel
                    |
                    +--java.applet.Applet
                          |
                          +--javax.swing.JApplet
                                |
                                +--acm.program.Program
                                      |
                                      +--acm.program.GraphicsProgram

public abstract class GraphicsProgram

extends Program

This class is a standard subclass of Program whose principal window is used for drawing graphics.

Method Summary

void	add(GObject gobj) Adds a new graphical object to this container.
void	add(GObject gobj, double x, double y) Adds the graphical object to this canvas and sets its location to the point (x, y).
void	add(GObject gobj, GPoint pt) Adds the graphical object to this canvas and sets its location to the specified point.
void	addKeyListeners() Adds the program as a KeyListener to the canvas.
void	addKeyListeners(KeyListener listener) Adds the specified listener as a KeyListener to the canvas.
void	addMouseListeners() Adds the program as both a MouseListener and MouseMotionListener to the canvas.
void	addMouseListeners(EventListener listener) Adds the specified listener as a MouseListener and/or MouseMotionListener, as appropriate, to the canvas.
GObject	getElement(int index) Returns the graphical object at the specified index, numbering from back to front in the the z dimension.
GObject	getElementAt(double x, double y) Returns the topmost graphical object that contains the point (x, y), or null if no such object exists.
GObject	getElementAt(GPoint pt) Returns the topmost graphical object that contains the specified point, or null if no such object exists.
int	getElementCount() Returns the number of graphical objects stored in this GCanvas.
GCanvas	getGCanvas() Returns the GCanvas object used by this program.
void	init() The init method is called at startup time before the run method is called.
Iterator	iterator() Returns an Iterator that cycles through the elements within this container in the default direction, which is from back to front.
Iterator	iterator(int direction) Returns an Iterator that cycles through the elements within this container in the specified direction, which must be one of the constants FRONT_TO_BACK or BACK_TO_FRONT from the GContainer interface.
void	remove(GObject gobj) Removes a graphical object from this container.
void	removeAll() Removes all graphical objects from this container.
void	run() Contains the code to be executed for each specific program subclass.
void	waitForClick() Waits for a mouse click in the window before proceeding.

Inherited Method Summary

IOConsole	getConsole() Returns the console associated with this program.
IODialog	getDialog() Returns the dialog used for user interaction.
BufferedReader	getReader() Returns a BufferedReader whose input comes from the console.
String	getTitle() Gets the title of this program.
PrintWriter	getWriter() Returns a PrintWriter whose output is directed to the console.
void	pause(double milliseconds) Delays the calling thread for the specified time, which is expressed in milliseconds.
void	print(String value) Displays the argument value on the console, leaving the cursor at the end of the output.
void	println() Advances the console cursor to the beginning of the next line.
void	println(String value) Displays the argument value on the console and then advances the cursor to the next line.
boolean	readBoolean() Reads and returns a boolean value (true or false).
boolean	readBoolean(String prompt) Prompts the user to enter a boolean value.
boolean	readBoolean(String prompt, String trueLabel, String falseLabel) Prompts the user to enter a boolean value, which is matched against the labels provided.
double	readDouble() Reads and returns a double-precision value from the user.
double	readDouble(String prompt) Prompts the user to enter a double-precision number, which is returned as the value of this method.
int	readInt() Reads and returns an integer value from the user.
int	readInt(String prompt) Prompts the user to enter an integer.
String	readLine() Reads and returns a line of input from the console.
String	readLine(String prompt) Prompts the user for a line of input.
void	setTitle(String title) Sets the title of this program.

Method Detail

public void add(GObject gobj)

Adds a new graphical object to this container.

Usage:

add(gobj);

Parameter:

gobj	The graphical object to add

public final void add(GObject gobj, double x, double y)

Adds the graphical object to this canvas and sets its location to the point (x, y).

Usage:

add(gobj, x, y);

Parameters:

gobj	The graphical object to add
x	The new x-coordinate for the object
y	The new y-coordinate for the object

public final void add(GObject gobj, GPoint pt)

Adds the graphical object to this canvas and sets its location to the specified point.

Usage:

add(gobj, pt);

Parameters:

gobj	The graphical object to add
pt	The new coordinates of the point

public void addKeyListeners()

Adds the program as a KeyListener to the canvas.

Usage:

addKeyListeners();

public void addKeyListeners(KeyListener listener)

Adds the specified listener as a KeyListener to the canvas.

Usage:

addKeyListeners(listener);

Parameter:

listener

A KeyListener object

public void addMouseListeners()

Adds the program as both a MouseListener and MouseMotionListener to the canvas.

Usage:

addMouseListeners();

public void addMouseListeners(EventListener listener)

Adds the specified listener as a MouseListener and/or MouseMotionListener, as appropriate, to the canvas.

Usage:

addMouseListeners(listener);

Parameter:

listener

A listener object that is either a MouseListener, a MouseMotionListener, or both

public GObject getElement(int index)

Returns the graphical object at the specified index, numbering from back to front in the the z dimension.

Usage:

GObject gobj = getElement(index);

Parameter:

index

The index of the component to return

Returns:

The graphical object at the specified index

public GObject getElementAt(double x, double y)

Returns the topmost graphical object that contains the point (x, y), or null if no such object exists.

Usage:

GObject gobj = program.getElementAt(x, y);

Parameters:

x	The x-coordinate of the point being tested
y	The y-coordinate of the point being tested

Returns:

The graphical object at the specified location, or nullif no such object exists.

public final GObject getElementAt(GPoint pt)

Returns the topmost graphical object that contains the specified point, or null if no such object exists.

Usage:

GObject gobj = program.getElementAt(pt);

Parameter:

pt	The coordinates being tested

Returns:

The graphical object at the specified location, or nullif no such object exists

public int getElementCount()

Returns the number of graphical objects stored in this GCanvas.

Usage:	int n = getElementCount();
Returns:	The number of graphical objects in this GCanvas

public GCanvas getGCanvas()

Returns the GCanvas object used by this program.

Usage:	GCanvas gc = getGCanvas();
Returns:	The GCanvas object used by the program

public void init()

The init method is called at startup time before the run method is called. Subclasses can override this method to perform any initialization code that would ordinarily be included in an applet init method.

Usage:

program.init();

public Iterator iterator()

Returns an Iterator that cycles through the elements within this container in the default direction, which is from back to front. You can also run the iterator in the opposite direction by using the iterator(direction) form of this method.

Applets that want to run in browsers, however, should avoid using this method, because Iterator is not supported on 1.1 browsers. For maximum portability, you should rely instead on the getElementCount and getElement methods, which provide the same functionality in a browser-compatible way.

Usage:	Iterator i = iterator();
Returns:	An Iterator ranging over the elements of the container from back to front

public Iterator iterator(int direction)

Returns an Iterator that cycles through the elements within this container in the specified direction, which must be one of the constants FRONT_TO_BACK or BACK_TO_FRONT from the GContainer interface.

for (Iterator i = iterator(direction); i.hasNext(); )

Applets that want to run in browsers, however, should avoid using this method, because Iterator is not supported on 1.1 browsers. For maximum portability, you should rely instead on the getElementCount and getElement methods, which provide the same functionality in a browser-compatible way.

Usage:	Iterator i = iterator(direction);
Returns:	An Iterator ranging over the elements of the container in the specified direction

public void remove(GObject gobj)

Removes a graphical object from this container.

Usage:

remove(gobj);

Parameter:

gobj	The graphical object to remove

public void removeAll()

Removes all graphical objects from this container. Note that this definition overrides the Container version of removeAll, which is replaced by removeAllComponents.

Usage:

removeAll();

public void run()

Contains the code to be executed for each specific program subclass. If you are defining your own GraphicsProgram class, you need to override the definition of run so that it contains the code for your application.

public void waitForClick()

Waits for a mouse click in the window before proceeding.

Usage:

waitForClick();