csa120.shape
Class Canvas

java.lang.Object
  csa120.shape.Canvas

Direct Known Subclasses:

World

public class Canvas

extends Object

Canvas is a class to allow for simple graphical drawing on a canvas. Drawable objects can be added to and removed from the canvas. The canvas is drawn only when the refresh() method is explicitly called. Furthermore, if this canvas is created by a ControlledThread the refresh() will incur a forced pause or delay based upon the settings of the Controller. This code was originally based upon a general purpose Canvas, made for the BlueJ "shapes" example, by Bruce Quig and Michael Kolling.

Constructor Summary

Canvas(String title, int width, int height)
Create a Canvas (with white background as default)

Canvas(String title, int width, int height, Color bgColor)
Create a Canvas.

Canvas(String title, int width, int height, String bgName)
Create a Canvas.

Method Summary

void	add(Drawable obj) Add a drawable object to the canvas (however canvas is not automatically refreshed)
void	clear() Clear all drawable objects from the canvas (however canvas is not automatically refreshed)
void	destroy() Destroys the canvas, closing the associated window.
Color	getBackgroundColor() Returns current background color
int	getHeight() get the height of the canvas
int	getWidth() get the width of the canvas
void	refresh() Redraw all objects currently on the Canvas and then process desired pause if in a ControlledThread
void	remove(Drawable obj) Remove a drawable object from the canvas (however canvas is not automatically refreshed)
void	setBackgroundColor(Color c) Sets the current background color
void	setBackgroundColor(String cName) Sets the current background color based upon a list of several known color names from java.awt.Color.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Canvas

public Canvas(String title,
              int width,
              int height,
              Color bgColor)

Create a Canvas.

Parameters:

title - title to appear in Canvas Frame

width - the desired width for the canvas

height - the desired height for the canvas

bgColor - the desired background color of the canvas

Canvas

public Canvas(String title,
              int width,
              int height,
              String bgName)

Create a Canvas.

Parameters:

title - title to appear in Canvas Frame

width - the desired width for the canvas

height - the desired height for the canvas

bgName - the name of the desired background color

Canvas

public Canvas(String title,
              int width,
              int height)

Create a Canvas (with white background as default)

Parameters:

title - title to appear in Canvas Frame

width - the desired width for the canvas

height - the desired height for the canvas

Method Detail

getWidth

public int getWidth()

get the width of the canvas

Returns:

canvas width

getHeight

public int getHeight()

get the height of the canvas

Returns:

canvas height

remove

public void remove(Drawable obj)

Remove a drawable object from the canvas (however canvas is not automatically refreshed)

Parameters:

obj - object to remove

destroy

public void destroy()

Destroys the canvas, closing the associated window.

clear

public void clear()

Clear all drawable objects from the canvas (however canvas is not automatically refreshed)

add

public void add(Drawable obj)

Add a drawable object to the canvas (however canvas is not automatically refreshed)

Parameters:

obj - object to add

refresh

public void refresh()

Redraw all objects currently on the Canvas and then process desired pause if in a ControlledThread

getBackgroundColor

public Color getBackgroundColor()

Returns current background color

Returns:

the color

setBackgroundColor

public void setBackgroundColor(Color c)

Sets the current background color

Parameters:

c - the new color

setBackgroundColor

public void setBackgroundColor(String cName)

Sets the current background color based upon a list of several known color names from java.awt.Color. (e.g., "black", "blue", "cyan", ...)

Parameters:

cName - the name of the desired new color