Class Canvas

java.lang.Object
  Canvas

public class Canvas
extends java.lang.Object

Class Canvas - a class to allow for simple graphical drawing on a canvas.

Nested Class Summary

protected class

Canvas.CanvasPane Nested class CanvasPane - the actual canvas component contained in the Canvas frame.

Field Summary

protected Canvas.CanvasPane

canvas

Constructor Summary

Canvas()
Create a Canvas with default title, height, width and background color ("Canvas", 300, 300, white).

Canvas(java.lang.String title)
Create a Canvas with default height, width and background color (300, 300, white).

Method Summary

void	drawFilledOval(int x1, int y1, int x2, int y2) Draws a filled oval on the Canvas.
void	drawFilledPolygon(int[] x, int[] y, int size) Draws a filled polygon on the Canvas.
void	drawFilledRectangle(int x1, int y1, int x2, int y2) Draws a filled rectangle on the Canvas.
void	drawLine(int x1, int y1, int x2, int y2) Draws a line on the Canvas.
void	drawOval(int x1, int y1, int x2, int y2) Draws an oval on the Canvas.
void	drawPolygon(int[] x, int[] y, int size) Draws a polygon on the Canvas.
void	drawRectangle(int x1, int y1, int x2, int y2) Draws a rectangle on the Canvas.
void	drawString(java.lang.String text, int x, int y) Draws a String on the Canvas.
void	erase() Erase the whole canvas.
void	eraseOval(int x1, int y1, int x2, int y2) Erases an oval on the Canvas.
void	eraseRectangle(int x1, int y1, int x2, int y2) Erases a rectangle on the Canvas.
void	eraseString(java.lang.String text, int x, int y) Erases a String on the Canvas.
void	fillBackground(java.awt.Color newColor) Fills in the Canvas (background) with the specified color.
java.awt.Font	getFont() Returns the current font of the canvas.
java.awt.Color	getInkColor() Returns the current pen color.
boolean	isVisible() Provide information on visibility of the Canvas.
void	setFont(java.awt.Font newFont) changes the current Font used on the Canvas
void	setFontSize(int newSize) Sets the point size of the current font to the specified value.
void	setInkColor(java.awt.Color newColor) Sets the "pen" (outline) color for the Canvas.
void	setSize(int width, int height) Sets the size of the canvas.
void	setVisible(boolean visible) Set the canvas visibility and brings canvas to the front of screen when made visible.
void	wait(int milliseconds) Waits for a specified number of milliseconds before finishing.

Methods inherited from class java.lang.Object

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

Field Detail

canvas

protected Canvas.CanvasPane canvas

Constructor Detail

Canvas

public Canvas(java.lang.String title)

Create a Canvas with default height, width and background color (300, 300, white).

Parameters:

title - title to appear in Canvas Frame

Canvas

public Canvas()

Create a Canvas with default title, height, width and background color ("Canvas", 300, 300, white).

Method Detail

setInkColor

public void setInkColor(java.awt.Color newColor)

Sets the "pen" (outline) color for the Canvas.

Parameters:

newColor - The color to which to set the pen/drawing tool.

getInkColor

public java.awt.Color getInkColor()

Returns the current pen color.

setVisible

public void setVisible(boolean visible)

Set the canvas visibility and brings canvas to the front of screen when made visible. This method can also be used to bring an already visible canvas to the front of other windows.

Parameters:

visible - boolean value representing the desired visibility of the canvas (true or false)

isVisible

public boolean isVisible()

Provide information on visibility of the Canvas.

Returns:

true if canvas is visible, false otherwise

erase

public void erase()

Erase the whole canvas.

drawString

public void drawString(java.lang.String text,
                       int x,
                       int y)

Draws a String on the Canvas.

Parameters:

text - the String to be displayed

x - x co-ordinate for text placement

y - y co-ordinate for text placement

eraseString

public void eraseString(java.lang.String text,
                        int x,
                        int y)

Erases a String on the Canvas.

Parameters:

text - the String to be displayed

x - x co-ordinate for text placement

y - y co-ordinate for text placement

drawLine

public void drawLine(int x1,
                     int y1,
                     int x2,
                     int y2)

Draws a line on the Canvas.

Parameters:

x1 - x co-ordinate of start of line

y1 - y co-ordinate of start of line

x2 - x co-ordinate of end of line

y2 - y co-ordinate of end of line

drawRectangle

public void drawRectangle(int x1,
                          int y1,
                          int x2,
                          int y2)

Draws a rectangle on the Canvas.

Parameters:

x1 - x co-ordinate of top left corner

y1 - y co-ordinate of top left corner

x2 - width

y2 - height

drawFilledRectangle

public void drawFilledRectangle(int x1,
                                int y1,
                                int x2,
                                int y2)

Draws a filled rectangle on the Canvas.

Parameters:

x1 - x co-ordinate of top left corner

y1 - y co-ordinate of top left corner

x2 - width

y2 - height

drawPolygon

public void drawPolygon(int[] x,
                        int[] y,
                        int size)

Draws a polygon on the Canvas.

Parameters:

x - array of x co-ordinates of polygon points

y - array of y co-ordinates of polygon points

size - the number of points (vertices) in the polygon

drawFilledPolygon

public void drawFilledPolygon(int[] x,
                              int[] y,
                              int size)

Draws a filled polygon on the Canvas.

Parameters:

x - array of x co-ordinates of polygon points

y - array of y co-ordinates of polygon points

size - the number of points (vertices) in the polygon

eraseRectangle

public void eraseRectangle(int x1,
                           int y1,
                           int x2,
                           int y2)

Erases a rectangle on the Canvas.

Parameters:

x1 - x co-ordinate of top left corner

y1 - y co-ordinate of top left corner

x2 - width

y2 - height

drawOval

public void drawOval(int x1,
                     int y1,
                     int x2,
                     int y2)

Draws an oval on the Canvas.

Parameters:

x1 - x co-ordinate of top left corner

y1 - y co-ordinate of top left corner

x2 - width

y2 - height

drawFilledOval

public void drawFilledOval(int x1,
                           int y1,
                           int x2,
                           int y2)

Draws a filled oval on the Canvas.

Parameters:

x1 - x co-ordinate of top left corner

y1 - y co-ordinate of top left corner

x2 - width

y2 - height

eraseOval

public void eraseOval(int x1,
                      int y1,
                      int x2,
                      int y2)

Erases an oval on the Canvas.

Parameters:

x1 - x co-ordinate of top left corner

y1 - y co-ordinate of top left corner

x2 - width

y2 - height

fillBackground

public void fillBackground(java.awt.Color newColor)

Fills in the Canvas (background) with the specified color.

Parameters:

newColor - the new color for the background of the Canvas

setFont

public void setFont(java.awt.Font newFont)

changes the current Font used on the Canvas

Parameters:

newFont - new font to be used for String output

getFont

public java.awt.Font getFont()

Returns the current font of the canvas.

Returns:

the font currently in use

setFontSize

public void setFontSize(int newSize)

Sets the point size of the current font to the specified value. The style and font family remain the same.

Parameters:

newSize - the new point size

setSize

public void setSize(int width,
                    int height)

Sets the size of the canvas.

Parameters:

width - new width

height - new height

wait

public void wait(int milliseconds)

Waits for a specified number of milliseconds before finishing. This provides an easy way to specify a small delay which can be used when producing animations.

Parameters:

milliseconds - the number