Turtle

java.lang.Object
- java.util.Observable
- - Media.Turtle

```
public class Turtle
extends java.util.Observable
```
This class provides line drawing (vector graphics) capabilities based on Turtle Graphics (Seymour Papert). A Turtle draws on a Canvas on a BasicForm.

Version:

1.0 July 08

Author:

A. Cheesman

Field Summary

Fields
Modifier and Type Field and Description

static int FAST

static int MEDIUM

static int SLOW

Fields
Modifier and Type	Field and Description
`static int`	`FAST`
`static int`	`MEDIUM`
`static int`	`SLOW`

Constructor Summary

Constructors
Constructor and Description
`Turtle()` Creates a Turtle drawing at a slow speed with a black pen of width 1.
`Turtle(java.awt.Color c)` Creates a Turtle drawing at slow speed with a pen of specified color and width 1.
`Turtle(int speed)` Creates a Turtle drawing at a specified speed with a black pen of width 1.
`Turtle(int speed, java.awt.Color c)` Creates a Turtle drawing at a specified speed with a pen of specified color and width 1.
`Turtle(int speed, int width)` Creates a Turtle drawing at a specified speed with a black pen of specified width.
`Turtle(int speed, int width, java.awt.Color c)` Creates a Turtle drawing at a specified speed with a pen of specified width and color.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`backward(double pixels)` Moves turtle the specified number of pixels backwards.
`boolean`	`forward(double pixels)` Moves turtle the specified number of pixels forwards.
`double`	`getAngle()` Returns the current angle the turtle is facing.
`java.awt.Color`	`getPenColor()` Returns the current color.
`int`	`getPenWidth()` Returns the width of the pen.
`int`	`getScreenX()` Returns the current x coordinate of the turtle.
`int`	`getScreenY()` Returns the current y coordinate of the turtle.
`int`	`getSpeed()` Returns the current drawing speed
`boolean`	`isPenDown()` Returns the current pen status (down == true)
`void`	`left(double newAngle)` Changes the direction the turtle faces by newAngle radians to the left.
`boolean`	`moveTo(double x2, double y2)` Moves the turtle to the new location using cartiasian co-ordinates.
`void`	`penDown()` Puts the pen down.
`void`	`penUp()` Lifts the pen up.
`void`	`right(double newAngle)` Changes the direction the turtle faces by newAngle radians to the right.
`void`	`setCanvas(BasicIO.GeneralCanvas gc)` Used by BasicForm.
`void`	`setJFrame(javax.swing.JFrame frame)` Used by BasicForm.
`void`	`setPenColor(java.awt.Color c)` Sets the color of the pen.
`void`	`setPenWidth(int x)` Sets the width of the pen the turtle draws with.
`void`	`setSpeed(int speed)` Sets the speed of the turtle

Methods inherited from class java.util.Observable
addObserver, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SLOW
```
public static final int SLOW
```
    See Also:
    
    Constant Field Values
  - MEDIUM
```
public static final int MEDIUM
```
    See Also:
    
    Constant Field Values
  - FAST
```
public static final int FAST
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Turtle
```
public Turtle(int speed,
              int width,
              java.awt.Color c)
```
    Creates a Turtle drawing at a specified speed with a pen of specified width and color.
    
    Parameters:
    
    speed - the speed of the turtle
    
    width - the width of the pen
    
    c - the color of the pen
  - Turtle
```
public Turtle(int speed,
              int width)
```
    Creates a Turtle drawing at a specified speed with a black pen of specified width.
    
    Parameters:
    
    speed - the speed of the turtle
    
    width - the width of the pen
  - Turtle
```
public Turtle(int speed,
              java.awt.Color c)
```
    Creates a Turtle drawing at a specified speed with a pen of specified color and width 1.
    
    Parameters:
    
    speed - the speed of the turtle
    
    c - the color of the pen
  - Turtle
```
public Turtle(int speed)
```
    Creates a Turtle drawing at a specified speed with a black pen of width 1.
    
    Parameters:
    
    speed - the speed of the turtle
  - Turtle
```
public Turtle(java.awt.Color c)
```
    Creates a Turtle drawing at slow speed with a pen of specified color and width 1.
    
    Parameters:
    
    c - the color of the pen
  - Turtle
```
public Turtle()
```
    Creates a Turtle drawing at a slow speed with a black pen of width 1.
- Method Detail
  - forward
```
public boolean forward(double pixels)
```
    Moves turtle the specified number of pixels forwards.
    
    Parameters:
    
    pixels - number of pixels to move forward
  - setSpeed
```
public void setSpeed(int speed)
```
    Sets the speed of the turtle
    
    Parameters:
    
    speed - new speed of the turtle
  - backward
```
public boolean backward(double pixels)
```
    Moves turtle the specified number of pixels backwards.
    
    Parameters:
    
    pixels - number of pixels to move backward
  - moveTo
```
public boolean moveTo(double x2,
                      double y2)
```
    Moves the turtle to the new location using cartiasian co-ordinates.
    
    Parameters:
    
    x2 - the new x coord of the turtle
    
    y2 - the new y coord of the turtle
  - right
```
public void right(double newAngle)
```
    Changes the direction the turtle faces by newAngle radians to the right.
    
    Parameters:
    
    newAngle - the amount to increase the angle to the right
  - left
```
public void left(double newAngle)
```
    Changes the direction the turtle faces by newAngle radians to the left.
    
    Parameters:
    
    newAngle - the amount to increase the angle to the left
  - getScreenX
```
public int getScreenX()
```
    Returns the current x coordinate of the turtle.
    
    Returns:
    
    int the x co-ordinate of the turtle.
  - getScreenY
```
public int getScreenY()
```
    Returns the current y coordinate of the turtle.
    
    Returns:
    
    int the y co-ordinate of the turtle.
  - getPenWidth
```
public int getPenWidth()
```
    Returns the width of the pen.
    
    Returns:
    
    int the width of the pen.
  - isPenDown
```
public boolean isPenDown()
```
    Returns the current pen status (down == true)
    
    Returns:
    
    boolean the pen is down.
  - getSpeed
```
public int getSpeed()
```
    Returns the current drawing speed
    
    Returns:
    
    int the drawing speed of the turtle.
  - penDown
```
public void penDown()
```
    Puts the pen down.
  - penUp
```
public void penUp()
```
    Lifts the pen up.
  - setPenColor
```
public void setPenColor(java.awt.Color c)
```
    Sets the color of the pen.
    
    Parameters:
    
    c - new Colour for the turtle's pen.
  - setPenWidth
```
public void setPenWidth(int x)
```
    Sets the width of the pen the turtle draws with. This method ensures you do not set the width < 1.
    
    Parameters:
    
    x - new width for the pen
  - getAngle
```
public double getAngle()
```
    Returns the current angle the turtle is facing.
    
    Returns:
    
    double the angle (0-2pi) the turtle is facing.
  - getPenColor
```
public java.awt.Color getPenColor()
```
    Returns the current color.
    
    Returns:
    
    Color the color of the pen.
  - setJFrame
```
public void setJFrame(javax.swing.JFrame frame)
```
    Used by BasicForm. Informs the Turtle what frame it is drawing on so that turtle movement is visible in real time.
    
    Parameters:
    
    frame - the frame the turtle is drawing on
  - setCanvas
```
public void setCanvas(BasicIO.GeneralCanvas gc)
```
    Used by BasicForm. Informs the Turtle what camvas it is drawing on so that turtle movement is visible in real time.
    
    Parameters:
    
    gc - the canvas the turtle is drawing on

Class Turtle

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.util.Observable

Methods inherited from class java.lang.Object

Field Detail

SLOW

MEDIUM

FAST

Constructor Detail

Turtle

Turtle

Turtle

Turtle

Turtle

Turtle

Method Detail

forward

setSpeed

backward

moveTo

right

left

getScreenX

getScreenY

getPenWidth

isPenDown

getSpeed

penDown

penUp

setPenColor

setPenWidth

getAngle

getPenColor

setJFrame

setCanvas