elan
Class Context

java.lang.Object
  |
  +--elan.Context

public class Context

extends java.lang.Object

Stores and manages the internal state of the IDE. Most commands, either GUI or model related, pass through this class.

Method Summary

void	addLegalCommand(java.lang.String command) adds a command to the list of legal/valid avaible slogo commands
void	appendErrorMessage(java.lang.String error) adds an error message to the list of messages for the user
void	appendMessage(java.lang.String update) adds a message to the list of messages for the user
void	back(double amount) moves the Turtle backward
void	clean() cleans the turtle canvas (i.e.
void	clearMessages() clears all messages to be shown to user
void	clearScreen() resets the Turtle's location to default location & clears all lines from canvas
void	forward(double amount) moves the Turtle foward
java.awt.Color	getBackground()
java.lang.Object[]	getCoreCommands()
java.lang.Object[]	getCustomCommands()
static Context	getInstance()
java.lang.Object[]	getMessages()
java.awt.Color	getPenColor()
float	getPenWidth()
java.awt.geom.Point2D	getTurtleCoords()
int	getTurtleDisplacement()
double	getTurtleHeading()
java.awt.Image	getTurtleImage()
double	getTurtleXCor()
double	getTurtleYCor()
void	home() resets the Turtle's location to default location
boolean	isPenDown()
boolean	isTurtleVisible()
void	load(java.io.File file) loads an existing file into the file manager and compiles the file
void	loadNew(java.lang.String filename) loads a new file into the file manager
void	print()
void	removeLegalCommand(java.lang.String command) removes a custom function from the list of available custom functions
void	save(java.lang.String filename) saves an existing file in the file manager and writes the file to disk
void	setBackground(java.awt.Color c) set the color of the background on the Canvas Frame
void	setPenColor(java.awt.Color c) set the Turtle's pen color to the specified value
void	setPenDown(boolean b)
void	setPenWidth(float width) set the size/width of the Turtle's pen
void	setTurtleCoords(double x, double y) set the Turtle's x-coordinate & y-coordinate
void	setTurtleDisplacement(int value) set the Turtle's displacement (i.e.
void	setTurtleHeading(double change) set the Turtle's heading
void	setTurtleHeadingAbsolute(int newHeading) set the Turtle's heading to the specified value
void	setTurtleImage(java.awt.Image im) set the Turtle's image on the drawing canvas
void	setTurtleVisibility(boolean vis) set the visibility of the Turtle
void	setTurtleXCor(double change) set the Turtle's x-coordinate
void	setTurtleYCor(double change) set the Turtle's y-coordinate
void	sortCustomCommands() sorts the list of available custom functions
void	towards(double lhs, double rhs) moves the Turtle towards ...
void	update() updates the view of the entire IDE

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static Context getInstance()

Returns:

the single instance of this object

getTurtleDisplacement

public int getTurtleDisplacement()

Returns:

current displacement of the Turtle

setTurtleDisplacement

public void setTurtleDisplacement(int value)

set the Turtle's displacement (i.e. change between previous position and new position)

Parameters:

value - displacement to which to set the Turtle

getTurtleXCor

public double getTurtleXCor()

Returns:

Turtle's x-coordinate

getTurtleYCor

public double getTurtleYCor()

Returns:

Turtle's y-coordinate

setTurtleXCor

public void setTurtleXCor(double change)

set the Turtle's x-coordinate

Parameters:

change - displacement in x direction to which to set the Turtle

setTurtleYCor

public void setTurtleYCor(double change)

set the Turtle's y-coordinate

Parameters:

change - displacement in y direction to which to set the Turtle

setTurtleCoords

public void setTurtleCoords(double x,
                            double y)

set the Turtle's x-coordinate & y-coordinate

getTurtleCoords

public java.awt.geom.Point2D getTurtleCoords()

Returns:

current Point at which the Turtle is located

setTurtleImage

public void setTurtleImage(java.awt.Image im)

set the Turtle's image on the drawing canvas

Parameters:

im - image to which to set the turtle

getTurtleImage

public java.awt.Image getTurtleImage()

Returns:

current Image representing Turtle

setTurtleHeading

public void setTurtleHeading(double change)

set the Turtle's heading

Parameters:

change - amount by which to change the Turtle's current heading (see also setTurtleHeadingAbsolute(double d) )

setTurtleHeadingAbsolute

public void setTurtleHeadingAbsolute(int newHeading)

set the Turtle's heading to the specified value

getTurtleHeading

public double getTurtleHeading()

Returns:

heading at which turtle is pointing

getMessages

public java.lang.Object[] getMessages()

Returns:

array of messages to be shown to user

appendMessage

public void appendMessage(java.lang.String update)

adds a message to the list of messages for the user

Parameters:

update - message to append

appendErrorMessage

public void appendErrorMessage(java.lang.String error)

adds an error message to the list of messages for the user

Parameters:

error - message to append

clearMessages

public void clearMessages()

clears all messages to be shown to user

setPenDown

public void setPenDown(boolean b)

isPenDown

public boolean isPenDown()

Returns:

true - if pen is down

setPenColor

public void setPenColor(java.awt.Color c)

set the Turtle's pen color to the specified value

Parameters:

c - the color to which to set the pen

getPenColor

public java.awt.Color getPenColor()

Returns:

the color of the Turtle's pen

setPenWidth

public void setPenWidth(float width)

set the size/width of the Turtle's pen

Parameters:

width - the width to which to set the Turtle's pen

getPenWidth

public float getPenWidth()

Returns:

the size/width of the Turtle's pen

setBackground

public void setBackground(java.awt.Color c)

set the color of the background on the Canvas Frame

Parameters:

c - the color to which to set the background

getBackground

public java.awt.Color getBackground()

Returns:

the set color for the canvas

setTurtleVisibility

public void setTurtleVisibility(boolean vis)

set the visibility of the Turtle

Parameters:

vis - true - if Turtle is visible

isTurtleVisible

public boolean isTurtleVisible()

Returns:

true - if Turtle is visible

addLegalCommand

public void addLegalCommand(java.lang.String command)

adds a command to the list of legal/valid avaible slogo commands

Parameters:

command - command to add to the list of available custom functions

removeLegalCommand

public void removeLegalCommand(java.lang.String command)

removes a custom function from the list of available custom functions

Parameters:

command - command to remove from the list of available custom functions

sortCustomCommands

public void sortCustomCommands()

sorts the list of available custom functions

getCustomCommands

public java.lang.Object[] getCustomCommands()

Returns:

all of the user-defined commands

getCoreCommands

public java.lang.Object[] getCoreCommands()

Returns:

the list of core SLOGO commands

clean

public void clean()

cleans the turtle canvas (i.e. clears all lines)

home

public void home()

resets the Turtle's location to default location

clearScreen

public void clearScreen()

resets the Turtle's location to default location & clears all lines from canvas

towards

public void towards(double lhs,
                    double rhs)

moves the Turtle towards ...

forward

public void forward(double amount)

moves the Turtle foward

Parameters:

amount - number to units of which to move the Turtle

back

public void back(double amount)

moves the Turtle backward

Parameters:

amount - number to units of which to move the Turtle

save

public void save(java.lang.String filename)

saves an existing file in the file manager and writes the file to disk

Parameters:

filename - name of file being saved

load

public void load(java.io.File file)

loads an existing file into the file manager and compiles the file

Parameters:

file - File to load into file manager

loadNew

public void loadNew(java.lang.String filename)

loads a new file into the file manager

Parameters:

filename - name of new file opened in file manager (NOTE: actual file is not created and written out until the file has been saved)

update

public void update()

updates the view of the entire IDE

print

public void print()