graph

Class Markers

java.lang.Object

graph.Markers

public class Markers
extends Object

This class installs, manipulates and draws markers. Markers are stroked using the line drawing method of the class Graph. This means that any stroked figure can become a marker.

Constructor Summary

Constructors

Constructor and Description
Markers() The class contructor
Markers(URL file) Instantiate the Marker class and load marker definitions from the parsed URL.

Method Summary

Modifier and Type	Method and Description
void	AddMarker(int n, boolean[] draw, int[] x, int[] y) Add the definition of a new marker.
void	AddMarker(int m, int n, boolean[] draw, int[] x, int[] y) Add the definition of a new marker.
void	ClearMarkers() Clear All markers.
void	DeleteMarker(int n) Delete the marker with the given index.
void	draw(Graphics g, int m, double scale, int x, int y) draw the marker
void	LoadMarkers(URL file) This method reads the marker file and loads the marker definitions.

Methods inherited from class java.lang.Object

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

Constructor Detail

Markers

public Markers()

The class contructor

Markers

public Markers(URL file)
        throws IOException

Instantiate the Marker class and load marker definitions from the parsed URL. The format of the file is easily worked out from the default marker file marker.txt.

Parameters:

file - The URL of the data file to read

Throws:

IOException - if there is an error with the IO stream.

Method Detail

AddMarker

public void AddMarker(int m,
                      int n,
                      boolean[] draw,
                      int[] x,
                      int[] y)

Add the definition of a new marker. The arrays contain the vertex points of the marker. The boolean array is used to define a relative draw or move to the vertex. The first vertex should always be a move (The boolean array is "true" for a relative draw.

Parameters:

m - The index of the marker. The first marker has index 1.

n - The number of vertices required to stroke the marker.

draw - Boolean array containing relative move/draw instructions. "true" is a draw.

x - Integer array containing the pixel x position of the vertices. All positions are relative to the center of the marker.

y - Integer array containing the pixel y postions of the vertices.

AddMarker

public void AddMarker(int n,
                      boolean[] draw,
                      int[] x,
                      int[] y)

Add the definition of a new marker. The new marker is appended onto the marker list. The center of the marker is assumed to be at (0,0).

Parameters:

n - number of move/draw commands

draw - true if the point is to drawn to, false if the point is to be moved to.

x - X pixel to move/draw to.

x - Y pixel to move/draw to.

DeleteMarker

public void DeleteMarker(int n)

Delete the marker with the given index. the first marker has index 1.

Parameters:

n - The index of the marker to delete. Markers start at index 1.

ClearMarkers

public void ClearMarkers()

Clear All markers.

LoadMarkers

public void LoadMarkers(URL file)
                 throws IOException

This method reads the marker file and loads the marker definitions. The format of the file is simple. The following are the keywords.

start

starts a new marker definition.

end

ends a marker definition.

m x y

move to position x,y

l x y

line to position x,y

All line drawing is relative to the previous position. The center of the marker is assumed to be at (0,0). As always blank lines are ignored and comments begin with a # character.

Parameters:

file - URL of file to load

Throws:

IOException - If there is an IO error

draw

public void draw(Graphics g,
                 int m,
                 double scale,
                 int x,
                 int y)

draw the marker

Parameters:

g - Graphics context

m - Index of the marker to draw

scale - scale factor. All coordinates are multiplied by this factor.

x - Coordinate where to draw the marker

y - Coordinate where to draw the marker