Package org.faceless.graph.output

Class Output

java.lang.Object

org.faceless.graph.output.Output

Direct Known Subclasses:

PDF2Output

public abstract class Output
extends java.lang.Object

The Output class is the abstract base class for all Output canvases in the graph Library. It defines some very primitive drawing methods (point, line, polygon and text) which need to be overridden by more concrete subclasses in order to render the graphs.

The main method in the Output class of interest to end-users is the render(org.faceless.graph.Graph) method, which takes a Graph as an argument and renders that graph to this output stream.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	textAlign	textAlign shows where a line of text is drawn on the canvas in relation to the point that's given.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Output()

Method Summary

Modifier and Type	Method	Description
abstract boolean	canPattern()	Return true if this subclass out Output can handle pattern fills.
abstract boolean	canRotate()	Return true if this subclass out Output can handle rotated text.
abstract BoundingBox	getCanvas()	Return the canvas as a BoundingBox.
abstract Graph	getGraph()	Return the graph being rendered.
protected Point	getTextAnchor(double x, double y, double w, double h, int align)	Returns the point that the text should be placed at for this canvas, based on it's alignment.
abstract BoundingBox	getTextBox(java.lang.String text, Style style)	Return the bounding box for given string in the specified style.
abstract void	line(double x1, double y1, double x2, double y2)	Draw a line from x1,y1 to x2,y2 on the canvas, in the current colour
abstract void	poly(java.lang.String name, double[] x, double[] y, int num)	Draw and fill a polygon on the canvas, in the current colour.
abstract void	render(Graph g)	Render the Graph to this Output object.
protected Point	rotate(Point cen, Point in, double ang)	For use only by subclasses of Output.
abstract void	setColor(java.awt.Paint s)	Set the current pen, font and fill colour
abstract void	setLineDash(double on, double off, double phase)	Set the line dash pattern
abstract void	setLineThickness(double thickness)	Set the line thickness (1 being default, 2 twice as thick, etc.) on platforms that support it.
abstract void	text(java.lang.String text, double x, double y, Style s)	Draw a line of text at the specified position in the specified style.

Methods inherited from class java.lang.Object

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

Field Detail

textAlign

protected int textAlign

textAlign shows where a line of text is drawn on the canvas in relation to the point that's given. java.awt.Graphics and most PostScript devices align the baseline (bottom for our purposes) and left of the text to the given point, so this is the default, but it may be overridden by subclasses

Constructor Detail

Output

protected Output()

Method Detail

getTextBox

public abstract BoundingBox getTextBox(java.lang.String text,
                                       Style style)

Return the bounding box for given string in the specified style.

Parameters:

text - The string to return the size for.

style - The style to apply to the text before returning it's size. The aspects of the style that may affect this include font, rotation and alignment

getCanvas

public abstract BoundingBox getCanvas()

Return the canvas as a BoundingBox. The final graph will be sized to fit this box.

canRotate

public abstract boolean canRotate()

Return true if this subclass out Output can handle rotated text.

canPattern

public abstract boolean canPattern()

Return true if this subclass out Output can handle pattern fills.

Since:

1.0.13

setColor

public abstract void setColor(java.awt.Paint s)

Set the current pen, font and fill colour

setLineThickness

public abstract void setLineThickness(double thickness)

Set the line thickness (1 being default, 2 twice as thick, etc.) on platforms that support it.

setLineDash

public abstract void setLineDash(double on,
                                 double off,
                                 double phase)

Set the line dash pattern

text

public abstract void text(java.lang.String text,
                          double x,
                          double y,
                          Style s)

Draw a line of text at the specified position in the specified style.

Parameters:

text - The line of text to draw.

x - The x position to place the text at, measured from the left of the canvas.

y - The y position to place the text at, measured from the bottom of the canvas.

style - The style to apply to the text. Aspects of the style that will be used include Color, Font, Alignment and Rotation

line

public abstract void line(double x1,
                          double y1,
                          double x2,
                          double y2)

Draw a line from x1,y1 to x2,y2 on the canvas, in the current colour

poly

public abstract void poly(java.lang.String name,
                          double[] x,
                          double[] y,
                          int num)

Draw and fill a polygon on the canvas, in the current colour. The corners of the polygon are specified by the arrays of X and Y values. The polygon has no borders, and is filled with the current colour. Subclasses should handle the cases where several of the points are the same.

Parameters:

name - The name of the dataset that is being drawn. Not used in the current release, but will eventually be user for interaction with rendered graphs

x - the array of X co-ordinates

y - the array of Y co-ordinates

num - the number of co-ordinates in the array

render

public abstract void render(Graph g)
                     throws java.io.IOException

Render the Graph to this Output object.

Throws:

java.io.IOException

getGraph

public abstract Graph getGraph()

Return the graph being rendered. For internal use.

Since:

1.0.3

rotate

protected final Point rotate(Point cen,
                             Point in,
                             double ang)

For use only by subclasses of Output. Rotate and return a given point around a given center by the specified angle

Parameters:

cen - The center of rotation

in - The point to be rotated

ang - The angle in degrees clockwise

getTextAnchor

protected final Point getTextAnchor(double x,
                                    double y,
                                    double w,
                                    double h,
                                    int align)

Returns the point that the text should be placed at for this canvas, based on it's alignment. So, for example, if the canvas has an alignment of BOTTOM+LEFT, and the text has an alignment of TOP+LEFT, the returned point will be (x,y-height)

Parameters:

x - The X position of the point in the text as specifed by align

y - The Y position of the point in the text as specifed by align

w - The width of the text

h - The height of the text *above the baseline*. For best results descenders should not be included in this height.

align - The alignment of the text. Taken from Style.getAlign()