uk.ac.starlink.ttools.plot2

Class Axis

java.lang.Object

uk.ac.starlink.ttools.plot2.Axis

@Equality
public abstract class Axis
extends Object

Does geometry and drawing for a straight line axis. Linear and logarithmic scales are supported; obtain one using the createAxis factory method.

Since:

12 Feb 2013

Author:

Mark Taylor

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Axis(int glo, int ghi, double dlo, double dhi) Constructor.

Method Summary

Modifier and Type	Method and Description
static Axis	createAxis(int glo, int ghi, double dlo, double dhi, boolean log, boolean flip) Factory method to create a linear or logarithmic axis.
abstract double[]	dataPan(double d0, double d1) Returns the data bounds that result from performing an axis pan between two given data positions.
abstract double	dataToGraphics(double d) Converts a data coordinate to the graphics position on this axis.
abstract double[]	dataZoom(double d0, double factor) Returns the data bounds that result from performing an axis zoom about a given data position.
void	drawLabels(Tick[] ticks, String title, Captioner captioner, TickLook tickLook, Orientation orient, boolean invert, Graphics g) Draws an axis title and supplied tickmarks.
double[]	getDataLimits() Returns the axis data bounds.
int[]	getGraphicsLimits() Returns the axis graphics bounds.
Rectangle	getLabelBounds(Tick[] ticks, String title, Captioner captioner, Orientation orient, boolean invert) Determines the bounds for axis and tickmark annotations.
abstract double	graphicsToData(double g) Converts a graphics position on this axis to a data coordinate.
abstract boolean	isLinear() Indicates whether the scaling on this axis is linear.
static double[]	pan(double dlo, double dhi, double d0, double d1, boolean isLog) Utility method for axis panning.
static double[]	zoom(double dlo, double dhi, double d0, double factor, boolean isLog) Utility method for axis zooming.

Methods inherited from class java.lang.Object

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

Constructor Detail

Axis

protected Axis(int glo,
               int ghi,
               double dlo,
               double dhi)

Constructor.

Parameters:

glo - minimum graphics coordinate

ghi - maximum graphics coordinate

dlo - minimum data coordinate

dhi - maximum data coordinate

Method Detail

dataToGraphics

public abstract double dataToGraphics(double d)

Converts a data coordinate to the graphics position on this axis.

Parameters:

d - data coordinate

Returns:

graphics coordinate

graphicsToData

public abstract double graphicsToData(double g)

Converts a graphics position on this axis to a data coordinate.

Parameters:

g - graphics coordinate

Returns:

data coordinate

dataZoom

public abstract double[] dataZoom(double d0,
                                  double factor)

Returns the data bounds that result from performing an axis zoom about a given data position.

Parameters:

d0 - data reference position for zoom

factor - amount to zoom

Returns:

2-element array giving new new data min/max coordinates

dataPan

public abstract double[] dataPan(double d0,
                                 double d1)

Returns the data bounds that result from performing an axis pan between two given data positions.

Parameters:

d0 - source data position

d1 - destination data position

Returns:

2-element array giving new new data min/max coordinates

getGraphicsLimits

public int[] getGraphicsLimits()

Returns the axis graphics bounds. The first element of the result (glo) is always strictly less than the second (ghi).

Returns:

2-element array giving the graphics min/max coordinates

getDataLimits

public double[] getDataLimits()

Returns the axis data bounds. The first element of the result (dlo) is always strictly less than the second (dhi).

Returns:

2-element array giving the data min/max coordinates

isLinear

public abstract boolean isLinear()

Indicates whether the scaling on this axis is linear.

Returns:

true iff this axis is linear

drawLabels

public void drawLabels(Tick[] ticks,
                       String title,
                       Captioner captioner,
                       TickLook tickLook,
                       Orientation orient,
                       boolean invert,
                       Graphics g)

Draws an axis title and supplied tickmarks.

Parameters:

ticks - tickmark array

title - axis label text, may be null

captioner - text positioning object

tickLook - tick drawing style

orient - axis orientation code

invert - whether to reverse sense of axis

g - graphics context

getLabelBounds

public Rectangle getLabelBounds(Tick[] ticks,
                                String title,
                                Captioner captioner,
                                Orientation orient,
                                boolean invert)

Determines the bounds for axis and tickmark annotations. The returned value is a bounding box for everything that would be drawn by a corresponding call to drawLabels(uk.ac.starlink.ttools.plot2.Tick[], java.lang.String, uk.ac.starlink.ttools.plot2.Captioner, uk.ac.starlink.ttools.plot2.TickLook, uk.ac.starlink.ttools.plot2.Orientation, boolean, java.awt.Graphics).

Parameters:

ticks - tickmark array

title - axis label text, may be null

captioner - text positioning object

orient - axis orientation code

invert - whether to reverse sense of axis

Returns:

bounding box for all annotations

createAxis

public static Axis createAxis(int glo,
                              int ghi,
                              double dlo,
                              double dhi,
                              boolean log,
                              boolean flip)

Factory method to create a linear or logarithmic axis.

Parameters:

glo - minimum graphics coordinate

ghi - maximum graphics coordinate

dlo - minimum data coordinate

dhi - maximum data coordinate

log - true for logarithmic scaling, false for linear

flip - true if the data coordinates should run in the opposite sense to the graphics coordinates

pan

public static double[] pan(double dlo,
                           double dhi,
                           double d0,
                           double d1,
                           boolean isLog)

Utility method for axis panning.

Parameters:

dlo - initial axis lower bound

dhi - initial axis upper bound

d0 - pan gesture start position

d1 - pan gesture end position

isLog - false for linear axis, true for logarithmic

Returns:

2-element array giving final (panned) axis {lower,upper} bounds

zoom

public static double[] zoom(double dlo,
                            double dhi,
                            double d0,
                            double factor,
                            boolean isLog)

Utility method for axis zooming.

Parameters:

dlo - initial axis lower bound

dhi - initial axis upper bound

d0 - zoom gesture reference position

factor - zoom factor

isLog - false for linear axis, true for logarithmic

Returns:

2-element array giving final (zoomed) axis {lower,upper} bounds