edu.hws.jcm.draw
Class CoordinateRect

java.lang.Object
  |
  +--edu.hws.jcm.draw.CoordinateRect

All Implemented Interfaces:

Computable, InputObject, Limits, java.io.Serializable, Tieable

public class CoordinateRect

extends java.lang.Object

implements Tieable, Limits, Computable, InputObject

A CoordinateRect represents a rectagular region in the xy-plane, specified by values xmin,xmax,ymin,ymax. The conditions ymin < ymax and xmin < xmax are enforced. (Values are swapped if necessary, and if min==max, they are reset to -1 and +1. If any of the values are set to an infinite or NaN value, then the coordinate rect won't display anything except the message "Error: undefined limits".)

When the Rect is mapped onto the screen, there can be a gap of a specified number of pixels between the min,max values and the edges of the rectangle on the screen. If the gap is non-zero, then the actual range of coordinates on the rect is larger than the range from the specifed min to max. (This is done mainly so I could have axes that don't quite reach the edges of the rect.)

A CoordinateRect maintains a list of Drawable items. When the Rect's draw() method is called, it calls the draw() method of each of the Drawable items it contains. When its compute() method is called, it calls the compute() method of any Drawable that is a Computable. When its checkInput() method is called, it calls the checkInput() method of any Drawable that is an InputObject.

A CoordinateRect represents a rectangular region in a DisplayCanvas. It has a reference to that Canvas, which is set automatically when it is added to the canvas. If the size, range, or gap on the CoordinateRect change, it will ask the Canvas to redraw the area it occupies.

The values of xmin, xmax, ymin, ymax are exported as Value objects, which can be used elsewhere in your program. The Value objects can be obtained by calling getValueObject(). If you do this, you should add the objects that depend on those values to a Controller and register the Controller to listen for changes from this CoordinateRect by calling the CoordinateRect.setOnChange(Controller) method.

See Also:

Serialized Form

Field Summary

protected boolean	changed Set to true when one of the limits or the gap has changed.
protected java.util.Vector	drawItems Drawable items contained in this CoordinateRect
protected Controller	onChange If non-null, this is the Controller that is notified when the limits change.
protected Tie	syncWith This contains other Limit objects with which the CoordinateRect is synchronizing.
static int	XMAX A constant for use with the getValueObject() method to specify which Value is to be returned.
static int	XMIN A constant for use with the getValueObject() method to specify which Value is to be returned.
static int	YMAX A constant for use with the getValueObject() method to specify which Value is to be returned.
static int	YMIN A constant for use with the getValueObject() method to specify which Value is to be returned.

Constructor Summary

CoordinateRect()
Create a CoordinateRect with default limits: -5, 5, -5, 5.

CoordinateRect(double xmin, double xmax, double ymin, double ymax)
Create a CoordinateRect with specified limits.

Method Summary

void	add(Drawable d) Add a drawable item to the CoordinateRect.
void	checkInput() When this is called, the CoordinateRect will call the checkInput method of any Drawable it contains that is also an InputObject.
void	clearRestoreBuffer() A CoordinateRect can store its current limits in a buffer.
void	compute() When this is called, the CoordinateRect will call the compute method of any Drawable it contains that is also a Computable.
protected void	doDraw(java.awt.Graphics g) Draw all the Drawable items.
void	draw(java.awt.Graphics g, int width, int height) Draw in rect with upperleft corner (0,0) and specified width,height.
void	draw(java.awt.Graphics g, int left, int top, int width, int height) Draw in specified rect.
double[]	equalizeAxes() Reset limits, if necessary, so scales on the axes are the same.
Drawable	getDrawable(int i) Get the i-th Drawable in this Rect, or null if i is less than zero or greater than or equal to the number of items.
int	getDrawableCount() Returns the number of Drawable items that are in this CoordinateRect.
int	getGap() Get the gap, in pixels, between the edges of the CoordinateRect and the limits specified by xmin, xmax, ymin, and ymax.
int	getHeight() Get the height in pixels of this CoordinateRect in the DisplayCanvas that contains it.
int	getLeft() Get the left edge of this CoordinateRect in the DisplayCanvas that contains it.
double[]	getLimits() Get an array containing the limits on the CoordinateRect in the order xmin, xmax, ymin, ymax.
Controller	getOnChange() Get the controller that is notified when the limits on this CoordinateRect change.
double	getPixelHeight() Return the height of one pixel in this coordinate system.
double	getPixelWidth() Return the width of one pixel in this coordinate system.
long	getSerialNumber() Return the serial number of the CoordinateRect, which is incremented each time the limits change.
int	getTop() Get the top edge of this CoordinateRect in the DisplayCanvas that contains it.
Value	getValueObject(int which) Get a Value object representing one of the limits on this CoordinateRect.
int	getWidth() Get the width in pixels of this CoordinateRect in the DisplayCanvas that contains it.
double	getXmax() Get the maximum x-coordinate.
double	getXmin() Get the mimimum x-coordinate.
double	getYmax() Get the maximum x-coordinate.
double	getYmin() Get the mimimum y-coordinate.
void	notifyControllerOnChange(Controller c) Method required by InputObject interface; in this class, it calls the same method recursively on any input objects containted in this CoordinateRect.
double	pixelToX(int h) Convert a horizontal pixel coordinate into an x-coordinate.
double	pixelToY(int y) Convert a vertical pixel coordinate into a y-coordinate.
void	remove(Drawable d) Remove the given Drawable item, if present in this CoordinateRect.
double[]	restore() A CoordinateRect can store its current limits in a buffer.
void	setGap(int g) Set the gap.
void	setLimits(double[] d) Set the coordinate limits from array; extra elements in array are ignored.
void	setLimits(double xmin, double xmax, double ymin, double ymax) Set the limits on the CoordinteRect
void	setOnChange(Controller c) Specify a controller to be notified when the limits on this CoordinateRect change.
void	setRestoreBuffer() Save current limits in buffer.
void	setSyncWith(Tie tie) Set the Tie object that is used to synchronize this CoordinareRect with other objects.
void	sync(Tie tie, Tieable newest) Part of the Tieable interface.
int	xToPixel(double x) Convert an x-coodinate into a horizontal pixel coordinate.
int	yToPixel(double y) Convert a y-coodinate into a vertical pixel coordinate.
double[]	zoomIn() Change limits to zoom in by a factor of 2.
double[]	zoomInOnPixel(int x, int y) Change limits to zoom in by a factor of 2, centered on a specified point.
double[]	zoomOut() Change limits to zoom out by a factor of 2.
double[]	zoomOutFromPixel(int x, int y) Change limits to zoom out by a factor of 2, centered on a specified point.

Methods inherited from class java.lang.Object

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

Field Detail

drawItems

protected java.util.Vector drawItems

Drawable items contained in this CoordinateRect

changed

protected boolean changed

Set to true when one of the limits or the gap has changed.

syncWith

protected Tie syncWith

This contains other Limit objects with which the CoordinateRect is synchronizing. This is ordinarily managed by a LimitControlPanel, so you don't have to worry about it. (However, you can also sync several CoordinateRects even in the absense of a LimitControlPanel. To do so, create the Tie that ties the CoordinateRect and pass it to the setSyncWith() method of each CoordinateRect. It is NOT necessary to add the Tie to a Controller. Synchronization is handled by the CoordinateRects themselves.

XMIN

public static final int XMIN

A constant for use with the getValueObject() method to specify which Value is to be returned. XMIN specifies that the Value is the minimum x-coordinate on the CoordinateRect.

XMAX

public static final int XMAX

A constant for use with the getValueObject() method to specify which Value is to be returned. XMAX specifies that the Value is the maximum x-coordinate on the CoordinateRect.

YMIN

public static final int YMIN

A constant for use with the getValueObject() method to specify which Value is to be returned. YMIN specifies that the Value is the minimum y-coordinate on the CoordinateRect.

YMAX

public static final int YMAX

A constant for use with the getValueObject() method to specify which Value is to be returned. YMAX specifies that the Value is the maximum y-coordinate on the CoordinateRect.

onChange

protected Controller onChange

If non-null, this is the Controller that is notified when the limits change.

Constructor Detail

CoordinateRect

public CoordinateRect()

Create a CoordinateRect with default limits: -5, 5, -5, 5.

CoordinateRect

public CoordinateRect(double xmin,
                      double xmax,
                      double ymin,
                      double ymax)

Create a CoordinateRect with specified limits.

Method Detail

getXmin

public double getXmin()

Get the mimimum x-coordinate.

getXmax

public double getXmax()

Get the maximum x-coordinate.

getYmin

public double getYmin()

Get the mimimum y-coordinate.

getYmax

public double getYmax()

Get the maximum x-coordinate.

getGap

public int getGap()

Get the gap, in pixels, between the edges of the CoordinateRect and the limits specified by xmin, xmax, ymin, and ymax.

setGap

public void setGap(int g)

Set the gap. This is ignored if g is less than zero. This gap is the number of pixels between the edges of the CoordinateRect and the limits specified by xmin, xmax, ymin, and ymax. The default value is 5.

getLimits

public double[] getLimits()

Get an array containing the limits on the CoordinateRect in the order xmin, xmax, ymin, ymax.

Specified by:

getLimits in interface Limits

setLimits

public void setLimits(double xmin,
                      double xmax,
                      double ymin,
                      double ymax)

Set the limits on the CoordinteRect

Parameters:

xmin - the minimum x-coordinate on the CoordinateRect

xmax - the maximum x-coordinate on the CoordinateRect

ymin - the minimum y-coordinate on the CoordinateRect

ymax - the maximum y-coordinate on the CoordinateRect

setLimits

public void setLimits(double[] d)

Set the coordinate limits from array; extra elements in array are ignored. This is ignored if the array is null or has fewer than 4 members. The order of values in the array is xmin, xmax, ymin, ymax.

Specified by:

setLimits in interface Limits

Following copied from interface: edu.hws.jcm.awt.Limits

Parameters:

A - 4-element array containing the new xmin, xmax, ymin, and ymax.

setOnChange

public void setOnChange(Controller c)

Specify a controller to be notified when the limits on this CoordinateRect change.

getOnChange

public Controller getOnChange()

Get the controller that is notified when the limits on this CoordinateRect change. This can be null.

getValueObject

public Value getValueObject(int which)

Get a Value object representing one of the limits on this CoordinateRect. The parameter should be one of the constants CoordinateRect.XMIN, CoordinateRect.XMAX, CoordinateRect.YMIN, or CoordinateRect.YMAX. (If not, it is treated the same as YMAX).

getSerialNumber

public long getSerialNumber()

Return the serial number of the CoordinateRect, which is incremented each time the limits change. Part of the Tieable interface. Not meant to be called directly.

Specified by:

getSerialNumber in interface Tieable

setSyncWith

public void setSyncWith(Tie tie)

Set the Tie object that is used to synchronize this CoordinareRect with other objects. This is ordinarily called by a LimitControlPanel, so you don't have to worry about it.

sync

public void sync(Tie tie,
                 Tieable newest)

Part of the Tieable interface. Not meant to be called directly.

Specified by:

sync in interface Tieable

getLeft

public int getLeft()

Get the left edge of this CoordinateRect in the DisplayCanvas that contains it. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

getWidth

public int getWidth()

Get the width in pixels of this CoordinateRect in the DisplayCanvas that contains it. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

getTop

public int getTop()

Get the top edge of this CoordinateRect in the DisplayCanvas that contains it. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

getHeight

public int getHeight()

Get the height in pixels of this CoordinateRect in the DisplayCanvas that contains it. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

getPixelWidth

public double getPixelWidth()

Return the width of one pixel in this coordinate system. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

getPixelHeight

public double getPixelHeight()

Return the height of one pixel in this coordinate system. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

xToPixel

public int xToPixel(double x)

Convert an x-coodinate into a horizontal pixel coordinate. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

yToPixel

public int yToPixel(double y)

Convert a y-coodinate into a vertical pixel coordinate. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

pixelToX

public double pixelToX(int h)

Convert a horizontal pixel coordinate into an x-coordinate. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

pixelToY

public double pixelToY(int y)

Convert a vertical pixel coordinate into a y-coordinate. (This is only valid when the CoordinateRect has actually been displayed. It is meant mainly to be used by Drawables in this CoordinateRect.)

restore

public double[] restore()

A CoordinateRect can store its current limits in a buffer. These limits can be restored by a call to this method. Only one level of save/restore is provided. If limits have not been saved, then nothing happens. The original limits on the CoordinateRect are saves automatically when the CoordinateRect is first created.

Returns:

an array containing new limits.

clearRestoreBuffer

public void clearRestoreBuffer()

A CoordinateRect can store its current limits in a buffer. This method clears that buffer.

setRestoreBuffer

public void setRestoreBuffer()

Save current limits in buffer. They can be restored later by a call to the restore() method. Only one level of save/restore is provided.

zoomIn

public double[] zoomIn()

Change limits to zoom in by a factor of 2. A maximal zoom is enforced. The center of the rectangle does not move.

Returns:

an array of the new limits, or null if limits don't change.

zoomOut

public double[] zoomOut()

Change limits to zoom out by a factor of 2. A maximal zoom is enforced. The center of the rectangle does not move.

Returns:

an array of the new limits, or null if limits don't change.

zoomInOnPixel

public double[] zoomInOnPixel(int x,
                              int y)

Change limits to zoom in by a factor of 2, centered on a specified point. A maximal zoom is enforced. The point does not move. Only valid when CoordinateRect is displayed in a rectangle on the screen.

Parameters:

x - the horizontal pixel coordinate of the center point of the zoom

y - the vertical pixel coordinate of the center point of the zoom

Returns:

an array of the new limits, or null if limits don't change.

zoomOutFromPixel

public double[] zoomOutFromPixel(int x,
                                 int y)

Change limits to zoom out by a factor of 2, centered on a specified point. A maximal zoom is enforced. The point (x,y) does not move. Valid only if CoordinateRect has been drawn.

Parameters:

x - the horizontal pixel coordinate of the center point of the zoom

y - the vertical pixel coordinate of the center point of the zoom

Returns:

an array of the new limits, or null if limits don't change.

equalizeAxes

public double[] equalizeAxes()

Reset limits, if necessary, so scales on the axes are the same. Only valid of the CoordinateRect has been drawn.

Returns:

an array with the new limits, or null if limits don't change.

checkInput

public void checkInput()

When this is called, the CoordinateRect will call the checkInput method of any Drawable it contains that is also an InputObject. This is ordinarly only called by a DisplayCanvas.

Specified by:

checkInput in interface InputObject

compute

public void compute()

When this is called, the CoordinateRect will call the compute method of any Drawable it contains that is also a Computable. This is ordinarly only called by a DisplayCanvas.

Specified by:

compute in interface Computable

notifyControllerOnChange

public void notifyControllerOnChange(Controller c)

Method required by InputObject interface; in this class, it calls the same method recursively on any input objects containted in this CoordinateRect. This is meant to be called by JCMPanel.gatherInputs().

Specified by:

notifyControllerOnChange in interface InputObject

add

public void add(Drawable d)

Add a drawable item to the CoordinateRect.

remove

public void remove(Drawable d)

Remove the given Drawable item, if present in this CoordinateRect.

getDrawableCount

public int getDrawableCount()

Returns the number of Drawable items that are in this CoordinateRect.

getDrawable

public Drawable getDrawable(int i)

Get the i-th Drawable in this Rect, or null if i is less than zero or greater than or equal to the number of items.

Parameters:

i - The number of the item to be returned, where the first item is number zero.

draw

public void draw(java.awt.Graphics g,
                 int width,
                 int height)

Draw in rect with upperleft corner (0,0) and specified width,height. This is not ordinarily called directly.

draw

public void draw(java.awt.Graphics g,
                 int left,
                 int top,
                 int width,
                 int height)

Draw in specified rect. This is not ordinarily called directly.

doDraw

protected void doDraw(java.awt.Graphics g)

Draw all the Drawable items. This is called by the draw() method and is not meant to be called directly. However, it might be overridden in a subclass.