Package org.gvsig.fmap.mapcontrol.tools

Class AreaListenerImpl

java.lang.Object

org.gvsig.fmap.mapcontrol.tools.AreaListenerImpl

All Implemented Interfaces:

PolylineListener, ToolListener

public class AreaListenerImpl
extends Object
implements PolylineListener

Listener for calculating the area of a polygon, defined in the associated MapControl object.

If the view port of the associated MapControl isn't projected gets the area according the geographical coordinates.

Author:

Vicente Caballero Navarro

Field Summary

Fields

Modifier and Type	Field	Description
protected MeasureEvent	event	Information about all vertexes and GeneralPathXs of the polyline.
protected MapControl	mapCtrl	Reference to the MapControl object that uses.

Constructor Summary

Constructors

Constructor	Description
AreaListenerImpl(MapControl mc)	Creates a new listener for calculating the area of a polygon.

Method Summary

Modifier and Type	Method	Description
boolean	cancelDrawing()	Determines if the drawing process that this tool executes on the MapControl instance could be canceled or not.
Image	getImageCursor()	Gets the Cursor associated to this tool.
static void	main(String[] args)
void	pointFixed(MeasureEvent event)	Called when user executes a mouse click and selects a vertex of the polyline.
void	points(MeasureEvent event)	Called when user moves the mouse after selecting a vertex of the polyline.
void	polylineFinished(MeasureEvent event)	Called when user executes a double click with the mouse, finishing the drawn of the polyline.
protected double	returnArea(Point2D point)	Returns the area of the polygon, using returnCoordsArea if the ViewPort of the associated MapControl is projected, or using returnGeoCArea if isn't.
double	returnCoordsArea(Double[] xs, Double[] ys, Point2D point)	Returns the area of the polygon using point as initial, in real values with the current measure unit, according the projection in the ViewPort of the MapControl.
double	returnGeoCArea(Double[] xs, Double[] ys, Point2D point)	Returns the area in geographical coordinates of the polygon, according the Haversine function.

Methods inherited from class java.lang.Object

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

Field Details

mapCtrl

protected MapControl mapCtrl

Reference to the MapControl object that uses.

event

protected MeasureEvent event

Information about all vertexes and GeneralPathXs of the polyline.

Constructor Details

AreaListenerImpl

public AreaListenerImpl(MapControl mc)

Creates a new listener for calculating the area of a polygon.

Parameters:

mc - the MapControl where is calculated the area

Method Details

points

public void points(MeasureEvent event)

Description copied from interface: PolylineListener

Called when user moves the mouse after selecting a vertex of the polyline.

Each kind of polyline listener calculates different information with the data of the MeasureEvent, according its nature.

Specified by:

points in interface PolylineListener

Parameters:

event - information about the mouse event, and geometry data of the polyline

returnArea

protected double returnArea(Point2D point)

Returns the area of the polygon, using returnCoordsArea if the ViewPort of the associated MapControl is projected, or using returnGeoCArea if isn't.

Parameters:

point - unused parameter

Returns:

area from the vertexes stored at the measure event in real coordinates, or, if the MapControl isn't projected, in geographical coordinates

See Also:

• returnCoordsArea(Double[], Double[], Point2D)
• returnGeoCArea(Double[], Double[], Point2D)

returnCoordsArea

public double returnCoordsArea(Double[] xs,
 Double[] ys,
 Point2D point)

Returns the area of the polygon using point as initial, in real values with the current measure unit, according the projection in the ViewPort of the MapControl.

Parameters:

xs - abscissa coordinate of all vertexes of the polygon

ys - ordinate coordinate of all vertexes of the polygon

point - point 2D used as first vertex in the calculation of the area

Returns:

the area of the polygon

main

public static void main(String[] args)

returnGeoCArea

public double returnGeoCArea(Double[] xs,
 Double[] ys,
 Point2D point)

Returns the area in geographical coordinates of the polygon, according the Haversine function.

See Also:

• Geo.sphericalPolyArea(double[], double[], int)

getImageCursor

public Image getImageCursor()

Description copied from interface: ToolListener

Gets the Cursor associated to this tool.

Specified by:

getImageCursor in interface ToolListener

Returns:

component with the bitmap associated to this tool

pointFixed

public void pointFixed(MeasureEvent event)

Description copied from interface: PolylineListener

Called when user executes a mouse click and selects a vertex of the polyline.

Specified by:

pointFixed in interface PolylineListener

Parameters:

event - information about the mouse event, and geometry data of the polyline

polylineFinished

public void polylineFinished(MeasureEvent event)

Description copied from interface: PolylineListener

Called when user executes a double click with the mouse, finishing the drawn of the polyline.

All features of the active and vector layers of the associated MapControl object that their area intersect with the polygonal area defined in the event, will be selected.

Specified by:

polylineFinished in interface PolylineListener

Parameters:

event - information about the mouse event, and geometry data of the polyline

cancelDrawing

public boolean cancelDrawing()

Description copied from interface: ToolListener

Determines if the drawing process that this tool executes on the MapControl instance could be canceled or not.

Specified by:

cancelDrawing in interface ToolListener

Returns:

true if is cancellable; otherwise returns false