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World Wind is a collection of components that interactively display 3D geographic information within Java applications or applets.
/*
* Copyright (C) 2012 United States Government as represented by the Administrator of the
* National Aeronautics and Space Administration.
* All Rights Reserved.
*/
package gov.nasa.worldwind.render;
import gov.nasa.worldwind.avlist.AVKey;
import gov.nasa.worldwind.util.*;
import java.awt.*;
/**
* Defines the relationship of an image, label or other screen-space item relative to another screen-space item. An
* offset contains an X coordinate, a Y coordinate, and for each of these a separate "units" string indicating the
* coordinate units.
*
* Recognized "units" values are {@link AVKey#PIXELS}, which indicates pixel units relative to the lower left corner of
* the screen-space item, {@link AVKey#FRACTION}, which indicates that the units are fractions of the screen-space
* item's width and height, relative to its lower left corner, and {@link AVKey#INSET_PIXELS}, which indicates units of
* pixels but with origin at the screen-space item's upper right.
*
* This class implements the functionality of a KML Offset.
*
* @author tag
* @version $Id: Offset.java 1171 2013-02-11 21:45:02Z dcollins $
*/
public class Offset
{
public static final Offset CENTER = Offset.fromFraction(0.5, 0.5);
public static final Offset BOTTOM_CENTER = Offset.fromFraction(0.5, 0.0);
public static final Offset TOP_CENTER = Offset.fromFraction(0.5, 1.0);
public static final Offset LEFT_CENTER = Offset.fromFraction(0.0, 0.5);
public static final Offset RIGHT_CENTER = Offset.fromFraction(1.0, 0.5);
protected Double x;
protected Double y;
protected String xUnits;
protected String yUnits;
public Offset(Double x, Double y, String xUnits, String yUnits)
{
this.x = x;
this.y = y;
this.xUnits = xUnits;
this.yUnits = yUnits;
}
/**
* Creates a new offset from explicit fraction coordinates.
*
* @param xFraction the offset's X coordinate as a fraction of the containing rectangle.
* @param yFraction the offset's Y coordinate as a fraction of the containing rectangle.
*
* @return a new offset with the specified X and Y coordinates.
*/
public static Offset fromFraction(double xFraction, double yFraction)
{
return new Offset(xFraction, yFraction, AVKey.FRACTION, AVKey.FRACTION);
}
/**
* Returns the hot spot's X coordinate. See {@link #setXUnits(String)} for a description of the hot spot.
*
* @return the hot spot's X coordinate.
*/
public Double getX()
{
return x;
}
/**
* Specifies the hot spot's X coordinate, in units specified by {@link #setXUnits(String)}.
*
* @param x the hot spot's X coordinate. May be null, in which case 0 is used during rendering.
*/
public void setX(Double x)
{
this.x = x;
}
/**
* Returns the hot spot's Y coordinate. See {@link #setYUnits(String)} for a description of the hot spot.
*
* @return the hot spot's Y coordinate.
*/
public Double getY()
{
return y;
}
/**
* Specifies the hot spot's Y coordinate, in units specified by {@link #setYUnits(String)}.
*
* @param y the hot spot's Y coordinate. May be null, in which case 0 is used during rendering.
*/
public void setY(Double y)
{
this.y = y;
}
/**
* Returns the units of the offset X value. See {@link #setXUnits(String)} for a description of the recognized
* values.
*
* @return the units of the offset X value, or null.
*/
public String getXUnits()
{
return xUnits;
}
/**
* Specifies the units of the offset X value. Recognized values are {@link AVKey#PIXELS}, which indicates pixel
* units relative to the lower left corner of the placemark image, {@link AVKey#FRACTION}, which indicates the units
* are fractions of the placemark image width and height, and {@link AVKey#INSET_PIXELS}, which indicates units of
* pixels but with origin in the upper left.
*
* @param units the units of the offset X value. If null, {@link AVKey#PIXELS} is used during rendering.
*/
public void setXUnits(String units)
{
this.xUnits = units;
}
/**
* Returns the units of the offset Y value. See {@link #setYUnits(String)} for a description of the recognized
* values.
*
* @return the units of the offset Y value, or null.
*/
public String getYUnits()
{
return yUnits;
}
/**
* Specifies the units of the offset Y value. Recognized values are {@link AVKey#PIXELS}, which indicates pixel
* units relative to the lower left corner of the placemark image, {@link AVKey#FRACTION}, which indicates the units
* are fractions of the placemark image width and height, and {@link AVKey#INSET_PIXELS}, which indicates units of
* pixels but with origin in the upper left.
*
* @param units the units of the offset Y value. If null, {@link AVKey#PIXELS} is used during rendering.
*/
public void setYUnits(String units)
{
this.yUnits = units;
}
/**
* Computes the X and Y offset specified by this offset applied to a specified rectangle.
*
* @param width the rectangle width.
* @param height the rectangle height.
* @param xScale an optional scale to apply to the X coordinate of the offset. May be null.
* @param yScale an optional scale to apply to the Y coordinate of the offset. May be null.
*
* @return the result of applying this offset to the specified rectangle and incorporating the optional scales.
*/
public Point.Double computeOffset(double width, double height, Double xScale, Double yScale)
{
double dx = 0;
double dy = 0;
if (this.getX() != null)
{
String units = this.getXUnits();
if (AVKey.PIXELS.equals(units))
dx = this.getX();
else if (AVKey.INSET_PIXELS.equals(units))
dx = width - this.getX();
else if (AVKey.FRACTION.equals(units))
dx = (width * this.getX());
else
dx = this.getX(); // treat as pixels
}
if (this.getY() != null)
{
String units = this.getYUnits();
if (AVKey.PIXELS.equals(units))
dy = this.getY();
else if (AVKey.INSET_PIXELS.equals(units))
dy = height - this.getY();
else if (AVKey.FRACTION.equals(units))
dy = (height * this.getY());
else
dy = this.getY(); // treat as pixels
}
if (xScale != null)
dx *= xScale;
if (yScale != null)
dy *= yScale;
return new Point.Double(dx, dy);
}
/**
* Saves the offset's current state in the specified restorableSupport. If context is not
* null, the state is appended to it. Otherwise the state is added to the
* RestorableSupport root. This state can be restored later by calling {@link
* #restoreState(gov.nasa.worldwind.util.RestorableSupport, gov.nasa.worldwind.util.RestorableSupport.StateObject)}.
*
* @param restorableSupport the RestorableSupport that receives the offset's state.
* @param context the StateObject the state is appended to, if not null.
*
* @throws IllegalArgumentException if restorableSupport is null.
*/
public void getRestorableState(RestorableSupport restorableSupport, RestorableSupport.StateObject context)
{
if (restorableSupport == null)
{
String message = Logging.getMessage("nullValue.RestorableSupportIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
if (this.getX() != null)
restorableSupport.addStateValueAsDouble(context, "x", this.getX());
if (this.getY() != null)
restorableSupport.addStateValueAsDouble(context, "y", this.getY());
if (this.getXUnits() != null)
restorableSupport.addStateValueAsString(context, "xUnits", this.getXUnits());
if (this.getYUnits() != null)
restorableSupport.addStateValueAsString(context, "yUnits", this.getYUnits());
}
/**
* Restores the state of any offset parameters contained in the specified RestorableSupport. If the
* StateObject is not null it's searched for state values, otherwise the
* RestorableSupport root is searched.
*
* @param restorableSupport the RestorableSupport that contains the offset's state.
* @param context the StateObject to search for state values, if not null.
*
* @throws IllegalArgumentException if restorableSupport is null.
*/
public void restoreState(RestorableSupport restorableSupport, RestorableSupport.StateObject context)
{
if (restorableSupport == null)
{
String message = Logging.getMessage("nullValue.RestorableSupportIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
Double d = restorableSupport.getStateValueAsDouble(context, "x");
if (d != null)
this.setX(d);
d = restorableSupport.getStateValueAsDouble(context, "y");
if (d != null)
this.setY(d);
String s = restorableSupport.getStateValueAsString(context, "xUnits");
if (s != null)
this.setXUnits(s);
s = restorableSupport.getStateValueAsString(context, "yUnits");
if (s != null)
this.setYUnits(s);
}
@Override
public boolean equals(Object o)
{
if (this == o)
return true;
if (o == null || getClass() != o.getClass())
return false;
Offset that = (Offset) o;
if (this.x != null ? !this.x.equals(that.x) : that.x != null)
return false;
if (this.y != null ? !this.y.equals(that.y) : that.y != null)
return false;
if (this.xUnits != null ? !this.xUnits.equals(that.xUnits) : that.xUnits != null)
return false;
//noinspection RedundantIfStatement
if (this.yUnits != null ? !this.yUnits.equals(that.yUnits) : that.yUnits != null)
return false;
return true;
}
@Override
public int hashCode()
{
int result = this.x != null ? this.x.hashCode() : 0;
result = 31 * result + (this.y != null ? this.y.hashCode() : 0);
result = 31 * result + (this.xUnits != null ? this.xUnits.hashCode() : 0);
result = 31 * result + (this.yUnits != null ? this.yUnits.hashCode() : 0);
return result;
}
}