com.luciad.maps

Class MapScale

java.lang.Object

com.luciad.maps.MapScale

All Implemented Interfaces:

Comparable<MapScale>

public final class MapScale
extends Object
implements Comparable<MapScale>

This class represents a map scale, a ratio of a distance on the map to the corresponding actual distance.

For example: a map scale of 1:50000 means that 1 centimeter on a map corresponds with 500 meters on the ground.

This class gives a natural ordering to map scales, from zoomed out to zoomed in. When a part of the API takes an ordered collection as input, it must be ordered according to this natural ordering (unless stated otherwise).

In order for a Map instance to interpret MapScale values correctly, it needs to know the DPI (see Map#getDpi) value of the screen on which it is rendered.

See also the related article

Field Summary

Fields

Modifier and Type	Field and Description
static MapScale	MaxZoomedIn The value that represents a maximally zoomed in map scale (1:0 ≈ the maximum double value)
static MapScale	MaxZoomedOut The value that represents a maximally zoomed out map scale (1:inf == 0)

Constructor Summary

Constructors

Constructor and Description
MapScale(double value) Creates a new MapScale based on the given ratio.

Method Summary

Modifier and Type	Method and Description
int	compareTo(MapScale other)
boolean	equals(Object other)
static MapScale	fromDenominator(double denominator) Creates a map scale from a denominator value.
double	getDenominator() Returns the denominator of this map scale.
double	getValue() Returns the scale value.
int	hashCode()
String	toString()
MapScale	zoomIn(double factor) Creates a new MapScale which is zoomed in with a given factor.
MapScale	zoomOut(double factor) Creates a new MapScale which is zoomed outn with a given factor.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

MaxZoomedOut

public static final MapScale MaxZoomedOut

The value that represents a maximally zoomed out map scale (1:inf == 0)

MaxZoomedIn

public static final MapScale MaxZoomedIn

The value that represents a maximally zoomed in map scale (1:0 ≈ the maximum double value)

Constructor Detail

MapScale

public MapScale(double value)
         throws IllegalArgumentException

Creates a new MapScale based on the given ratio.

Parameters:

value - a value that represents 1 / denominator. For example: a MapScale of 1:50000 can be created using 0.00002 (=1/50000) as value.

Throws:

IllegalArgumentException - when the map scale is smaller than 0.

Method Detail

fromDenominator

@NotNull
public static MapScale fromDenominator(double denominator)
                                         throws IllegalArgumentException

Creates a map scale from a denominator value.

For example when using 1:50000 as map scale, the denominator is 50000.

Parameters:

denominator - the scale denominator.

Returns:

a map scale that corresponds to 1:denominator

Throws:

IllegalArgumentException - when the denominator is negative.

zoomOut

@NotNull
public MapScale zoomOut(double factor)

Creates a new MapScale which is zoomed outn with a given factor.

For example, when applying this method on a 1:50000 scale, with a factor or 2, the resulting map scale will be 1:100000.

Parameters:

factor - the factor using which to zoom out

Returns:

a new map scale that is zoomed out using the given factor.

zoomIn

@NotNull
public MapScale zoomIn(double factor)

Creates a new MapScale which is zoomed in with a given factor.

For example, when applying this method on a 1:50000 scale, with a factor or 2, the resulting map scale will be 1:25000.

Parameters:

factor - the factor using which to zoom in

Returns:

a new map scale that is zoomed in using the given factor.

getValue

public double getValue()

Returns the scale value.

Returns:

the scale value.

getDenominator

public double getDenominator()

Returns the denominator of this map scale.

For example when the Map Scale is 1:50000, this method returns 50000.

Returns:

the denominator of this map scale.

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

@NotNull
public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(@NotNull
                     MapScale other)

Specified by:

compareTo in interface Comparable<MapScale>