gov.nasa.worldwind.render

Class SurfaceText

java.lang.Object

gov.nasa.worldwind.avlist.AVListImpl

gov.nasa.worldwind.WWObjectImpl

gov.nasa.worldwind.render.AbstractSurfaceObject

gov.nasa.worldwind.render.SurfaceText

All Implemented Interfaces:

AVList, Draggable, MessageListener, Movable, GeographicText, OrderedRenderable, PreRenderable, Renderable, SurfaceObject, SurfaceRenderable, WWObject, PropertyChangeListener, EventListener

public class SurfaceText
extends AbstractSurfaceObject
implements GeographicText, Movable, Draggable

Renders a string of text on the surface of the globe. The text will appear draped over terrain. Surface text is drawn at a constant geographic size: it will appear larger when the view zooms in on the text and smaller when the view zooms out.

Nested Class Summary

Nested classes/interfaces inherited from class gov.nasa.worldwind.render.AbstractSurfaceObject

AbstractSurfaceObject.CacheEntry, AbstractSurfaceObject.SurfaceObjectStateKey

Field Summary

Fields

Modifier and Type	Field and Description
protected Color	bgColor Background color for the text.
protected Color	color Color to use to draw the text.
static Color	DEFAULT_COLOR Default text color.
static Font	DEFAULT_FONT Default font.
static Offset	DEFAULT_OFFSET Default offset.
static double	DEFAULT_TEXT_SIZE_IN_METERS Default text size.
protected boolean	dragEnabled Dragging Support
protected DraggableSupport	draggableSupport
protected LatLon	drawLocation The lower-left location of the text box after applying offset.
protected Font	font Font to use to draw the text.
protected Position	location Location at which to draw the text.
protected Offset	offset Offset that specifies where to place the text in relation to it's geographic position.
protected double	pixelSizeInMeters Geographic size of a pixel.
protected double	priority Text priority.
protected double	scale Scaling factor applied to the text to maintain a constant geographic size.
protected boolean	spansAntimeridian Indicates whether this text spans the dateline.
protected CharSequence	text The text to draw.
protected Rectangle2D	textBounds Bounds of the text in pixels.
protected double	textSizeInMeters The height of the text in meters.

Fields inherited from class gov.nasa.worldwind.render.AbstractSurfaceObject

delegateOwner, drawBoundingSectors, enableBatchPicking, extentCache, lastModifiedTime, nextUniqueId, pickLayer, pickSupport, pickTileBuilder, uniqueId, visible

Constructor Summary

Constructors

Constructor and Description
SurfaceText(String text, Position position) Create a new surface text object.
SurfaceText(String text, Position position, Font font, Color color) Create a new surface text object.

Method Summary

Modifier and Type	Method and Description
protected void	applyDrawTransform(DrawContext dc, SurfaceTileDrawContext sdc) Apply a transform to the GL state to draw the text at the proper location and scale.
protected Color	computeBackgroundColor(Color color) Compute a background color that contrasts with the text color.
protected void	computeGeometry(DrawContext dc, SurfaceTileDrawContext sdc) Compute the text size and position.
protected double	computePixelSize(DrawContext dc, SurfaceTileDrawContext sdc) Compute the size of a pixel in the surface tile.
protected Sector[]	computeSector(DrawContext dc) Compute the sector covered by this surface text.
protected Color	determineBackgroundColor(Color color) Determine the text background color.
protected void	doDrag(DragContext dragContext)
void	drag(DragContext dragContext) Drag the object given the provided DragContext.
protected void	drawGeographic(DrawContext dc, SurfaceTileDrawContext sdc) Causes the SurfaceObject to render itself to the specified region in geographic coordinates.
protected void	drawText(DrawContext dc) Draw the text.
Color	getBackgroundColor() Indicates the background color used to draw the text.
Color	getColor() Indicates the color used to draw the text.
Font	getFont() Indicates the font used to draw the text.
Offset	getOffset() Returns the text offset.
Position	getPosition() Indicates the geographic position of the text.
double	getPriority() Indicates the text priority.
Position	getReferencePosition() A position associated with the object that indicates its aggregate geographic position.
List<Sector>	getSectors(DrawContext dc) Returns a list of sectors indicating the geographic region that bounds this renderable for the specified draw context.
CharSequence	getText() Indicates the text contained in this object.
protected TextRenderer	getTextRenderer(DrawContext dc) Get the text renderer to use to draw text.
double	getTextSize()
boolean	isDragEnabled() Indicates whether the object is enabled for dragging.
protected boolean	isSmall() Determine if the text is too small to draw.
void	move(Position position) Shift the shape over the globe's surface while maintaining its original azimuth, its orientation relative to North.
void	moveTo(Position position) Move the shape over the globe's surface while maintaining its original azimuth, its orientation relative to North.
void	preRender(DrawContext dc) Causes the surface object to prepare a representation of itself which can be drawn on the surface terrain, using the provided draw context.
void	setBackgroundColor(Color background) Specifies the background color used to draw the text.
void	setColor(Color color) Specifies the color used to draw the text.
void	setDragEnabled(boolean enabled) Controls whether the object is enabled for dragging.
void	setFont(Font font) Specifies the font used to draw the text.
void	setOffset(Offset offset) Specifies a location relative to the label position at which to align the label.
void	setPosition(Position position) Specifies the geographic position of the text.
void	setPriority(double priority) Specifies the text priority.
void	setText(CharSequence text) Specifies the text.
void	setTextSize(double meters)
protected void	updateTextBounds(DrawContext dc) Determine the text bounds.

Methods inherited from class gov.nasa.worldwind.render.AbstractSurfaceObject

buildPickRepresentation, clearCaches, computeExtent, computeExtent, createPickedObject, createPickTileBuilder, drawBoundingSectors, drawOrderedRenderable, drawPickRepresentation, getDelegateOwner, getDistanceFromEye, getExtent, getStateKey, getUniqueId, intersectsFrustum, intersectsPickFrustum, intersectsVisibleSector, isDrawBoundingSectors, isEnableBatchPicking, isVisible, makeOrderedPreRenderable, makeOrderedRenderable, nextUniqueId, pick, pickBatched, pickOrderedRenderable, render, setDelegateOwner, setDrawBoundingSectors, setEnableBatchPicking, setVisible, updateModifiedTime

Methods inherited from class gov.nasa.worldwind.WWObjectImpl

onMessage, propertyChange

Methods inherited from class gov.nasa.worldwind.avlist.AVListImpl

addPropertyChangeListener, addPropertyChangeListener, clearList, copy, firePropertyChange, firePropertyChange, getBooleanValue, getBooleanValue, getChangeSupport, getDoubleValue, getDoubleValue, getEntries, getIntegerValue, getIntegerValue, getLongValue, getLongValue, getRestorableStateForAVPair, getStringValue, getStringValue, getStringValue, getValue, getValues, hasKey, removeKey, removePropertyChangeListener, removePropertyChangeListener, setValue, setValues

Methods inherited from class java.lang.Object

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

Methods inherited from interface gov.nasa.worldwind.render.GeographicText

isVisible, setVisible

Methods inherited from interface gov.nasa.worldwind.avlist.AVList

addPropertyChangeListener, addPropertyChangeListener, clearList, copy, firePropertyChange, firePropertyChange, getEntries, getStringValue, getValue, getValues, hasKey, removeKey, removePropertyChangeListener, removePropertyChangeListener, setValue, setValues

Field Detail

bgColor

protected Color bgColor

Background color for the text. By default color will be generated to contrast with the text color.

color

protected Color color

Color to use to draw the text. Defaults to DEFAULT_COLOR.

DEFAULT_COLOR

public static final Color DEFAULT_COLOR

Default text color.

DEFAULT_FONT

public static final Font DEFAULT_FONT

Default font.

DEFAULT_OFFSET

public static final Offset DEFAULT_OFFSET

Default offset. The default offset centers the text on its geographic position both horizontally and vertically.

DEFAULT_TEXT_SIZE_IN_METERS

public static final double DEFAULT_TEXT_SIZE_IN_METERS

Default text size.

See Also:

Constant Field Values

dragEnabled

protected boolean dragEnabled

Dragging Support

draggableSupport

protected DraggableSupport draggableSupport

drawLocation

protected LatLon drawLocation

The lower-left location of the text box after applying offset.

font

protected Font font

Font to use to draw the text. Defaults to DEFAULT_FONT.

location

protected Position location

Location at which to draw the text.

offset

protected Offset offset

Offset that specifies where to place the text in relation to it's geographic position.

pixelSizeInMeters

protected double pixelSizeInMeters

Geographic size of a pixel.

priority

protected double priority

Text priority. Can be used to implement text culling.

scale

protected double scale

Scaling factor applied to the text to maintain a constant geographic size.

spansAntimeridian

protected boolean spansAntimeridian

Indicates whether this text spans the dateline.

text

protected CharSequence text

The text to draw.

textBounds

protected Rectangle2D textBounds

Bounds of the text in pixels.

textSizeInMeters

protected double textSizeInMeters

The height of the text in meters.

Constructor Detail

SurfaceText

public SurfaceText(String text,
                   Position position)

Create a new surface text object.

Parameters:

text - Text to draw.

position - Geographic location at which to draw the text.

SurfaceText

public SurfaceText(String text,
                   Position position,
                   Font font,
                   Color color)

Create a new surface text object.

Parameters:

text - Text to draw.

position - Geographic location at which to draw the text.

font - Font to use when drawing text.

color - Color to use when drawing text.

Method Detail

applyDrawTransform

protected void applyDrawTransform(DrawContext dc,
                                  SurfaceTileDrawContext sdc)

Apply a transform to the GL state to draw the text at the proper location and scale.

Parameters:

dc - Current draw context.

sdc - Current surface tile draw context.

computeBackgroundColor

protected Color computeBackgroundColor(Color color)

Compute a background color that contrasts with the text color.

Parameters:

color - text color.

Returns:

a color that contrasts with the text color.

computeGeometry

protected void computeGeometry(DrawContext dc,
                               SurfaceTileDrawContext sdc)

Compute the text size and position.

Parameters:

dc - Current draw context.

sdc - Current surface tile draw context.

computePixelSize

protected double computePixelSize(DrawContext dc,
                                  SurfaceTileDrawContext sdc)

Compute the size of a pixel in the surface tile.

Parameters:

dc - Current draw context.

sdc - Current surface tile draw context.

Returns:

The size of a tile pixel in meters.

computeSector

protected Sector[] computeSector(DrawContext dc)

Compute the sector covered by this surface text.

Parameters:

dc - Current draw context.

Returns:

The sector covered by the surface text.

determineBackgroundColor

protected Color determineBackgroundColor(Color color)

Determine the text background color. This method returns the user specified background color, or a computed default color if the user has not set a background color.

Parameters:

color - text color.

Returns:

the user specified background color, or a default color that contrasts with the text color.

doDrag

protected void doDrag(DragContext dragContext)

drag

public void drag(DragContext dragContext)

Description copied from interface: Draggable

Drag the object given the provided DragContext.

Specified by:

drag in interface Draggable

Parameters:

dragContext - the DragContext of this dragging event.

drawGeographic

protected void drawGeographic(DrawContext dc,
                              SurfaceTileDrawContext sdc)

Causes the SurfaceObject to render itself to the specified region in geographic coordinates. The specified viewport denotes the geographic region and its corresponding screen viewport.

Specified by:

drawGeographic in class AbstractSurfaceObject

Parameters:

dc - the current draw context.

sdc - the context containing a geographic region and screen viewport corresponding to a surface tile.

drawText

protected void drawText(DrawContext dc)

Draw the text.

Parameters:

dc - Current draw context.

getBackgroundColor

public Color getBackgroundColor()

Indicates the background color used to draw the text.

Specified by:

getBackgroundColor in interface GeographicText

Returns:

Current background color.

getColor

public Color getColor()

Indicates the color used to draw the text.

Specified by:

getColor in interface GeographicText

Returns:

Current text color.

getFont

public Font getFont()

Indicates the font used to draw the text.

Specified by:

getFont in interface GeographicText

Returns:

Current font.

getOffset

public Offset getOffset()

Returns the text offset. The offset determines how to position the text relative to its geographic position.

Returns:

the text offset.

See Also:

setOffset(Offset)

getPosition

public Position getPosition()

Indicates the geographic position of the text.

Specified by:

getPosition in interface GeographicText

Returns:

The text position.

getPriority

public double getPriority()

Indicates the text priority. The priority can be used to implement text culling.

Specified by:

getPriority in interface GeographicText

Returns:

The text priority.

getReferencePosition

public Position getReferencePosition()

A position associated with the object that indicates its aggregate geographic position. The chosen position varies among implementers of this interface. For objects defined by a list of positions, the reference position is typically the first position in the list. For symmetric objects the reference position is often the center of the object. In many cases the object's reference position may be explicitly specified by the application.

Specified by:

getReferencePosition in interface Movable

Returns:

the object's reference position, or null if no reference position is available.

getSectors

public List<Sector> getSectors(DrawContext dc)

Returns a list of sectors indicating the geographic region that bounds this renderable for the specified draw context.

The returned list typically contains one sector that bounds this renderable in geographic coordinates. When this renderable spans the anti-meridian - the +/- 180 degree meridian - the returned list contains two sectors, one on either side of the anti-meridian.

Specified by:

getSectors in interface SurfaceRenderable

Parameters:

dc - the draw context for which to determine this renderable's geographic bounds.

Returns:

a list of one or two sectors that bound this renderable.

getText

public CharSequence getText()

Indicates the text contained in this object.

Specified by:

getText in interface GeographicText

Returns:

The current text.

getTextRenderer

protected TextRenderer getTextRenderer(DrawContext dc)

Get the text renderer to use to draw text.

Parameters:

dc - Current draw context.

Returns:

The text renderer that will be used to draw the surface text.

getTextSize

public double getTextSize()

isDragEnabled

public boolean isDragEnabled()

Description copied from interface: Draggable

Indicates whether the object is enabled for dragging.

Specified by:

isDragEnabled in interface Draggable

Returns:

true if the object is enabled, else false.

isSmall

protected boolean isSmall()

Determine if the text is too small to draw.

Returns:

true if the height of the text is less than one pixel.

move

public void move(Position position)

Shift the shape over the globe's surface while maintaining its original azimuth, its orientation relative to North.

Specified by:

move in interface Movable

Parameters:

position - the latitude and longitude to add to the shape's reference position.

moveTo

public void moveTo(Position position)

Move the shape over the globe's surface while maintaining its original azimuth, its orientation relative to North.

Specified by:

moveTo in interface Movable

Parameters:

position - the new position of the shape's reference position.

preRender

public void preRender(DrawContext dc)

Causes the surface object to prepare a representation of itself which can be drawn on the surface terrain, using the provided draw context.

Specified by:

preRender in interface PreRenderable

Specified by:

preRender in interface SurfaceObject

Overrides:

preRender in class AbstractSurfaceObject

Parameters:

dc - the current draw context.

setBackgroundColor

public void setBackgroundColor(Color background)

Specifies the background color used to draw the text.

Specified by:

setBackgroundColor in interface GeographicText

Parameters:

background - New background color.

setColor

public void setColor(Color color)

Specifies the color used to draw the text.

Specified by:

setColor in interface GeographicText

Parameters:

color - New color.

setDragEnabled

public void setDragEnabled(boolean enabled)

Description copied from interface: Draggable

Controls whether the object is enabled for dragging.

Specified by:

setDragEnabled in interface Draggable

Parameters:

enabled - true if the object is enabled, else false.

setFont

public void setFont(Font font)

Specifies the font used to draw the text.

Specified by:

setFont in interface GeographicText

Parameters:

font - New font.

setOffset

public void setOffset(Offset offset)

Specifies a location relative to the label position at which to align the label. The label text begins at the point indicated by the offset. An offset of (0, 0) aligns the left baseline of the text with the position. An offset of (-0.5, -0.5) fraction aligns the center of the text with the position.

A pixel based offset is interpreted based on the geographic size of the text. For example, if the text rendered "normally" in two dimensions would be 20 pixels tall, and the geographic text is 100 meters tall, then each pixel of text corresponds to 5 meters. So an offset of 2 pixels would correspond to a geographic offset of 10 meters.

Parameters:

offset - Offset that controls where to position the label relative to its geographic location.

setPosition

public void setPosition(Position position)

Specifies the geographic position of the text.

The offset determines how the text is placed relative to this position. The default offset centers the text on the position both horizontally and vertically.

Specified by:

setPosition in interface GeographicText

Parameters:

position - New text position.

See Also:

setOffset(Offset)

setPriority

public void setPriority(double priority)

Specifies the text priority. The priority can be used to implement text culling.

Specified by:

setPriority in interface GeographicText

Parameters:

priority - New priority.

setText

public void setText(CharSequence text)

Specifies the text.

Specified by:

setText in interface GeographicText

Parameters:

text - New text.

setTextSize

public void setTextSize(double meters)

updateTextBounds

protected void updateTextBounds(DrawContext dc)

Determine the text bounds.

Parameters:

dc - Current draw context.