org.geotools.renderer.label

Class LabelPainter

Object

LabelPainter

public class LabelPainter
extends Object

This class performs the layouting and painting of the single label (leaving the label cache the task to sort labels and locate the best label points)

Author:

Andrea Aime

Constructor Summary

Constructors

Constructor and Description
LabelPainter(Graphics2D graphics, LabelCacheImpl.LabelRenderingMode labelRenderingMode) Builds a new painter

Method Summary

Modifier and Type	Method and Description
double	getAscent() The full size above the baseline
Rectangle2D	getFullLabelBounds() Get the straight label bounds, taking into account halo, shield and line wrapping
LabelCacheItem	getLabel() Returns the current label item
Rectangle2D	getLabelBounds() Get the straight label bounds, without taking into account halo and shield
int	getLineCount() Number of lines for this label (more than 1 if the label has embedded newlines or if we're auto-wrapping it)
double	getLineHeight() Returns the line height for this label in pixels (for multiline labels, it's the height of the first line)
double	getLineHeightForAnchorY(double anchorY) Returns appropriate line height for the given displacemntY Should give Top line for max displacementY (1) and Bottom line for min displacemntY (0)
double	getLinePlacementYAnchor() Vertical centering is not trivial, because visually we want centering on characters such as a,m,e, and not centering on d,g whose center is affected by the full ascent or the full descent.
int	getStraightLabelWidth() Returns the width of the label, as painted in straight form (
void	paintCurvedLabel(LineStringCursor cursor) Paints a label that follows the line, centered in the current cursor position
void	paintStraightLabel(AffineTransform transform) Paints the label as a non curved one.
void	paintStraightLabel(AffineTransform transform, Coordinate labelPoint) Paints the label as a non curved one.
void	setLabel(LabelCacheItem labelItem) Sets the current label.

Methods inherited from class Object

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

Constructor Detail

LabelPainter

public LabelPainter(Graphics2D graphics,
                    LabelCacheImpl.LabelRenderingMode labelRenderingMode)

Builds a new painter

Method Detail

setLabel

public void setLabel(LabelCacheItem labelItem)

Sets the current label. The label will be laid out according to the label item settings (curved lines, auto wrapping, curved line usage) and the painter will be ready to draw it.

getLabel

public LabelCacheItem getLabel()

Returns the current label item

getLineHeight

public double getLineHeight()

Returns the line height for this label in pixels (for multiline labels, it's the height of the first line)

getLineHeightForAnchorY

public double getLineHeightForAnchorY(double anchorY)

Returns appropriate line height for the given displacemntY Should give Top line for max displacementY (1) and Bottom line for min displacemntY (0)

Returns:

height of appropriate line for passed label displacementY

getAscent

public double getAscent()

The full size above the baseline

getStraightLabelWidth

public int getStraightLabelWidth()

Returns the width of the label, as painted in straight form (

getLineCount

public int getLineCount()

Number of lines for this label (more than 1 if the label has embedded newlines or if we're auto-wrapping it)

getFullLabelBounds

public Rectangle2D getFullLabelBounds()

Get the straight label bounds, taking into account halo, shield and line wrapping

getLabelBounds

public Rectangle2D getLabelBounds()

Get the straight label bounds, without taking into account halo and shield

paintStraightLabel

public void paintStraightLabel(AffineTransform transform)
                        throws Exception

Paints the label as a non curved one. The positioning and rotation are provided by the transformation

Throws:

Exception

paintStraightLabel

public void paintStraightLabel(AffineTransform transform,
                               Coordinate labelPoint)
                        throws Exception

Paints the label as a non curved one. The positioning and rotation are provided by the transformation

Throws:

Exception

paintCurvedLabel

public void paintCurvedLabel(LineStringCursor cursor)

Paints a label that follows the line, centered in the current cursor position

getLinePlacementYAnchor

public double getLinePlacementYAnchor()

Vertical centering is not trivial, because visually we want centering on characters such as a,m,e, and not centering on d,g whose center is affected by the full ascent or the full descent. This method tries to computes the y anchor taking into account those.