de.javagl.viewer.painters

Class LabelPainter

java.lang.Object

de.javagl.viewer.painters.LabelPainter

All Implemented Interfaces:

ObjectPainter<java.lang.String>

public final class LabelPainter
extends java.lang.Object
implements ObjectPainter<java.lang.String>

Implementation of an ObjectPainter for strings that serve as labels, to be painted with a certain font and layout

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LabelPainter.LabelPaintState A class describing the state of a label that is about to be painted.

Constructor Summary

Constructors

Constructor and Description
LabelPainter() Creates a new label painter.

Method Summary

Modifier and Type	Method and Description
java.awt.Shape	computeLabelBounds(java.awt.geom.AffineTransform worldToScreen, java.lang.String label) Compute the bounds of the label when it is painted with this painter
double	getAngle() Returns the angle (in radians) about that the label will be rotated around its anchor point.
java.awt.Font	getFont() Returns the font that is used for the label.
java.awt.geom.Point2D	getLabelAnchor() Returns a new point that describes the current anchor position of the label.
java.awt.geom.Point2D	getLabelLocation() Returns a new point that describes the location of the label.
java.awt.Paint	getPaint() Returns the paint that is used for the label.
boolean	isTransformingLabels() Returns whether this painter is transforming the labels.
void	paint(java.awt.Graphics2D g, java.awt.geom.AffineTransform worldToScreen, double w, double h, java.lang.String label) Perform the painting operations for the given object on the given Graphics.
void	setAngle(double angleRad) Set the angle (in radians) about that the label will be rotated around its anchor point.
void	setFont(java.awt.Font font) Set the font that should be used for the label.
void	setLabelAnchor(double x, double y) Set the anchor position of the label.
void	setLabelLocation(double x, double y) Set the absolute location of the label.
void	setLabelPaintingCondition(java.util.function.Predicate<LabelPainter.LabelPaintState> labelPaintingCondition) Set the condition indicating whether a certain label should be painted.
void	setPaint(java.awt.Paint paint) Set the paint that should be used for the label.
void	setTransformingLabels(boolean transformingLabels) Set whether this painter is transforming the labels using the worldToScreen transform that is passed to its paint method.

Methods inherited from class java.lang.Object

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

Constructor Detail

LabelPainter

public LabelPainter()

Creates a new label painter.

• The label anchor will be at (0.5, 0.5), causing the label to be centered at the desired location
• The label location will be at (0.0, 0.0)
• The angle will be 0.0.
• The painter will be transforming the labels
• The font, paint and label painting condition will be null, causing the label to always be painted, with the default font and paint of the graphics context

Method Detail

setFont

public void setFont(java.awt.Font font)

Set the font that should be used for the label. If the given font is null, then the font of the graphics context will be used.

Parameters:

font - The font

getFont

public java.awt.Font getFont()

Returns the font that is used for the label. This may be null if no font was set explicitly.

Returns:

The font

setPaint

public void setPaint(java.awt.Paint paint)

Set the paint that should be used for the label. If the given paint is null, then the current paint of the graphics context will be used.

Parameters:

paint - The paint

getPaint

public java.awt.Paint getPaint()

Returns the paint that is used for the label. This may be null if no paint was set explicitly.

Returns:

The paint

setLabelAnchor

public void setLabelAnchor(double x,
                           double y)

Set the anchor position of the label. The anchor position describes a point relative to the bounding box of the label (so it is usually - but not necessarily - a point in [(0,0)...(1,1)]).

This is the point that will be placed at the label location. For example, in order to place the center of the label at a certain location, an anchor point of (0.5, 0.5) may be set.

This is also the point that the label is rotated about, when a non-zero rotation angle is set.

Parameters:

x - The x-coordinate of the anchor position

y - The y-coordinate of the anchor position

getLabelAnchor

public java.awt.geom.Point2D getLabelAnchor()

Returns a new point that describes the current anchor position of the label. See setLabelAnchor(double, double).

Returns:

The new point storing the anchor position

setLabelLocation

public void setLabelLocation(double x,
                             double y)

Set the absolute location of the label. This is the location of the label, relative to the origin of the world coordinate system that this painter is painting to.

Parameters:

x - The x coordinate of the location

y - The y-coordinate of the location

getLabelLocation

public java.awt.geom.Point2D getLabelLocation()

Returns a new point that describes the location of the label. See setLabelLocation(double, double).

Returns:

The new point storing the location

setAngle

public void setAngle(double angleRad)

Set the angle (in radians) about that the label will be rotated around its anchor point.

Parameters:

angleRad - The rotation angle, in radians

getAngle

public double getAngle()

Returns the angle (in radians) about that the label will be rotated around its anchor point.

Returns:

The rotation angle, in radians

setTransformingLabels

public void setTransformingLabels(boolean transformingLabels)

Set whether this painter is transforming the labels using the worldToScreen transform that is passed to its paint method.

If this is set to true, then the label strings will be transformed with the worldToScreen transform, like all other painted elements: When the view is scaled, then the text will be scaled. When the view is rotated, then the labels will be rotated.

If this is set to false, then the labels will be fixed. This means that they will always be painted with the size that is defined via the font, and they will always be oriented horizontally (unless they are rotated by this painter itself, via the angle).

Parameters:

transformingLabels - Whether this painter is transforming the labels

isTransformingLabels

public boolean isTransformingLabels()

Returns whether this painter is transforming the labels. See setTransformingLabels(boolean).

Returns:

Whether this painter is transforming the labels

setLabelPaintingCondition

public void setLabelPaintingCondition(java.util.function.Predicate<LabelPainter.LabelPaintState> labelPaintingCondition)

Set the condition indicating whether a certain label should be painted.

The given predicate will receive the LabelPainter.LabelPaintState of each label that is about to be painted. It has to be assumed that the same LabelPainter.LabelPaintState instance will be used for all these calls. So the predicate may not store and / or modify the LabelPainter.LabelPaintState.

If the given condition is null, then the labels will always be painted.

Parameters:

labelPaintingCondition - The label painting condition

paint

public void paint(java.awt.Graphics2D g,
                  java.awt.geom.AffineTransform worldToScreen,
                  double w,
                  double h,
                  java.lang.String label)

Description copied from interface: ObjectPainter

Perform the painting operations for the given object on the given Graphics.

See Painter.paint(Graphics2D, AffineTransform, double, double) for more information about how the Graphics object is handled among painters.

Specified by:

paint in interface ObjectPainter<java.lang.String>

Parameters:

g - The Graphics used for painting

worldToScreen - The world-to-screen transform. This transform encapsulates the translation, rotation and scaling of the viewer to which this painter belongs.

w - The width of the area, in screen coordinates, in which this painter operates. This is the screen size of the viewer to which this painter belongs.

h - The height of the area, in screen coordinates, in which this painter operates. This is the screen size of the viewer to which this painter belongs.

label - The object to paint. One has to assume that this object may be null, in which case the painting operation will usually be skipped.

computeLabelBounds

public java.awt.Shape computeLabelBounds(java.awt.geom.AffineTransform worldToScreen,
                                         java.lang.String label)

Compute the bounds of the label when it is painted with this painter

Parameters:

worldToScreen - The world-to-screen transform

label - The label

Returns:

The label bounds