org.jdesktop.swingx.painter
Class AbstractPainter<T extends JComponent>

java.lang.Object
  org.jdesktop.swingx.JavaBean
      org.jdesktop.swingx.painter.AbstractPainter<T>

All Implemented Interfaces:

Painter<T>

Direct Known Subclasses:

AbstractGradientPainter, BackgroundPainter, CheckerboardPainter, CompoundPainter, GlossPainter, ImagePainter, MattePainter, PinstripePainter, ShapePainter, TextPainter

public abstract class AbstractPainter<T extends JComponent>
extends JavaBean
implements Painter<T>

A convenient base class from which concrete Painter implementations may extend. It extends JavaBean and thus provides property change notification (which is crucial for the Painter implementations to be available in a GUI builder). It also saves off the Graphics2D state in its "saveState" method, and restores that state in the "restoreState" method. Sublasses simply need to extend AbstractPainter and implement the paintBackground method.

For example, here is the paintBackground method of BackgroundPainter:

  public void paintBackground(Graphics2D g, JComponent component) {
      g.setColor(component.getBackground());
      g.fillRect(0, 0, component.getWidth(), component.getHeight());
  }
 

AbstractPainter provides a very useful default implementation of the paint method. It:

1. Saves off the old state
2. Sets any specified rendering hints
3. Sets the Clip if there is one
4. Sets the Composite if there is one
5. Delegates to paintBackground
6. Restores the original Graphics2D state

Specifying rendering hints can greatly improve the visual impact of your applications. For example, by default Swing doesn't do much in the way of antialiasing (except for Fonts, but that's another story). Pinstripes don't look so good without antialiasing. So if I were going to paint pinstripes, I might do it like this:

   PinstripePainter p = new PinstripePainter();
   p.setAntialiasing(RenderingHints.VALUE_ANTIALIAS_ON);
 

You can read more about antialiasing and other rendering hints in the java.awt.RenderingHints documentation. By nature, changing the rendering hints may have an impact on performance. Certain hints require more computation, others require less

Constructor Summary

AbstractPainter()
Creates a new instance of AbstractPainter

Method Summary

Object	getAlphaInterpolation()
Object	getAntialiasing()
Shape	getClip()
Object	getColorRendering()
Composite	getComposite()
Object	getDithering()
Effect[]	getEffects()
Object	getFractionalMetrics()
Object	getInterpolation()
Object	getRendering()
Object	getRenderingHint(RenderingHints.Key key)
Map<RenderingHints.Key,Object>	getRenderingHints()
Resize	getResizeClip()
Object	getStrokeControl()
Object	getTextAntialiasing()
boolean	isUseCache()
void	paint(Graphics2D g, T component) Paints on the given Graphics2D object some effect which may or may not be related to the given component.
protected abstract void	paintBackground(Graphics2D g, T component) Subclasses should implement this method and perform custom painting operations here.
protected void	restoreState(Graphics2D g) Restores previously saved state.
protected void	saveState(Graphics2D g) Saves the state in the given Graphics2D object so that it may be restored later.
void	setAlphaInterpolation(Object alphaInterpolation) Sets the technique used for interpolating alpha values.
void	setAntialiasing(Object antialiasing) Sets whether or not to antialias
void	setClip(Shape clip) Specifies the Shape to use for clipping the painting area.
void	setColorRendering(Object colorRendering) Sets the technique to use for rendering colors
void	setComposite(Composite c) Sets the Composite to use.
void	setDithering(Object dithering) Sets whether or not to dither
void	setEffects(BufferedImageOp... filters) A convenience method for specifying the effects to use based on BufferedImageOps.
void	setEffects(Effect... effects) Sets the effects to apply to the results of the AbstractPainter's painting operation.
void	setFractionalMetrics(Object fractionalMetrics) Sets whether or not to use fractional metrics
void	setInterpolation(Object interpolation) Sets the technique to use for interpolation (used esp. when scaling)
void	setRendering(Object rendering) Specifies a hint as to techniques to use with regards to rendering quality vs. speed
void	setRenderingHint(RenderingHints.Key key, Object hint) Set the given hint for the given key.
void	setRenderingHints(Map<RenderingHints.Key,Object> renderingHints) Sets the rendering hints to use.
void	setResizeClip(Resize r) Specifies the resize behavior of the clip.
void	setStrokeControl(Object strokeControl) Specifies a technique for rendering strokes
void	setTextAntialiasing(Object textAntialiasing) Sets the technique for anti-aliasing text.
void	setUseCache(boolean b) Sets whether to cache the painted image with a SoftReference in a BufferedImage between calls.

Methods inherited from class org.jdesktop.swingx.JavaBean

addPropertyChangeListener, addPropertyChangeListener, fireIndexedPropertyChange, fireIndexedPropertyChange, fireIndexedPropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getPropertyChangeListeners, getPropertyChangeListeners, hasListeners, removePropertyChangeListener, removePropertyChangeListener

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractPainter

public AbstractPainter()

Creates a new instance of AbstractPainter

Method Detail

setUseCache

public void setUseCache(boolean b)

Sets whether to cache the painted image with a SoftReference in a BufferedImage between calls. If true, and if the size of the component hasn't changed, then the cached image will be used rather than causing a painting operation.

This should be considered a hint, rather than absolute. Several factors may force repainting, including low memory, different component sizes, or possibly new rendering hint settings, etc.

Parameters:

b - whether or not to use the cache

isUseCache

public boolean isUseCache()

Returns:

whether or not the cache should be used

setEffects

public void setEffects(Effect... effects)

Sets the effects to apply to the results of the AbstractPainter's painting operation. Some common effects include blurs, shadows, embossing, and so forth. If the given effects is a null array, no effects will be used

Parameters:

effects - the Effects to apply to the results of the AbstractPainter's painting operation

setEffects

public void setEffects(BufferedImageOp... filters)

A convenience method for specifying the effects to use based on BufferedImageOps. These will each be individually wrapped by an ImageEffect and then setEffects(Effect... effects) will be called with the resulting array

Parameters:

filters - the BufferedImageOps to wrap as effects

getEffects

public Effect[] getEffects()

Returns:

effects a defensive copy of the Effects to apply to the results of the AbstractPainter's painting operation. Will never null

setClip

public void setClip(Shape clip)

Specifies the Shape to use for clipping the painting area. This may be null

Parameters:

clip - the Shape to use to clip the area. Whatever is inside this shape will be kept, everything else "clipped". May be null. If null, the clipping is not set on the graphics object

getClip

public Shape getClip()

Returns:

the clipping shape

setResizeClip

public void setResizeClip(Resize r)

Specifies the resize behavior of the clip. As with all other properties that rely on Resize, the value of the width/height of the shape will represent a percentage of the width/height of the component, as a value between 0 and 1

Parameters:

r - value indication whether/how to resize the clip. If null, Resize.NONE will be used

getResizeClip

public Resize getResizeClip()

Returns:

value indication whether/how to resize the clip. Will never be null

setComposite

public void setComposite(Composite c)

Sets the Composite to use. For example, you may specify a specific AlphaComposite so that when this Painter paints, any content in the drawing area is handled properly

Parameters:

c - The composite to use. If null, then no composite will be specified on the graphics object

getComposite

public Composite getComposite()

Returns:

the composite

getAlphaInterpolation

public Object getAlphaInterpolation()

Returns:

the technique used for interpolating alpha values. May be one of:

• RenderingHints.VALUE_ALPHA_INTERPOLATION_SPEED
• RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY
• RenderingHints.VALUE_ALPHA_INTERPOLATION_DEFAULT

setAlphaInterpolation

public void setAlphaInterpolation(Object alphaInterpolation)

Sets the technique used for interpolating alpha values.

Parameters:

alphaInterpolation - May be one of:

• RenderingHints.VALUE_ALPHA_INTERPOLATION_SPEED
• RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY
• RenderingHints.VALUE_ALPHA_INTERPOLATION_DEFAULT

getAntialiasing

public Object getAntialiasing()

Returns:

whether or not to antialias May be one of:

• RenderingHints.VALUE_ANTIALIAS_DEFAULT
• RenderingHints.VALUE_ANTIALIAS_OFF
• RenderingHints.VALUE_ANTIALIAS_ON

setAntialiasing

public void setAntialiasing(Object antialiasing)

Sets whether or not to antialias

Parameters:

antialiasing - May be one of:

• RenderingHints.VALUE_ANTIALIAS_DEFAULT
• RenderingHints.VALUE_ANTIALIAS_OFF
• RenderingHints.VALUE_ANTIALIAS_ON

getColorRendering

public Object getColorRendering()

Returns:

the technique to use for rendering colors May be one of:

• RenderingHints.VALUE_COLOR_RENDER_DEFAULT
• RenderingHints.VALUE_RENDER_QUALITY
• RenderingHints.VALUE_RENDER_SPEED

setColorRendering

public void setColorRendering(Object colorRendering)

Sets the technique to use for rendering colors

Parameters:

colorRendering - May be one of:

• RenderingHints.VALUE_COLOR_RENDER_DEFAULT
• RenderingHints.VALUE_RENDER_QUALITY
• RenderingHints.VALUE_RENDER_SPEED

getDithering

public Object getDithering()

Returns:

whether or not to dither May be one of:

• RenderingHints.VALUE_DITHER_DEFAULT
• RenderingHints.VALUE_DITHER_ENABLE
• RenderingHints.VALUE_DITHER_DISABLE

setDithering

public void setDithering(Object dithering)

Sets whether or not to dither

Parameters:

dithering - May be one of:

• RenderingHints.VALUE_DITHER_DEFAULT
• RenderingHints.VALUE_DITHER_ENABLE
• RenderingHints.VALUE_DITHER_DISABLE

getFractionalMetrics

public Object getFractionalMetrics()

Returns:

whether or not to use fractional metrics May be one of:

• RenderingHints.VALUE_FRACTIONALMETRICS_DEFAULT
• RenderingHints.VALUE_FRACTIONALMETRICS_OFF
• RenderingHints.VALUE_FRACTIONALMETRICS_ON

setFractionalMetrics

public void setFractionalMetrics(Object fractionalMetrics)

Sets whether or not to use fractional metrics

Parameters:

fractionalMetrics - May be one of:

• RenderingHints.VALUE_FRACTIONALMETRICS_DEFAULT
• RenderingHints.VALUE_FRACTIONALMETRICS_OFF
• RenderingHints.VALUE_FRACTIONALMETRICS_ON

getInterpolation

public Object getInterpolation()

Returns:

the technique to use for interpolation (used esp. when scaling) May be one of:

• RenderingHints.VALUE_INTERPOLATION_BICUBIC
• RenderingHints.VALUE_INTERPOLATION_BILINEAR
• RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR

setInterpolation

public void setInterpolation(Object interpolation)

Sets the technique to use for interpolation (used esp. when scaling)

Parameters:

interpolation - May be one of:

• RenderingHints.VALUE_INTERPOLATION_BICUBIC
• RenderingHints.VALUE_INTERPOLATION_BILINEAR
• RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR

getRendering

public Object getRendering()

Returns:

a hint as to techniques to use with regards to rendering quality vs. speed May be one of:

• RenderingHints.VALUE_RENDER_QUALITY
• RenderingHints.VALUE_RENDER_SPEED
• RenderingHints.VALUE_RENDER_DEFAULT

setRendering

public void setRendering(Object rendering)

Specifies a hint as to techniques to use with regards to rendering quality vs. speed

Parameters:

rendering - May be one of:

• RenderingHints.VALUE_RENDER_QUALITY
• RenderingHints.VALUE_RENDER_SPEED
• RenderingHints.VALUE_RENDER_DEFAULT

getStrokeControl

public Object getStrokeControl()

Returns:

technique for rendering strokes May be one of:

• RenderingHints.VALUE_STROKE_DEFAULT
• RenderingHints.VALUE_STROKE_NORMALIZE
• RenderingHints.VALUE_STROKE_PURE

setStrokeControl

public void setStrokeControl(Object strokeControl)

Specifies a technique for rendering strokes

Parameters:

strokeControl - May be one of:

• RenderingHints.VALUE_STROKE_DEFAULT
• RenderingHints.VALUE_STROKE_NORMALIZE
• RenderingHints.VALUE_STROKE_PURE

getTextAntialiasing

public Object getTextAntialiasing()

Returns:

technique for anti-aliasing text. (TODO this needs to be updated for Mustang. You may use the new Mustang values, and everything will work, but support in the GUI builder and documentation need to be added once we branch for Mustang)
May be one of:

• RenderingHints.VALUE_TEXT_ANTIALIAS_DEFAULT
• RenderingHints.VALUE_TEXT_ANTIALIAS_OFF
• RenderingHints.VALUE_TEXT_ANTIALIAS_ON

setTextAntialiasing

public void setTextAntialiasing(Object textAntialiasing)

Sets the technique for anti-aliasing text. (TODO this needs to be updated for Mustang. You may use the new Mustang values, and everything will work, but support in the GUI builder and documentation need to be added once we branch for Mustang)


Parameters:

textAntialiasing - May be one of:

• RenderingHints.VALUE_TEXT_ANTIALIAS_DEFAULT
• RenderingHints.VALUE_TEXT_ANTIALIAS_OFF
• RenderingHints.VALUE_TEXT_ANTIALIAS_ON

getRenderingHint

public Object getRenderingHint(RenderingHints.Key key)

Returns:

the rendering hint associated with the given key. May return null

setRenderingHint

public void setRenderingHint(RenderingHints.Key key,
                             Object hint)

Set the given hint for the given key. This will end up firing the appropriate property change event if the key is recognized. For example, if the key is RenderingHints.KEY_ANTIALIASING, then the setAntialiasing method will be called firing an "antialiasing" property change event if necessary. If the key is not recognized, no event will be fired but the key will be saved. The key must not be null

Parameters:

key - cannot be null

hint - must be a hint compatible with the given key

getRenderingHints

public Map<RenderingHints.Key,Object> getRenderingHints()

Returns:

a copy of the map of rendering hints held by this class. This returned value will never be null

setRenderingHints

public void setRenderingHints(Map<RenderingHints.Key,Object> renderingHints)

Sets the rendering hints to use. This will replace the rendering hints entirely, clearing any hints that were previously set.

Parameters:

renderingHints - map of hints. May be null. I null, a new Map of rendering hints will be created

saveState

protected void saveState(Graphics2D g)

Saves the state in the given Graphics2D object so that it may be restored later.

Parameters:

g - the Graphics2D object who's state will be saved

restoreState

protected void restoreState(Graphics2D g)

Restores previously saved state. A call to saveState must have occured prior to calling restoreState, or an IllegalStateException will be thrown.

Parameters:

g - the Graphics2D object to restore previously saved state to

paint

public void paint(Graphics2D g,
                  T component)

Description copied from interface: Painter

Paints on the given Graphics2D object some effect which may or may not be related to the given component. For example, BackgroundPainter will use the background property of the component and the width/height of the component to perform a fill rect. Most other Painters will disregard the component entirely, except to get the component width/height.

The Graphics2D object must be returned to the same state it started at by the end of the method. For example, if "setColor(c)" was called on the graphics object, it should be reset to the original color before the method returns.

Specified by:

paint in interface Painter<T extends JComponent>

Parameters:

g - The Graphics2D object in which to paint

component - The JComponent that the Painter is delegate for.

paintBackground

protected abstract void paintBackground(Graphics2D g,
                                        T component)

Subclasses should implement this method and perform custom painting operations here. Common behavior, such as setting the clip and composite, saving and restoring state, is performed in the "paint" method automatically, and then delegated here.

Parameters:

g - The Graphics2D object in which to paint

component - The JComponent that the Painter is delegate for.