Class AbstractRegionPainter

java.lang.Object
- javax.swing.plaf.nimbus.AbstractRegionPainter

All Implemented Interfaces:: Painter<JComponent>

public abstract class AbstractRegionPainter
extends Object
implements Painter<JComponent>

Convenient base class for defining Painter instances for rendering a region or component in Nimbus.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`protected static class`	`AbstractRegionPainter.PaintContext`	A class encapsulating state useful when painting.

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`AbstractRegionPainter()`	Create a new AbstractRegionPainter

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`configureGraphics(Graphics2D g)`	Configures the given Graphics2D.
`protected float`	`decodeAnchorX(float x, float dx)`	Decodes and returns a float value representing the actual pixel location for the anchor point given the encoded X value of the control point, and the offset distance to the anchor from that control point.
`protected float`	`decodeAnchorY(float y, float dy)`	Decodes and returns a float value representing the actual pixel location for the anchor point given the encoded Y value of the control point, and the offset distance to the anchor from that control point.
`protected Color`	`decodeColor(Color color1, Color color2, float midPoint)`	Decodes and returns a color, which is derived from a offset between two other colors.
`protected Color`	`decodeColor(String key, float hOffset, float sOffset, float bOffset, int aOffset)`	Decodes and returns a color, which is derived from a base color in UI defaults.
`protected LinearGradientPaint`	`decodeGradient(float x1, float y1, float x2, float y2, float[] midpoints, Color[] colors)`	Given parameters for creating a LinearGradientPaint, this method will create and return a linear gradient paint.
`protected RadialGradientPaint`	`decodeRadialGradient(float x, float y, float r, float[] midpoints, Color[] colors)`	Given parameters for creating a RadialGradientPaint, this method will create and return a radial gradient paint.
`protected float`	`decodeX(float x)`	Decodes and returns a float value representing the actual pixel location for the given encoded X value.
`protected float`	`decodeY(float y)`	Decodes and returns a float value representing the actual pixel location for the given encoded y value.
`protected abstract void`	`doPaint(Graphics2D g, JComponent c, int width, int height, Object[] extendedCacheKeys)`	Actually performs the painting operation.
`protected Color`	`getComponentColor(JComponent c, String property, Color defaultColor, float saturationOffset, float brightnessOffset, int alphaOffset)`	Get a color property from the given JComponent.
`protected Object[]`	`getExtendedCacheKeys(JComponent c)`	Get any extra attributes which the painter implementation would like to include in the image cache lookups.
`protected abstract AbstractRegionPainter.PaintContext`	`getPaintContext()`	Gets the PaintContext for this painting operation.

Methods declared in class java.lang.Object

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

Methods declared in interface javax.swing.Painter

paint

Constructor Detail

AbstractRegionPainter

protected AbstractRegionPainter()

Create a new AbstractRegionPainter

Method Detail

getExtendedCacheKeys

protected Object[] getExtendedCacheKeys(JComponent c)

Get any extra attributes which the painter implementation would like to include in the image cache lookups. This is checked for every call of the paint(g, c, w, h) method.

Parameters:: c - The component on the current paint call
Returns:: Array of extra objects to be included in the cache key

getPaintContext

protected abstract AbstractRegionPainter.PaintContext getPaintContext()

Gets the PaintContext for this painting operation. This method is called on every paint, and so should be fast and produce no garbage. The PaintContext contains information such as cache hints. It also contains data necessary for decoding points at runtime, such as the stretching insets, the canvas size at which the encoded points were defined, and whether the stretching insets are inverted.

This method allows for subclasses to package the painting of different states with possibly different canvas sizes, etc, into one AbstractRegionPainter implementation.

Returns:: a PaintContext associated with this paint operation.

configureGraphics

protected void configureGraphics(Graphics2D g)

Configures the given Graphics2D. Often, rendering hints or compositing rules are applied to a Graphics2D object prior to painting, which should affect all of the subsequent painting operations. This method provides a convenient hook for configuring the Graphics object prior to rendering, regardless of whether the render operation is performed to an intermediate buffer or directly to the display.

Parameters:: g - The Graphics2D object to configure. Will not be null.

doPaint

protected abstract void doPaint(Graphics2D g,
                                JComponent c,
                                int width,
                                int height,
                                Object[] extendedCacheKeys)

Actually performs the painting operation. Subclasses must implement this method. The graphics object passed may represent the actual surface being rendered to, or it may be an intermediate buffer. It has also been pre-translated. Simply render the component as if it were located at 0, 0 and had a width of width and a height of height. For performance reasons, you may want to read the clip from the Graphics2D object and only render within that space.

Parameters:: g - The Graphics2D surface to paint to; c - The JComponent related to the drawing event. For example, if the region being rendered is Button, then c will be a JButton. If the region being drawn is ScrollBarSlider, then the component will be JScrollBar. This value may be null.; width - The width of the region to paint. Note that in the case of painting the foreground, this value may differ from c.getWidth().; height - The height of the region to paint. Note that in the case of painting the foreground, this value may differ from c.getHeight().; extendedCacheKeys - The result of the call to getExtendedCacheKeys()

decodeX

protected final float decodeX(float x)

Decodes and returns a float value representing the actual pixel location for the given encoded X value.

Parameters:: x - an encoded x value (0...1, or 1...2, or 2...3)
Returns:: the decoded x value
Throws:: IllegalArgumentException - if x < 0 or x > 3

decodeY

protected final float decodeY(float y)

Decodes and returns a float value representing the actual pixel location for the given encoded y value.

Parameters:: y - an encoded y value (0...1, or 1...2, or 2...3)
Returns:: the decoded y value
Throws:: IllegalArgumentException - if y < 0 or y > 3

decodeAnchorX

protected final float decodeAnchorX(float x,
                                    float dx)

Decodes and returns a float value representing the actual pixel location for the anchor point given the encoded X value of the control point, and the offset distance to the anchor from that control point.

Parameters:: x - an encoded x value of the bezier control point (0...1, or 1...2, or 2...3); dx - the offset distance to the anchor from the control point x
Returns:: the decoded x location of the control point
Throws:: IllegalArgumentException - if x < 0 or x > 3

decodeAnchorY

protected final float decodeAnchorY(float y,
                                    float dy)

Decodes and returns a float value representing the actual pixel location for the anchor point given the encoded Y value of the control point, and the offset distance to the anchor from that control point.

Parameters:: y - an encoded y value of the bezier control point (0...1, or 1...2, or 2...3); dy - the offset distance to the anchor from the control point y
Returns:: the decoded y position of the control point
Throws:: IllegalArgumentException - if y < 0 or y > 3

decodeColor

protected final Color decodeColor(String key,
                                  float hOffset,
                                  float sOffset,
                                  float bOffset,
                                  int aOffset)

Decodes and returns a color, which is derived from a base color in UI defaults.

Parameters:: key - A key corresponding to the value in the UI Defaults table of UIManager where the base color is defined; hOffset - The hue offset used for derivation.; sOffset - The saturation offset used for derivation.; bOffset - The brightness offset used for derivation.; aOffset - The alpha offset used for derivation. Between 0...255
Returns:: The derived color, whose color value will change if the parent uiDefault color changes.

decodeColor

protected final Color decodeColor(Color color1,
                                  Color color2,
                                  float midPoint)

Decodes and returns a color, which is derived from a offset between two other colors.

Parameters:: color1 - The first color; color2 - The second color; midPoint - The offset between color 1 and color 2, a value of 0.0 is color 1 and 1.0 is color 2;
Returns:: The derived color

decodeGradient

protected final LinearGradientPaint decodeGradient(float x1,
                                                   float y1,
                                                   float x2,
                                                   float y2,
                                                   float[] midpoints,
                                                   Color[] colors)

Given parameters for creating a LinearGradientPaint, this method will create and return a linear gradient paint. One primary purpose for this method is to avoid creating a LinearGradientPaint where the start and end points are equal. In such a case, the end y point is slightly increased to avoid the overlap.

Parameters:: x1 - x1; y1 - y1; x2 - x2; y2 - y2; midpoints - the midpoints; colors - the colors
Returns:: a valid LinearGradientPaint. This method never returns null.
Throws:: NullPointerException - if midpoints array is null, or colors array is null,; IllegalArgumentException - if start and end points are the same points, or midpoints.length != colors.length, or colors is less than 2 in size, or a midpoints value is less than 0.0 or greater than 1.0, or the midpoints are not provided in strictly increasing order

decodeRadialGradient

protected final RadialGradientPaint decodeRadialGradient(float x,
                                                         float y,
                                                         float r,
                                                         float[] midpoints,
                                                         Color[] colors)

Given parameters for creating a RadialGradientPaint, this method will create and return a radial gradient paint. One primary purpose for this method is to avoid creating a RadialGradientPaint where the radius is non-positive. In such a case, the radius is just slightly increased to avoid 0.

Parameters:: x - x-coordinate; y - y-coordinate; r - radius; midpoints - the midpoints; colors - the colors
Returns:: a valid RadialGradientPaint. This method never returns null.
Throws:: NullPointerException - if midpoints array is null, or colors array is null; IllegalArgumentException - if r is non-positive, or midpoints.length != colors.length, or colors is less than 2 in size, or a midpoints value is less than 0.0 or greater than 1.0, or the midpoints are not provided in strictly increasing order

getComponentColor

protected final Color getComponentColor(JComponent c,
                                        String property,
                                        Color defaultColor,
                                        float saturationOffset,
                                        float brightnessOffset,
                                        int alphaOffset)

Get a color property from the given JComponent. First checks for a getXXX() method and if that fails checks for a client property with key property. If that still fails to return a Color then defaultColor is returned.

Parameters:: c - The component to get the color property from; property - The name of a bean style property or client property; defaultColor - The color to return if no color was obtained from the component.; saturationOffset - additively modifies the HSB saturation component of the color returned (ignored if default color is returned).; brightnessOffset - additively modifies the HSB brightness component of the color returned (ignored if default color is returned).; alphaOffset - additively modifies the ARGB alpha component of the color returned (ignored if default color is returned).
Returns:: The color that was obtained from the component or defaultColor