Class AbstractRegionPainter

Constructors

AbstractRegionPainter

protected AbstractRegionPainter()

Create a new AbstractRegionPainter

Methods

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()

Returns:

a PaintContext associated with this paint operation.

configureGraphics

protected void configureGraphics(Graphics2D g)

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