How to use

StandardGradientPaintTransformer

in

org.jfree.ui

/**
 * Creates a new instance of <code>DialBackground</code>.  The
 *
 * @param paint  the paint (<code>null</code> not permitted).
 *
 * @throws IllegalArgumentException if <code>paint</code> is
 *     <code>null</code>.
 */
public DialBackground(Paint paint) {
  if (paint == null) {
    throw new IllegalArgumentException("Null 'paint' argument.");
  }
  this.paint = paint;
  this.gradientPaintTransformer = new StandardGradientPaintTransformer();
}

/**
 * Creates a new legend graphic.
 *
 * @param shape  the shape (<code>null</code> not permitted).
 * @param fillPaint  the fill paint (<code>null</code> not permitted).
 */
public LegendGraphic(Shape shape, Paint fillPaint) {
  if (shape == null) {
    throw new IllegalArgumentException("Null 'shape' argument.");
  }
  if (fillPaint == null) {
    throw new IllegalArgumentException("Null 'fillPaint' argument.");
  }
  this.shapeVisible = true;
  this.shape = shape;
  this.shapeAnchor = RectangleAnchor.CENTER;
  this.shapeLocation = RectangleAnchor.CENTER;
  this.shapeFilled = true;
  this.fillPaint = fillPaint;
  this.fillPaintTransformer = new StandardGradientPaintTransformer();
  setPadding(2.0, 2.0, 2.0, 2.0);
}

this.shapeFilled = shapeFilled;
this.fillPaint = fillPaint;
this.fillPaintTransformer = new StandardGradientPaintTransformer();
this.shapeOutlineVisible = shapeOutlineVisible;
this.outlinePaint = outlinePaint;

/**
 * Constructs a new renderer.
 *
 * @param margin  the percentage amount to trim from the width of each bar.
 */
public XYBarRenderer(double margin) {
  super();
  this.margin = margin;
  this.base = 0.0;
  this.useYInterval = false;
  this.gradientPaintTransformer = new StandardGradientPaintTransformer();
  this.drawBarOutline = false;
  this.legendBar = new Rectangle2D.Double(-3.0, -5.0, 6.0, 10.0);
  this.barPainter = getDefaultBarPainter();
  this.shadowsVisible = getDefaultShadowsVisible();
  this.shadowXOffset = 4.0;
  this.shadowYOffset = 4.0;
  this.barAlignmentFactor = -1.0;
}

this.legendArea = area;
this.useFillPaint = false;
this.gradientTransformer = new StandardGradientPaintTransformer();

this.positiveBarPaint = positiveBarPaint;
this.negativeBarPaint = negativeBarPaint;
setGradientPaintTransformer(new StandardGradientPaintTransformer(
    GradientPaintTransformType.CENTER_VERTICAL));
setMinimumBarLength(1.0);

this.shapeFilled = shapeFilled;
this.fillPaint = fillPaint;
this.fillPaintTransformer = new StandardGradientPaintTransformer();
this.shapeOutlineVisible = shapeOutlineVisible;
this.outlinePaint = outlinePaint;

/**
 * Creates a new bar renderer with default settings.
 */
public BarRenderer() {
  super();
  this.base = 0.0;
  this.includeBaseInRange = true;
  this.itemMargin = DEFAULT_ITEM_MARGIN;
  this.drawBarOutline = false;
  this.maximumBarWidth = 1.0;
    // 100 percent, so it will not apply unless changed
  this.positiveItemLabelPositionFallback = null;
  this.negativeItemLabelPositionFallback = null;
  this.gradientPaintTransformer = new StandardGradientPaintTransformer();
  this.minimumBarLength = 0.0;
  setBaseLegendShape(new Rectangle2D.Double(-4.0, -4.0, 8.0, 8.0));
  this.barPainter = getDefaultBarPainter();
  this.shadowsVisible = getDefaultShadowsVisible();
  this.shadowPaint = Color.gray;
  this.shadowXOffset = 4.0;
  this.shadowYOffset = 4.0;
}

/**
 * Creates a dial chart.
 *
 * @return A dial chart.
 */
private static JFreeChart createDialChart(){
  DialPlot plot = new DialPlot();
  plot.setDialFrame(new StandardDialFrame());
  GradientPaint gp = new GradientPaint(new Point(),
      new Color(255, 255, 255), new Point(),
      new Color(170, 170, 220));
  DialBackground db = new DialBackground(gp);
  db.setGradientPaintTransformer(new StandardGradientPaintTransformer(
      GradientPaintTransformType.VERTICAL));
  plot.setBackground(db);
  plot.addPointer(new DialPointer.Pin());
  DialCap cap = new DialCap();
  plot.setCap(cap);
  return new JFreeChart(plot);
}

  type = GradientPaintTransformType.VERTICAL;
db.setGradientPaintTransformer(new StandardGradientPaintTransformer(type));
plot.setBackground(db);

if (fillPaint instanceof GradientPaint) {
  GradientPaint gp = (GradientPaint) fillPaint;
  GradientPaintTransformer t = new StandardGradientPaintTransformer();
  fillPaint = t.transform(gp, areaState.area.getBounds());