Examples with LinearGradientPaint java.awt.LinearGradientPaint used on opensource projects

Example 6 with LinearGradientPaint

use of java.awt.LinearGradientPaint in project poi by apache.

the class DrawPaint method createLinearGradientPaint.

protected Paint createLinearGradientPaint(GradientPaint fill, Graphics2D graphics) {
    // TODO: we need to find the two points for gradient - the problem is, which point at the outline
    // do you take? My solution would be to apply the gradient rotation to the shape in reverse
    // and then scan the shape for the largest possible horizontal distance
    double angle = fill.getGradientAngle();
    if (!fill.isRotatedWithShape()) {
        angle -= shape.getRotation();
    }
    Rectangle2D anchor = DrawShape.getAnchor(graphics, shape);
    final double h = anchor.getHeight(), w = anchor.getWidth(), x = anchor.getX(), y = anchor.getY();
    AffineTransform at = AffineTransform.getRotateInstance(Math.toRadians(angle), anchor.getCenterX(), anchor.getCenterY());
    double diagonal = Math.sqrt(h * h + w * w);
    Point2D p1 = new Point2D.Double(x + w / 2 - diagonal / 2, y + h / 2);
    p1 = at.transform(p1, null);
    Point2D p2 = new Point2D.Double(x + w, y + h / 2);
    p2 = at.transform(p2, null);
    if (p1.equals(p2)) {
        // gradient paint on the same point throws an exception ... and doesn't make sense
        return null;
    }
    float[] fractions = fill.getGradientFractions();
    Color[] colors = new Color[fractions.length];
    int i = 0;
    for (ColorStyle fc : fill.getGradientColors()) {
        // if fc is null, use transparent color to get color of background
        colors[i++] = (fc == null) ? TRANSPARENT : applyColorTransform(fc);
    }
    return new LinearGradientPaint(p1, p2, fractions, colors);
}