sf.util.Color Maven / Gradle / Ivy

/*
========================================================================
SchemaCrawler
http://www.schemacrawler.com
Copyright (c) 2000-2016, Sualeh Fatehi .
All rights reserved.
------------------------------------------------------------------------

SchemaCrawler is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SchemaCrawler and the accompanying materials are made available under
the terms of the Eclipse Public License v1.0, GNU General Public License
v3 or GNU Lesser General Public License v3.

You may elect to redistribute this code under any of these licenses.

The Eclipse Public License is available at:
http://www.eclipse.org/legal/epl-v10.html

The GNU General Public License v3 and the GNU Lesser General Public
License v3 are available at:
http://www.gnu.org/licenses/

========================================================================
*/
package sf.util;


/**
 * Color breaks the dependency on java.awt.Color. The AWT comes with a
 * lot of baggage, and is not part of Java Compact Profile 2.
 *
 * @author Sualeh Fatehi
 */
public final class Color
{

  public static Color white = new Color(255, 255, 255);

  /**
   * 
   * Converting from HSV (HSB in Java) to RGB without using
   * java.awt.Color
   */
  public static Color fromHSV(final float hue,
                              final float saturation,
                              final float value)
  {
    final float normaliedHue = hue - (float) Math.floor(hue);
    final int h = (int) (normaliedHue * 6);
    final float f = normaliedHue * 6 - h;
    final float p = value * (1 - saturation);
    final float q = value * (1 - f * saturation);
    final float t = value * (1 - (1 - f) * saturation);

    switch (h)
    {
      case 0:
        return rgbToString(value, t, p);
      case 1:
        return rgbToString(q, value, p);
      case 2:
        return rgbToString(p, value, t);
      case 3:
        return rgbToString(p, q, value);
      case 4:
        return rgbToString(t, p, value);
      case 5:
        return rgbToString(value, p, q);
      default:
        throw new RuntimeException(String
          .format("Could not convert from HSV (%f, %f, %f) to RGB",
                  normaliedHue,
                  saturation,
                  value));
    }
  }

  public static Color rgbToString(final float r, final float g, final float b)
  {
    return new Color((int) (r * 255 + 0.5),
                     (int) (g * 255 + 0.5),
                     (int) (b * 255 + 0.5));
  }

  private final int r, g, b;

  private Color(final int r, final int g, final int b)
  {
    if (r < 0)
    {
      this.r = 0;
    }
    else if (r > 255)
    {
      this.r = 255;
    }
    else
    {
      this.r = r;
    }

    if (g < 0)
    {
      this.g = 0;
    }
    else if (g > 255)
    {
      this.g = 255;
    }
    else
    {
      this.g = g;
    }

    if (b < 0)
    {
      this.b = 0;
    }
    else if (b > 255)
    {
      this.b = 255;
    }
    else
    {
      this.b = b;
    }
  }

  @Override
  public String toString()
  {
    final int rgb = (r & 0xFF) << 16 | (g & 0xFF) << 8 | (b & 0xFF) << 0;

    final String htmlColor = "#" + Integer.toHexString(rgb).toUpperCase();
    return htmlColor;
  }

}