color.java

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   * @see ColorModel#getRGBdefault()
   * @see #getRed()
   * @see #getGreen()
   * @see #getBlue()
   * @see #getRGB()
   * @see #Color(int, boolean)
   */
  public Color(int value)
  {
    this(value, false);
  }

  /**
   * Initializes a new instance of <code>Color</code> using the specified
   * RGB value. The blue value is in bits 0-7, green in bits 8-15, and
   * red in bits 16-23. The alpha value is in bits 24-31, unless hasalpha
   * is false, in which case alpha is set to 255. When drawing to screen, the
   * actual color may be adjusted to the best match of hardware capabilities.
   *
   * @param value the RGB value
   * @param hasalpha true if value includes the alpha
   * @see ColorModel#getRGBdefault()
   * @see #getRed()
   * @see #getGreen()
   * @see #getBlue()
   * @see #getAlpha()
   * @see #getRGB()
   */
  public Color(int value, boolean hasalpha)
  {
    // Note: SystemColor calls this constructor, setting falpha to 0; but
    // code in getRGBComponents correctly reports falpha as 1.0 to the user
    // for all instances of SystemColor since frgbvalue is left null here.
    if (hasalpha)
      falpha = ((value & ALPHA_MASK) >> 24) / 255f;
    else
      {
        value |= ALPHA_MASK;
        falpha = 1;
      }
    this.value = value;
    cs = null;
  }

  /**
   * Initializes a new instance of <code>Color</code> using the specified
   * RGB values. These must be in the range of 0.0-1.0. Alpha is assigned
   * the value of 1.0 (opaque). When drawing to screen, the actual color may
   * be adjusted to the best match of hardware capabilities.
   *
   * @param red the red component of the RGB value
   * @param green the green component of the RGB value
   * @param blue the blue component of the RGB value
   * @throws IllegalArgumentException tf the values are out of range 0.0f-1.0f
   * @see #getRed()
   * @see #getGreen()
   * @see #getBlue()
   * @see #getRGB()
   * @see #Color(float, float, float, float)
   */
  public Color(float red, float green, float blue)
  {
    this(red, green, blue, 1.0f);
  }

  /**
   * Initializes a new instance of <code>Color</code> using the specified
   * RGB and alpha values. These must be in the range of 0.0-1.0. When drawing
   * to screen, the actual color may be adjusted to the best match of
   * hardware capabilities.
   *
   * @param red the red component of the RGB value
   * @param green the green component of the RGB value
   * @param blue the blue component of the RGB value
   * @param alpha the alpha value of the color
   * @throws IllegalArgumentException tf the values are out of range 0.0f-1.0f
   * @see #getRed()
   * @see #getGreen()
   * @see #getBlue()
   * @see #getAlpha()
   * @see #getRGB()
   */
  public Color(float red, float green, float blue, float alpha)
  {
    value = convert(red, green, blue, alpha);
    frgbvalue = new float[] {red, green, blue};
    falpha = alpha;
    cs = null;
  }

  /**
   * Creates a color in the given ColorSpace with the specified alpha. The
   * array must be non-null and have enough elements for the color space
   * (for example, RGB requires 3 elements, CMYK requires 4). When drawing
   * to screen, the actual color may be adjusted to the best match of
   * hardware capabilities.
   *
   * @param space the color space of components
   * @param components the color components, except alpha
   * @param alpha the alpha value of the color
   * @throws NullPointerException if cpsace or components is null
   * @throws ArrayIndexOutOfBoundsException if components is too small
   * @throws IllegalArgumentException if alpha or any component is out of range
   * @see #getComponents(float[])
   * @see #getColorComponents(float[])
   */
  public Color(ColorSpace space, float[] components, float alpha)
  {
    frgbvalue = space.toRGB(components);
    fvalue = components;
    falpha = alpha;
    cs = space;
    value = convert(frgbvalue[0], frgbvalue[1], frgbvalue[2], alpha);
  }

  /**
   * Returns the red value for this color, as an integer in the range 0-255
   * in the sRGB color space.
   *
   * @return the red value for this color
   * @see #getRGB()
   */
  public int getRed()
  {
    // Do not inline getRGB() to value, because of SystemColor.
    return (getRGB() & RED_MASK) >> 16;
  }

  /**
   * Returns the green value for this color, as an integer in the range 0-255
   * in the sRGB color space.
   *
   * @return the green value for this color
   * @see #getRGB()
   */
  public int getGreen()
  {
    // Do not inline getRGB() to value, because of SystemColor.
    return (getRGB() & GREEN_MASK) >> 8;
  }

  /**
   * Returns the blue value for this color, as an integer in the range 0-255
   * in the sRGB color space.
   *
   * @return the blue value for this color
   * @see #getRGB()
   */
  public int getBlue()
  {
    // Do not inline getRGB() to value, because of SystemColor.
    return getRGB() & BLUE_MASK;
  }

  /**
   * Returns the alpha value for this color, as an integer in the range 0-255.
   *
   * @return the alpha value for this color
   * @see #getRGB()
   */
  public int getAlpha()
  {
    // Do not inline getRGB() to value, because of SystemColor.
    return (getRGB() & ALPHA_MASK) >> 24;
  }

  /**
   * Returns the RGB value for this color, in the sRGB color space. The blue
   * value will be in bits 0-7, green in 8-15, red in 6-23, and alpha value in
   * 24-31.
   *
   * @return the RGB value for this color
   * @see ColorModel#getRGBdefault()
   * @see #getRed()
   * @see #getGreen()
   * @see #getBlue()
   * @see #getAlpha()
   */
  public int getRGB()
  {
    return value;
  }

  /**
   * Returns a brighter version of this color. This is done by increasing the
   * RGB values by an arbitrary scale factor. The new color is opaque (an
   * alpha of 255). Note that this method and the <code>darker()</code>
   * method are not necessarily inverses.
   *
   * @return a brighter version of this color
   * @see #darker()
   */
  public Color brighter()
  {
    // Do not inline getRGB() to this.value, because of SystemColor.
    int value = getRGB();
    int red = (value & RED_MASK) >> 16;
    int green = (value & GREEN_MASK) >> 8;
    int blue = value & BLUE_MASK;
    // We have to special case 0-2 because they won't scale by division.
    red = red < 3 ? 3 : (int) Math.min(255, red / BRIGHT_SCALE);
    green = green < 3 ? 3 : (int) Math.min(255, green / BRIGHT_SCALE);
    blue = blue < 3 ? 3 : (int) Math.min(255, blue / BRIGHT_SCALE);
    return new Color(red, green, blue, 255);
  }

  /**
   * Returns a darker version of this color. This is done by decreasing the
   * RGB values by an arbitrary scale factor. The new color is opaque (an
   * alpha of 255). Note that this method and the <code>brighter()</code>
   * method are not necessarily inverses.
   *
   * @return a darker version of this color
   * @see #brighter()
   */
  public Color darker()
  {
    // Do not inline getRGB() to this.value, because of SystemColor.
    int value = getRGB();
    return new Color((int) (((value & RED_MASK) >> 16) * BRIGHT_SCALE),
                     (int) (((value & GREEN_MASK) >> 8) * BRIGHT_SCALE),
                     (int) ((value & BLUE_MASK) * BRIGHT_SCALE), 255);
  }

  /**
   * Returns a hash value for this color. This is simply the color in 8-bit
   * precision, in the format 0xAARRGGBB (alpha, red, green, blue).
   *
   * @return a hash value for this color
   */
  public int hashCode()
  {
    return value;
  }

  /**
   * Tests this object for equality against the specified object.  This will
   * be true if and only if the specified object is an instance of
   * <code>Color</code> and has the same 8-bit integer red, green, and blue
   * values as this object. Note that two colors may be slightly different
   * as float values, but round to the same integer values. Also note that
   * this does not accurately compare SystemColors, since that class does
   * not store its internal data in RGB format like regular colors.
   *
   * @param obj the object to compare to
   * @return true if the specified object is semantically equal to this one
   */
  public boolean equals(Object obj)
  {
    return obj instanceof Color && ((Color) obj).value == value;
  }

  /**
   * Returns a string representation of this object. Subclasses may return
   * any desired format, except for null, but this implementation returns
   * <code>getClass().getName() + "[r=" + getRed() + ",g=" + getGreen()
   * + ",b=" + getBlue() + ']'</code>.
   *
   * @return a string representation of this object
   */
  public String toString()
  {
    return getClass().getName() + "[r=" + ((value & RED_MASK) >> 16)
      + ",g=" + ((value & GREEN_MASK) >> 8) + ",b=" + (value & BLUE_MASK)
      + ']';
  }

  /**
   * Converts the specified string to a number, using Integer.decode, and
   * creates a new instance of <code>Color</code> from the value. The alpha
   * value will be 255 (opaque).
   *
   * @param str the numeric color string
   * @return a new instance of <code>Color</code> for the string
   * @throws NumberFormatException if the string cannot be parsed
   * @throws NullPointerException if the string is null
   * @see Integer#decode(String)
   * @see #Color(int)
   * @since 1.1
   */
  public static Color decode(String str)
  {
    return new Color(Integer.decode(str).intValue(), false);
  }

  /**
   * Returns a new instance of <code>Color</code> from the value of the
   * system property named by the specified string.  If the property does not
   * exist, or cannot be parsed, then <code>null</code> will be returned.
   *
   * @param prop the system property to retrieve
   * @throws SecurityException if getting the property is denied
   * @see #getColor(String, Color)
   * @see Integer#getInteger(String)
   */
  public static Color getColor(String prop)
  {
    return getColor(prop, null);
  }

  /**
   * Returns a new instance of <code>Color</code> from the value of the
   * system property named by the specified string.  If the property does
   * not exist, or cannot be parsed, then the default color value will be
   * returned.
   *
   * @param prop the system property to retrieve
   * @param defcolor the default color
   * @throws SecurityException if getting the property is denied
   * @see Integer#getInteger(String)
   */
  public static Color getColor(String prop, Color defcolor)
  {
    Integer val = Integer.getInteger(prop, null);
    return val == null ? defcolor
      : new Color(val.intValue(), false);
  }

  /**
   * Returns a new instance of <code>Color</code> from the value of the
   * system property named by the specified string.  If the property does
   * not exist, or cannot be parsed, then the default RGB value will be
   * used to create a return value.
   *
   * @param prop the system property to retrieve
   * @param defrgb the default RGB value
   * @throws SecurityException if getting the property is denied
   * @see #getColor(String, Color)
   * @see Integer#getInteger(String, int)
   */
  public static Color getColor(String prop, int defrgb)
  {
    Color c = getColor(prop, null);
    return c == null ? new Color(defrgb, false) : c;
  }