Package com.helger.css.utils

Class CSSColorHelper

java.lang.Object
com.helger.css.utils.CSSColorHelper
@Immutable public final class CSSColorHelper extends Object
Provides color handling sanity methods.
Author:
Philip Helger

  • Field Details

    • RGB_MIN

      public static final int RGB_MIN
      RGB minimum value
      See Also:

    • RGB_MAX

      public static final int RGB_MAX
      RGB maximum value
      See Also:

    • RGB_RANGE

      public static final int RGB_RANGE
      RGB range (max-min+1)
      See Also:

    • HSL_MIN

      public static final int HSL_MIN
      HSL minimum value (for Hue only)
      See Also:

    • HSL_MAX

      public static final int HSL_MAX
      HSL maximum value (for Hue only)
      See Also:

    • HSL_RANGE

      public static final int HSL_RANGE
      HSL range (max-min+1) (for Hue only)
      See Also:

    • PERCENTAGE_MIN

      public static final int PERCENTAGE_MIN
      Percentage minimum value (for HSL)
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    • PERCENTAGE_MAX

      public static final int PERCENTAGE_MAX
      Percentage maximum value (for HSL)
      See Also:

    • OPACITY_MIN

      public static final float OPACITY_MIN
      Minimum opacity value
      See Also:

    • OPACITY_MAX

      public static final float OPACITY_MAX
      Maximum opacity value
      See Also:

  • Method Details

    • isColorValue

      public static boolean isColorValue(@Nullable String sValue)
      Check if the passed string is any color value.
      Parameters:
      sValue - The value to check. May be null.
      Returns:
      true if the passed value is not null, not empty and a valid CSS color value.
      See Also:

    • isRGBColorValue

      public static boolean isRGBColorValue(@Nullable String sValue)
      Check if the passed String is valid CSS RGB color value. Example value: rgb(255,0,0)
      Parameters:
      sValue - The value to check. May be null.
      Returns:
      true if it is a CSS RGB color value, false if not

    • getParsedRGBColorValue

      @Nullable public static CSSRGB getParsedRGBColorValue(@Nullable String sValue)
      Extract the CSS RGB color value from the passed String. Example value: rgb(255,0,0)
      Parameters:
      sValue - The value to extract the value from. May be null.
      Returns:
      null if the passed value is not a valid CSS RGB color value.

    • isRGBAColorValue

      public static boolean isRGBAColorValue(@Nullable String sValue)
      Check if the passed String is valid CSS RGBA color value. Example value: rgba(255,0,0, 0.1)
      Parameters:
      sValue - The value to check. May be null.
      Returns:
      true if it is a CSS RGBA color value, false if not

    • getParsedRGBAColorValue

      @Nullable public static CSSRGBA getParsedRGBAColorValue(@Nullable String sValue)

    • isHSLColorValue

      public static boolean isHSLColorValue(@Nullable String sValue)
      Check if the passed String is valid CSS HSL color value. Example value: hsl(255,0%,0%)
      Parameters:
      sValue - The value to check. May be null.
      Returns:
      true if it is a CSS HSL color value, false if not

    • getParsedHSLColorValue

      @Nullable public static CSSHSL getParsedHSLColorValue(@Nullable String sValue)

    • isHSLAColorValue

      public static boolean isHSLAColorValue(@Nullable String sValue)
      Check if the passed String is valid CSS HSLA color value. Example value: hsla(255,0%,0%, 0.1)
      Parameters:
      sValue - The value to check. May be null.
      Returns:
      true if it is a CSS HSLA color value, false if not

    • getParsedHSLAColorValue

      @Nullable public static CSSHSLA getParsedHSLAColorValue(@Nullable String sValue)

    • isHexColorValue

      public static boolean isHexColorValue(@Nullable String sValue)
      Check if the passed String is valid CSS hex color value. Example value: #ff0000
      Parameters:
      sValue - The value to check. May be null.
      Returns:
      true if it is a CSS hex color value, false if not

    • getRGBValue

      @Nonnegative public static int getRGBValue(int nRGBPart)
      Convert the passed value to a valid RGB value in the range 0-255.
      Parameters:
      nRGBPart - The original value
      Returns:
      The value between 0 and 255.

    • getOpacityToUse

      @Nonnegative public static float getOpacityToUse(float fOpacity)
      Ensure that the passed opacity value is in the range OPACITY_MIN and OPACITY_MAX.
      Parameters:
      fOpacity - The original opacity
      Returns:
      The opacity in the correct range between 0 and 1.

    • getRGBColorValue

      @Nonnull @Nonempty public static String getRGBColorValue(int nRed, int nGreen, int nBlue)
      Get the passed values as CSS RGB color value
      Parameters:
      nRed - Red - is scaled to 0-255
      nGreen - Green - is scaled to 0-255
      nBlue - Blue - is scaled to 0-255
      Returns:
      The CSS string to use

    • getRGBAColorValue

      @Nonnull @Nonempty public static String getRGBAColorValue(int nRed, int nGreen, int nBlue, float fOpacity)
      Get the passed values as CSS RGBA color value
      Parameters:
      nRed - Red - is scaled to 0-255
      nGreen - Green - is scaled to 0-255
      nBlue - Blue - is scaled to 0-255
      fOpacity - Opacity to use - is scaled to 0-1.
      Returns:
      The CSS string to use

    • getHSLHueValue

      @Nonnegative public static int getHSLHueValue(int nHSLPart)
      Get the passed value as a valid HSL Hue value in the range of 0-359
      Parameters:
      nHSLPart - Source Hue
      Returns:
      Hue value in the range of 0-359

    • getHSLHueValue

      @Nonnegative public static float getHSLHueValue(float fHSLPart)
      Get the passed value as a valid HSL Hue value in the range of 0-359
      Parameters:
      fHSLPart - Source Hue
      Returns:
      Hue value in the range of 0-359

    • getHSLPercentageValue

      @Nonnegative public static int getHSLPercentageValue(int nHSLPart)
      Get the passed value as a valid HSL Saturation or Lightness value in the range of 0-100 (percentage).
      Parameters:
      nHSLPart - Source value
      Returns:
      Target value in the range of 0- 100

    • getHSLPercentageValue

      @Nonnegative public static float getHSLPercentageValue(float nHSLPart)
      Get the passed value as a valid HSL Saturation or Lightness value in the range of PERCENTAGE_MIN-PERCENTAGE_MAX (percentage).
      Parameters:
      nHSLPart - Source value
      Returns:
      Target value in the range of 0- 100

    • getHSLColorValue

      @Nonnull @Nonempty public static String getHSLColorValue(int nHue, int nSaturation, int nLightness)
      Get the passed values as CSS HSL color value
      Parameters:
      nHue - Hue - is scaled to 0-359
      nSaturation - Saturation - is scaled to 0-100
      nLightness - Lightness - is scaled to 0-100
      Returns:
      The CSS string to use

    • getHSLColorValue

      @Nonnull @Nonempty public static String getHSLColorValue(float fHue, float fSaturation, float fLightness)
      Get the passed values as CSS HSL color value
      Parameters:
      fHue - Hue - is scaled to 0-359
      fSaturation - Saturation - is scaled to 0-100
      fLightness - Lightness - is scaled to 0-100
      Returns:
      The CSS string to use

    • getHSLAColorValue

      @Nonnull @Nonempty public static String getHSLAColorValue(int nHue, int nSaturation, int nLightness, float fOpacity)
      Get the passed values as CSS HSLA color value
      Parameters:
      nHue - Hue - is scaled to 0-359
      nSaturation - Saturation - is scaled to 0-100
      nLightness - Lightness - is scaled to 0-100
      fOpacity - Opacity - is scaled to 0-1
      Returns:
      The CSS string to use

    • getHSLAColorValue

      @Nonnull @Nonempty public static String getHSLAColorValue(float fHue, float fSaturation, float fLightness, float fOpacity)
      Get the passed values as CSS HSLA color value
      Parameters:
      fHue - Hue - is scaled to 0-359
      fSaturation - Saturation - is scaled to 0-100
      fLightness - Lightness - is scaled to 0-100
      fOpacity - Opacity - is scaled to 0-1
      Returns:
      The CSS string to use

    • getHexColorValue

      @Nonnull @Nonempty public static String getHexColorValue(int nRed, int nGreen, int nBlue)

    • getRGBAsHSLValue

      @Nonnull @Nonempty public static float[] getRGBAsHSLValue(int nRed, int nGreen, int nBlue)
      Get the passed RGB values as HSL values compliant for CSS in the CSS range (0-359, 0-100, 0-100)
      Parameters:
      nRed - red value
      nGreen - green value
      nBlue - blue value
      Returns:
      An array of 3 floats, containing hue, saturation and lightness (in this order). The first value is in the range 0-359, and the remaining two values are in the range 0-100 (percentage).

    • getHSLAsRGBValue

      @Nonnull @Nonempty public static int[] getHSLAsRGBValue(float fHue, float fSaturation, float fLightness)
      Get the passed RGB values as HSL values compliant for CSS in the CSS range (0-359, 0-100, 0-100)
      Parameters:
      fHue - the hue component of the color - in the range 0-359
      fSaturation - the saturation of the color - in the range 0-100
      fLightness - the lightness of the color - in the range 0-100
      Returns:
      An array of 3 ints, containing red, green and blue (in this order). All values are in the range 0-255.