ColorUtils - Android SDK

Classes
- BitmapCompat
- ColorUtils

Summary: Methods | Inherited Methods | [Expand All]

public class

ColorUtils

extends Object

java.lang.Object
↳	android.support.v4.graphics.ColorUtils

Class Overview

A set of color-related utility methods, building upon those available in Color.

Summary

Public Methods
static int	HSLToColor(float[] hsl) Convert HSL (hue-saturation-lightness) components to a RGB color.
static void	RGBToHSL(int r, int g, int b, float[] hsl) Convert RGB components to HSL (hue-saturation-lightness).
static double	calculateContrast(int foreground, int background) Returns the contrast ratio between `foreground` and `background`.
static double	calculateLuminance(int color) Returns the luminance of a color.
static int	calculateMinimumAlpha(int foreground, int background, float minContrastRatio) Calculates the minimum alpha value which can be applied to `foreground` so that would have a contrast value of at least `minContrastRatio` when compared to `background`.
static void	colorToHSL(int color, float[] hsl) Convert the ARGB color to its HSL (hue-saturation-lightness) components.
static int	compositeColors(int foreground, int background) Composite two potentially translucent colors over each other and returns the result.
static int	setAlphaComponent(int color, int alpha) Set the alpha component of `color` to be `alpha`.

[Expand]

Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

Public Methods

public static int HSLToColor (float[] hsl)

Convert HSL (hue-saturation-lightness) components to a RGB color.

hsl[0] is Hue [0 .. 360)
hsl[1] is Saturation [0...1]
hsl[2] is Lightness [0...1]

If hsv values are out of range, they are pinned.

Parameters

hsl	3 element array which holds the input HSL components.

Returns

the resulting RGB color

public static void RGBToHSL (int r, int g, int b, float[] hsl)

Convert RGB components to HSL (hue-saturation-lightness).

hsl[0] is Hue [0 .. 360)
hsl[1] is Saturation [0...1]
hsl[2] is Lightness [0...1]

Parameters

r	red component value [0..255]
g	green component value [0..255]
b	blue component value [0..255]
hsl	3 element array which holds the resulting HSL components.

public static double calculateContrast (int foreground, int background)

Returns the contrast ratio between foreground and background. background must be opaque.

Formula defined here.

public static double calculateLuminance (int color)

Returns the luminance of a color. Formula defined here: http://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef

public static int calculateMinimumAlpha (int foreground, int background, float minContrastRatio)

Calculates the minimum alpha value which can be applied to foreground so that would have a contrast value of at least minContrastRatio when compared to background.

Parameters

foreground	the foreground color.
background	the background color. Should be opaque.
minContrastRatio	the minimum contrast ratio.

Returns

the alpha value in the range 0-255, or -1 if no value could be calculated.

public static void colorToHSL (int color, float[] hsl)

Convert the ARGB color to its HSL (hue-saturation-lightness) components.

hsl[0] is Hue [0 .. 360)
hsl[1] is Saturation [0...1]
hsl[2] is Lightness [0...1]

Parameters

color	the ARGB color to convert. The alpha component is ignored.
hsl	3 element array which holds the resulting HSL components.

public static int compositeColors (int foreground, int background)

Composite two potentially translucent colors over each other and returns the result.

public static int setAlphaComponent (int color, int alpha)

Set the alpha component of color to be alpha.

Results

Classes

ColorUtils

Class Overview

Summary

Public Methods

public static int HSLToColor (float[] hsl)

Parameters

Returns

public static void RGBToHSL (int r, int g, int b, float[] hsl)

Parameters

public static double calculateContrast (int foreground, int background)

public static double calculateLuminance (int color)

public static int calculateMinimumAlpha (int foreground, int background, float minContrastRatio)

Parameters

Returns

public static void colorToHSL (int color, float[] hsl)

Parameters

public static int compositeColors (int foreground, int background)

public static int setAlphaComponent (int color, int alpha)