org.eclipse.birt.report.model.api.util

Class ColorUtil

java.lang.Object

org.eclipse.birt.report.model.api.util.ColorUtil

public class ColorUtil
extends java.lang.Object

Utility class to do color parsing or converting work. A color is a either a keyword or a numerical RGB specification.

Color property format preference have the following choices:

• INT_FORMAT, display color as an integer.
• HTML_FORMAT ( #RRGGBB )
• JAVA_FORMAT ( 0xRRGGBB )
• CSS_ABSOLUTE_FORMAT ( RGB(r,g,b) )
• CSS_RELATIVE_FORMAT ( RGB(r%,g%,b%) )

Field Summary

Fields

Modifier and Type	Field and Description
static int	CSS_ABSOLUTE_FORMAT Color display preference for CSS absolute style: RGB(r,g,b).
static int	CSS_RELATIVE_FORMAT Color display preference for CSS relative style: RGB(r%,g%,b%).
static int	DEFAULT_FORMAT Default format for display preference: CSS_ABSOLUTE_FORMAT.
static int	HTML_FORMAT Color display preference for HTML style: #RRGGBB.
static int	INT_FORMAT Useful constant for Color display preference, display Color as integer.
static int	JAVA_FORMAT Color display preference for JAVA style: 0xRRGGBB.

Constructor Summary

Constructors

Constructor and Description
ColorUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static java.lang.String	format(int rgbValue, int rgbFormat) Formats an integer RGB value according to the format preference provided.
static java.lang.String	format(java.lang.String value, int rgbFormat) Formats an color value according to the format preference provided.
static int	formRGB(int r, int g, int b) Calculates the integer color value given its red, blue, green values.
static java.lang.String	getPredefinedColor(int rgb) Gets a css predefined color given its rgb value.
static int[]	getRGBs(int rgbValue) Returns the Red, Blue, Green value for a integer RGB color value.
static int[]	getRGBs(java.lang.String colorValue) Returns the Red, Blue, Green value for a color value.
static boolean	isCssAbsolute(java.lang.String value) Indicates whether the color value is of valid css absolute format: "RGB(r,g,b)".
static boolean	isCssRelative(java.lang.String value) Indicates whether the color value is of a valid css relative format: "RGB( r%, g%, b%)".
static int	parseColor(java.lang.String value) Parses the string color value as a color keyword or a numerical RGB notation, return its corresponding rgb integer value.
static int	parsePredefinedColor(java.lang.String color) Gets the integer value of a predefined color.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

HTML_FORMAT

public static final int HTML_FORMAT

Color display preference for HTML style: #RRGGBB. #RRGGBB

See Also:

Constant Field Values

INT_FORMAT

public static final int INT_FORMAT

Useful constant for Color display preference, display Color as integer.

See Also:

Constant Field Values

JAVA_FORMAT

public static final int JAVA_FORMAT

Color display preference for JAVA style: 0xRRGGBB.

See Also:

Constant Field Values

CSS_ABSOLUTE_FORMAT

public static final int CSS_ABSOLUTE_FORMAT

Color display preference for CSS absolute style: RGB(r,g,b).

See Also:

Constant Field Values

CSS_RELATIVE_FORMAT

public static final int CSS_RELATIVE_FORMAT

Color display preference for CSS relative style: RGB(r%,g%,b%).

See Also:

Constant Field Values

DEFAULT_FORMAT

public static final int DEFAULT_FORMAT

Default format for display preference: CSS_ABSOLUTE_FORMAT.

See Also:

Constant Field Values

Constructor Detail

ColorUtil

public ColorUtil()

Method Detail

parsePredefinedColor

public static int parsePredefinedColor(java.lang.String color)

Gets the integer value of a predefined color. The color should be a predefined color name, otherwise -1 is returned.

Parameters:

color - a given color name, it is case insensitive.

Returns:

the integer value of a predefined color, return -1 if the name of the given color is not defined.

getPredefinedColor

public static java.lang.String getPredefinedColor(int rgb)

Gets a css predefined color given its rgb value.

Parameters:

rgb - integer rgb value.

Returns:

a css predefined color if there is a predefined color matches the given rgb, return null otherwise.

isCssAbsolute

public static boolean isCssAbsolute(java.lang.String value)

Indicates whether the color value is of valid css absolute format: "RGB(r,g,b)". The RGB prefix is case insensitive and r, g, b should be integer value. Whitespace characters are allowed around the numerical values. The followings are some cases of valid css absolute colors:

• RGB(255,0,0)
• Rgb( 255, 0, 0)
• rgb(300,300,300)

Parameters:

value - a string color value

Returns:

true if the color value is in a valid css absolute color representation.

isCssRelative

public static boolean isCssRelative(java.lang.String value)

Indicates whether the color value is of a valid css relative format: "RGB( r%, g%, b%)". The RGB prefix is case insensitive and r, g, b should be a float value. Whitespace characters are allowed around the numerical values. The followings are some cases of valid css relative colors:

• RGB(100%,0%,0%)
• Rgb( 100% , 0% , 0% )
• rgb(200%,200%,200%)

Parameters:

value - a string color value

Returns:

true if the color value is in a valid css relative. color representation.

format

public static java.lang.String format(int rgbValue,
                      int rgbFormat)

Formats an integer RGB value according to the format preference provided. An integer RGB value can be formatted as follows:

• INT_FORMAT, display color as an integer.
• HTML_FORMAT ( #RRGGBB )
• JAVA_FORMAT ( 0xRRGGBB )
• CSS_ABSOLUTE_FORMAT ( RGB(r,g,b) )
• CSS_RELATIVE_FORMAT ( RGB(r%,g%,b%) )

The integer value will first be converted into 6-digits hex format(filling "0" from left), so only the right most 6 digits will be used.

Parameters:

rgbValue - integer RGB value for a color

rgbFormat - Color display preference, one of Color display preference constants. For example, CSS_ABSOLUTE_FORMAT that will convert into style "RGB(255,0,0)". If the preference provided is not in the predefined list, then CSS_ABSOLUTE_FORMATwill be applied.

Returns:

a string representation of the color in the target format.

See Also:

INT_FORMAT, HTML_FORMAT, JAVA_FORMAT, CSS_ABSOLUTE_FORMAT, CSS_RELATIVE_FORMAT, DEFAULT_FORMAT

format

public static java.lang.String format(java.lang.String value,
                      int rgbFormat)

Formats an color value according to the format preference provided. See parseColor(String)for the allowed color value representations.

Parameters:

value - a given string containing one of the allowed notation.

rgbFormat - Color display preference, one of Color display preference constants. For example, CSS_ABSOLUTE_FORMAT that will convert into style "RGB(255,0,0)". If the preference provided is not in the predefined list, then CSS_ABSOLUTE_FORMATwill be applied.

Returns:

a string representation of the color in the target format.

Throws:

java.lang.NumberFormatException - if the String representing a numerical value does not contain a parsable integer.

See Also:

INT_FORMAT, HTML_FORMAT, JAVA_FORMAT, CSS_ABSOLUTE_FORMAT, CSS_RELATIVE_FORMAT, DEFAULT_FORMAT, parseColor(String), format(int, int)

parseColor

public static int parseColor(java.lang.String value)

Parses the string color value as a color keyword or a numerical RGB notation, return its corresponding rgb integer value. The string value can be one of the followings:

• A decimal number: "16711680". The number will be clipped into 0~#FFFFFF
• A hexadecimal number in HTML format. '#' immediately followed by either three or six hexadecimal characters. The three-digit RGB notation (#rgb) is converted into six-digit form (#rrggbb) by replicating digits, not by adding zeros. For example, #fb0 expands to #ffbb00. Values outside "#FFFFFF" will be clipped.
• A hexadecimal number in Java format: "0xRRGGBB"
• A css predefined color name: "red", "green", "yellow" etc.
• A css absolute or relative notation: "rgb(r,g,b)" or "rgb(r%,g%,b%)". 'rgb(' followed by a comma-separated list of three numerical values (either three integer values in the range of 0-255, or three percentage values in the range of 0.0% to 100.0%) followed by '), Values outside the numerical ranges will be clipped. Whitespace characters are allowed around the numerical values.

These examples given a allowed color value that can be parsed into an integer.

• "16711680"
• "#FFFF00"
• "#FFFF00F", will be clipped into "#FFFFFF"
• "0xFF00FF"
• "red" or "green"
• rgb(255,0,0)
• rgb(100.0%,0%,0%)

Parameters:

value - a given string containing one of the allowed notation.

Returns:

the integer value of the color, return -1 if the value is not in one of the allowed format. If the value is in a valid integer format, return value will be clipped to 0 ~ 0xFFFFFF

getRGBs

public static int[] getRGBs(int rgbValue)

Returns the Red, Blue, Green value for a integer RGB color value. The given RGB value should be in the scope of (0~0xFFFFFF), otherwise return null.

Parameters:

rgbValue - a given integer RGB color value.

Returns:

an array containing Red, Blue, Green separately. Return null if the value is not in (0~0xFFFFFF).

getRGBs

public static int[] getRGBs(java.lang.String colorValue)

Returns the Red, Blue, Green value for a color value. The given string containing one of the allowed notations.

Parameters:

colorValue - a given string color value in one of the allowed notations.

Returns:

an array containing Red, Blue, Green separately. Return null if the given color value is not parsable.

formRGB

public static int formRGB(int r,
          int g,
          int b)

Calculates the integer color value given its red, blue, green values. If any color factor is over 0xFF, it will be clipped to 0xFF; if any color factor is below 0, it will be increased to 0.

Parameters:

r - red value.

g - green value.

b - blue value.

Returns:

the integer color value of the given color factors.