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How do i take a string with the name of a color and then convert that to an integer so that I can call a Color constructor?

Example:

How can I turn a statement like this into something that works? 

String color="RED"
int c1=parseInt(color)
new Color(c1);

I know this won't work but is there anything like a parseColor() method that can take your String and return an int?

Jason C
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user3587186
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  • Instead of String can you java.awt.Color? Then you can use something like this: Color.BLACK.getRGB(); – mprabhat Nov 25 '14 at 20:33
  • If you're providing a string anyway, what's wrong with Color.RED? – Gilbert Le Blanc Nov 25 '14 at 20:34
  • Color(int) takes a packed int of the RGB value of the color, there is little or no relationship between "RED" and the packaged int value. You'd need to devise your own mappings – MadProgrammer Nov 25 '14 at 20:37
  • @GilbertLeBlanc et al.: It is presumed that the string would not be known until runtime, otherwise the OP would likely not be asking this. – Jason C Nov 25 '14 at 20:46
  • exactly jason, the color is decided via a parameter sent to the program thus i need to decipher the parameter and create the color that is wished to be used. – user3587186 Nov 25 '14 at 20:48
  • See also http://stackoverflow.com/questions/7352477/using-java-can-i-convert-a-human-readable-color-name-into-an-integer-array?rq=1 (*Possible* duplicate although it does not go into the details of converting a `Color` to some arbitrary packed integer form - but that is fairly trivial. You guys decide, I won't dupehammer it. Interestingly, the accepted answer there is the reflection option.) – Jason C Nov 25 '14 at 20:48

3 Answers3

1

The int in the constructor is a derivative from RGB that you can calculate like this

int rgb = red;
rgb = (rgb << 8) + green;
rgb = (rgb << 8) + blue;

check Convert RGB values to Integer

now as Jason said no built-in, but there's already a class ColorUtils with all the human readable names already captured witin an enum, with the accompanying R, G, B ints. You would have to add the method to calculate the int from the RGB and you'll have your solution in no time

pasting a standalone class in case the link becomes unavailable one day

import java.awt.Color;
import java.util.ArrayList;

/**
 * Java Code to get a color name from rgb/hex value/awt color
 * 
 * The part of looking up a color name from the rgb values is edited from
 * https://gist.github.com/nightlark/6482130#file-gistfile1-java (that has some errors) by Ryan Mast (nightlark)
 * 
 * @author Xiaoxiao Li
 * 
 */
public class ColorUtils {

    /**
     * Initialize the color list that we have.
     */
    private ArrayList<ColorName> initColorList() {
        ArrayList<ColorName> colorList = new ArrayList<ColorName>();
        colorList.add(new ColorName("AliceBlue", 0xF0, 0xF8, 0xFF));
        colorList.add(new ColorName("AntiqueWhite", 0xFA, 0xEB, 0xD7));
        colorList.add(new ColorName("Aqua", 0x00, 0xFF, 0xFF));
        colorList.add(new ColorName("Aquamarine", 0x7F, 0xFF, 0xD4));
        colorList.add(new ColorName("Azure", 0xF0, 0xFF, 0xFF));
        colorList.add(new ColorName("Beige", 0xF5, 0xF5, 0xDC));
        colorList.add(new ColorName("Bisque", 0xFF, 0xE4, 0xC4));
        colorList.add(new ColorName("Black", 0x00, 0x00, 0x00));
        colorList.add(new ColorName("BlanchedAlmond", 0xFF, 0xEB, 0xCD));
        colorList.add(new ColorName("Blue", 0x00, 0x00, 0xFF));
        colorList.add(new ColorName("BlueViolet", 0x8A, 0x2B, 0xE2));
        colorList.add(new ColorName("Brown", 0xA5, 0x2A, 0x2A));
        colorList.add(new ColorName("BurlyWood", 0xDE, 0xB8, 0x87));
        colorList.add(new ColorName("CadetBlue", 0x5F, 0x9E, 0xA0));
        colorList.add(new ColorName("Chartreuse", 0x7F, 0xFF, 0x00));
        colorList.add(new ColorName("Chocolate", 0xD2, 0x69, 0x1E));
        colorList.add(new ColorName("Coral", 0xFF, 0x7F, 0x50));
        colorList.add(new ColorName("CornflowerBlue", 0x64, 0x95, 0xED));
        colorList.add(new ColorName("Cornsilk", 0xFF, 0xF8, 0xDC));
        colorList.add(new ColorName("Crimson", 0xDC, 0x14, 0x3C));
        colorList.add(new ColorName("Cyan", 0x00, 0xFF, 0xFF));
        colorList.add(new ColorName("DarkBlue", 0x00, 0x00, 0x8B));
        colorList.add(new ColorName("DarkCyan", 0x00, 0x8B, 0x8B));
        colorList.add(new ColorName("DarkGoldenRod", 0xB8, 0x86, 0x0B));
        colorList.add(new ColorName("DarkGray", 0xA9, 0xA9, 0xA9));
        colorList.add(new ColorName("DarkGreen", 0x00, 0x64, 0x00));
        colorList.add(new ColorName("DarkKhaki", 0xBD, 0xB7, 0x6B));
        colorList.add(new ColorName("DarkMagenta", 0x8B, 0x00, 0x8B));
        colorList.add(new ColorName("DarkOliveGreen", 0x55, 0x6B, 0x2F));
        colorList.add(new ColorName("DarkOrange", 0xFF, 0x8C, 0x00));
        colorList.add(new ColorName("DarkOrchid", 0x99, 0x32, 0xCC));
        colorList.add(new ColorName("DarkRed", 0x8B, 0x00, 0x00));
        colorList.add(new ColorName("DarkSalmon", 0xE9, 0x96, 0x7A));
        colorList.add(new ColorName("DarkSeaGreen", 0x8F, 0xBC, 0x8F));
        colorList.add(new ColorName("DarkSlateBlue", 0x48, 0x3D, 0x8B));
        colorList.add(new ColorName("DarkSlateGray", 0x2F, 0x4F, 0x4F));
        colorList.add(new ColorName("DarkTurquoise", 0x00, 0xCE, 0xD1));
        colorList.add(new ColorName("DarkViolet", 0x94, 0x00, 0xD3));
        colorList.add(new ColorName("DeepPink", 0xFF, 0x14, 0x93));
        colorList.add(new ColorName("DeepSkyBlue", 0x00, 0xBF, 0xFF));
        colorList.add(new ColorName("DimGray", 0x69, 0x69, 0x69));
        colorList.add(new ColorName("DodgerBlue", 0x1E, 0x90, 0xFF));
        colorList.add(new ColorName("FireBrick", 0xB2, 0x22, 0x22));
        colorList.add(new ColorName("FloralWhite", 0xFF, 0xFA, 0xF0));
        colorList.add(new ColorName("ForestGreen", 0x22, 0x8B, 0x22));
        colorList.add(new ColorName("Fuchsia", 0xFF, 0x00, 0xFF));
        colorList.add(new ColorName("Gainsboro", 0xDC, 0xDC, 0xDC));
        colorList.add(new ColorName("GhostWhite", 0xF8, 0xF8, 0xFF));
        colorList.add(new ColorName("Gold", 0xFF, 0xD7, 0x00));
        colorList.add(new ColorName("GoldenRod", 0xDA, 0xA5, 0x20));
        colorList.add(new ColorName("Gray", 0x80, 0x80, 0x80));
        colorList.add(new ColorName("Green", 0x00, 0x80, 0x00));
        colorList.add(new ColorName("GreenYellow", 0xAD, 0xFF, 0x2F));
        colorList.add(new ColorName("HoneyDew", 0xF0, 0xFF, 0xF0));
        colorList.add(new ColorName("HotPink", 0xFF, 0x69, 0xB4));
        colorList.add(new ColorName("IndianRed", 0xCD, 0x5C, 0x5C));
        colorList.add(new ColorName("Indigo", 0x4B, 0x00, 0x82));
        colorList.add(new ColorName("Ivory", 0xFF, 0xFF, 0xF0));
        colorList.add(new ColorName("Khaki", 0xF0, 0xE6, 0x8C));
        colorList.add(new ColorName("Lavender", 0xE6, 0xE6, 0xFA));
        colorList.add(new ColorName("LavenderBlush", 0xFF, 0xF0, 0xF5));
        colorList.add(new ColorName("LawnGreen", 0x7C, 0xFC, 0x00));
        colorList.add(new ColorName("LemonChiffon", 0xFF, 0xFA, 0xCD));
        colorList.add(new ColorName("LightBlue", 0xAD, 0xD8, 0xE6));
        colorList.add(new ColorName("LightCoral", 0xF0, 0x80, 0x80));
        colorList.add(new ColorName("LightCyan", 0xE0, 0xFF, 0xFF));
        colorList.add(new ColorName("LightGoldenRodYellow", 0xFA, 0xFA, 0xD2));
        colorList.add(new ColorName("LightGray", 0xD3, 0xD3, 0xD3));
        colorList.add(new ColorName("LightGreen", 0x90, 0xEE, 0x90));
        colorList.add(new ColorName("LightPink", 0xFF, 0xB6, 0xC1));
        colorList.add(new ColorName("LightSalmon", 0xFF, 0xA0, 0x7A));
        colorList.add(new ColorName("LightSeaGreen", 0x20, 0xB2, 0xAA));
        colorList.add(new ColorName("LightSkyBlue", 0x87, 0xCE, 0xFA));
        colorList.add(new ColorName("LightSlateGray", 0x77, 0x88, 0x99));
        colorList.add(new ColorName("LightSteelBlue", 0xB0, 0xC4, 0xDE));
        colorList.add(new ColorName("LightYellow", 0xFF, 0xFF, 0xE0));
        colorList.add(new ColorName("Lime", 0x00, 0xFF, 0x00));
        colorList.add(new ColorName("LimeGreen", 0x32, 0xCD, 0x32));
        colorList.add(new ColorName("Linen", 0xFA, 0xF0, 0xE6));
        colorList.add(new ColorName("Magenta", 0xFF, 0x00, 0xFF));
        colorList.add(new ColorName("Maroon", 0x80, 0x00, 0x00));
        colorList.add(new ColorName("MediumAquaMarine", 0x66, 0xCD, 0xAA));
        colorList.add(new ColorName("MediumBlue", 0x00, 0x00, 0xCD));
        colorList.add(new ColorName("MediumOrchid", 0xBA, 0x55, 0xD3));
        colorList.add(new ColorName("MediumPurple", 0x93, 0x70, 0xDB));
        colorList.add(new ColorName("MediumSeaGreen", 0x3C, 0xB3, 0x71));
        colorList.add(new ColorName("MediumSlateBlue", 0x7B, 0x68, 0xEE));
        colorList.add(new ColorName("MediumSpringGreen", 0x00, 0xFA, 0x9A));
        colorList.add(new ColorName("MediumTurquoise", 0x48, 0xD1, 0xCC));
        colorList.add(new ColorName("MediumVioletRed", 0xC7, 0x15, 0x85));
        colorList.add(new ColorName("MidnightBlue", 0x19, 0x19, 0x70));
        colorList.add(new ColorName("MintCream", 0xF5, 0xFF, 0xFA));
        colorList.add(new ColorName("MistyRose", 0xFF, 0xE4, 0xE1));
        colorList.add(new ColorName("Moccasin", 0xFF, 0xE4, 0xB5));
        colorList.add(new ColorName("NavajoWhite", 0xFF, 0xDE, 0xAD));
        colorList.add(new ColorName("Navy", 0x00, 0x00, 0x80));
        colorList.add(new ColorName("OldLace", 0xFD, 0xF5, 0xE6));
        colorList.add(new ColorName("Olive", 0x80, 0x80, 0x00));
        colorList.add(new ColorName("OliveDrab", 0x6B, 0x8E, 0x23));
        colorList.add(new ColorName("Orange", 0xFF, 0xA5, 0x00));
        colorList.add(new ColorName("OrangeRed", 0xFF, 0x45, 0x00));
        colorList.add(new ColorName("Orchid", 0xDA, 0x70, 0xD6));
        colorList.add(new ColorName("PaleGoldenRod", 0xEE, 0xE8, 0xAA));
        colorList.add(new ColorName("PaleGreen", 0x98, 0xFB, 0x98));
        colorList.add(new ColorName("PaleTurquoise", 0xAF, 0xEE, 0xEE));
        colorList.add(new ColorName("PaleVioletRed", 0xDB, 0x70, 0x93));
        colorList.add(new ColorName("PapayaWhip", 0xFF, 0xEF, 0xD5));
        colorList.add(new ColorName("PeachPuff", 0xFF, 0xDA, 0xB9));
        colorList.add(new ColorName("Peru", 0xCD, 0x85, 0x3F));
        colorList.add(new ColorName("Pink", 0xFF, 0xC0, 0xCB));
        colorList.add(new ColorName("Plum", 0xDD, 0xA0, 0xDD));
        colorList.add(new ColorName("PowderBlue", 0xB0, 0xE0, 0xE6));
        colorList.add(new ColorName("Purple", 0x80, 0x00, 0x80));
        colorList.add(new ColorName("Red", 0xFF, 0x00, 0x00));
        colorList.add(new ColorName("RosyBrown", 0xBC, 0x8F, 0x8F));
        colorList.add(new ColorName("RoyalBlue", 0x41, 0x69, 0xE1));
        colorList.add(new ColorName("SaddleBrown", 0x8B, 0x45, 0x13));
        colorList.add(new ColorName("Salmon", 0xFA, 0x80, 0x72));
        colorList.add(new ColorName("SandyBrown", 0xF4, 0xA4, 0x60));
        colorList.add(new ColorName("SeaGreen", 0x2E, 0x8B, 0x57));
        colorList.add(new ColorName("SeaShell", 0xFF, 0xF5, 0xEE));
        colorList.add(new ColorName("Sienna", 0xA0, 0x52, 0x2D));
        colorList.add(new ColorName("Silver", 0xC0, 0xC0, 0xC0));
        colorList.add(new ColorName("SkyBlue", 0x87, 0xCE, 0xEB));
        colorList.add(new ColorName("SlateBlue", 0x6A, 0x5A, 0xCD));
        colorList.add(new ColorName("SlateGray", 0x70, 0x80, 0x90));
        colorList.add(new ColorName("Snow", 0xFF, 0xFA, 0xFA));
        colorList.add(new ColorName("SpringGreen", 0x00, 0xFF, 0x7F));
        colorList.add(new ColorName("SteelBlue", 0x46, 0x82, 0xB4));
        colorList.add(new ColorName("Tan", 0xD2, 0xB4, 0x8C));
        colorList.add(new ColorName("Teal", 0x00, 0x80, 0x80));
        colorList.add(new ColorName("Thistle", 0xD8, 0xBF, 0xD8));
        colorList.add(new ColorName("Tomato", 0xFF, 0x63, 0x47));
        colorList.add(new ColorName("Turquoise", 0x40, 0xE0, 0xD0));
        colorList.add(new ColorName("Violet", 0xEE, 0x82, 0xEE));
        colorList.add(new ColorName("Wheat", 0xF5, 0xDE, 0xB3));
        colorList.add(new ColorName("White", 0xFF, 0xFF, 0xFF));
        colorList.add(new ColorName("WhiteSmoke", 0xF5, 0xF5, 0xF5));
        colorList.add(new ColorName("Yellow", 0xFF, 0xFF, 0x00));
        colorList.add(new ColorName("YellowGreen", 0x9A, 0xCD, 0x32));
        return colorList;
    }

    /**
     * Get the closest color name from our list
     * 
     * @param r
     * @param g
     * @param b
     * @return
     */
    public String getColorNameFromRgb(int r, int g, int b) {
        ArrayList<ColorName> colorList = initColorList();
        ColorName closestMatch = null;
        int minMSE = Integer.MAX_VALUE;
        int mse;
        for (ColorName c : colorList) {
            mse = c.computeMSE(r, g, b);
            if (mse < minMSE) {
                minMSE = mse;
                closestMatch = c;
            }
        }

        if (closestMatch != null) {
            return closestMatch.getName();
        } else {
            return "No matched color name.";
        }
    }

    /**
     * Convert hexColor to rgb, then call getColorNameFromRgb(r, g, b)
     * 
     * @param hexColor
     * @return
     */
    public String getColorNameFromHex(int hexColor) {
        int r = (hexColor & 0xFF0000) >> 16;
        int g = (hexColor & 0xFF00) >> 8;
        int b = (hexColor & 0xFF);
        return getColorNameFromRgb(r, g, b);
    }

    public int colorToHex(Color c) {
        return Integer.decode("0x"
                + Integer.toHexString(c.getRGB()).substring(2));
    }

    public String getColorNameFromColor(Color color) {
        return getColorNameFromRgb(color.getRed(), color.getGreen(),
                color.getBlue());
    }

    /**
     * SubClass of ColorUtils. In order to lookup color name
     * 
     * @author Xiaoxiao Li
     * 
     */
    public class ColorName {
        public int r, g, b;
        public String name;

        public ColorName(String name, int r, int g, int b) {
            this.r = r;
            this.g = g;
            this.b = b;
            this.name = name;
        }

        public int computeMSE(int pixR, int pixG, int pixB) {
            return (int) (((pixR - r) * (pixR - r) + (pixG - g) * (pixG - g) + (pixB - b)
                    * (pixB - b)) / 3);
        }

        public int getR() {
            return r;
        }

        public int getG() {
            return g;
        }

        public int getB() {
            return b;
        }

        public String getName() {
            return name;
        }
    }
}
Community
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Master Slave
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  • Someone asked me to put that slightly improved Version here: http://pastebin.com/yhddqFSC – Fabian Bettag Nov 19 '16 at 18:52
  • His message: "I updated the code a bit. Main changes: Changing functions to static, adding a color-from-name function and improving the color-to-name functions by changing the method responsible to calculate the distances between the colors. It used color distance in sRGB and that does not match human-perceived distance while the L*a*b* color space which was used is intended to be a perceptually uniform colorspace" – Fabian Bettag Nov 19 '16 at 19:21
0

There's not really a "built-in" standard way to do this (note also that you're specifically looking for English names for colors). You'll have to resort to other solutions. For example:

  • You could just implement it yourself, with a set of names you want to support. A Map, a big ol' if, or even creative use of an enum are all options.

  • You could use something like ColorStringParser from JSAP. You have a third-party dependency now but it takes care of all the dirty work, and supports HTML colors, RGB triplets, and names all at once.

  • You could use reflection creatively to look up the static fields of Color by name. This would be a bit kludgy, though.

The simplest, really, is to probably just roll your own with a Map<String,Color> or Map<String,Integer>; converting strings to lowercase as needed to provide case-insensitivity if desired. If you don't mind adding a dependency, I'd probably just go with JSAP's parser.

Jason C
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0

Well I don't think there is any such method available anywhere. There are some predefined color provided you can use them. e.g.:

String enteredColor = "RED";
if(enteredCode.equalsIgnoreCase("red") {
return Color.RED;
}

although above code is not best approach.

What you can do (if you know predefined input string's) is you can map the names with there RGB values. Then based on input create color abject and return.

Naresh Kalra
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