Color Class 1

[jgroh9]

All,
I need some help regarding the color class and reading files. I have a text file that lists various colors such as magenta, blue, red, yellow. I can read the file no problem to get the color names. The problem is how do I convert these names to a meaning color to display objects in whatever color I read in from the file? Each color is on a different line in the text file.

So I need something like:
graphics.setColor(Color.fileReadInput);

When I read the color name in from the file it is a String data type.
Any help is greatly appreciated.
Thanks

 

[stefanwagner]

Do you have the standard 16 color names?
Like here:

$JAVA_HOME/docs/api/java/awt/Color.html

You could use a small Map, which maps names to colors, or use introspection, to find the color-constant for a given name.

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[stefanwagner]

Here is some code, using reflection:

	public ColorName2Value (String name)
	{
		Color c = getColorForName (name);
		if (c != null)
			System.out.println ("RGB = " + c.getRGB ());
		else System.out.println ("color not found");
	}

	private Field findColorName (String name)
	{
		try
		{
			Class clazz = Class.forName ("java.awt.Color");
			// System.out.println (clazz.toString ());
			Field [] fa = clazz.getFields ();
			for (Field field : fa)
			{
				String found = field.toString ();
				if (found.equals ("public static final java.awt.Color java.awt.Color." + name))
				{
					return field;
				}
			}
			System.out.println ("nix found");
		}
		catch (ClassNotFoundException e)
		{
			System.err.println (e.getMessage ());
		}
		return null;
	}

	private Color getColorForName (String name)
	{
		Color c = null;
		Field f = findColorName (name);
		if (f != null)
		{
			try
			{
				Object o = f.get (f.toString ());
				c = (Color) o;
			}
			catch (IllegalAccessException iae)
			{
				System.err.println (iae.getMessage ());
			}
			catch (ClassCastException cce)
			{
				System.err.println ("class cast exception! " + cce.getMessage ());
			}
		}
		return c;
	}

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[jgroh9]

stefanwagner,
Thanks for the replies. That was exactly what I was looking for. It seems so simple now that you have shown how it is done.
Thanks again

 

[stefanwagner]

But I don't like the solution, because of the reflection.

A Hashmap with hardcoded values (which we can produce with the help of the above method) would be much better to understand.

Using Java1.5 we could use enums much more elegant:

	public enum NColor
	{
		BLACK	(-16777216),
		BLUE 	(-16776961),
		YELLOW 	(-256),
		RED 	(-65536);
		// and so on...

		private final int rgb;

		NColor (int rgb)
		{
			this.rgb = rgb;
		}

		public int getRGB () { return rgb; }
	}

	/** */
	public ColorEnum ()
	{
		for (NColor nc : NColor.values ())
		{
			System.out.println (nc.toString () + "\t" + nc.getRGB ());
		}
	}

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