Keyboard Layout library to find Neighboring Keys given an input key (java preferable) [closed]

Question

Does anyone know of a library (preferably java) that can give me neighboring keys given a key input for US_ENGLISH standard keyboard?

E.g. if I input the character 'd', I should get the following characters returned: [w,e,r,s,f,x,c,v].

Alternatively a grid manipulation api would work too (so that I can instantiate a grid with a qwerty keyboard layout and use it to find my neighbors).

Note 1: I am using the words 'character' and 'key' synonymously to refer to characters.

Note 2: I know I can hard-code a method to map the 50-or-so primary keys to their neighbors. I am looking for a better solution.

Thank You.

Roughen

Answer 1

I agree with BlueNovember but in case you want a more "mathematical" solution check this. First you create a grid of characters and then you return all of them that has a distance smaller than 2 from the key passed... Kinda useless but it's a nice exercise :)

public class Test {

    static String chars = "qwertyuiopasdfghjkl;zxcvbnm,.";

    public static void main(String[] args) {
        System.out.println(getNeighboringKeys('f'));
        System.out.println(getNeighboringKeys('u'));
        System.out.println(getNeighboringKeys('m'));
        System.out.println(getNeighboringKeys('q'));
    }

    public static String getNeighboringKeys(char key) {
        StringBuffer result = new StringBuffer();
        for (char c : chars.toCharArray()) {
            if (c!=key && distance(c,key)<2) {
                result.append(c);
            }
        }
        return result.toString();
    }

    public static double distance(char c1, char c2) {
        return Math.sqrt(Math.pow(colOf(c2)-colOf(c1),2)+Math.pow(rowOf(c2)-rowOf(c1),2));
    }

    public static int rowOf(char c) {
        return chars.indexOf(c) / 10;
    }

    public static int colOf(char c) {
        return chars.indexOf(c) % 10;
    }
}

Mckean

Thanks. The getNeighboringKeys method could be optimized to do lesser operations though. – Roughen

The optimization would yield too small a performance boost to justify the additional time to try and optimize it.. I mean there are only 80 keys more or less in the grid and you call this rarely. But be my guest and post the optimized version if you do it :) – Mckean

Answer 2

I gave up on this and just let the user choose what keys are suitably adjacent. In this project an enum Key relates each command to a keyCode, and this dialog lets the user change the mapping. The result is saved in Preferences.

Ousley

Answer 3

I'd be surprised if there is a solution better than Note 2.

What would the library be doing underneath, if not this? Keys don't have any relationship to each other you can build from.

Gulp

I was thinking about a library that returns a different result for a different LOCALE (E.g. US_ENGLISH / FRENCH) or keyboard type (E.g. DVORAK/QWERTY). – Roughen

Fair enough. Your question does specifically state US_ENGLISH though. The locale is going to be problematic; if I, as a UK-keyboard user with UK locale, set my locale to US, my \ key is still in the same place, but the OS would see it as a \ from US keyboard, which is elsewhere on the keyboard. – Gulp

Answer 4

Be careful when you do this. For example, next to D are ZERSFXCV, not WERSFXCV if you're in France. And if you use Dvorak, it's YFGIHXBM. If you're in Turkey, it might be 567ORUTK.

Pines

Yes. This is why I wanted to use a library if it existed. – Roughen