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.

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;
    }
}