wmii keyboard events handler for node.js. Depends on wmiir.js and wmii_events.js.

wmii_keys.js

// wmii keybindings and keyboard event module
// Adam R. Nelson
// August 2013

var wmiir  = require('./wmiir.js');
var events = require('./wmii_events.js');

var globalKeys = {};
var modeKeys = {};
var currentMode = null;
var modes = {};

function rewriteKeyFile(callback) {
    var keyData = Object.keys(modeKeys).concat(Object.keys(globalKeys)).join('\n');
    wmiir.write('/keys', keyData, callback);
}

events.on('Key', function(key) {
    var handler = modeKeys[key] || globalKeys[key];
    if (handler) handler();
});

// Binds the key `key` to the function `keyAction`, globally.
// If `callback` is passed, it will be called after the keybinding is written
// to wmii's filesystem.
exports.bindKey = function(key, keyAction, callback) {
    globalKeys[key] = keyAction;
    rewriteKeyFile(callback);
};

// Takes an object (`keyBindings`) that maps key names to callback functions.
// Each key will be bound, globally, to its value (which should be a function).
// If `callback` is passed, it will be called after all keybindings are written
// to wmii's filesystem.
exports.bindKeys = function(keyBindings, callback) {
    for (var key in keyBindings) {
        globalKeys[key] = keyBindings[key];
    }
    rewriteKeyFile(callback);
};

// Removes the global keybinding for `key`, if one exists. Keybindings
// belonging to modes will be unaffected.
// If `callback` is passed, it will be called after the keybinding changes are
// written to wmii's filesystem.
exports.unbindKey = function(key, callback) {
    globalKeys[key] = undefined;
    rewriteKeyFile(callback);
};

// Removes all global keybindings. Keybindings belonging to modes will be
// unaffected.
// If `callback` is passed, it will be called after the keybinding changes are
// written to wmii's filesystem.
exports.unbindAll = function(callback) {
    globalKeys = {};
    rewriteKeyFile(callback);
};

// Defines a mode, with the name `modeName`. `keyBindings` should be an object
// that maps key names to callback functions. Within the new mode, all of the
// keys in `keyBindings` will be bound to their valies (which should be
// functions).
// If a mode named `modeName` already exists, this mode will replace it.
exports.defineMode = function(modeName, keyBindings) {
    modes[modeName] = keyBindings;
};

// Returns the name of the currently-active mode.
exports.getMode = function() {
    return currentMode;
};

// Sets the current mode to `modeName`, if a mode with that name exists.
// Unbinds all keys bound in the current mode, and binds all keys belonging to
// the new mode.
// Emits a 'ModeChanged' event if the mode was changed successfully, or an
// 'Error' event if it was not.
// If `callback` is passed, it will be called after the keybinding changes are
// written to wmii's filesystem. It will be passed one argument, a boolean,
// indicating whether the mode change succeeded.
exports.setMode = function(modeName, callback) {
    try {
        var mode = modes[modeName];
        if (!mode) {
            events.emit('Error', 'No such mode: ' + modeName);
            if (callback) callback(false);
            return;
        }
        currentMode = modeName;
        modeKeys = mode;
        rewriteKeyFile(function(err) {
            if (err) {
                events.emit('Error', err.message || err);
            } else {
                events.emit('ModeChanged', modeName);
            }
            if (callback) callback(true);
        });
    } catch (ex) {
        console.log(ex);
    }
};