keyManager.js

define(function(require, exports, module) {
	'use strict';

	//Helper function that merges two or more objects into one.
	function collect() {
		var ret = {};
		var len = arguments.length;
		for (var i = 0; i < len; i++) {
			for (var p in arguments[i]) {
				if (arguments[i].hasOwnProperty(p)) {
					ret[p] = arguments[i][p];
				}
			}
		}
		return ret;
	}

	var triggerKeys = {
		commandToggle: {
			keyCode: 18,
			location: [2],
			btnName: 'rightAlt',
			isPressed: false,
			releaseAfterFunc: false,
			func: function() {}
		}
	};

	var modifierKeys = {
		textSelection: {
			keyCode: 16,
			location: [1],
			btnName: 'leftShift',
			isPressed: false,
			releaseAfterFunc: false,
			func: function() {}
		},
		gazeManualOffset: {
			keyCode: 190,
			location: [0],
			btnName: 'fullStop',
			isPressed: false,
			releaseAfterFunc: false,
			func: function() {}
		},
	};

	var commandKeys = {
		click: {
			keyCode: 81,
			location: [0],
			btnName: 'Q',
			isPressed: false,
			releaseAfterFunc: true,
			func: require('./movements').cursorClick
		},
		verticalScroll: {
			keyCode: 90,
			location: [0],
			btnName: 'Z',
			isPressed: false,
			releaseAfterFunc: false,
			func: require('./movements').verticalScroll
		},
		verticalCursorScroll: {
			keyCode: 70,
			location: [0],
			btnName: 'F',
			isPressed: false,
			releaseAfterFunc: false,
			func: require('./movements').verticalCursorScroll
		},
		horizontalCursorScroll: {
			keyCode: 82,
			location: [0],
			btnName: 'R',
			isPressed: false,
			releaseAfterFunc: false,
			func: require('./movements').horizontalCursorScroll
		},
		selectHoveredWord: {
			keyCode: 80,
			location: [0],
			btnName: 'P',
			isPressed: false,
			releaseAfterFunc: true,
			func: require('./movements').selectHoveredWord
		},
		cursorUp: {
			keyCode: 87,
			location: [0],
			btnName: 'W',
			isPressed: false,
			releaseAfterFunc: true,
			func: require('./movements').arrowKeysMovements('up')
		},
		cursorDown: {
			keyCode: 83,
			location: [0],
			btnName: 'S',
			isPressed: false,
			releaseAfterFunc: true,
			func: require('./movements').arrowKeysMovements('down')
		},
		cursorLeft: {
			keyCode: 65,
			location: [0],
			btnName: 'A',
			isPressed: false,
			releaseAfterFunc: true,
			func: require('./movements').arrowKeysMovements('left')
		},
		cursorRight: {
			keyCode: 68,
			location: [0],
			btnName: 'D',
			isPressed: false,
			releaseAfterFunc: true,
			func: require('./movements').arrowKeysMovements('right')
		}
	};

	var keys = collect(triggerKeys, modifierKeys, commandKeys);

	var isKeyPressed = function(key) {
		return key.isPressed;
	};

	function setKeyPressed(key) {
		if (key) {
			key.isPressed = true;
		}
	}

	function setKeyReleased(key) {
		if (key) {
			key.isPressed = false;

			//Reset all other keys if the command key is released
			if (key === keys.commandToggle) {
				for (var k in keys) {
					if (keys[k].hasOwnProperty("isPressed")) {
						keys[k].isPressed = false;
					}
				}
			}
		}
	}

	function getKeyFromCode(keyCode) {
		for (var k in keys) {
			if (keys[k].keyCode === keyCode)
				return keys[k];
		}

		return undefined;
	}

	function getKeyFromCodeAndLocation(keyCode, keyLocation) {
		for (var k in keys) {
			if (keys[k].keyCode === keyCode && keys[k].location.indexOf(keyLocation) !== -1)
				return keys[k];
		}

		return undefined;
	}

	function isValidKeyCommand(key) {
		if (key === keys.commandToggle || !keys.commandToggle.isPressed) {
			return false;
		}

		return isKeyPressed(key);
	}


	//Note: This works only for 2 level objects such as mine, it is not flexible at all. As Brackets doesn't allow other libraries, I cannot use lodash or similar, so this solution is enough.
	function setUserDefinedKeys(userKeys) {
		if (userKeys && Object.keys(userKeys).length) {

			Object.keys(userKeys).forEach(function(key) {
				Object.keys(userKeys[key]).forEach(function(inKey) {
					if (inKey in keys[key]) {
						keys[key][inKey] = userKeys[key][inKey];
					}
				});
			});
		}
	}

	exports.getKeyFromCodeAndLocation = getKeyFromCodeAndLocation;
	exports.getKeyFromCode = getKeyFromCode;
	exports.isValidKeyCommand = isValidKeyCommand;
	exports.isKeyPressed = isKeyPressed;
	exports.setKeyPressed = setKeyPressed;
	exports.setKeyReleased = setKeyReleased;
	exports.setUserDefinedKeys = setUserDefinedKeys;
	exports.keys = keys;
});