/*
This file is part of Ext JS 4.2

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-05-16 14:36:50 (f9be68accb407158ba2b1be2c226a6ce1f649314)
*/
/**
 * Provides a convenient wrapper for normalized keyboard navigation. KeyNav allows you to bind navigation keys to
 * function calls that will get called when the keys are pressed, providing an easy way to implement custom navigation
 * schemes for any UI component.
 *
 * The following are all of the possible keys that can be implemented: enter, space, left, right, up, down, tab, esc,
 * pageUp, pageDown, del, backspace, home, end.
 *
 * Usage:
 *
 *     var nav = new Ext.util.KeyNav({
 *         target : "my-element",
 *         left   : function(e){
 *             this.moveLeft(e.ctrlKey);
 *         },
 *         right  : function(e){
 *             this.moveRight(e.ctrlKey);
 *         },
 *         enter  : function(e){
 *             this.save();
 *         },
 *         
 *         // Binding may be a function specifiying fn, scope and defaultAction
 *         esc: {
 *             fn: this.onEsc,
 *             defaultEventAction: false
 *         },
 *         scope : this
 *     });
 */
Ext.define('Ext.util.KeyNav', {
    alternateClassName: 'Ext.KeyNav',

    requires: ['Ext.util.KeyMap'],

    statics: {
        keyOptions: {
            left: 37,
            right: 39,
            up: 38,
            down: 40,
            space: 32,
            pageUp: 33,
            pageDown: 34,
            del: 46,
            backspace: 8,
            home: 36,
            end: 35,
            enter: 13,
            esc: 27,
            tab: 9
        }
    },

    constructor: function(config) {
        var me = this;
        if (arguments.length === 2) {
            me.legacyConstructor.apply(me, arguments);
            return;
        }
        me.setConfig(config);
    },

    /**
     * @private
     * Old constructor signature.
     * @param {String/HTMLElement/Ext.Element} el The element or its ID to bind to
     * @param {Object} config The config
     */
    legacyConstructor: function(el, config) {
        this.setConfig(Ext.apply({
            target: el
        }, config));
    },

    /**
     * Sets up a configuration for the KeyNav.
     * @private
     * @param {Object} config A configuration object as specified in the constructor.
     */
    setConfig: function(config) {
        var me = this,
            keymapCfg = {
                target: config.target,
                ignoreInputFields: config.ignoreInputFields,
                eventName: me.getKeyEvent('forceKeyDown' in config ? config.forceKeyDown : me.forceKeyDown, config.eventName)
            },
            map, keyCodes, defaultScope, keyName, binding;

        if (me.map) {
            me.map.destroy();
        }

        if (config.processEvent) {
            keymapCfg.processEvent = config.processEvent;
            keymapCfg.processEventScope = config.processEventScope||me;
        }

        // If they specified a KeyMap to use, use it
        if (config.keyMap) {
            map = me.map = config.keyMap;
        }
        // Otherwise, create one, and remember to destroy it on destroy
        else {
            map = me.map = new Ext.util.KeyMap(keymapCfg);
            me.destroyKeyMap = true;
        }
        keyCodes = Ext.util.KeyNav.keyOptions;
        defaultScope = config.scope || me;

        for (keyName in keyCodes) {
            if (keyCodes.hasOwnProperty(keyName)) {

                // There is a property named after a key name.
                // It may be a function or an binding spec containing handler, scope and defaultAction configs
                if (binding = config[keyName]) {
                    if (typeof binding === 'function') {
                        binding = {
                            handler: binding,
                            defaultEventAction: (config.defaultEventAction !== undefined) ? config.defaultEventAction : me.defaultEventAction
                        };
                    }
                    map.addBinding({
                        key: keyCodes[keyName],
                        handler: Ext.Function.bind(me.handleEvent, binding.scope||defaultScope, binding.handler||binding.fn, true),
                        defaultEventAction: (binding.defaultEventAction !== undefined) ? binding.defaultEventAction : me.defaultEventAction
                    });
                }
            }
        }

        map.disable();
        if (!config.disabled) {
            map.enable();
        }
    },

    /**
     * Method for filtering out the map argument
     * @private
     * @param {Number} keyCode
     * @param {Ext.EventObject} event
     * @param {Object} options Contains the handler to call
     */
    handleEvent: function(keyCode, event, handler){
        return handler.call(this, event);
    },

    /**
     * @cfg {Boolean} disabled
     * True to disable this KeyNav instance.
     */
    disabled: false,

    /**
     * @cfg {String} defaultEventAction
     * The method to call on the {@link Ext.EventObject} after this KeyNav intercepts a key. Valid values are {@link
     * Ext.EventObject#stopEvent}, {@link Ext.EventObject#preventDefault} and {@link Ext.EventObject#stopPropagation}.
     *
     * If a falsy value is specified, no method is called on the key event.
     */
    defaultEventAction: "stopEvent",

    /**
     * @cfg {Boolean} forceKeyDown
     * Handle the keydown event instead of keypress. KeyNav automatically does this for IE since IE does not propagate
     * special keys on keypress, but setting this to true will force other browsers to also handle keydown instead of
     * keypress.
     */
    forceKeyDown: false,

    /**
     * @cfg {Ext.Component/Ext.Element/HTMLElement/String} target
     * The object on which to listen for the event specified by the {@link #eventName} config option.
     */

    /**
     * @cfg {String} eventName
     * The event to listen for to pick up key events.
     */
    eventName: 'keypress',

    /**
     * @cfg {Function} processEvent
     * An optional event processor function which accepts the argument list provided by the {@link #eventName configured
     * event} of the {@link #target}, and returns a keyEvent for processing by the KeyMap.
     *
     * This may be useful when the {@link #target} is a Component with s complex event signature. Extra information from
     * the event arguments may be injected into the event for use by the handler functions before returning it.
     */

    /**
     * @cfg {Object} [processEventScope=this]
     * The scope (`this` context) in which the {@link #processEvent} method is executed.
     */

    /**
     * @cfg {Boolean} [ignoreInputFields=false]
     * Configure this as `true` if there are any input fields within the {@link #target}, and this KeyNav
     * should not process events from input fields, (`&lt;input>, &lt;textarea> and elements with `contentEditable="true"`)
     */

    /**
     * @cfg {Ext.util.KeyMap} [keyMap]
     * An optional pre-existing {@link Ext.util.KeyMap KeyMap} to use to listen for key events. If not specified,
     * one is created.
     */

    /**
     * Destroy this KeyNav.
     * @param {Boolean} removeEl Pass `true` to remove the element associated with this KeyNav.
     */
    destroy: function(removeEl) {
        if (this.destroyKeyMap) {
            this.map.destroy(removeEl);
        }
        delete this.map;
    },

    /**
     * Enables this KeyNav.
     */
    enable: function() {
        // this.map will be removed if destroyed
        if (this.map) {
            this.map.enable();
            this.disabled = false;
        }
    },

    /**
     * Disables this KeyNav.
     */
    disable: function() {
        // this.map will be removed if destroyed
        if (this.map) {
            this.map.disable();
        }
        this.disabled = true;
    },

    /**
     * Convenience function for setting disabled/enabled by boolean.
     * @param {Boolean} disabled
     */
    setDisabled : function(disabled) {
        this.map.setDisabled(disabled);
        this.disabled = disabled;
    },

    /**
     * @private
     * Determines the event to bind to listen for keys. Defaults to the {@link #eventName} value, but
     * may be overridden the {@link #forceKeyDown} setting.
     *
     * The useKeyDown option on the EventManager modifies the default {@link #eventName} to be `keydown`,
     * but a configured {@link #eventName} takes priority over this.
     *
     * @return {String} The type of event to listen for.
     */
    getKeyEvent: function(forceKeyDown, configuredEventName) {
        if (forceKeyDown || (Ext.EventManager.useKeyDown && !configuredEventName)) {
            return 'keydown';
        } else {
            return configuredEventName||this.eventName;
        }
    }
});