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/**
 * @fileoverview This file contains IME mode interface.
 */

'use strict';

console.assert(skk, 'ime.js must be loaded prior to this module');

/**
 * Enumeration contains input mode class names.
 * @enum {string}
 */
skk.InputMode = {
  ASCII: 'Ascii',
  KANA: 'Kana',
  // modes for Kanji
  PREEDIT: 'Preedit',
  CONVERSION: 'Conversion'
};

/**
 * Namespace for input mode classes.
 */
skk.mode = {};

/**
 * Interface represents input mode.
 * @interface
 */
skk.mode.InputModeInterface = function() {};

/**
 * Resets current status of the input mode.
 */
skk.mode.InputModeInterface.prototype.reset = function() {};

/**
 * Called when the input mode was initialized and activated.
 */
skk.mode.InputModeInterface.prototype.enter = skk.abstractMethod;

/**
 * Called when the input mode was destroyed.
 */
skk.mode.InputModeInterface.prototype.leave = skk.abstractMethod;

/**
 * Called when the input mode was suspended temporarily.
 */
skk.mode.InputModeInterface.prototype.suspend = skk.abstractMethod;

/**
 * Called when the input mode was resumed from temporary suspend.
 */
skk.mode.InputModeInterface.prototype.resume = skk.abstractMethod;

/**
 * Processes key event before it sent to addKey() method.
 * This method is mainly used for mode switching.
 * @param {KeyboardEvent} keyEvent Key event sent from browser.
 * @return {?KeyboardEvent} Key event to be processed by {@code addKey}.
 *     If return value is null, the key event never sent to {@code addKey}.
 */
skk.mode.InputModeInterface.prototype.prepareForKey = skk.abstractMethod;

/**
 * Processes key event.
 * @param {KeyboardEvent} keyEvent Dispathed by onKeyEvent() handler.
 * @return {boolean} True if the given key handled by this method.
 *     Otherwise returns false to mean that system should handle it.
 */
skk.mode.InputModeInterface.prototype.addKey = skk.abstractMethod;