overleaf/services/web/public/js/ace/keyboard/keybinding.js

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 * Distributed under the BSD license:
 *
 * Copyright (c) 2010, Ajax.org B.V.
 * All rights reserved.
 * 
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 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
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 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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define(function(require, exports, module) {
"use strict";

var keyUtil  = require("../lib/keys");
var event = require("../lib/event");

var KeyBinding = function(editor) {
    this.$editor = editor;
    this.$data = { };
    this.$handlers = [];
    this.setDefaultHandler(editor.commands);
};

(function() {
    this.setDefaultHandler = function(kb) {
        this.removeKeyboardHandler(this.$defaultHandler);
        this.$defaultHandler = kb;
        this.addKeyboardHandler(kb, 0);
        this.$data = {editor: this.$editor};
    };

    this.setKeyboardHandler = function(kb) {
        var h = this.$handlers;
        if (h[h.length - 1] == kb)
            return;

        while (h[h.length - 1] && h[h.length - 1] != this.$defaultHandler)
            this.removeKeyboardHandler(h[h.length - 1]);

        this.addKeyboardHandler(kb, 1);
    };

    this.addKeyboardHandler = function(kb, pos) {
        if (!kb)
            return;
        var i = this.$handlers.indexOf(kb);
        if (i != -1)
            this.$handlers.splice(i, 1);

        if (pos == undefined)
            this.$handlers.push(kb);
        else
            this.$handlers.splice(pos, 0, kb);

        if (i == -1 && kb.attach)
            kb.attach(this.$editor);
    };

    this.removeKeyboardHandler = function(kb) {
        var i = this.$handlers.indexOf(kb);
        if (i == -1)
            return false;
        this.$handlers.splice(i, 1);
        kb.detach && kb.detach(this.$editor);
        return true;
    };

    this.getKeyboardHandler = function() {
        return this.$handlers[this.$handlers.length - 1];
    };

    this.$callKeyboardHandlers = function (hashId, keyString, keyCode, e) {
        var toExecute;
        var success = false;
        var commands = this.$editor.commands;

        for (var i = this.$handlers.length; i--;) {
            toExecute = this.$handlers[i].handleKeyboard(
                this.$data, hashId, keyString, keyCode, e
            );
            if (!toExecute || !toExecute.command)
                continue;
            
            // allow keyboardHandler to consume keys
            if (toExecute.command == "null") {
                success = true;
            } else {
                success = commands.exec(toExecute.command, this.$editor, toExecute.args, e);                
            }
            // do not stop input events to not break repeating
            if (success && e && hashId != -1 && 
                toExecute.passEvent != true && toExecute.command.passEvent != true
            ) {
                event.stopEvent(e);
            }
            if (success)
                break;
        }
        return success;
    };

    this.onCommandKey = function(e, hashId, keyCode) {
        var keyString = keyUtil.keyCodeToString(keyCode);
        this.$callKeyboardHandlers(hashId, keyString, keyCode, e);
    };

    this.onTextInput = function(text) {
        var success = this.$callKeyboardHandlers(-1, text);
        if (!success)
            this.$editor.commands.exec("insertstring", this.$editor, text);
    };

}).call(KeyBinding.prototype);

exports.KeyBinding = KeyBinding;
});