static/panes/editor.js

// Copyright (c) 2016, Matt Godbolt
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// 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.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
// 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 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
"use strict";
var _ = require('underscore');
var $ = require('jquery');
var colour = require('../colour');
var loadSaveLib = require('../loadSave');
var FontScale = require('../fontscale');
var Components = require('../components');
var monaco = require('../monaco');
var options = require('../options');
var Alert = require('../alert');
var local = require('../local');
var ga = require('../analytics');
require('../modes/cppp-mode');
require('../modes/d-mode');
require('../modes/rust-mode');
require('../modes/ispc-mode');
require('../modes/haskell-mode');
require('../modes/clean-mode');
require('../modes/pascal-mode');
require('../modes/cuda-mode');
require('../modes/zig-mode');
require('../modes/nc-mode');
require('selectize');

var loadSave = new loadSaveLib.LoadSave();

var languages = options.languages;


function Editor(hub, state, container) {
    this.id = state.id || hub.nextEditorId();
    this.container = container;
    this.domRoot = container.getElement();
    this.domRoot.html($('#codeEditor').html());
    this.hub = hub;
    this.eventHub = hub.createEventHub();
    // Should probably be its own function somewhere
    this.settings = JSON.parse(local.get('settings', '{}'));
    this.ourCompilers = {};
    this.httpRoot = window.httpRoot;
    if (!this.httpRoot.endsWith('/')) {
        this.httpRoot += '/';
    }
    this.widgetsByCompiler = {};
    this.asmByCompiler = {};
    this.busyCompilers = {};
    this.colours = [];

    this.decorations = {};
    this.prevDecorations = [];

    this.fadeTimeoutId = -1;

    this.editorSourceByLang = {};
    this.alertSystem = new Alert();
    this.alertSystem.prefixMessage = "Editor #" + this.id + ": ";

    this.langKeys = _.keys(languages);
    this.initLanguage(state);

    var root = this.domRoot.find(".monaco-placeholder");
    var legacyReadOnly = state.options && !!state.options.readOnly;
    this.editor = monaco.editor.create(root[0], {
        scrollBeyondLastLine: false,
        language: this.currentLanguage.monaco,
        fontFamily: 'Consolas, "Liberation Mono", Courier, monospace',
        readOnly: !!options.readOnly || legacyReadOnly,
        glyphMargin: !options.embedded,
        quickSuggestions: false,
        fixedOverflowWidgets: true,
        minimap: {
            maxColumn: 80
        },
        folding: true,
        lineNumbersMinChars: options.embedded ? 1 : 3,
        emptySelectionClipboard: true,
        autoIndent: true
    });

    if (state.source !== undefined) {
        this.setSource(state.source);
    } else {
        this.updateEditorCode();
    }

    var startFolded = /^[/*#;]+\s*setup.*/;
    if (state.source && state.source.match(startFolded)) {
        // With reference to https://github.com/Microsoft/monaco-editor/issues/115
        // I tried that and it didn't work, but a delay of 500 seems to "be enough".
        setTimeout(_.bind(function () {
            this.editor.getAction("editor.fold").run();
        }, this), 500);
    }

    this.initEditorActions();
    this.initButtons(state);
    this.initCallbacks();

    var usableLanguages = _.filter(languages, function (language) {
        return hub.compilerService.compilersByLang[language.id];
    });

    this.languageBtn.selectize({
        sortField: 'name',
        valueField: 'id',
        labelField: 'name',
        searchField: ['name'],
        options: _.map(usableLanguages, _.identity),
        items: [this.currentLanguage.id]
    }).on('change', _.bind(function (e) {
        this.onLanguageChange($(e.target).val());
    }, this));
    this.selectize = this.languageBtn[0].selectize;
    // We suppress posting changes until the user has stopped typing by:
    // * Using _.debounce() to run emitChange on any key event or change
    //   only after a delay.
    // * Only actually triggering a change if the document text has changed from
    //   the previous emitted.
    this.lastChangeEmitted = null;
    this.onSettingsChange(this.settings);
    // this.editor.on("keydown", _.bind(function () {
    //     // Not strictly a change; but this suppresses changes until some time
    //     // after the last key down (be it an actual change or a just a cursor
    //     // movement etc).
    //     this.debouncedEmitChange();
    // }, this));

    this.updateTitle();
    this.updateState();
    ga.proxy('send', {
        hitType: 'event',
        eventCategory: 'OpenViewPane',
        eventAction: 'Editor'
    });
    ga.proxy('send', {
        hitType: 'event',
        eventCategory: 'LanguageChange',
        eventAction: this.currentLanguage.id
    });
}

// If compilerId is undefined, every compiler will be pinged
Editor.prototype.maybeEmitChange = function (force, compilerId) {
    var source = this.getSource();
    if (!force && source === this.lastChangeEmitted) return;
    this.lastChangeEmitted = source;
    this.eventHub.emit('editorChange', this.id, this.lastChangeEmitted, this.currentLanguage.id, compilerId);
};

Editor.prototype.updateState = function () {
    var state = {
        id: this.id,
        source: this.getSource(),
        lang: this.currentLanguage.id
    };
    this.fontScale.addState(state);
    this.container.setState(state);
};

Editor.prototype.setSource = function (newSource) {
    this.editor.getModel().setValue(newSource);
};

Editor.prototype.getSource = function () {
    return this.editor.getModel().getValue();
};

Editor.prototype.initLanguage = function (state) {
    this.currentLanguage = languages[this.langKeys[0]];
    this.waitingForLanguage = state.source && !state.lang;
    if (languages[this.settings.defaultLanguage]) {
        this.currentLanguage = languages[this.settings.defaultLanguage];
    }
    if (languages[state.lang]) {
        this.currentLanguage = languages[state.lang];
    } else if (this.settings.newEditorLastLang && languages[this.hub.lastOpenedLangId]) {
        this.currentLanguage = languages[this.hub.lastOpenedLangId];
    }
};

Editor.prototype.initCallbacks = function () {
    this.fontScale.on('change', _.bind(this.updateState, this));

    this.container.on('resize', this.resize, this);
    this.container.on('shown', this.resize, this);
    this.container.on('open', _.bind(function () {
        this.eventHub.emit('editorOpen', this.id);
    }, this));
    this.container.on('destroy', this.close, this);
    this.container.layoutManager.on('initialised', function () {
        // Once initialized, let everyone know what text we have.
        this.maybeEmitChange();
    }, this);

    this.eventHub.on('compilerOpen', this.onCompilerOpen, this);
    this.eventHub.on('compilerClose', this.onCompilerClose, this);
    this.eventHub.on('compiling', this.onCompiling, this);
    this.eventHub.on('compileResult', this.onCompileResponse, this);
    this.eventHub.on('selectLine', this.onSelectLine, this);
    this.eventHub.on('editorSetDecoration', this.onEditorSetDecoration, this);
    this.eventHub.on('settingsChange', this.onSettingsChange, this);
    this.eventHub.on('conformanceViewOpen', this.onConformanceViewOpen, this);
    this.eventHub.on('conformanceViewClose', this.onConformanceViewClose, this);
    this.eventHub.on('resize', this.resize, this);

    this.editor.getModel().onDidChangeContent(_.bind(function () {
        this.debouncedEmitChange();
        this.updateState();
    }, this));

    this.editor.onMouseLeave(_.bind(function () {
        this.fadeTimeoutId = setTimeout(_.bind(function () {
            this.clearCompilerLinkedLines();
            this.fadeTimeoutId = -1;
        }, this), 5000);
    }, this));

    this.mouseMoveThrottledFunction = _.throttle(_.bind(function (e) {
        if (e !== null && e.target !== null && this.settings.hoverShowSource && e.target.position !== null) {
            this.tryCompilerLinkLine(e.target.position.lineNumber, false);
        }
    }, this), 250);

    this.editor.onMouseMove(_.bind(function (e) {
        this.mouseMoveThrottledFunction(e);
        // This can't be throttled or we can clear a timeout where we're already outside
        if (this.fadeTimeoutId !== -1) {
            clearTimeout(this.fadeTimeoutId);
            this.fadeTimeoutId = -1;
        }
    }, this));

    this.eventHub.on('initialised', this.maybeEmitChange, this);
};

Editor.prototype.initButtons = function (state) {
    this.fontScale = new FontScale(this.domRoot, state, this.editor);
    this.languageBtn = this.domRoot.find('.change-language');
    // Ensure that the button is disabled if we don't have nothing to select
    // Note that is might be disabled for other reasons beforehand
    if (this.langKeys.length <= 1) {
        this.languageBtn.prop("disabled", true);
    }
    var addCompilerButton = this.domRoot.find('.btn.add-compiler');
    var paneAdderDropdown = this.domRoot.find('.add-pane');

    var togglePaneAdder = function () {
        paneAdderDropdown.dropdown('toggle');
    };
    this.topBar = this.domRoot.find('.top-bar');

    // NB a new compilerConfig needs to be created every time; else the state is shared
    // between all compilers created this way. That leads to some nasty-to-find state
    // bugs e.g. https://github.com/mattgodbolt/compiler-explorer/issues/225
    var getCompilerConfig = _.bind(function () {
        return Components.getCompiler(this.id, this.currentLanguage.id);
    }, this);

    var getConformanceConfig = _.bind(function () {
        return Components.getConformanceView(this.id, this.getSource());
    }, this);

    this.container.layoutManager
        .createDragSource(addCompilerButton, getCompilerConfig)
        ._dragListener.on('dragStart', togglePaneAdder);

    addCompilerButton.click(_.bind(function () {
        var insertPoint = this.hub.findParentRowOrColumn(this.container) ||
            this.container.layoutManager.root.contentItems[0];
        insertPoint.addChild(getCompilerConfig);
    }, this));

    this.conformanceViewerButton = this.domRoot.find('.btn.conformance');

    this.container.layoutManager
        .createDragSource(this.conformanceViewerButton, getConformanceConfig)
        ._dragListener.on('dragStart', togglePaneAdder);
    this.conformanceViewerButton.click(_.bind(function () {
        var insertPoint = this.hub.findParentRowOrColumn(this.container) ||
            this.container.layoutManager.root.contentItems[0];
        insertPoint.addChild(getConformanceConfig);
    }, this));

    this.hideable = this.domRoot.find('.hideable');

    this.loadSaveButton = this.domRoot.find('.load-save');
    this.initLoadSaver();
    $(this.domRoot).keydown(_.bind(function (event) {
        if ((event.ctrlKey || event.metaKey) && String.fromCharCode(event.which).toLowerCase() === 's') {
            this.showLoadSaver();
            if (loadSave.onSaveToFile(this.id)) {
                event.preventDefault();
            }
        }
    }, this));
};

Editor.prototype.changeLanguage = function (newLang) {
    this.selectize.setValue(newLang);
};

Editor.prototype.clearCompilerLinkedLines = function () {
    _.each(this.asmByCompiler, _.bind(function (asms, compilerId) {
        this.eventHub.emit('compilerSetDecorations', compilerId, -1, false);
    }, this));
};

Editor.prototype.tryCompilerLinkLine = function (thisLineNumber, reveal) {
    _.each(this.asmByCompiler, _.bind(function (asms, compilerId) {
        var targetLines = [];
        _.each(asms, function (asmLine, i) {
            if (asmLine.source && asmLine.source.file === null && asmLine.source.line === thisLineNumber) {
                targetLines.push(i + 1);
            }
        });
        this.eventHub.emit('compilerSetDecorations', compilerId, targetLines, reveal);
    }, this));
};

Editor.prototype.initEditorActions = function () {
    this.editor.addAction({
        id: 'compile',
        label: 'Compile',
        keybindings: [monaco.KeyMod.CtrlCmd | monaco.KeyCode.Enter],
        keybindingContext: null,
        contextMenuGroupId: 'navigation',
        contextMenuOrder: 1.5,
        run: _.bind(function () {
            this.maybeEmitChange();
        }, this)
    });

    this.editor.addAction({
        id: 'toggleCompileOnChange',
        label: 'Toggle compile on change',
        keybindings: [monaco.KeyMod.CtrlCmd | monaco.KeyMod.Shift | monaco.KeyCode.Enter],
        keybindingContext: null,
        run: _.bind(function () {
            this.eventHub.emit('modifySettings', {
                compileOnChange: !this.settings.compileOnChange
            });
            this.alertSystem
                .notify('Compile on change has been toggled ' + (this.settings.compileOnChange ? 'ON' : 'OFF'), {
                    group: "togglecompile",
                    alertClass: this.settings.compileOnChange ? "notification-on" : "notification-off",
                    dismissTime: 3000
                });
        }, this)
    });

    this.editor.addAction({
        id: 'clang-format',
        label: 'Format text',
        keybindings: [monaco.KeyMod.CtrlCmd | monaco.KeyCode.F9],
        keybindingContext: null,
        contextMenuGroupId: 'help',
        contextMenuOrder: 1.5,
        run: _.bind(this.formatCurrentText, this)
    });

    this.editor.addAction({
        id: 'toggleColourisation',
        label: 'Toggle colourisation',
        keybindings: [monaco.KeyMod.CtrlCmd | monaco.KeyMod.Shift | monaco.KeyCode.F1],
        keybindingContext: null,
        run: _.bind(function () {
            this.eventHub.emit('modifySettings', {
                colouriseAsm: !this.settings.colouriseAsm
            });
        }, this)
    });

    this.editor.addAction({
        id: 'viewasm',
        label: 'Scroll to assembly',
        keybindings: [monaco.KeyMod.CtrlCmd | monaco.KeyCode.F10],
        keybindingContext: null,
        contextMenuGroupId: 'navigation',
        contextMenuOrder: 1.5,
        run: _.bind(function (ed) {
            this.tryCompilerLinkLine(ed.getPosition().lineNumber, true);
        }, this)
    });
};

Editor.prototype.doesMatchEditor = function (otherSource) {
    return otherSource === this.getSource();
};

Editor.prototype.confirmOverwrite = function (yes) {
    this.alertSystem.ask("Changes were made to the code",
        "Changes were made to the code while it was being processed. Overwrite changes?",
        {yes: yes, no: null});
};

Editor.prototype.formatCurrentText = function () {
    var previousSource = this.getSource();
    var currentPosition = this.editor.getPosition();
    $.ajax({
        type: 'POST',
        url: window.location.origin + this.httpRoot + 'api/format/clangformat',
        dataType: 'json',  // Expected
        contentType: 'application/json',  // Sent
        data: JSON.stringify({
            source: previousSource,
            base: this.settings.formatBase
        }),
        success: _.bind(function (result) {
            if (result.exit === 0) {
                if (this.doesMatchEditor(previousSource)) {
                    this.setSource(result.answer);
                    this.numberUsedLines();
                    this.editor.setPosition(currentPosition);
                } else {
                    this.confirmOverwrite(_.bind(function () {
                        this.setSource(result.answer);
                        this.numberUsedLines();
                        this.editor.setPosition(currentPosition);
                    }, this), null);
                }
            } else {
                // Ops, the formatter itself failed!
                this.alertSystem.notify("We encountered an error formatting your code: " + result.answer, {
                    group: "formatting",
                    alertClass: "notification-error"
                });
            }
        }, this),
        error: _.bind(function (xhr, e_status, error) {
            // Hopefully we have not exploded!
            if (xhr.responseText) {
                try {
                    var res = JSON.parse(xhr.responseText);
                    error = res.answer || error;
                } catch (e) {
                    // continue regardless of error
                }
            }
            error = error || "Unknown error";
            this.alertSystem.notify("We ran into some issues while formatting your code: " + error, {
                group: "formatting",
                alertClass: "notification-error"
            });
        }, this),
        cache: true
    });
};

Editor.prototype.resize = function () {
    var topBarHeight = this.updateAndCalcTopBarHeight();
    //var topBarHeight = this.topBar.outerHeight(true) || 0;
    this.editor.layout({
        width: this.domRoot.width(),
        height: this.domRoot.height() - topBarHeight
    });
};

Editor.prototype.updateAndCalcTopBarHeight = function () {
    var width = this.domRoot.width();
    if (width === this.cachedTopBarHeightAtWidth) {
        return this.cachedTopBarHeight;
    }
    // If we save vertical space by hiding stuff that's OK to hide
    // when thin, then hide that stuff.
    this.hideable.show();
    var topBarHeightMax = this.topBar.outerHeight(true);
    this.hideable.hide();
    var topBarHeightMin = this.topBar.outerHeight(true);
    var topBarHeight = topBarHeightMin;
    if (topBarHeightMin === topBarHeightMax) {
        this.hideable.show();
        topBarHeight = topBarHeightMax;
    }
    this.cachedTopBarHeight = topBarHeight;
    this.cachedTopBarHeightAtWidth = width;
    return topBarHeight;
};

Editor.prototype.onSettingsChange = function (newSettings) {
    var before = this.settings;
    var after = newSettings;
    this.settings = _.clone(newSettings);

    this.editor.updateOptions({
        autoClosingBrackets: this.settings.autoCloseBrackets,
        tabSize: this.settings.tabWidth,
        quickSuggestions: this.settings.showQuickSuggestions,
        contextmenu: this.settings.useCustomContextMenu,
        minimap: {
            enabled: this.settings.showMinimap && !options.embedded
        }
    });

    // * Turn off auto.
    // * edit code
    // * change compiler or compiler options (out of date code is used)
    var bDac = before.compileOnChange ? before.delayAfterChange : 0;
    var aDac = after.compileOnChange ? after.delayAfterChange : 0;
    if (bDac !== aDac || !this.debouncedEmitChange) {
        if (aDac) {
            this.debouncedEmitChange = _.debounce(_.bind(function () {
                this.maybeEmitChange();
            }, this), after.delayAfterChange);
            this.maybeEmitChange(true);
        } else {
            this.debouncedEmitChange = _.noop;
        }
    }

    if (before.hoverShowSource && !after.hoverShowSource) {
        this.onEditorSetDecoration(this.id, -1, false);
    }

    this.numberUsedLines();
};

Editor.prototype.numberUsedLines = function () {
    var result = {};
    // First, note all lines used.
    _.each(this.asmByCompiler, function (asm) {
        _.each(asm, function (asmLine) {
            // If the line has a source indicator, and the source indicator is null (i.e. the
            // user's input file), then tag it as used.
            if (asmLine.source && asmLine.source.file === null && asmLine.source.line > 0)
                result[asmLine.source.line - 1] = true;
        });
    });
    // Now assign an ordinal to each used line.
    var ordinal = 0;
    _.each(result, function (v, k) {
        result[k] = ordinal++;
    });

    if (_.any(this.busyCompilers)) return;
    this.updateColours(this.settings.colouriseAsm ? result : []);
};

Editor.prototype.updateColours = function (colours) {
    this.colours = colour.applyColours(this.editor, colours, this.settings.colourScheme, this.colours);
    this.eventHub.emit('colours', this.id, colours, this.settings.colourScheme);
};

Editor.prototype.onCompilerOpen = function (compilerId, editorId) {
    if (editorId === this.id) {
        // On any compiler open, rebroadcast our state in case they need to know it.
        if (this.waitingForLanguage) {
            var glCompiler = _.find(this.container.layoutManager.root.getComponentsByName("compiler"), function (c) {
                return c.id === compilerId;
            });
            if (glCompiler) {
                var selected = _.find(options.compilers, function (compiler) {
                    return compiler.id === glCompiler.originalCompilerId;
                });
                if (selected) {
                    this.changeLanguage(selected.lang);
                }
            }
        }
        this.maybeEmitChange(true, compilerId);
        this.ourCompilers[compilerId] = true;
    }
};

Editor.prototype.onCompilerClose = function (compilerId) {
    if (this.ourCompilers[compilerId]) {
        monaco.editor.setModelMarkers(this.editor.getModel(), compilerId, []);
        delete this.widgetsByCompiler[compilerId];
        delete this.asmByCompiler[compilerId];
        delete this.busyCompilers[compilerId];
        delete this.ourCompilers[compilerId];
        this.numberUsedLines();
    }
};

Editor.prototype.onCompiling = function (compilerId) {
    if (!this.ourCompilers[compilerId]) return;
    this.busyCompilers[compilerId] = true;
};

Editor.prototype.onCompileResponse = function (compilerId, compiler, result) {
    if (!this.ourCompilers[compilerId]) return;
    this.busyCompilers[compilerId] = false;
    var output = (result.stdout || []).concat(result.stderr || []);
    var widgets = _.compact(_.map(output, function (obj) {
        if (!obj.tag) return;
        var severity = 3; // error
        if (obj.tag.text.match(/^warning/)) severity = 2;
        if (obj.tag.text.match(/^note/)) severity = 1;
        return {
            severity: severity,
            message: obj.tag.text,
            source: compiler.name + ' #' + compilerId,
            startLineNumber: obj.tag.line,
            startColumn: obj.tag.column || 0,
            endLineNumber: obj.tag.line,
            endColumn: obj.tag.column ? -1 : Infinity
        };
    }, this));
    monaco.editor.setModelMarkers(this.editor.getModel(), compilerId, widgets);
    this.decorations.tags = _.map(widgets, function (tag) {
        return {
            range: new monaco.Range(tag.startLineNumber, tag.startColumn, tag.startLineNumber + 1, 1),
            options: {
                isWholeLine: false,
                inlineClassName: "error-code"
            }
        };
    }, this);
    this.updateDecorations();
    this.asmByCompiler[compilerId] = result.asm;
    this.numberUsedLines();
};

Editor.prototype.onSelectLine = function (id, lineNum) {
    if (Number(id) === this.id) {
        this.editor.setSelection({line: lineNum - 1, ch: 0}, {line: lineNum, ch: 0});
    }
};

Editor.prototype.onEditorSetDecoration = function (id, lineNum, reveal) {
    if (Number(id) === this.id) {
        if (reveal && lineNum)
            this.editor.revealLineInCenter(lineNum);
        this.decorations.linkedCode = lineNum === -1 || !lineNum ? [] : [{
            range: new monaco.Range(lineNum, 1, lineNum, 1),
            options: {
                isWholeLine: true,
                linesDecorationsClassName: 'linked-code-decoration-margin',
                inlineClassName: 'linked-code-decoration-inline'
            }
        }];
        this.updateDecorations();
    }
};

Editor.prototype.updateDecorations = function () {
    this.prevDecorations = this.editor.deltaDecorations(this.prevDecorations, _.flatten(_.values(this.decorations)));
};

Editor.prototype.onConformanceViewOpen = function (editorId) {
    if (editorId === this.id) {
        this.conformanceViewerButton.attr("disabled", true);
    }
};

Editor.prototype.onConformanceViewClose = function (editorId) {
    if (editorId === this.id) {
        this.conformanceViewerButton.attr("disabled", false);
    }
};

Editor.prototype.showLoadSaver = function () {
    this.loadSaveButton.click();
};

Editor.prototype.initLoadSaver = function () {
    this.loadSaveButton
        .off('click')
        .click(_.bind(function () {
            loadSave.run(_.bind(function (text) {
                this.setSource(text);
                this.updateState();
                this.maybeEmitChange();
            }, this), this.getSource(), this.currentLanguage);
        }, this));
};

Editor.prototype.onLanguageChange = function (newLangId) {
    if (languages[newLangId]) {
        if (newLangId !== this.currentLanguage.id) {
            var oldLangId = this.currentLanguage.id;
            this.currentLanguage = languages[newLangId];
            if (!this.waitingForLanguage) {
                this.editorSourceByLang[oldLangId] = this.getSource();
                this.updateEditorCode();
            }
            this.initLoadSaver();
            monaco.editor.setModelLanguage(this.editor.getModel(), this.currentLanguage.monaco);
            this.updateTitle();
            this.updateState();
            // Broadcast the change to other panels
            this.eventHub.emit("languageChange", this.id, newLangId);
            this.maybeEmitChange(true);
            ga.proxy('send', {
                hitType: 'event',
                eventCategory: 'LanguageChange',
                eventAction: newLangId
            });
        }
        this.waitingForLanguage = false;
    }
};

Editor.prototype.updateTitle = function () {
    this.container.setTitle(this.currentLanguage.name + " source #" + this.id);
};

// Called every time we change language, so we get the relevant code
Editor.prototype.updateEditorCode = function () {
    this.setSource(this.editorSourceByLang[this.currentLanguage.id] || languages[this.currentLanguage.id].example);
};

Editor.prototype.close = function () {
    this.eventHub.unsubscribe();
    this.eventHub.emit('editorClose', this.id);
    this.editor.dispose();
};

module.exports = {
    Editor: Editor
};