gnome-shell/js/misc/util.js

// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
/* exported findUrls, spawn, spawnCommandLine, spawnApp, trySpawnCommandLine,
            createTimeLabel, insertSorted, lerp, GNOMEversionCompare,
            DBusSenderChecker, Highlighter */

const Gio = imports.gi.Gio;
const GLib = imports.gi.GLib;
const Shell = imports.gi.Shell;
const St = imports.gi.St;
const GnomeDesktop = imports.gi.GnomeDesktop;

const Main = imports.ui.main;
const {formatTime} = imports.misc.dateUtils;

// http://daringfireball.net/2010/07/improved_regex_for_matching_urls
const _balancedParens = '\\([^\\s()<>]+\\)';
const _leadingJunk = '[\\s`(\\[{\'\\"<\u00AB\u201C\u2018]';
const _notTrailingJunk = '[^\\s`!()\\[\\]{};:\'\\".,<>?\u00AB\u00BB\u200E\u200F\u201C\u201D\u2018\u2019\u202A\u202C]';

const _urlRegexp = new RegExp(
    `(^|${_leadingJunk})` +
    '(' +
        '(?:' +
            '(?:http|https|ftp)://' +             // scheme://
            '|' +
            'www\\d{0,3}[.]' +                    // www.
            '|' +
            '[a-z0-9.\\-]+[.][a-z]{2,4}/' +       // foo.xx/
        ')' +
        '(?:' +                                   // one or more:
            '[^\\s()<>]+' +                       // run of non-space non-()
            '|' +                                 // or
            `${_balancedParens}` +                // balanced parens
        ')+' +
        '(?:' +                                   // end with:
            `${_balancedParens}` +                // balanced parens
            '|' +                                 // or
            `${_notTrailingJunk}` +               // last non-junk char
        ')' +
    ')', 'gi');

let _desktopSettings = null;

// findUrls:
// @str: string to find URLs in
//
// Searches @str for URLs and returns an array of objects with %url
// properties showing the matched URL string, and %pos properties indicating
// the position within @str where the URL was found.
//
// Return value: the list of match objects, as described above
function findUrls(str) {
    let res = [], match;
    while ((match = _urlRegexp.exec(str)))
        res.push({ url: match[2], pos: match.index + match[1].length });
    return res;
}

// spawn:
// @argv: an argv array
//
// Runs @argv in the background, handling any errors that occur
// when trying to start the program.
function spawn(argv) {
    try {
        trySpawn(argv);
    } catch (err) {
        _handleSpawnError(argv[0], err);
    }
}

// spawnCommandLine:
// @commandLine: a command line
//
// Runs @commandLine in the background, handling any errors that
// occur when trying to parse or start the program.
function spawnCommandLine(commandLine) {
    try {
        let [success_, argv] = GLib.shell_parse_argv(commandLine);
        trySpawn(argv);
    } catch (err) {
        _handleSpawnError(commandLine, err);
    }
}

// spawnApp:
// @argv: an argv array
//
// Runs @argv as if it was an application, handling startup notification
function spawnApp(argv) {
    try {
        let app = Gio.AppInfo.create_from_commandline(argv.join(' '), null,
                                                      Gio.AppInfoCreateFlags.SUPPORTS_STARTUP_NOTIFICATION);

        let context = global.create_app_launch_context(0, -1);
        app.launch([], context);
    } catch (err) {
        _handleSpawnError(argv[0], err);
    }
}

// trySpawn:
// @argv: an argv array
//
// Runs @argv in the background. If launching @argv fails,
// this will throw an error.
function trySpawn(argv) {
    var success_, pid;
    try {
        [success_, pid] = GLib.spawn_async(
            null, argv, null,
            GLib.SpawnFlags.SEARCH_PATH | GLib.SpawnFlags.DO_NOT_REAP_CHILD,
            () => {
                try {
                    global.context.restore_rlimit_nofile();
                } catch (err) {
                }
            }
        );
    } catch (err) {
        /* Rewrite the error in case of ENOENT */
        if (err.matches(GLib.SpawnError, GLib.SpawnError.NOENT)) {
            throw new GLib.SpawnError({
                code: GLib.SpawnError.NOENT,
                message: _('Command not found'),
            });
        } else if (err instanceof GLib.Error) {
            // The exception from gjs contains an error string like:
            //   Error invoking GLib.spawn_command_line_async: Failed to
            //   execute child process "foo" (No such file or directory)
            // We are only interested in the part in the parentheses. (And
            // we can't pattern match the text, since it gets localized.)
            let message = err.message.replace(/.*\((.+)\)/, '$1');
            throw new err.constructor({ code: err.code, message });
        } else {
            throw err;
        }
    }

    // Async call, we don't need the reply though
    GnomeDesktop.start_systemd_scope(argv[0], pid, null, null, null, () => {});

    // Dummy child watch; we don't want to double-fork internally
    // because then we lose the parent-child relationship, which
    // can break polkit.  See https://bugzilla.redhat.com//show_bug.cgi?id=819275
    GLib.child_watch_add(GLib.PRIORITY_DEFAULT, pid, () => {});
}

// trySpawnCommandLine:
// @commandLine: a command line
//
// Runs @commandLine in the background. If launching @commandLine
// fails, this will throw an error.
function trySpawnCommandLine(commandLine) {
    let success_, argv;

    try {
        [success_, argv] = GLib.shell_parse_argv(commandLine);
    } catch (err) {
        // Replace "Error invoking GLib.shell_parse_argv: " with
        // something nicer
        err.message = err.message.replace(/[^:]*: /, `${_('Could not parse command:')}\n`);
        throw err;
    }

    trySpawn(argv);
}

function _handleSpawnError(command, err) {
    let title = _("Execution of “%s” failed:").format(command);
    Main.notifyError(title, err.message);
}

function createTimeLabel(date, params) {
    if (_desktopSettings == null)
        _desktopSettings = new Gio.Settings({ schema_id: 'org.gnome.desktop.interface' });

    let label = new St.Label({ text: formatTime(date, params) });
    _desktopSettings.connectObject(
        'changed::clock-format', () => (label.text = formatTime(date, params)),
        label);
    return label;
}

// lowerBound:
// @array: an array or array-like object, already sorted
//         according to @cmp
// @val: the value to add
// @cmp: a comparator (or undefined to compare as numbers)
//
// Returns the position of the first element that is not
// lower than @val, according to @cmp.
// That is, returns the first position at which it
// is possible to insert @val without violating the
// order.
// This is quite like an ordinary binary search, except
// that it doesn't stop at first element comparing equal.

function lowerBound(array, val, cmp) {
    let min, max, mid, v;
    cmp ||= (a, b) => a - b;

    if (array.length == 0)
        return 0;

    min = 0;
    max = array.length;
    while (min < (max - 1)) {
        mid = Math.floor((min + max) / 2);
        v = cmp(array[mid], val);

        if (v < 0)
            min = mid + 1;
        else
            max = mid;
    }

    return min == max || cmp(array[min], val) < 0 ? max : min;
}

// insertSorted:
// @array: an array sorted according to @cmp
// @val: a value to insert
// @cmp: the sorting function
//
// Inserts @val into @array, preserving the
// sorting invariants.
// Returns the position at which it was inserted
function insertSorted(array, val, cmp) {
    let pos = lowerBound(array, val, cmp);
    array.splice(pos, 0, val);

    return pos;
}

function lerp(start, end, progress) {
    return start + progress * (end - start);
}

// _GNOMEversionToNumber:
// @version: a GNOME version element
//
// Like Number() but returns sortable values for special-cases
// 'alpha' and 'beta'. Returns NaN for unhandled 'versions'.
function _GNOMEversionToNumber(version) {
    let ret = Number(version);
    if (!isNaN(ret))
        return ret;
    if (version === 'alpha')
        return -2;
    if (version === 'beta')
        return -1;
    return ret;
}

// GNOMEversionCompare:
// @version1: a string containing a GNOME version
// @version2: a string containing another GNOME version
//
// Returns an integer less than, equal to, or greater than
// zero, if version1 is older, equal or newer than version2
function GNOMEversionCompare(version1, version2) {
    const v1Array = version1.split('.');
    const v2Array = version2.split('.');

    for (let i = 0; i < Math.max(v1Array.length, v2Array.length); i++) {
        let elemV1 = _GNOMEversionToNumber(v1Array[i] || '0');
        let elemV2 = _GNOMEversionToNumber(v2Array[i] || '0');
        if (elemV1 < elemV2)
            return -1;
        if (elemV1 > elemV2)
            return 1;
    }

    return 0;
}

var DBusSenderChecker = class {
    /**
     * @param {string[]} allowList - list of allowed well-known names
     */
    constructor(allowList) {
        this._allowlistMap = new Map();

        this._uninitializedNames = new Set(allowList);
        this._initializedPromise = new Promise(resolve => {
            this._resolveInitialized = resolve;
        });

        this._watchList = allowList.map(name => {
            return Gio.DBus.watch_name(Gio.BusType.SESSION,
                name,
                Gio.BusNameWatcherFlags.NONE,
                (conn_, name_, owner) => {
                    this._allowlistMap.set(name, owner);
                    this._checkAndResolveInitialized(name);
                },
                () => {
                    this._allowlistMap.delete(name);
                    this._checkAndResolveInitialized(name);
                });
        });
    }

    /**
     * @param {string} name - bus name for which the watcher got initialized
     */
    _checkAndResolveInitialized(name) {
        if (this._uninitializedNames.delete(name) &&
            this._uninitializedNames.size === 0)
            this._resolveInitialized();
    }

    /**
     * @async
     * @param {string} sender - the bus name that invoked the checked method
     * @returns {bool}
     */
    async _isSenderAllowed(sender) {
        await this._initializedPromise;
        return [...this._allowlistMap.values()].includes(sender);
    }

    /**
     * Check whether the bus name that invoked @invocation maps
     * to an entry in the allow list.
     *
     * @async
     * @throws
     * @param {Gio.DBusMethodInvocation} invocation - the invocation
     * @returns {void}
     */
    async checkInvocation(invocation) {
        if (global.context.unsafe_mode)
            return;

        if (await this._isSenderAllowed(invocation.get_sender()))
            return;

        throw new GLib.Error(Gio.DBusError,
            Gio.DBusError.ACCESS_DENIED,
            `${invocation.get_method_name()} is not allowed`);
    }

    /**
     * @returns {void}
     */
    destroy() {
        for (const id in this._watchList)
            Gio.DBus.unwatch_name(id);
        this._watchList = [];
    }
};

/* @class Highlighter Highlight given terms in text using markup. */
var Highlighter = class {
    /**
     * @param {?string[]} terms - list of terms to highlight
     */
    constructor(terms) {
        if (!terms)
            return;

        const escapedTerms = terms
            .map(term => Shell.util_regex_escape(term))
            .filter(term => term.length > 0);

        if (escapedTerms.length === 0)
            return;

        this._highlightRegex = new RegExp(
            `(${escapedTerms.join('|')})`, 'gi');
    }

    /**
     * Highlight all occurences of the terms defined for this
     * highlighter in the provided text using markup.
     *
     * @param {string} text - text to highlight the defined terms in
     * @returns {string}
     */
    highlight(text) {
        if (!this._highlightRegex)
            return GLib.markup_escape_text(text, -1);

        let escaped = [];
        let lastMatchEnd = 0;
        let match;
        while ((match = this._highlightRegex.exec(text))) {
            if (match.index > lastMatchEnd) {
                let unmatched = GLib.markup_escape_text(
                    text.slice(lastMatchEnd, match.index), -1);
                escaped.push(unmatched);
            }
            let matched = GLib.markup_escape_text(match[0], -1);
            escaped.push(`<b>${matched}</b>`);
            lastMatchEnd = match.index + match[0].length;
        }
        let unmatched = GLib.markup_escape_text(
            text.slice(lastMatchEnd), -1);
        escaped.push(unmatched);

        return escaped.join('');
    }
};