Add initial update mechanism

Makefile

@@ -2,7 +2,7 @@
 
 UUID = dash-to-panel@jderose9.github.com
 BASE_MODULES = extension.js stylesheet.css metadata.json COPYING README.md
-EXTRA_MODULES = appIcons.js convenience.js panel.js panelManager.js proximity.js intellihide.js panelStyle.js overview.js taskbar.js transparency.js windowPreview.js prefs.js utils.js Settings.ui
+EXTRA_MODULES = appIcons.js convenience.js panel.js panelManager.js proximity.js intellihide.js panelStyle.js overview.js taskbar.js transparency.js windowPreview.js prefs.js update.js utils.js Settings.ui
 EXTRA_IMAGES = highlight_stacked_bg.svg
 TOLOCALIZE =  prefs.js appIcons.js
 MSGSRC = $(wildcard po/*.po)

extension.js

@@ -33,6 +33,7 @@ const Signals = imports.signals;
 const Me = ExtensionUtils.getCurrentExtension();
 const Convenience = Me.imports.convenience;
 const PanelManager = Me.imports.panelManager;
+const Update = Me.imports.update;
 const Utils = Me.imports.utils;
 
 const UBUNTU_DOCK_UUID = 'ubuntu-dock@ubuntu.com';
@@ -90,6 +91,8 @@ function _enable() {
     panelManager = new PanelManager.dtpPanelManager(settings);
     panelManager.enable();
     
+    settings.connect('changed::version-to-install', () => Update.installRelease(settings.get_string('version-to-install')));
+
     Utils.removeKeybinding('open-application-menu');
     Utils.addKeybinding(
         'open-application-menu',

schemas/org.gnome.shell.extensions.dash-to-panel.gschema.xml

@@ -66,6 +66,9 @@
     <value value='4' nick='bolder'/>
   </enum>
   <schema path="/org/gnome/shell/extensions/dash-to-panel/" id="org.gnome.shell.extensions.dash-to-panel">
+    <key type="s" name="version-to-install">
+      <default>''</default>
+    </key>
     <key name="panel-position" enum="org.gnome.shell.extensions.dash-to-panel.position">
       <default>'BOTTOM'</default>
       <summary>Panel position</summary>

update.js

@@ -0,0 +1,174 @@
+/*
+ * This file is part of the Dash-To-Panel extension for Gnome 3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+const GLib = imports.gi.GLib;
+const Gio = imports.gi.Gio;
+const Soup = imports.gi.Soup;
+const FileUtils = imports.misc.fileUtils;
+
+const Me = imports.misc.extensionUtils.getCurrentExtension();
+const Gettext = imports.gettext.domain(Me.metadata['gettext-domain']);
+const _ = Gettext.gettext;
+
+const releaseApiUrl = 'https://api.github.com/repos/home-sweet-gnome/dash-to-panel/releases/';
+
+let httpSession;
+
+function getLatestReleaseInfo(cb) {
+    getReleaseInfo('latest', cb);
+}
+
+function getTaggedReleaseInfo(releaseTag, cb) {
+    getReleaseInfo('tags/' + releaseTag, cb);
+}
+
+function getReleaseInfo(suffix, cb) {
+    let message = Soup.form_request_new_from_hash('GET', releaseApiUrl + suffix, {});
+
+    getHttpMessageResponseBody(message, (err, body) => {
+        if (err) {
+            return cb(err);
+        }
+
+        try {
+            let release = JSON.parse(body.data);
+            let releaseInfo = {
+                name: release.name, 
+                tag: release.tag_name,
+                zipUrl: (release.assets.length ? release.assets[0].browser_download_url : ''),
+            };
+
+            cb(null, releaseInfo);
+        } catch (e) {
+            cb(e.message);
+        }
+    });
+}
+
+function installRelease(releaseAssetUrl) {
+    getHttpMessageResponseBody(Soup.form_request_new_from_hash('GET', releaseAssetUrl, {}), (err, body) => {
+        if (err) {
+            return notifyInstallResult(err);
+        }
+
+        let name = 'dtp_install';
+        let zipFile = createTmp(name + '.zip');
+        let stream = zipFile.replace(null, false, Gio.FileCreateFlags.NONE, null);
+        let extDir = Gio.file_new_for_path(Me.path);
+        let tmpDir = createTmp(name, true);
+        let bckDir = createTmp(Me.uuid, true);
+
+        stream.write_bytes(body.flatten().get_as_bytes(), null);
+        stream.close(null);
+
+        unzipFile(zipFile, tmpDir, err => {
+            if (err) {
+                return notifyInstallResult(err);
+            }
+            
+            try {
+                let [success, out, err, exitCode] = GLib.spawn_command_line_sync('pidof "gnome-shell-extension-prefs"');
+
+                FileUtils.recursivelyMoveDir(extDir, bckDir);
+                FileUtils.recursivelyMoveDir(tmpDir, extDir);
+
+                if (success && !exitCode) {
+                    GLib.spawn_command_line_sync('kill -9 ' + imports.byteArray.toString(out));
+                }
+            } catch (e) {
+                FileUtils.recursivelyDeleteDir(extDir, false);
+                FileUtils.recursivelyMoveDir(bckDir, extDir);
+
+                return notifyInstallResult(e.message);
+            }
+
+            notifyInstallResult(null);
+        });
+    });
+}
+
+function notifyInstallResult(err) {
+    let Meta = imports.gi.Meta;
+    let icon = 'information';
+    let action = 0;
+
+    if (err) {
+        var msg = _('Error: ') + err;
+        icon = 'error';
+    } else if (Meta.is_wayland_compositor()) {
+        msg = _('Update successful, please log out/in');
+        action = { text: _('Log out'), func: () => new imports.misc.systemActions.getDefault().activateLogout() };
+    } else {
+        msg = _('Update successful, please restart GNOME Shell');
+        action = { text: _('Restart GNOME Shell'), func: () => Meta.restart(_("Restarting GNOME Shell…")) };
+    }
+
+    Me.imports.utils.notify('Dash to Panel', msg, 'dialog-' + icon, action);
+}
+
+function createTmp(name, isDir) {
+    let tmp = Gio.file_new_for_path('/tmp/' + name);
+
+    if (isDir && tmp.query_exists(null)) {
+        FileUtils.recursivelyDeleteDir(tmp, false);
+    }
+
+    return tmp;
+}
+
+function unzipFile(zipFile, destDir, cb) {
+    let [success, pid] = GLib.spawn_async(
+        null,
+        ['unzip', '-uod', destDir.get_path(), '--', zipFile.get_path()],
+        null,
+        GLib.SpawnFlags.SEARCH_PATH | GLib.SpawnFlags.DO_NOT_REAP_CHILD | GLib.SpawnFlags.STDOUT_TO_DEV_NULL,
+        null
+    );
+
+    if (!success) {
+        return cb('unzip spawn error');
+    }
+
+    GLib.child_watch_add(GLib.PRIORITY_DEFAULT, pid, (pid, status) => {
+        GLib.spawn_close_pid(pid);
+
+        if (status != 0) {
+            return cb('extraction error')
+        }
+        
+        return cb(null);
+    });
+}
+
+function getHttpMessageResponseBody(message, cb) {
+    if (!httpSession) {
+        httpSession = new Soup.Session();
+        httpSession.user_agent = Me.metadata.uuid;
+    }
+
+    httpSession.queue_message(message, (httpSession, message) => {
+        try {
+            if (!message.response_body || !message.response_body.data) {
+                return cb('No data received');
+            }
+
+            return cb(null, message.response_body);
+        } catch (e) {
+            return cb(e.message);
+        }
+    });
+}

utils.js

@@ -32,6 +32,7 @@ const Shell = imports.gi.Shell;
 const St = imports.gi.St;
 const Mainloop = imports.mainloop;
 const Main = imports.ui.main;
+const MessageTray = imports.ui.messageTray;
 const Tweener = imports.ui.tweener;
 const Util = imports.misc.util;
 
@@ -412,7 +413,25 @@ var activateSiblingWindow = function(windows, direction, startWindow) {
     if (windowIndex != nextWindowIndex) {
         Main.activateWindow(windows[nextWindowIndex]);
     }
-}
+};
+
+var notify = function(title, text, iconName, action) {
+    let source = new MessageTray.SystemNotificationSource();
+    let notification = new MessageTray.Notification(source, title, text);
+    
+    if (iconName) {
+        source.createIcon = function() {
+            return new St.Icon({ icon_name: iconName });
+        };
+    }   
+
+    if (action) {
+        notification.addAction(action.text, action.func);
+    }
+
+    Main.messageTray.add(source);
+    source.notify(notification);
+};
 
 /*
  * This is a copy of the same function in utils.js, but also adjust horizontal scrolling