[gnome-shell] Add remote access indication and control

[Florian Müllner <fmuellner src gnome org>]

commit 0d5bae384400e200b46e4dd975f089f102ada972
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Jul 20 16:50:50 2018 +0200

    Add remote access indication and control
    
    Add an indicator for when there is something access the display server
    remotely. This could be 1) remote desktop, 2) screen cast or 3) remote
    control, but all effectively applications using
    org.freedesktop.portal.ScreenCast or org.gnome.portal.RemoteDesktop as
    well as gnome-remote-desktop using the corresponding org.gnome.Mutter
    APIs directly.
    
    As it is now, it'll simply show a single icon for when anything is
    having an active session, and a single action "Turn off" that'll close
    every active session.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/160

 js/js-resources.gresource.xml |  1 +
 js/ui/panel.js                |  3 ++
 js/ui/status/remoteAccess.js  | 80 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+)
---
diff --git a/js/js-resources.gresource.xml b/js/js-resources.gresource.xml
index 883b62d66..cc1da4461 100644
--- a/js/js-resources.gresource.xml
+++ b/js/js-resources.gresource.xml
@@ -130,6 +130,7 @@
     <file>ui/status/rfkill.js</file>
     <file>ui/status/volume.js</file>
     <file>ui/status/bluetooth.js</file>
+    <file>ui/status/remoteAccess.js</file>
     <file>ui/status/screencast.js</file>
     <file>ui/status/system.js</file>
     <file>ui/status/thunderbolt.js</file>
diff --git a/js/ui/panel.js b/js/ui/panel.js
index 6f3ac9cb3..05241abdc 100644
--- a/js/ui/panel.js
+++ b/js/ui/panel.js
@@ -710,6 +710,7 @@ var AggregateMenu = new Lang.Class({
             this._bluetooth = null;
         }
 
+        this._remoteAccess = new imports.ui.status.remoteAccess.RemoteAccessApplet();
         this._power = new imports.ui.status.power.Indicator();
         this._rfkill = new imports.ui.status.rfkill.Indicator();
         this._volume = new imports.ui.status.volume.Indicator();
@@ -730,6 +731,7 @@ var AggregateMenu = new Lang.Class({
         if (this._bluetooth) {
             this._indicators.add_child(this._bluetooth.indicators);
         }
+        this._indicators.add_child(this._remoteAccess.indicators);
         this._indicators.add_child(this._rfkill.indicators);
         this._indicators.add_child(this._volume.indicators);
         this._indicators.add_child(this._power.indicators);
@@ -744,6 +746,7 @@ var AggregateMenu = new Lang.Class({
         if (this._bluetooth) {
             this.menu.addMenuItem(this._bluetooth.menu);
         }
+        this.menu.addMenuItem(this._remoteAccess.menu);
         this.menu.addMenuItem(this._location.menu);
         this.menu.addMenuItem(this._rfkill.menu);
         this.menu.addMenuItem(this._power.menu);
diff --git a/js/ui/status/remoteAccess.js b/js/ui/status/remoteAccess.js
new file mode 100644
index 000000000..ffa334001
--- /dev/null
+++ b/js/ui/status/remoteAccess.js
@@ -0,0 +1,80 @@
+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
+
+const Lang = imports.lang;
+const Meta = imports.gi.Meta;
+
+const PanelMenu = imports.ui.panelMenu;
+const PopupMenu = imports.ui.popupMenu;
+
+var RemoteAccessApplet = new Lang.Class({
+    Name: 'RemoteAccessApplet',
+    Extends: PanelMenu.SystemIndicator,
+
+    _init() {
+        this.parent();
+
+        let backend = Meta.get_backend();
+        let controller = backend.get_remote_access_controller();
+
+        if (!controller)
+            return;
+
+        // We can't possibly know about all types of screen sharing on X11, so
+        // showing these controls on X11 might give a false sense of security.
+        // Thus, only enable these controls when using Wayland, where we are
+        // in control of sharing.
+        if (!Meta.is_wayland_compositor())
+            return;
+
+        this._handles = new Set();
+        this._indicator = null;
+        this._menuSection = null;
+
+        controller.connect('new-handle', (controller, handle) => {
+            this._onNewHandle(handle);
+        });
+    },
+
+    _ensureControls() {
+        if (this._indicator)
+            return;
+
+        this._indicator = this._addIndicator();
+        this._indicator.icon_name = 'screen-shared-symbolic';
+        this._item =
+            new PopupMenu.PopupSubMenuMenuItem(_("Screen is Being Shared"),
+                                               true);
+        this._item.menu.addAction(_("Turn off"),
+                                  () => {
+                                      for (let handle of this._handles)
+                                            handle.stop();
+                                  });
+        this._item.icon.icon_name = 'screen-shared-symbolic';
+        this.menu.addMenuItem(this._item);
+    },
+
+    _sync() {
+        if (this._handles.size == 0) {
+            this._indicator.visible = false;
+            this._item.actor.visible = false;
+        } else {
+            this._indicator.visible = true;
+            this._item.actor.visible = true;
+        }
+    },
+
+    _onStopped(handle) {
+        this._handles.delete(handle);
+        this._sync();
+    },
+
+    _onNewHandle(handle) {
+        this._handles.add(handle);
+        handle.connect('stopped', this._onStopped.bind(this));
+
+        if (this._handles.size == 1) {
+            this._ensureControls();
+            this._sync();
+        }
+    },
+});