[gnome-shell/wip/rstrode/rhel-8.0.0: 31/50] Add app introspection API

[Ray Strode <halfline src gnome org>]

commit bb2764dc69d74f81bc31cdb58e6b923a68bacd41
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Sep 5 11:15:30 2018 +0200

    Add app introspection API
    
    Add a D-Bus API that allows the API user to introspect the application
    state of the shell. Currently the only exposed information is list of
    running applications and which one is active (i.e. has focus).
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/326
    (cherry picked from commit 10c68c6b952959d105c3126fc61f22a199e8e848)

 data/meson.build                    |   3 +-
 data/org.gnome.Shell.Introspect.xml |  37 ++++++++++++
 data/org.gnome.shell.gschema.xml.in |   8 +++
 js/js-resources.gresource.xml       |   1 +
 js/misc/introspect.js               | 116 ++++++++++++++++++++++++++++++++++++
 js/ui/main.js                       |   4 ++
 6 files changed, 168 insertions(+), 1 deletion(-)
---
diff --git a/data/meson.build b/data/meson.build
index 7c9807721..fee44f02e 100644
--- a/data/meson.build
+++ b/data/meson.build
@@ -46,7 +46,8 @@ dbus_interfaces = [
   'org.gnome.Shell.Screencast.xml',
   'org.gnome.Shell.Screenshot.xml',
   'org.gnome.ShellSearchProvider.xml',
-  'org.gnome.ShellSearchProvider2.xml'
+  'org.gnome.ShellSearchProvider2.xml',
+  'org.gnome.Shell.Introspect.xml'
 ]
 install_data(dbus_interfaces, install_dir: ifacedir)
 
diff --git a/data/org.gnome.Shell.Introspect.xml b/data/org.gnome.Shell.Introspect.xml
new file mode 100644
index 000000000..10c48d635
--- /dev/null
+++ b/data/org.gnome.Shell.Introspect.xml
@@ -0,0 +1,37 @@
+<!DOCTYPE node PUBLIC
+'-//freedesktop//DTD D-BUS Object Introspection 1.0//EN'
+'http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd'>
+<node>
+
+  <!--
+      org.gnome.Shell.Introspect:
+      @short_description: Introspection interface
+
+      The interface used to introspect the state of Shell, such as running
+      applications, currently active application, etc.
+  -->
+  <interface name="org.gnome.Shell.Introspect">
+
+    <!--
+        RunningApplicationsChanged:
+        @short_description: Notifies when the running applications changes
+    -->
+    <signal name="RunningApplicationsChanged" />
+
+    <!--
+        GetRunningApplications:
+        @short_description: Retrieves the description of all running applications
+
+        Each application is associated by an application ID. The details of
+        each application consists of a varlist of keys and values. Available
+        keys are listed below.
+
+        'active-on-seats' - (as)   list of seats the application is active on
+                                   (a seat only has at most one active
+                                   application)
+    -->
+    <method name="GetRunningApplications">
+      <arg name="apps" direction="out" type="a{sa{sv}}" />
+    </method>
+  </interface>
+</node>
diff --git a/data/org.gnome.shell.gschema.xml.in b/data/org.gnome.shell.gschema.xml.in
index 6f1459c86..c1c0bd473 100644
--- a/data/org.gnome.shell.gschema.xml.in
+++ b/data/org.gnome.shell.gschema.xml.in
@@ -90,6 +90,14 @@
         adapter is ever seen not to have devices associated to it.
       </description>
     </key>
+    <key name="introspect" type="b">
+      <default>false</default>
+      <summary>Enable introspection API</summary>
+      <description>
+        Enables a D-Bus API that allows to introspect the application state of
+        the shell.
+      </description>
+    </key>
     <child name="keybindings" schema="org.gnome.shell.keybindings"/>
     <child name="keyboard" schema="org.gnome.shell.keyboard"/>
   </schema>
diff --git a/js/js-resources.gresource.xml b/js/js-resources.gresource.xml
index 22ba047d8..5deb7fd18 100644
--- a/js/js-resources.gresource.xml
+++ b/js/js-resources.gresource.xml
@@ -19,6 +19,7 @@
     <file>misc/history.js</file>
     <file>misc/ibusManager.js</file>
     <file>misc/inputMethod.js</file>
+    <file>misc/introspect.js</file>
     <file>misc/jsParse.js</file>
     <file>misc/keyboardManager.js</file>
     <file>misc/loginManager.js</file>
diff --git a/js/misc/introspect.js b/js/misc/introspect.js
new file mode 100644
index 000000000..05ef9e637
--- /dev/null
+++ b/js/misc/introspect.js
@@ -0,0 +1,116 @@
+const Gio = imports.gi.Gio;
+const GLib = imports.gi.GLib;
+const Lang = imports.lang;
+const Meta = imports.gi.Meta;
+const Shell = imports.gi.Shell;
+
+const INTROSPECT_SCHEMA = 'org.gnome.shell';
+const INTROSPECT_KEY = 'introspect';
+const APP_WHITELIST = ['org.freedesktop.impl.portal.desktop.gtk'];
+
+const IntrospectDBusIface = '<node> \
+  <interface name="org.gnome.Shell.Introspect"> \
+    <signal name="RunningApplicationsChanged" /> \
+    <method name="GetRunningApplications"> \
+      <arg name="apps" direction="out" type="a{sa{sv}}" /> \
+    </method> \
+  </interface> \
+</node>';
+
+var IntrospectService = new Lang.Class({
+    Name: 'IntrospectService',
+
+    _init() {
+        this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(IntrospectDBusIface,
+                                                             this);
+        this._dbusImpl.export(Gio.DBus.session, '/org/gnome/Shell/Introspect');
+        Gio.DBus.session.own_name('org.gnome.Shell.Introspect',
+                                  Gio.BusNameOwnerFlags.REPLACE,
+                                  null, null);
+
+        this._runningApplications = {};
+        this._runningApplicationsDirty = true;
+        this._activeApplication = null;
+        this._activeApplicationDirty = true;
+
+        this._appSystem = Shell.AppSystem.get_default();
+        this._appSystem.connect('app-state-changed',
+                                () => {
+                                    this._runningApplicationsDirty = true;
+                                    this._syncRunningApplications();
+                                });
+
+        this._settings = new Gio.Settings({ schema_id: INTROSPECT_SCHEMA });
+
+        let tracker = Shell.WindowTracker.get_default();
+        tracker.connect('notify::focus-app',
+                        () => {
+                            this._activeApplicationDirty = true;
+                            this._syncRunningApplications();
+                        });
+
+        this._syncRunningApplications();
+    },
+
+    _isStandaloneApp(app) {
+        let windows = app.get_windows();
+
+        return app.get_windows().some(w => w.transient_for == null);
+    },
+
+    _isIntrospectEnabled() {
+       return this._settings.get_boolean(INTROSPECT_KEY);
+    },
+
+    _isSenderWhitelisted(sender) {
+       return APP_WHITELIST.includes(sender);
+    },
+
+    _syncRunningApplications() {
+        let tracker = Shell.WindowTracker.get_default();
+        let apps = this._appSystem.get_running();
+        let seatName = "seat0";
+        let newRunningApplications = {};
+
+        let newActiveApplication = null;
+        let focusedApp = tracker.focus_app;
+
+        for (let app of apps) {
+            let appInfo = {};
+            let isAppActive = (focusedApp == app);
+
+            if (!this._isStandaloneApp(app))
+                continue;
+
+            if (isAppActive) {
+                appInfo['active-on-seats'] = new GLib.Variant('as', [seatName]);
+                newActiveApplication = app.get_id();
+            }
+
+            newRunningApplications[app.get_id()] = appInfo;
+        }
+
+        if (this._runningApplicationsDirty ||
+            (this._activeApplicationDirty &&
+             this._activeApplication != newActiveApplication)) {
+            this._runningApplications = newRunningApplications;
+            this._activeApplication = newActiveApplication;
+
+            this._dbusImpl.emit_signal('RunningApplicationsChanged', null);
+        }
+        this._runningApplicationsDirty = false;
+        this._activeApplicationDirty = false;
+    },
+
+    GetRunningApplicationsAsync(params, invocation) {
+        if (!this._isIntrospectEnabled() &&
+            !this._isSenderWhitelisted(invocation.get_sender())) {
+            invocation.return_error_literal(Gio.DBusError,
+                                            Gio.DBusError.ACCESS_DENIED,
+                                            'App introspection not allowed');
+            return;
+        }
+
+        invocation.return_value(new GLib.Variant('(a{sa{sv}})', [this._runningApplications]));
+    }
+});
diff --git a/js/ui/main.js b/js/ui/main.js
index d86cf9e81..a8779bf09 100644
--- a/js/ui/main.js
+++ b/js/ui/main.js
@@ -20,6 +20,7 @@ const Environment = imports.ui.environment;
 const ExtensionSystem = imports.ui.extensionSystem;
 const ExtensionDownloader = imports.ui.extensionDownloader;
 const InputMethod = imports.misc.inputMethod;
+const Introspect = imports.misc.introspect;
 const Keyboard = imports.ui.keyboard;
 const MessageTray = imports.ui.messageTray;
 const ModalDialog = imports.ui.modalDialog;
@@ -82,6 +83,7 @@ var keyboard = null;
 var layoutManager = null;
 var kbdA11yDialog = null;
 var inputMethod = null;
+var introspectService = null;
 let _startDate;
 let _defaultCssStylesheet = null;
 let _cssStylesheet = null;
@@ -187,6 +189,8 @@ function _initializeUI() {
     windowAttentionHandler = new WindowAttentionHandler.WindowAttentionHandler();
     componentManager = new Components.ComponentManager();
 
+    introspectService = new Introspect.IntrospectService();
+
     layoutManager.init();
     overview.init();