[gnome-shell] locatePointer: Add implementation in gnome-shell

[Carlos Garnacho <carlosg src gnome org>]

commit 443c8347eaa6be143bb07a0f1960539d247bccff
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Wed Feb 20 10:12:36 2019 +0100

    locatePointer: Add implementation in gnome-shell
    
    The "locate pointer" functionality was implemented in gnome settings
    daemon using X11 protocols and would fail when run under Wayland.
    
    With Wayland, there is no global coordinate space exposed to the clients
    so this functionality cannot be implemented as a separate program.
    
    Instead, add the "locate pointer" functionality in gnome-shell so that
    it works in both X11 and Wayland.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/981
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/413
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/453
    https://gitlab.gnome.org/GNOME/gsettings-desktop-schemas/merge_requests/19
    https://gitlab.gnome.org/GNOME/gnome-settings-daemon/merge_requests/86

 data/theme/gnome-shell-sass/_common.scss |  9 +++++++++
 js/js-resources.gresource.xml            |  1 +
 js/ui/locatePointer.js                   | 24 ++++++++++++++++++++++++
 js/ui/main.js                            | 10 ++++++++++
 src/gnome-shell-plugin.c                 |  9 +++++++++
 src/shell-global-private.h               |  2 ++
 src/shell-global.c                       | 14 ++++++++++++++
 7 files changed, 69 insertions(+)
---
diff --git a/data/theme/gnome-shell-sass/_common.scss b/data/theme/gnome-shell-sass/_common.scss
index 64cc612aa..c8c53d557 100644
--- a/data/theme/gnome-shell-sass/_common.scss
+++ b/data/theme/gnome-shell-sass/_common.scss
@@ -1159,6 +1159,15 @@ StScrollBar {
   border: 1px solid $selected_bg_color;
 }
 
+// Pointer location
+.ripple-pointer-location {
+  width: 50px;
+  height: 50px;
+  border-radius: 25px 25px 25px 25px; // radius the size of the box give us the curve
+  background-color: lighten(transparentize($selected_bg_color, 0.7), 30%);
+  box-shadow: 0 0 2px 2px lighten($selected_bg_color, 20%);
+}
+
 // not really top bar only
 .popup-menu-arrow { icon-size: 1.09em; }
 .popup-menu-icon { icon-size: 1.09em; }
diff --git a/js/js-resources.gresource.xml b/js/js-resources.gresource.xml
index 135b8e885..7807cce9d 100644
--- a/js/js-resources.gresource.xml
+++ b/js/js-resources.gresource.xml
@@ -64,6 +64,7 @@
     <file>ui/keyboard.js</file>
     <file>ui/layout.js</file>
     <file>ui/lightbox.js</file>
+    <file>ui/locatePointer.js</file>
     <file>ui/lookingGlass.js</file>
     <file>ui/magnifier.js</file>
     <file>ui/magnifierDBus.js</file>
diff --git a/js/ui/locatePointer.js b/js/ui/locatePointer.js
new file mode 100644
index 000000000..52a0bc486
--- /dev/null
+++ b/js/ui/locatePointer.js
@@ -0,0 +1,24 @@
+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
+
+const { Clutter, Gio, GLib, St } = imports.gi;
+const Ripples = imports.ui.ripples;
+const Main = imports.ui.main;
+
+const LOCATE_POINTER_KEY = "locate-pointer";
+const LOCATE_POINTER_SCHEMA = "org.gnome.desktop.interface"
+
+var locatePointer = class {
+    constructor() {
+        this._settings = new Gio.Settings({schema_id: LOCATE_POINTER_SCHEMA});
+        this._ripples = new Ripples.Ripples(0.5, 0.5, 'ripple-pointer-location');
+        this._ripples.addTo(Main.uiGroup);
+    }
+
+    show() {
+        if (!this._settings.get_boolean("locate-pointer"))
+            return;
+
+        let [x, y, mods] = global.get_pointer();
+        this._ripples.playAnimation(x, y);
+    }
+};
diff --git a/js/ui/main.js b/js/ui/main.js
index d9f287cd9..b3cd69283 100644
--- a/js/ui/main.js
+++ b/js/ui/main.js
@@ -37,6 +37,7 @@ const WindowManager = imports.ui.windowManager;
 const Magnifier = imports.ui.magnifier;
 const XdndHandler = imports.ui.xdndHandler;
 const KbdA11yDialog = imports.ui.kbdA11yDialog;
+const LocatePointer = imports.ui.locatePointer;
 
 const A11Y_SCHEMA = 'org.gnome.desktop.a11y.keyboard';
 const STICKY_KEYS_ENABLE = 'stickykeys-enable';
@@ -74,6 +75,7 @@ var layoutManager = null;
 var kbdA11yDialog = null;
 var inputMethod = null;
 var introspectService = null;
+var locatePointer = null;
 let _startDate;
 let _defaultCssStylesheet = null;
 let _cssStylesheet = null;
@@ -92,6 +94,8 @@ function _sessionUpdated() {
     wm.allowKeybinding('overlay-key', Shell.ActionMode.NORMAL |
                                       Shell.ActionMode.OVERVIEW);
 
+    wm.allowKeybinding('locate-pointer-key', Shell.ActionMode.ALL);
+
     wm.setCustomKeybindingHandler('panel-run-dialog',
                                   Shell.ActionMode.NORMAL |
                                   Shell.ActionMode.OVERVIEW,
@@ -165,6 +169,8 @@ function _initializeUI() {
     kbdA11yDialog = new KbdA11yDialog.KbdA11yDialog();
     wm = new WindowManager.WindowManager();
     magnifier = new Magnifier.Magnifier();
+    locatePointer = new LocatePointer.locatePointer();
+
     if (LoginManager.canLock())
         screenShield = new ScreenShield.ScreenShield();
 
@@ -190,6 +196,10 @@ function _initializeUI() {
             overview.toggle();
     });
 
+    global.connect('locate-pointer', () => {
+        locatePointer.show();
+    });
+
     global.display.connect('show-restart-message', (display, message) => {
         showRestartMessage(message);
         return true;
diff --git a/src/gnome-shell-plugin.c b/src/gnome-shell-plugin.c
index 35a9a8bcb..2e491646c 100644
--- a/src/gnome-shell-plugin.c
+++ b/src/gnome-shell-plugin.c
@@ -346,6 +346,13 @@ gnome_shell_plugin_create_inhibit_shortcuts_dialog (MetaPlugin *plugin,
   return _shell_wm_create_inhibit_shortcuts_dialog (get_shell_wm (), window);
 }
 
+static void
+gnome_shell_plugin_locate_pointer (MetaPlugin *plugin)
+{
+  GnomeShellPlugin *shell_plugin = GNOME_SHELL_PLUGIN (plugin);
+  _shell_global_locate_pointer (shell_plugin->global);
+}
+
 static void
 gnome_shell_plugin_class_init (GnomeShellPluginClass *klass)
 {
@@ -378,6 +385,8 @@ gnome_shell_plugin_class_init (GnomeShellPluginClass *klass)
 
   plugin_class->create_close_dialog = gnome_shell_plugin_create_close_dialog;
   plugin_class->create_inhibit_shortcuts_dialog = gnome_shell_plugin_create_inhibit_shortcuts_dialog;
+
+  plugin_class->locate_pointer = gnome_shell_plugin_locate_pointer;
 }
 
 static void
diff --git a/src/shell-global-private.h b/src/shell-global-private.h
index df53236aa..9969691cb 100644
--- a/src/shell-global-private.h
+++ b/src/shell-global-private.h
@@ -18,4 +18,6 @@ GjsContext *_shell_global_get_gjs_context (ShellGlobal  *global);
 gboolean _shell_global_check_xdnd_event (ShellGlobal  *global,
                                          XEvent       *xev);
 
+void _shell_global_locate_pointer (ShellGlobal  *global);
+
 #endif /* __SHELL_GLOBAL_PRIVATE_H__ */
diff --git a/src/shell-global.c b/src/shell-global.c
index 293053d0b..70120c2da 100644
--- a/src/shell-global.c
+++ b/src/shell-global.c
@@ -115,6 +115,7 @@ enum {
 enum
 {
  NOTIFY_ERROR,
+ LOCATE_POINTER,
  LAST_SIGNAL
 };
 
@@ -357,6 +358,13 @@ shell_global_class_init (ShellGlobalClass *klass)
                     G_TYPE_NONE, 2,
                     G_TYPE_STRING,
                     G_TYPE_STRING);
+  shell_global_signals[LOCATE_POINTER] =
+      g_signal_new ("locate-pointer",
+                    G_TYPE_FROM_CLASS (klass),
+                    G_SIGNAL_RUN_LAST,
+                    0,
+                    NULL, NULL, NULL,
+                    G_TYPE_NONE, 0);
 
   g_object_class_install_property (gobject_class,
                                    PROP_SESSION_MODE,
@@ -1732,3 +1740,9 @@ shell_global_get_persistent_state (ShellGlobal  *global,
 {
   return load_variant (global->userdatadir_path, property_type, property_name);
 }
+
+void
+_shell_global_locate_pointer (ShellGlobal *global)
+{
+  g_signal_emit (global, shell_global_signals[LOCATE_POINTER], 0);
+}