remote-desktop/session: Add regions for all monitors if input-only

If we're a input-only remote desktop session, create libei regions on an
absolute pointer device corresponding to all logical monitors. This
allows absolute pointer motions without screen casting.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3228>

src/backends/meta-eis-client.c

@@ -272,8 +272,8 @@ add_viewport_region (struct eis_device *eis_device,
   eis_region_set_physical_scale (eis_region, scale);
 
   mapping_id = meta_eis_viewport_get_mapping_id (viewport);
-  g_warn_if_fail (mapping_id);
-  eis_region_set_mapping_id (eis_region, mapping_id);
+  if (mapping_id)
+    eis_region_set_mapping_id (eis_region, mapping_id);
 
   eis_region_set_user_data (eis_region, viewport);
   eis_region_add (eis_region);

src/backends/meta-eis.c

@@ -331,6 +331,21 @@ meta_eis_remove_viewport (MetaEis         *eis,
   g_signal_emit (eis, signals[VIEWPORTS_CHANGED], 0);
 }
 
+void
+meta_eis_take_viewports (MetaEis *eis,
+                         GList   *viewports)
+{
+  eis->viewports = g_list_concat (eis->viewports, viewports);
+  g_signal_emit (eis, signals[VIEWPORTS_CHANGED], 0);
+}
+
+void
+meta_eis_remove_all_viewports (MetaEis *eis)
+{
+  g_clear_pointer (&eis->viewports, g_list_free);
+  g_signal_emit (eis, signals[VIEWPORTS_CHANGED], 0);
+}
+
 GList *
 meta_eis_peek_viewports (MetaEis *eis)
 {

src/backends/meta-eis.h

@@ -50,6 +50,11 @@ void meta_eis_add_viewport (MetaEis         *eis,
 void meta_eis_remove_viewport (MetaEis         *eis,
                                MetaEisViewport *viewport);
 
+void meta_eis_take_viewports (MetaEis *eis,
+                              GList   *viewports);
+
+void meta_eis_remove_all_viewports (MetaEis *eis);
+
 GList * meta_eis_peek_viewports (MetaEis *eis);
 
 MetaEisDeviceTypes meta_eis_get_device_types (MetaEis *eis);

src/backends/meta-remote-desktop-session.c

@@ -34,6 +34,7 @@
 #include "backends/meta-dbus-session-watcher.h"
 #include "backends/meta-dbus-session-manager.h"
 #include "backends/meta-eis.h"
+#include "backends/meta-logical-monitor.h"
 #include "backends/meta-screen-cast-session.h"
 #include "backends/meta-remote-access-controller-private.h"
 #include "backends/x11/meta-backend-x11.h"
@@ -104,6 +105,8 @@ struct _MetaRemoteDesktopSession
   guint transfer_request_timeout_id;
 
   GHashTable *mapping_ids;
+
+  gulong monitors_changed_handler_id;
 };
 
 static void initable_init_iface (GInitableIface *iface);
@@ -135,9 +138,124 @@ G_DEFINE_TYPE (MetaRemoteDesktopSessionHandle,
                meta_remote_desktop_session_handle,
                META_TYPE_REMOTE_ACCESS_HANDLE)
 
+struct _MetaLogicalMonitorViewport
+{
+  GObject parent;
+
+  MetaLogicalMonitor *logical_monitor;
+};
+
+#define META_TYPE_LOGICAL_MONITOR_VIEWPORT (meta_logical_monitor_viewport_get_type ())
+G_DECLARE_FINAL_TYPE (MetaLogicalMonitorViewport, meta_logical_monitor_viewport,
+                      META, LOGICAL_MONITOR_VIEWPORT,
+                      GObject)
+
+static void meta_eis_viewport_init_iface (MetaEisViewportInterface *iface);
+
+G_DEFINE_FINAL_TYPE_WITH_CODE (MetaLogicalMonitorViewport,
+                               meta_logical_monitor_viewport,
+                               G_TYPE_OBJECT,
+                               G_IMPLEMENT_INTERFACE (META_TYPE_EIS_VIEWPORT,
+                                                      meta_eis_viewport_init_iface))
+
 static MetaRemoteDesktopSessionHandle *
 meta_remote_desktop_session_handle_new (MetaRemoteDesktopSession *session);
 
+static gboolean
+meta_logical_monitor_viewport_is_standalone (MetaEisViewport *viewport)
+{
+  return FALSE;
+}
+
+static const char *
+meta_logical_monitor_viewport_get_mapping_id (MetaEisViewport *viewport)
+{
+  return NULL;
+}
+
+static gboolean
+meta_logical_monitor_viewport_get_position (MetaEisViewport *viewport,
+                                            int             *out_x,
+                                            int             *out_y)
+{
+  MetaLogicalMonitorViewport *logical_monitor_viewport =
+    META_LOGICAL_MONITOR_VIEWPORT (viewport);
+  MtkRectangle layout;
+
+  layout = meta_logical_monitor_get_layout (logical_monitor_viewport->logical_monitor);
+  *out_x = layout.x;
+  *out_y = layout.y;
+  return TRUE;
+}
+
+static void
+meta_logical_monitor_viewport_get_size (MetaEisViewport *viewport,
+                                        int             *out_width,
+                                        int             *out_height)
+{
+  MetaLogicalMonitorViewport *logical_monitor_viewport =
+    META_LOGICAL_MONITOR_VIEWPORT (viewport);
+  MtkRectangle layout;
+
+  layout = meta_logical_monitor_get_layout (logical_monitor_viewport->logical_monitor);
+  *out_width = layout.width;
+  *out_height = layout.height;
+}
+
+static double
+meta_logical_monitor_viewport_get_physical_scale (MetaEisViewport *viewport)
+{
+  MetaLogicalMonitorViewport *logical_monitor_viewport =
+    META_LOGICAL_MONITOR_VIEWPORT (viewport);
+
+  return meta_logical_monitor_get_scale (logical_monitor_viewport->logical_monitor);
+}
+
+static gboolean
+meta_logical_monitor_viewport_transform_coordinate (MetaEisViewport *viewport,
+                                                    double           x,
+                                                    double           y,
+                                                    double          *out_x,
+                                                    double          *out_y)
+{
+  *out_x = x;
+  *out_y = y;
+  return TRUE;
+}
+
+static void
+meta_eis_viewport_init_iface (MetaEisViewportInterface *eis_viewport_iface)
+{
+  eis_viewport_iface->is_standalone = meta_logical_monitor_viewport_is_standalone;
+  eis_viewport_iface->get_mapping_id = meta_logical_monitor_viewport_get_mapping_id;
+  eis_viewport_iface->get_position = meta_logical_monitor_viewport_get_position;
+  eis_viewport_iface->get_size = meta_logical_monitor_viewport_get_size;
+  eis_viewport_iface->get_physical_scale = meta_logical_monitor_viewport_get_physical_scale;
+  eis_viewport_iface->transform_coordinate = meta_logical_monitor_viewport_transform_coordinate;
+}
+
+static void
+meta_logical_monitor_viewport_class_init (MetaLogicalMonitorViewportClass *klass)
+{
+}
+
+static void
+meta_logical_monitor_viewport_init (MetaLogicalMonitorViewport *logical_monitor_viewport)
+{
+}
+
+static MetaLogicalMonitorViewport *
+meta_logical_monitor_viewport_new (MetaLogicalMonitor *logical_monitor)
+{
+  MetaLogicalMonitorViewport *logical_monitor_viewport;
+
+  logical_monitor_viewport = g_object_new (META_TYPE_LOGICAL_MONITOR_VIEWPORT,
+                                           NULL);
+  logical_monitor_viewport->logical_monitor = logical_monitor;
+
+  return logical_monitor_viewport;
+}
+
 static MetaDisplay *
 display_from_session (MetaRemoteDesktopSession *session)
 {
@@ -219,6 +337,40 @@ on_stream_removed (MetaScreenCastSession    *screen_cast_session,
   meta_eis_remove_viewport (session->eis, META_EIS_VIEWPORT (stream));
 }
 
+static void
+add_logical_monitor_viewports (MetaRemoteDesktopSession *session)
+{
+  MetaBackend *backend =
+    meta_dbus_session_manager_get_backend (session->session_manager);
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  GList *logical_monitors;
+  GList *l;
+  GList *viewports = NULL;
+
+  logical_monitors =
+    meta_monitor_manager_get_logical_monitors (monitor_manager);
+  for (l = logical_monitors; l; l = l->next)
+    {
+      MetaLogicalMonitor *logical_monitor = l->data;
+      MetaLogicalMonitorViewport *logical_monitor_viewport;
+
+      logical_monitor_viewport =
+        meta_logical_monitor_viewport_new (logical_monitor);
+      viewports = g_list_append (viewports, logical_monitor_viewport);
+    }
+
+  meta_eis_remove_all_viewports (session->eis);
+  meta_eis_take_viewports (session->eis, viewports);
+}
+
+static void
+on_monitors_changed (MetaMonitorManager       *monitor_manager,
+                     MetaRemoteDesktopSession *session)
+{
+  add_logical_monitor_viewports (session);
+}
+
 static void
 initialize_viewports (MetaRemoteDesktopSession *session)
 {
@@ -245,6 +397,18 @@ initialize_viewports (MetaRemoteDesktopSession *session)
                         G_CALLBACK (on_stream_removed),
                         session);
     }
+  else
+    {
+      MetaBackend *backend =
+        meta_dbus_session_manager_get_backend (session->session_manager);
+      MetaMonitorManager *monitor_manager =
+        meta_backend_get_monitor_manager (backend);
+
+      add_logical_monitor_viewports (session);
+      session->monitors_changed_handler_id =
+        g_signal_connect (monitor_manager, "monitors-changed",
+                          G_CALLBACK (on_monitors_changed), session);
+    }
 }
 
 static gboolean
@@ -275,6 +439,10 @@ meta_remote_desktop_session_close (MetaDbusSession *dbus_session)
     META_REMOTE_DESKTOP_SESSION (dbus_session);
   MetaDBusRemoteDesktopSession *skeleton =
     META_DBUS_REMOTE_DESKTOP_SESSION (session);
+  MetaBackend *backend =
+    meta_dbus_session_manager_get_backend (session->session_manager);
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
 
   session->started = FALSE;
 
@@ -289,6 +457,9 @@ meta_remote_desktop_session_close (MetaDbusSession *dbus_session)
       session->screen_cast_session = NULL;
     }
 
+  g_clear_signal_handler (&session->monitors_changed_handler_id,
+                          monitor_manager);
+
   g_clear_object (&session->virtual_pointer);
   g_clear_object (&session->virtual_keyboard);
   g_clear_object (&session->virtual_touchscreen);