xdg-activation: add focus stealing prevention when using tokens

metadata/xdg-activation.xml

@@ -14,6 +14,11 @@
 			<_long>Whether to reject activation requests if a newer request has arrived since their creation.</_long>
 			<default>false</default>
 		</option>
+		<option name="focus_stealing_prevention" type="bool">
+			<_short>Prevent stealing focus by an activation request</_short>
+			<_long>Whether to reject an activation request if the user interacted with a different view since its creation.</_long>
+			<default>true</default>
+		</option>
 		<option name="timeout" type="int">
 			<_short>Timeout for activation (in seconds)</_short>
 			<_long>Focus requests will be ignored if at least this amount of time has elapsed between creating and using it.</_long>

plugins/protocols/xdg-activation.cpp

@@ -35,6 +35,12 @@ class wayfire_xdg_activation_protocol_impl : public wf::plugin_interface_t
         xdg_activation_new_token.disconnect();
         xdg_activation_token_destroy.disconnect();
         last_token = nullptr;
+        if (last_view)
+        {
+            last_view->disconnect(&on_view_unmapped);
+            last_view->disconnect(&on_view_deactivated);
+            last_view = nullptr;
+        }
     }
 
     bool is_unloadable() override
@@ -63,6 +69,17 @@ class wayfire_xdg_activation_protocol_impl : public wf::plugin_interface_t
 
             last_token = nullptr; // avoid reusing the same token
 
+            if (last_view)
+            {
+                last_view->disconnect(&on_view_unmapped);
+                last_view->disconnect(&on_view_deactivated);
+                last_view = nullptr;
+            } else if (prevent_focus_stealing)
+            {
+                LOGI("Denying focus request, requesting view has been deactivated");
+                return;
+            }
+
             wayfire_view view = wf::wl_surface_to_wayfire_view(event->surface->resource);
             if (!view)
             {
@@ -99,6 +116,25 @@ class wayfire_xdg_activation_protocol_impl : public wf::plugin_interface_t
                 return;
             }
 
+            // unset any previously saved view
+            if (last_view)
+            {
+                last_view->disconnect(&on_view_unmapped);
+                last_view->disconnect(&on_view_deactivated);
+                last_view = nullptr;
+            }
+
+            wayfire_view view = wf::wl_surface_to_wayfire_view(token->surface->resource);
+            if (view)
+            {
+                last_view = wf::toplevel_cast(view); // might return nullptr
+                if (last_view)
+                {
+                    last_view->connect(&on_view_unmapped);
+                    last_view->connect(&on_view_deactivated);
+                }
+            }
+
             // update our token and connect its destroy signal
             last_token = token;
             xdg_activation_token_destroy.disconnect();
@@ -128,14 +164,43 @@ class wayfire_xdg_activation_protocol_impl : public wf::plugin_interface_t
         }
     };
 
+    wf::signal::connection_t<wf::view_unmapped_signal> on_view_unmapped = [this] (auto)
+    {
+        last_view->disconnect(&on_view_unmapped);
+        last_view->disconnect(&on_view_deactivated);
+        // handle the case when last_view was a dialog that is closed by user interaction
+        last_view = last_view->parent;
+        if (last_view)
+        {
+            last_view->connect(&on_view_unmapped);
+            last_view->connect(&on_view_deactivated);
+        }
+    };
+
+    wf::signal::connection_t<wf::view_activated_state_signal> on_view_deactivated = [this] (auto)
+    {
+        if (last_view->activated)
+        {
+            // could be a spurious event, e.g. activating the parent
+            // view after closing a dialog
+            return;
+        }
+
+        last_view->disconnect(&on_view_unmapped);
+        last_view->disconnect(&on_view_deactivated);
+        last_view = nullptr;
+    };
+
     struct wlr_xdg_activation_v1 *xdg_activation;
     wf::wl_listener_wrapper xdg_activation_request_activate;
     wf::wl_listener_wrapper xdg_activation_new_token;
     wf::wl_listener_wrapper xdg_activation_token_destroy;
     struct wlr_xdg_activation_token_v1 *last_token = nullptr;
+    wayfire_toplevel_view last_view = nullptr; // view that created the token
 
     wf::option_wrapper_t<bool> check_surface{"xdg-activation/check_surface"};
     wf::option_wrapper_t<bool> only_last_token{"xdg-activation/only_last_request"};
+    wf::option_wrapper_t<bool> prevent_focus_stealing{"xdg-activation/focus_stealing_prevention"};
     wf::option_wrapper_t<int> timeout{"xdg-activation/timeout"};
 };