seat: always add view to focus stack on map

Currently if a view is mapped while some other view is fullscreen, it
will not be added to the focus stack, which means that if the fullscreen
view is then closed the view which was not added to the focus stack will
not be focused.

To fix this, always add views to the focus stack on map.

river/InputManager.zig

@@ -161,15 +161,6 @@ pub fn defaultSeat(self: Self) *Seat {
     return &self.seats.first.?.data;
 }
 
-/// Must be called whenever a view is unmapped.
-pub fn handleViewUnmap(self: Self, view: *View) void {
-    var it = self.seats.first;
-    while (it) |node| : (it = node.next) {
-        const seat = &node.data;
-        seat.handleViewUnmap(view);
-    }
-}
-
 /// Returns true if input is currently allowed on the passed surface.
 pub fn inputAllowed(self: Self, wlr_surface: *wlr.Surface) bool {
     return if (self.exclusive_client) |exclusive_client|

river/Seat.zig

@@ -149,27 +149,22 @@ pub fn focus(self: *Self, _target: ?*View) void {
         } else null;
     }
 
+    // Focus the target view or clear the focus if target is null
     if (target) |view| {
-        // Find or allocate a new node in the focus stack for the target view
+        // Find the node for this view in the focus stack and move it to the top.
         var it = self.focus_stack.first;
         while (it) |node| : (it = node.next) {
-            // If the view is found, move it to the top of the stack
             if (node.view == view) {
                 const new_focus_node = self.focus_stack.remove(node);
                 self.focus_stack.push(node);
                 break;
             }
         } else {
-            // The view is not in the stack, so allocate a new node and prepend it
-            const new_focus_node = util.gpa.create(ViewStack(*View).Node) catch return;
-            new_focus_node.view = view;
-            self.focus_stack.push(new_focus_node);
+            // A node is added when new Views are mapped in Seat.handleViewMap()
+            unreachable;
         }
-
-        // Focus the target view
         self.setFocusRaw(.{ .view = view });
     } else {
-        // Otherwise clear the focus
         self.setFocusRaw(.{ .none = {} });
     }
 }
@@ -288,6 +283,13 @@ pub fn handleActivity(self: Self) void {
     server.input_manager.idle.notifyActivity(self.wlr_seat);
 }
 
+pub fn handleViewMap(self: *Self, view: *View) !void {
+    const new_focus_node = try util.gpa.create(ViewStack(*View).Node);
+    new_focus_node.view = view;
+    self.focus_stack.append(new_focus_node);
+    self.focus(view);
+}
+
 /// Handle the unmapping of a view, removing it from the focus stack and
 /// setting the focus if needed.
 pub fn handleViewUnmap(self: *Self, view: *View) void {

river/View.zig

@@ -429,36 +429,30 @@ pub fn shouldTrackConfigure(self: Self) bool {
 }
 
 /// Called by the impl when the surface is ready to be displayed
-pub fn map(self: *Self) void {
+pub fn map(self: *Self) !void {
     log.debug("view '{s}' mapped", .{self.getTitle()});
 
     if (self.foreign_toplevel_handle == null) {
-        self.foreign_toplevel_handle = wlr.ForeignToplevelHandleV1.create(
-            server.foreign_toplevel_manager,
-        ) catch {
-            log.crit("out of memory", .{});
-            self.surface.?.resource.getClient().postNoMemory();
-            return;
-        };
+        const handle = try wlr.ForeignToplevelHandleV1.create(server.foreign_toplevel_manager);
+        self.foreign_toplevel_handle = handle;
 
-        self.foreign_toplevel_handle.?.events.request_activate.add(&self.foreign_activate);
-        self.foreign_toplevel_handle.?.events.request_fullscreen.add(&self.foreign_fullscreen);
-        self.foreign_toplevel_handle.?.events.request_close.add(&self.foreign_close);
+        handle.events.request_activate.add(&self.foreign_activate);
+        handle.events.request_fullscreen.add(&self.foreign_fullscreen);
+        handle.events.request_close.add(&self.foreign_close);
 
-        if (self.getTitle()) |s| self.foreign_toplevel_handle.?.setTitle(s);
-        if (self.getAppId()) |s| self.foreign_toplevel_handle.?.setAppId(s);
+        if (self.getTitle()) |s| handle.setTitle(s);
+        if (self.getAppId()) |s| handle.setAppId(s);
 
-        self.foreign_toplevel_handle.?.outputEnter(self.output.wlr_output);
+        handle.outputEnter(self.output.wlr_output);
     }
 
     // Add the view to the stack of its output
     const node = @fieldParentPtr(ViewStack(Self).Node, "view", self);
     self.output.views.attach(node, server.config.attach_mode);
 
-    // Focus the new view, assuming the seat is focusing the proper output
-    // and there isn't something else like a fullscreen view grabbing focus.
+    // Inform all seats that the view has been mapped so they can handle focus
     var it = server.input_manager.seats.first;
-    while (it) |seat_node| : (it = seat_node.next) seat_node.data.focus(self);
+    while (it) |seat_node| : (it = seat_node.next) try seat_node.data.handleViewMap(self);
 
     self.surface.?.sendEnter(self.output.wlr_output);
 
@@ -480,10 +474,7 @@ pub fn unmap(self: *Self) void {
 
     // Inform all seats that the view has been unmapped so they can handle focus
     var it = server.input_manager.seats.first;
-    while (it) |node| : (it = node.next) {
-        const seat = &node.data;
-        seat.handleViewUnmap(self);
-    }
+    while (it) |seat_node| : (it = seat_node.next) seat_node.data.handleViewUnmap(self);
 
     self.output.sendViewTags();
 

river/XdgToplevel.zig

@@ -231,7 +231,10 @@ fn handleMap(listener: *wl.Listener(*wlr.XdgSurface), xdg_surface: *wlr.XdgSurfa
         _ = toplevel.setTiled(.{ .top = true, .bottom = true, .left = true, .right = true });
     }
 
-    view.map();
+    view.map() catch {
+        log.crit("out of memory", .{});
+        xdg_surface.resource.getClient().postNoMemory();
+    };
 }
 
 /// Called when the surface is unmapped and will no longer be displayed.

river/XwaylandView.zig

@@ -207,7 +207,10 @@ fn handleMap(listener: *wl.Listener(*wlr.XwaylandSurface), xwayland_surface: *wl
         }
     }
 
-    view.map();
+    view.map() catch {
+        std.log.crit("out of memory", .{});
+        surface.resource.getClient().postNoMemory();
+    };
 }
 
 /// Called when the surface is unmapped and will no longer be displayed.