seat: set focus before starting transactions

Focus was made double-buffered in 96a91fd. However, much of the code
still behaved as if focus was separate from the transaction system.
This commit completes the work started in 96a91fd and ensures that
focus is applied consistently in a single transaction.

river/Cursor.zig

@@ -48,9 +48,14 @@ const Mode = union(enum) {
     fn enter(self: *Self, mode: @TagType(Mode), event: *c.wlr_event_pointer_button, view: *View) void {
         log.debug(.cursor, "enter {} mode", .{@tagName(mode)});
 
+        self.seat.focus(view);
+
         switch (mode) {
             .passthrough => unreachable,
-            .down => self.mode = .{ .down = view },
+            .down => {
+                self.mode = .{ .down = view };
+                view.output.root.startTransaction();
+            },
             .move, .resize => {
                 const cur_box = &view.current.box;
                 self.mode = switch (mode) {
@@ -366,8 +371,6 @@ fn handleButton(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
         // If the target surface has a view, give that view keyboard focus and
         // perhaps enter move/resize mode.
         if (View.fromWlrSurface(wlr_surface)) |view| {
-            self.seat.focus(view);
-
             if (event.state == .WLR_BUTTON_PRESSED and self.pressed_count == 1) {
                 // If the button is pressed and the pointer modifier is
                 // active, enter cursor mode or close view and return.

river/InputManager.zig

@@ -149,6 +149,8 @@ fn handleInhibitDeactivate(listener: ?*c.wl_listener, data: ?*c_void) callconv(.
     while (seat_it) |seat_node| : (seat_it = seat_node.next) {
         seat_node.data.focus(null);
     }
+
+    self.server.root.startTransaction();
 }
 
 /// This event is raised by the backend when a new input device becomes available.

river/LayerSurface.zig

@@ -154,6 +154,8 @@ fn handleUnmap(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
         const seat = &node.data;
         seat.focus(null);
     }
+
+    self.output.root.startTransaction();
 }
 
 fn handleCommit(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
@@ -181,6 +183,7 @@ fn handleCommit(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
     // TODO: only reconfigure if things haven't changed
     // https://github.com/swaywm/wlroots/issues/1079
     self.output.arrangeLayers();
+    self.output.root.startTransaction();
 }
 
 fn handleNewPopup(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {

river/Output.zig

@@ -304,7 +304,7 @@ pub fn arrangeViews(self: *Self) void {
     var it = ViewStack(View).pendingIterator(self.views.first, self.pending.tags);
     while (it.next()) |node| {
         const view = &node.view;
-        if (!view.pending.float) layout_count += 1;
+        if (!view.pending.float and !view.pending.fullscreen) layout_count += 1;
     }
 
     // If the usable area has a zero dimension, trying to arrange the layout
@@ -394,8 +394,6 @@ pub fn arrangeLayers(self: *Self) void {
             }
         }
     }
-
-    self.root.startTransaction();
 }
 
 /// Arrange the layer surfaces of a given layer
@@ -585,7 +583,7 @@ fn handleDestroy(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
     while (seat_it) |seat_node| : (seat_it = seat_node.next) {
         const seat = &seat_node.data;
         if (seat.focused_output == self) {
-            seat.focusOutput(self);
+            seat.focusOutput(fallback_output);
             seat.focus(null);
         }
     }

river/Root.zig

@@ -241,8 +241,4 @@ fn commitTransaction(self: *Self) void {
 
         if (view_tags_changed) output.sendViewTags();
     }
-
-    // Iterate over all seats and update focus
-    var it = self.server.input_manager.seats.first;
-    while (it) |seat_node| : (it = seat_node.next) seat_node.data.focus(null);
 }

river/Seat.zig

@@ -120,21 +120,21 @@ pub fn focus(self: *Self, _view: ?*View) void {
     // If the view is not currently visible, behave as if null was passed
     if (view) |v| {
         if (v.output != self.focused_output or
-            v.current.tags & self.focused_output.current.tags == 0) view = null;
+            v.pending.tags & self.focused_output.pending.tags == 0) view = null;
     }
 
     // If the target view is not fullscreen or null, then a fullscreen view
     // will grab focus if visible.
-    if (if (view) |v| !v.current.fullscreen else true) {
-        var it = ViewStack(*View).iterator(self.focus_stack.first, self.focused_output.current.tags);
+    if (if (view) |v| !v.pending.fullscreen else true) {
+        var it = ViewStack(*View).pendingIterator(self.focus_stack.first, self.focused_output.pending.tags);
         view = while (it.next()) |node| {
-            if (node.view.output == self.focused_output and node.view.current.fullscreen) break node.view;
+            if (node.view.output == self.focused_output and node.view.pending.fullscreen) break node.view;
         } else view;
     }
 
     if (view == null) {
         // Set view to the first currently visible view in the focus stack if any
-        var it = ViewStack(*View).iterator(self.focus_stack.first, self.focused_output.current.tags);
+        var it = ViewStack(*View).pendingIterator(self.focus_stack.first, self.focused_output.pending.tags);
         view = while (it.next()) |node| {
             if (node.view.output == self.focused_output) break node.view;
         } else null;
@@ -223,9 +223,6 @@ pub fn setFocusRaw(self: *Self, new_focus: FocusTarget) void {
     // Inform any clients tracking status of the change
     var it = self.status_trackers.first;
     while (it) |node| : (it = node.next) node.data.sendFocusedView();
-
-    // Start a transaction to apply the pending focus state
-    self.input_manager.server.root.startTransaction();
 }
 
 /// Focus the given output, notifying any listening clients of the change.

river/View.zig

@@ -351,7 +351,8 @@ pub fn map(self: *Self) void {
 
     self.output.sendViewTags();
 
-    self.output.arrangeViews();
+    if (!self.current.float) self.output.arrangeViews();
+
     self.output.root.startTransaction();
 }
 
@@ -377,11 +378,10 @@ pub fn unmap(self: *Self) void {
     self.output.sendViewTags();
 
     // Still need to arrange if fullscreened from the layout
-    if (!self.current.float) {
-        self.output.arrangeViews();
+    if (!self.current.float) self.output.arrangeViews();
+
     root.startTransaction();
 }
-}
 
 /// Destory the view and free the ViewStack node holding it.
 pub fn destroy(self: *const Self) void {

river/command/focus_view.zig

@@ -53,6 +53,7 @@ pub fn focusView(
         // Focus the next visible node if there is one
         if (it.next()) |node| {
             seat.focus(&node.view);
+            output.root.startTransaction();
             return;
         }
     }
@@ -65,4 +66,5 @@ pub fn focusView(
     };
 
     seat.focus(if (it.next()) |node| &node.view else null);
+    output.root.startTransaction();
 }

river/command/tags.zig

@@ -31,6 +31,7 @@ pub fn setFocusedTags(
     if (seat.focused_output.pending.tags != tags) {
         seat.focused_output.pending.tags = tags;
         seat.focused_output.arrangeViews();
+        seat.focus(null);
         seat.focused_output.root.startTransaction();
     }
 }
@@ -44,8 +45,10 @@ pub fn setViewTags(
 ) Error!void {
     const tags = try parseTags(allocator, args, out);
     if (seat.focused == .view) {
-        seat.focused.view.pending.tags = tags;
-        seat.focused.view.applyPending();
+        const view = seat.focused.view;
+        view.pending.tags = tags;
+        seat.focus(null);
+        view.applyPending();
     }
 }
 
@@ -62,6 +65,7 @@ pub fn toggleFocusedTags(
     if (new_focused_tags != 0) {
         output.pending.tags = new_focused_tags;
         output.arrangeViews();
+        seat.focus(null);
         output.root.startTransaction();
     }
 }
@@ -75,10 +79,12 @@ pub fn toggleViewTags(
 ) Error!void {
     const tags = try parseTags(allocator, args, out);
     if (seat.focused == .view) {
-        const new_tags = seat.focused.view.current.tags ^ tags;
+        const new_tags = seat.focused.view.pending.tags ^ tags;
         if (new_tags != 0) {
-            seat.focused.view.pending.tags = new_tags;
-            seat.focused.view.applyPending();
+            const view = seat.focused.view;
+            view.pending.tags = new_tags;
+            seat.focus(null);
+            view.applyPending();
         }
     }
 }