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/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();
         }
     }
 }