root: refactor transaction initiation

- require the caller to use Root.startTransaction() directly
- introduce View.applyPending() to unify logic
- introduce View.shouldTrackConfigure() to unify more logic
- update all callsites to intelligently rearrange only what is necessary

river/command/config.zig

@@ -31,7 +31,8 @@ pub fn borderWidth(
 
     const server = seat.input_manager.server;
     server.config.border_width = try std.fmt.parseInt(u32, args[1], 10);
-    server.root.arrange();
+    server.root.arrangeAll();
+    server.root.startTransaction();
 }
 
 pub fn viewPadding(
@@ -45,7 +46,8 @@ pub fn viewPadding(
 
     const server = seat.input_manager.server;
     server.config.view_padding = try std.fmt.parseInt(u32, args[1], 10);
-    server.root.arrange();
+    server.root.arrangeAll();
+    server.root.startTransaction();
 }
 
 pub fn outerPadding(
@@ -59,7 +61,8 @@ pub fn outerPadding(
 
     const server = seat.input_manager.server;
     server.config.outer_padding = try std.fmt.parseInt(u32, args[1], 10);
-    server.root.arrange();
+    server.root.arrangeAll();
+    server.root.startTransaction();
 }
 
 pub fn backgroundColor(

river/command/mod_master_count.zig

@@ -33,5 +33,6 @@ pub fn modMasterCount(
     const delta = try std.fmt.parseInt(i32, args[1], 10);
     const output = seat.focused_output;
     output.master_count = @intCast(u32, std.math.max(0, @intCast(i32, output.master_count) + delta));
-    seat.input_manager.server.root.arrange();
+    output.arrangeViews();
+    output.root.startTransaction();
 }

river/command/mod_master_factor.zig

@@ -35,6 +35,7 @@ pub fn modMasterFactor(
     const new_master_factor = std.math.min(std.math.max(output.master_factor + delta, 0.05), 0.95);
     if (new_master_factor != output.master_factor) {
         output.master_factor = new_master_factor;
-        seat.input_manager.server.root.arrange();
+        output.arrangeViews();
+        output.root.startTransaction();
     }
 }

river/command/send_to_output.zig

@@ -54,7 +54,9 @@ pub fn sendToOutput(
         seat.focused.view.sendToOutput(destination_output);
 
         // Handle the change and focus whatever's next in the focus stack
-        root.arrange();
         seat.focus(null);
+        seat.focused_output.arrangeViews();
+        destination_output.arrangeViews();
+        root.startTransaction();
     }
 }

river/command/tags.zig

@@ -30,7 +30,8 @@ pub fn setFocusedTags(
     const tags = try parseTags(allocator, args, out);
     if (seat.focused_output.pending.tags != tags) {
         seat.focused_output.pending.tags = tags;
-        seat.input_manager.server.root.arrange();
+        seat.focused_output.arrangeViews();
+        seat.focused_output.root.startTransaction();
     }
 }
 
@@ -44,7 +45,7 @@ pub fn setViewTags(
     const tags = try parseTags(allocator, args, out);
     if (seat.focused == .view) {
         seat.focused.view.pending.tags = tags;
-        seat.focused.view.output.root.arrange();
+        seat.focused.view.applyPending();
     }
 }
 
@@ -60,7 +61,8 @@ pub fn toggleFocusedTags(
     const new_focused_tags = output.pending.tags ^ tags;
     if (new_focused_tags != 0) {
         output.pending.tags = new_focused_tags;
-        seat.input_manager.server.root.arrange();
+        output.arrangeViews();
+        output.root.startTransaction();
     }
 }
 
@@ -76,7 +78,7 @@ pub fn toggleViewTags(
         const new_tags = seat.focused.view.current.tags ^ tags;
         if (new_tags != 0) {
             seat.focused.view.pending.tags = new_tags;
-            seat.focused.view.output.root.arrange();
+            seat.focused.view.applyPending();
         }
     }
 }

river/command/toggle_float.zig

@@ -40,18 +40,6 @@ pub fn toggleFloat(
         if (seat.input_manager.isCursorActionTarget(view)) return;
 
         view.pending.float = !view.pending.float;
-
-        if (view.pending.float) {
-            // If switching from layout to float, restore the previous floating
-            // dimensions.
-            view.pending.box = view.float_box;
-            view.configure();
-        } else {
-            // If switching from float to layout save the floating dimensions
-            // for next time.
-            view.float_box = view.current.box;
-        }
-
-        view.output.root.arrange();
+        view.applyPending();
     }
 }

river/command/toggle_fullscreen.zig

@@ -38,6 +38,7 @@ pub fn toggleFullscreen(
         // Don't modify views which are the target of a cursor action
         if (seat.input_manager.isCursorActionTarget(view)) return;
 
-        view.setFullscreen(!view.pending.fullscreen);
+        view.pending.fullscreen = !view.pending.fullscreen;
+        view.applyPending();
     }
 }

river/command/zoom.zig

@@ -56,8 +56,9 @@ pub fn zoom(
         if (zoom_node) |to_bump| {
             output.views.remove(to_bump);
             output.views.push(to_bump);
-            seat.input_manager.server.root.arrange();
             seat.focus(&to_bump.view);
+            output.arrangeViews();
+            output.root.startTransaction();
         }
     }
 }