2 files changed, 38 insertions, 36 deletions

diff --git a/river/Output.zig b/river/Output.zig
index 3b083c6..04d92ff 100644
--- a/river/Output.zig
+++ b/river/Output.zig
@@ -419,22 +419,36 @@ fn handleDestroy(listener: *wl.Listener(*wlr.Output), _: *wlr.Output) void {
 fn handleRequestState(listener: *wl.Listener(*wlr.Output.event.RequestState), event: *wlr.Output.event.RequestState) void {
     const output = @fieldParentPtr(Self, "request_state", listener);
 
-    // TODO double buffer output state changes for frame perfection and cleaner code.
-    // Schedule a frame and commit in the frame handler.
-    if (!output.wlr_output.commitState(event.state)) {
+    output.applyState(event.state) catch {
         log.err("failed to commit requested state", .{});
         return;
+    };
+
+    server.root.applyPending();
+}
+
+// TODO double buffer output state changes for frame perfection and cleaner code.
+// Schedule a frame and commit in the frame handler.
+// Get rid of this function.
+pub fn applyState(output: *Self, state: *wlr.Output.State) error{CommitFailed}!void {
+
+    // We need to be precise about this state change to make assertions
+    // in handleEnableDisable() possible.
+    const enable_state_change = state.committed.enabled and
+        (state.enabled != output.wlr_output.enabled);
+
+    if (!output.wlr_output.commitState(state)) {
+        return error.CommitFailed;
     }
 
-    if (event.state.committed.enabled) {
+    if (enable_state_change) {
         output.handleEnableDisable();
     }
 
-    if (event.state.committed.mode) {
+    if (state.committed.mode) {
         output.updateBackgroundRect();
         output.arrangeLayers();
         server.lock_manager.updateLockSurfaceSize(output);
-        server.root.applyPending();
     }
 }
 
@@ -462,6 +476,8 @@ fn handleEnableDisable(output: *Self) void {
         output.lock_render_state = .blanked;
         output.normal_content.node.setEnabled(false);
         output.locked_content.node.setEnabled(true);
+
+        server.root.deactivateOutput(output);
     }
 }
 
diff --git a/river/Root.zig b/river/Root.zig
index 71cc1ef..b0c1d8d 100644
--- a/river/Root.zig
+++ b/river/Root.zig
@@ -264,8 +264,8 @@ fn handleNewOutput(_: *wl.Listener(*wlr.Output), wlr_output: *wlr.Output) void {
     };
 }
 
-/// Remove the output from root.active_outputs and evacuate views if it is a
-/// member of the list.
+/// Remove the output from root.active_outputs and the output layout.
+/// Evacuate views if necessary.
 pub fn deactivateOutput(root: *Self, output: *Output) void {
     {
         // If the output has already been removed, do nothing
@@ -273,11 +273,14 @@ pub fn deactivateOutput(root: *Self, output: *Output) void {
         while (it.next()) |o| {
             if (o == output) break;
         } else return;
-
-        output.active_link.remove();
-        output.active_link.init();
     }
 
+    root.output_layout.remove(output.wlr_output);
+    output.tree.node.setEnabled(false);
+
+    output.active_link.remove();
+    output.active_link.init();
+
     {
         var it = output.inflight.focus_stack.iterator(.forward);
         while (it.next()) |view| {
@@ -391,8 +394,6 @@ pub fn activateOutput(root: *Self, output: *Output) void {
     }
     assert(root.fallback.pending.focus_stack.empty());
     assert(root.fallback.pending.wm_stack.empty());
-
-    root.applyPending();
 }
 
 /// Trigger asynchronous application of pending state for all outputs and views.
@@ -774,33 +775,18 @@ fn processOutputConfig(
                 if (!wlr_output.testState(&proposed_state)) success = false;
             },
             .apply => {
-                if (wlr_output.commitState(&proposed_state)) {
-                    if (head.state.enabled) {
-                        // Just updates the output's position if it is already in the layout
-                        _ = self.output_layout.add(output.wlr_output, head.state.x, head.state.y) catch {
-                            std.log.err("out of memory", .{});
-                            success = false;
-                            continue;
-                        };
-                        output.tree.node.setEnabled(true);
-                        output.tree.node.setPosition(head.state.x, head.state.y);
-                        output.scene_output.setPosition(head.state.x, head.state.y);
-                        // Even though we call this in the output's handler for the mode event
-                        // it is necessary to call it here as well since changing e.g. only
-                        // the transform will require the dimensions of the background to be
-                        // updated but will not trigger a mode event.
-                        output.updateBackgroundRect();
-                        output.arrangeLayers();
-                    } else {
-                        self.deactivateOutput(output);
-                        self.output_layout.remove(output.wlr_output);
-                        output.tree.node.setEnabled(false);
-                    }
-                } else {
+                output.applyState(&proposed_state) catch {
                     std.log.scoped(.output_manager).err("failed to apply config to output {s}", .{
                         output.wlr_output.name,
                     });
                     success = false;
+                };
+                if (output.wlr_output.enabled) {
+                    // applyState() will always add the output to the layout on success, which means
+                    // that this function cannot fail as it does not need to allocate a new layout output.
+                    _ = self.output_layout.add(output.wlr_output, head.state.x, head.state.y) catch unreachable;
+                    output.tree.node.setPosition(head.state.x, head.state.y);
+                    output.scene_output.setPosition(head.state.x, head.state.y);
                 }
             },
         }