From 207529a185bddf4a1037e66d895adf82a2b04c09 Mon Sep 17 00:00:00 2001
From: Val Packett <val@invisiblethingslab.com>
Date: Fri, 20 Mar 2026 02:07:15 -0300
Subject: [PATCH] Handle hiding the titlebar for full screen mode

---
 src/deco.rs | 30 +++++++++++++++++++++---------
 src/xdg.rs  |  3 +++
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/deco.rs b/src/deco.rs
index c1539e9..4ec2c79 100644
--- a/src/deco.rs
+++ b/src/deco.rs
@@ -28,6 +28,7 @@ struct DecoParams {
     has_geometry: bool,
     prefers_ssd: bool,
     is_active: bool,
+    is_fullscreen: bool,
     bounds: Bounds,
     restricted_edges: Edges<bool>,
 }
@@ -133,9 +134,9 @@ impl DecoSurface {
 }
 
 impl Deco {
-    fn top_size(&self) -> i32 {
+    fn last_top_size(&self) -> i32 {
         let params = self.last_params.borrow();
-        if params.prefers_ssd {
+        if params.prefers_ssd && !params.is_fullscreen {
             self.border_size + 24
         } else {
             self.border_size
@@ -208,8 +209,14 @@ impl Deco {
             height,
         };
         let width = width + self.border_size * 2;
-        let height = height + self.top_size() + self.border_size;
-        (x - self.border_size, y - self.top_size(), width, height)
+        let height = height + self.last_top_size() + self.border_size;
+        // XXX: it's not good that we use the last state here!! Gotta buffer the geometry until commit and send on pre-commit?
+        (
+            x - self.border_size,
+            y - self.last_top_size(),
+            width,
+            height,
+        )
     }
 
     pub fn set_restricted_edges(&self, edges: Edges<bool>) {
@@ -222,6 +229,11 @@ impl Deco {
         params.is_active = is_active;
     }
 
+    pub fn set_fullscreen(&self, is_fullscreen: bool) {
+        let mut params = self.next_params.borrow_mut();
+        params.is_fullscreen = is_fullscreen;
+    }
+
     pub fn set_prefers_ssd(&self, prefers_ssd: bool) {
         let mut params = self.next_params.borrow_mut();
         params.prefers_ssd = prefers_ssd;
@@ -234,19 +246,19 @@ impl Deco {
     pub fn transform_configure(&self, width: i32, height: i32) -> (i32, i32) {
         (
             width - self.border_size * 2,
-            height - self.top_size() - self.border_size,
+            height - self.last_top_size() - self.border_size,
         )
     }
 
     pub fn transform_size(&self, width: i32, height: i32) -> (i32, i32) {
         (
             width + self.border_size * 2,
-            height + self.top_size() + self.border_size,
+            height + self.last_top_size() + self.border_size,
         )
     }
 
     pub fn transform_anchor(&self, x: i32, y: i32) -> (i32, i32) {
-        (x + self.border_size, y + self.top_size())
+        (x + self.border_size, y + self.last_top_size())
     }
 
     fn draw(&self) -> eyre::Result<()> {
@@ -286,13 +298,13 @@ impl Deco {
         self.wl_surface.send_damage_buffer(0, 0, width, height);
         let input_region = self.globals.wl_compositor.new_send_create_region();
         input_region.set_forward_to_client(false);
-        input_region.send_add(0, 0, width, self.top_size());
+        input_region.send_add(0, 0, width, self.last_top_size());
         input_region.send_add(0, 0, self.border_size, height);
         input_region.send_add(width - self.border_size, 0, self.border_size, height);
         input_region.send_add(0, height - self.border_size, width, self.border_size);
         self.wl_surface.send_set_input_region(Some(&input_region));
         self.subsurface
-            .send_set_position(bounds.x - self.border_size, bounds.y - self.top_size());
+            .send_set_position(bounds.x - self.border_size, bounds.y - self.last_top_size());
         self.wl_surface.send_commit();
         // let _ = self.globals.wl_display.new_send_sync();
         Ok(())
diff --git a/src/xdg.rs b/src/xdg.rs
index 6635acc..20b519d 100644
--- a/src/xdg.rs
+++ b/src/xdg.rs
@@ -250,6 +250,7 @@ impl ClientXdgToplevel {
     }
 }
 
+#[derive(PartialEq)]
 enum ToplevelState {
     Normal,
     Maximixed,
@@ -355,6 +356,8 @@ impl XdgToplevelHandler for ClientXdgToplevel {
         };
 
         self.deco.set_active(activated);
+        self.deco
+            .set_fullscreen(top_state == ToplevelState::Fullscreen);
         self.deco.set_restricted_edges(restricted_edges);
         let (width, height) = self.deco.transform_configure(width, height);
         let (_prefix, states, _suffix) = unsafe { outer_state.align_to::<u8>() };