WindowServer+LibGUI: Notify windows when their maximized state changes

Previously, GUI::Window::is_maximized() had to make a synchronous IPC
request to WindowServer in order to find out if the window was indeed
maximized.

This patch removes the need for synchronous IPC by instead pushing the
maximization state to clients when it changes.

The motivation for this change was that GUI::Statusbar was checking
if the containing window was maximized in its resize_event(), causing
all windows with a statusbar to block on sync IPC *during* resize.
Browser would typically block for ~15 milliseconds here every time
on my machine, continuously during live resize.

3 files changed, 5 insertions, 3 deletions

diff --git a/Userland/Services/WindowServer/Window.cpp b/Userland/Services/WindowServer/Window.cpp
index f372aff82c..525fbea829 100644
--- a/Userland/Services/WindowServer/Window.cpp
+++ b/Userland/Services/WindowServer/Window.cpp
@@ -497,6 +497,8 @@ void Window::set_maximized(bool maximized, Optional<Gfx::IntPoint> fixed_point)
     m_frame.did_set_maximized({}, maximized);
     Core::EventLoop::current().post_event(*this, make<ResizeEvent>(m_rect));
     set_default_positioned(false);
+
+    WindowManager::the().notify_minimization_state_changed(*this);
 }
 
 void Window::set_always_on_top(bool always_on_top)
diff --git a/Userland/Services/WindowServer/WindowClient.ipc b/Userland/Services/WindowServer/WindowClient.ipc
index 822d4a8ba9..0c67af3830 100644
--- a/Userland/Services/WindowServer/WindowClient.ipc
+++ b/Userland/Services/WindowServer/WindowClient.ipc
@@ -19,7 +19,7 @@ endpoint WindowClient
     key_up(i32 window_id, u32 code_point, u32 key, u32 modifiers, u32 scancode) =|
     window_activated(i32 window_id) =|
     window_deactivated(i32 window_id) =|
-    window_state_changed(i32 window_id, bool minimized, bool occluded) =|
+    window_state_changed(i32 window_id, bool minimized, bool maximized, bool occluded) =|
     window_close_request(i32 window_id) =|
     window_resized(i32 window_id, Gfx::IntRect new_rect) =|
 
diff --git a/Userland/Services/WindowServer/WindowManager.cpp b/Userland/Services/WindowServer/WindowManager.cpp
index bdbbe2c1a5..097f02d6c9 100644
--- a/Userland/Services/WindowServer/WindowManager.cpp
+++ b/Userland/Services/WindowServer/WindowManager.cpp
@@ -625,7 +625,7 @@ void WindowManager::notify_minimization_state_changed(Window& window)
     tell_wms_window_state_changed(window);
 
     if (window.client())
-        window.client()->async_window_state_changed(window.window_id(), window.is_minimized(), window.is_occluded());
+        window.client()->async_window_state_changed(window.window_id(), window.is_minimized(), window.is_maximized(), window.is_occluded());
 
     if (window.is_active() && window.is_minimized())
         pick_new_active_window(&window);
@@ -634,7 +634,7 @@ void WindowManager::notify_minimization_state_changed(Window& window)
 void WindowManager::notify_occlusion_state_changed(Window& window)
 {
     if (window.client())
-        window.client()->async_window_state_changed(window.window_id(), window.is_minimized(), window.is_occluded());
+        window.client()->async_window_state_changed(window.window_id(), window.is_minimized(), window.is_maximized(), window.is_occluded());
 }
 
 void WindowManager::notify_progress_changed(Window& window)