Unify behavior of resizable across platforms

This makes X11 and Wayland follow Windows and macOS, so the size of the
window could be set even though it has resizable attribute set to false.

Fixes rust-windowing#2242.

CHANGELOG.md

@@ -32,6 +32,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 - On Wayland, fix polling during consecutive `EventLoop::run_return` invocations.
 - On Windows, fix race issue creating fullscreen windows with `WindowBuilder::with_fullscreen`
 - On Android, `virtual_keycode` for `KeyboardInput` events is now filled in where a suitable match is found.
+- On Wayland and X11, fix window not resizing with `Window::set_inner_size` after calling `Window:set_resizable(false)`.
 
 # 0.26.1 (2022-01-05)
 

src/platform_impl/linux/wayland/window/mod.rs

@@ -216,6 +216,9 @@ impl Window {
             window_requests.clone(),
         );
 
+        // Set resizable state, so we can determine how to handle `Window::set_inner_size`.
+        window_handle.is_resizable.set(attributes.resizable);
+
         let mut winit_state = event_loop_window_target.state.borrow_mut();
 
         winit_state.window_map.insert(window_id, window_handle);

src/platform_impl/linux/wayland/window/shim.rs

@@ -150,6 +150,9 @@ pub struct WindowHandle {
     /// Current cursor icon.
     pub cursor_icon: Cell<CursorIcon>,
 
+    /// Whether the window is resizable.
+    pub is_resizable: Cell<bool>,
+
     /// Visible cursor or not.
     cursor_visible: Cell<bool>,
 
@@ -183,6 +186,7 @@ impl WindowHandle {
             size,
             pending_window_requests,
             cursor_icon: Cell::new(CursorIcon::Default),
+            is_resizable: Cell::new(true),
             confined: Cell::new(false),
             cursor_visible: Cell::new(true),
             pointers: Vec::new(),
@@ -418,7 +422,14 @@ pub fn handle_window_requests(winit_state: &mut WinitState) {
                     window_update.redraw_requested = true;
                 }
                 WindowRequest::FrameSize(size) => {
-                    // Set new size.
+                    if !window_handle.is_resizable.get() {
+                        // On Wayland non-resizable window is achieved by setting both min and max
+                        // size of the window to the same value.
+                        let size = Some((size.width, size.height));
+                        window_handle.window.set_max_size(size);
+                        window_handle.window.set_min_size(size);
+                    }
+
                     window_handle.window.resize(size.width, size.height);
 
                     // We should refresh the frame after resize.

src/platform_impl/linux/x11/window.rs

@@ -1115,8 +1115,15 @@ impl UnownedWindow {
     #[inline]
     pub fn set_inner_size(&self, size: Size) {
         let scale_factor = self.scale_factor();
-        let (width, height) = size.to_physical::<u32>(scale_factor).into();
-        self.set_inner_size_physical(width, height);
+        let size = size.to_physical::<u32>(scale_factor).into();
+        if !self.shared_state.lock().is_resizable {
+            self.update_normal_hints(|normal_hints| {
+                normal_hints.set_min_size(Some(size));
+                normal_hints.set_max_size(Some(size));
+            })
+            .expect("Failed to call `XSetWMNormalHints`");
+        }
+        self.set_inner_size_physical(size.0, size.1);
     }
 
     fn update_normal_hints<F>(&self, callback: F) -> Result<(), XError>

src/window.rs

@@ -665,8 +665,9 @@ impl Window {
 
     /// Sets whether the window is resizable or not.
     ///
-    /// Note that making the window unresizable doesn't exempt you from handling `Resized`, as that event can still be
-    /// triggered by DPI scaling, entering fullscreen mode, etc.
+    /// Note that making the window unresizable doesn't exempt you from handling `Resized`, as that
+    /// event can still be triggered by DPI scaling, entering fullscreen mode, etc. Also, the
+    /// window could still be resized by calling `[Window::set_inner_size]`.
     ///
     /// ## Platform-specific
     ///