implement setting the decoration mode for dialogs

src/shell/xdg/dialog.rs

@@ -4,7 +4,7 @@ use crate::reexports::protocols::xdg::decoration::zv1::client::zxdg_decoration_m
 use crate::shell::xdg::window::inner::{
     determine_decoration_mode, determine_window_state, determine_wm_capabilities, WindowInner,
 };
-use crate::shell::xdg::window::WindowConfigure;
+use crate::shell::xdg::window::{DecorationMode, WindowConfigure};
 use crate::shell::xdg::Dispatch2;
 use crate::shell::xdg::WindowDecorations;
 use crate::shell::WaylandSurface;
@@ -189,6 +189,22 @@ impl Dialog {
             self.inner.xdg_dialog.unset_modal();
         }
     }
+
+    /// Requests the dialog should use the specified decoration mode.
+    ///
+    /// A mode of [`None`] indicates that the dialog does not care what type of decorations are
+    /// used.
+    ///
+    /// The compositor will respond with a [`configure`](DialogHandler::configure). The configure
+    /// will indicate whether the dialog's decoration mode has changed.
+    ///
+    /// # Configure loops
+    ///
+    /// You should avoid sending multiple decoration mode requests to ensure you do not enter a
+    /// configure loop.
+    pub fn request_decoration_mode(&self, mode: Option<DecorationMode>) {
+        self.inner.window.request_decoration_mode(mode)
+    }
 }
 
 impl WaylandSurface for Dialog {

src/shell/xdg/window/inner.rs

@@ -50,6 +50,30 @@ pub struct WindowInner {
     pub pending_configure: Mutex<WindowConfigure>,
 }
 
+impl WindowInner {
+    /// Requests the surface should use the specified decoration mode.
+    ///
+    /// A mode of [`None`] indicates that the surface does not care what type of decorations are
+    /// used.
+    ///
+    /// The compositor will respond with a configure indicating whether the decoration mode has
+    /// changed.
+    ///
+    /// # Configure loops
+    ///
+    /// You should avoid sending multiple decoration mode requests to ensure you do not enter a
+    /// configure loop.
+    pub fn request_decoration_mode(&self, mode: Option<DecorationMode>) {
+        if let Some(toplevel_decoration) = &self.toplevel_decoration {
+            match mode {
+                Some(DecorationMode::Client) => toplevel_decoration.set_mode(Mode::ClientSide),
+                Some(DecorationMode::Server) => toplevel_decoration.set_mode(Mode::ServerSide),
+                None => toplevel_decoration.unset_mode(),
+            }
+        }
+    }
+}
+
 impl ProvidesBoundGlobal<zxdg_decoration_manager_v1::ZxdgDecorationManagerV1, 1> for XdgShell {
     fn bound_global(
         &self,

src/shell/xdg/window/mod.rs

@@ -11,7 +11,7 @@ use crate::reexports::client::{
 };
 use crate::reexports::csd_frame::{WindowManagerCapabilities, WindowState};
 use crate::reexports::protocols::{
-    xdg::decoration::zv1::client::zxdg_toplevel_decoration_v1::{self, Mode},
+    xdg::decoration::zv1::client::zxdg_toplevel_decoration_v1,
     xdg::shell::client::{xdg_surface, xdg_toplevel},
 };
 
@@ -261,13 +261,7 @@ impl Window {
     ///
     /// You should avoid sending multiple decoration mode requests to ensure you do not enter a configure loop.
     pub fn request_decoration_mode(&self, mode: Option<DecorationMode>) {
-        if let Some(toplevel_decoration) = &self.0.toplevel_decoration {
-            match mode {
-                Some(DecorationMode::Client) => toplevel_decoration.set_mode(Mode::ClientSide),
-                Some(DecorationMode::Server) => toplevel_decoration.set_mode(Mode::ServerSide),
-                None => toplevel_decoration.unset_mode(),
-            }
-        }
+        self.0.request_decoration_mode(mode)
     }
 
     pub fn move_(&self, seat: &wl_seat::WlSeat, serial: u32) {