refactor: make get_popup_toplevel() PopupKind agnostic

- for preparation to make unconstrain_popup() PopupKind agnostic.

src/shell/focus/target.rs

@@ -197,7 +197,7 @@ impl PointerFocusTarget {
             PointerFocusTarget::WlSurface {
                 toplevel: Some(PointerFocusToplevel::Popup(PopupKind::Xdg(popup))),
                 ..
-            } => get_popup_toplevel(popup)
+            } => get_popup_toplevel(&PopupKind::Xdg(popup.clone()))
                 .and_then(|s| shell.element_for_surface(&s).map(|mapped| (mapped, s)))
                 .and_then(|(m, s)| {
                     m.windows()
@@ -243,7 +243,7 @@ impl KeyboardFocusTarget {
         match self {
             KeyboardFocusTarget::Element(mapped) => mapped.wl_surface(),
             KeyboardFocusTarget::Popup(PopupKind::Xdg(xdg)) => {
-                get_popup_toplevel(xdg).map(Cow::Owned)
+                get_popup_toplevel(&PopupKind::Xdg(xdg.clone())).map(Cow::Owned)
             }
             _ => None,
         }

src/shell/layout/floating/mod.rs

@@ -1278,7 +1278,7 @@ impl FloatingLayout {
         let Some(focused) = (match target {
             KeyboardFocusTarget::Popup(popup) => {
                 let Some(toplevel_surface) = (match popup {
-                    PopupKind::Xdg(xdg) => get_popup_toplevel(&xdg),
+                    PopupKind::Xdg(_) => get_popup_toplevel(&popup),
                     PopupKind::InputMethod(_) => unreachable!(),
                 }) else {
                     return MoveResult::None;

src/shell/layout/tiling/mod.rs

@@ -2848,7 +2848,7 @@ impl TilingLayout {
         // if the focus is currently on a popup, treat it's toplevel as the target
         if let KeyboardFocusTarget::Popup(popup) = target {
             let toplevel_surface = match popup {
-                PopupKind::Xdg(xdg) => get_popup_toplevel(&xdg),
+                PopupKind::Xdg(_) => get_popup_toplevel(&popup),
                 PopupKind::InputMethod(_) => unreachable!(),
             }?;
             let root_id = tree.root_node_id()?;

src/shell/mod.rs

@@ -3883,7 +3883,7 @@ impl Shell {
         let Some(focused) = (match target {
             KeyboardFocusTarget::Popup(popup) => {
                 let Some(toplevel_surface) = (match popup {
-                    PopupKind::Xdg(xdg) => get_popup_toplevel(&xdg),
+                    PopupKind::Xdg(_) => get_popup_toplevel(&popup),
                     PopupKind::InputMethod(_) => unreachable!(),
                 }) else {
                     return FocusResult::None;

src/wayland/handlers/xdg_shell/popup.rs

@@ -24,7 +24,7 @@ use tracing::warn;
 
 impl Shell {
     pub fn unconstrain_popup(&self, surface: &PopupSurface) {
-        if let Some(parent) = get_popup_toplevel(surface) {
+        if let Some(parent) = get_popup_toplevel(&PopupKind::from(surface.clone())) {
             if let Some(elem) = self.element_for_surface(&parent) {
                 let (mut element_geo, output, is_tiled) =
                     if let Some(workspace) = self.space_for(elem) {
@@ -173,8 +173,11 @@ fn unconstrain_layer_popup(surface: &PopupSurface, output: &Output, layer_surfac
     });
 }
 
-pub fn get_popup_toplevel(popup: &PopupSurface) -> Option<WlSurface> {
+pub fn get_popup_toplevel(popup: &PopupKind) -> Option<WlSurface> {
-    let mut parent = popup.get_parent_surface()?;
+    let mut parent = match popup {
+        PopupKind::Xdg(popup) => popup.get_parent_surface()?,
+        PopupKind::InputMethod(popup) => popup.get_parent()?.surface.clone(),
+    };
     while get_role(&parent) == Some(XDG_POPUP_ROLE) {
         parent = with_states(&parent, |states| {
             states