refactor: extract dnd target and sidebar helpers

rust/spikes/leptos-tiptap-spike/generated/island/mnote-leptos-tiptap-spike-island.js

@@ -1284,7 +1284,7 @@ function __wbg_get_imports() {
             return ret;
         },
         __wbindgen_cast_0000000000000006: function(arg0, arg1) {
-            // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("KeyboardEvent")], shim_idx: 883, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
+            // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("KeyboardEvent")], shim_idx: 736, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
             const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__hd90af689bc3e71bf);
             return ret;
         },

rust/spikes/leptos-tiptap-spike/src/editor_runtime/block_dnd.rs

@@ -1,9 +1,10 @@
-//! Block handle 拖拽命中的纯几何 helper。
+//! Block handle 拖拽命中的 runtime helper。
 //!
-//! 本模块不查询 DOM、不处理 Leptos signal，也不分发 editor command；
-//! 调用方负责传入已经从页面中读取的坐标。
+//! 本模块只承接拖拽命中所需的窄 helper，不处理 Leptos signal，
+//! 也不分发 editor command；调用方负责保留编辑器状态编排。
 
 use crate::editor_runtime::block_hover_state::DropPlacement;
+use web_sys::{window, EventTarget};
 
 pub(crate) struct HandleCorridorGeometry {
     pub(crate) stage_left: f64,
@@ -56,6 +57,13 @@ pub(crate) fn drop_indicator_top(
     }
 }
 
+pub(crate) fn event_target_from_point(client_x: i32, client_y: i32) -> Option<EventTarget> {
+    window()
+        .and_then(|win| win.document())
+        .and_then(|document| document.element_from_point(client_x as f32, client_y as f32))
+        .map(Into::into)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

rust/spikes/leptos-tiptap-spike/src/lib.rs

@@ -22,8 +22,8 @@ use web_sys::{
 
 use editor_runtime::attachment_upload::dispatch_editor_upload_request;
 use editor_runtime::block_dnd::{
-    drop_indicator_top, drop_placement_from_block_point, pointer_in_handle_corridor_geometry,
-    HandleCorridorGeometry,
+    drop_indicator_top, drop_placement_from_block_point, event_target_from_point,
+    pointer_in_handle_corridor_geometry, HandleCorridorGeometry,
 };
 use editor_runtime::block_menu_overlay;
 use editor_runtime::block_menu_legacy_html::{
@@ -5430,10 +5430,7 @@ fn drop_indicator_from_target(
 }
 
 fn drop_indicator_from_point(client_x: i32, client_y: i32) -> Option<DropIndicatorState> {
-    let target = window()
-        .and_then(|win| win.document())
-        .and_then(|document| document.element_from_point(client_x as f32, client_y as f32))?;
-    let target: web_sys::EventTarget = target.into();
+    let target = event_target_from_point(client_x, client_y)?;
     drop_indicator_from_target(target, client_y)
 }