fix(files): make dropped-file handling explicit

webui/src/components/FileDropZone.tsx

@@ -1,5 +1,8 @@
-import { i18nMessage } from "../i18n/LanguageContext";import { useRef, useState, type CSSProperties, type ReactNode } from "react";
+import { i18nMessage } from "../i18n/LanguageContext";import { useRef, useState, type CSSProperties, type DragEvent as ReactDragEvent, type ReactNode } from "react";
 import { UploadCloud } from "lucide-react";
+import { resolveDroppedFiles } from "./resolveDroppedFiles";
+
+type RejectedDropReason = "disabled" | "empty" | "unreadable";
 
 export type FileDropZoneProps = {
   accept?: string;
@@ -14,6 +17,7 @@ export type FileDropZoneProps = {
   note?: ReactNode;
   className?: string;
   inputLabel?: string;
+  onRejectedDrop?: (reason: RejectedDropReason) => void;
   onFiles: (files: File[]) => void | Promise<void>;
 };
 
@@ -30,6 +34,7 @@ export default function FileDropZone({
   note,
   className = "",
   inputLabel = "i18n:govoplan-core.drop_files_here_or_click_to_select_files.7eda8608",
+  onRejectedDrop,
   onFiles
 }: FileDropZoneProps) {
   const inputRef = useRef<HTMLInputElement | null>(null);
@@ -52,6 +57,13 @@ export default function FileDropZone({
     }
   }
 
+  function prepareFileDrag(event: ReactDragEvent<HTMLDivElement>) {
+    event.preventDefault();
+    event.stopPropagation();
+    event.dataTransfer.dropEffect = interactionDisabled ? "none" : "copy";
+    if (!interactionDisabled) setDragActive(true);
+  }
+
   return (
     <>
       <div
@@ -70,15 +82,29 @@ export default function FileDropZone({
             inputRef.current?.click();
           }
         }}
-        onDragOver={(event) => {
+        onDragEnter={prepareFileDrag}
+        onDragOver={prepareFileDrag}
+        onDragLeave={(event) => {
           event.preventDefault();
-          if (!interactionDisabled) setDragActive(true);
+          event.stopPropagation();
+          if (event.relatedTarget instanceof Node && event.currentTarget.contains(event.relatedTarget)) return;
+          setDragActive(false);
         }}
-        onDragLeave={() => setDragActive(false)}
         onDrop={(event) => {
           event.preventDefault();
+          event.stopPropagation();
           setDragActive(false);
-          if (!interactionDisabled) void handleFiles(event.dataTransfer.files);
+          if (interactionDisabled) {
+            onRejectedDrop?.("disabled");
+            return;
+          }
+          void resolveDroppedFiles(event.dataTransfer).then((files) => {
+            if (files.length === 0) {
+              onRejectedDrop?.("empty");
+              return;
+            }
+            void handleFiles(files);
+          }).catch(() => onRejectedDrop?.("unreadable"));
         }}>
         
         {showProgress ?
@@ -110,4 +136,4 @@ export default function FileDropZone({
       
     </>);
 
-}
+}