Report folder scan progress to UI

Emit progress events from the Tauri backend and display them in the React UI. Backend: add total_files and an AtomicUsize completed counter, increment it per-file and emit a "folder-scan-progress" event with completed/total; also increase concurrent worker semaphore from 4 to 8 and adjust the checksum task to clone the window handle and return a result variable. Frontend: listen for "folder-scan-progress", store progress in state, show a determinate LinearProgress and a caption while scanning, initialize an indeterminate progress at scan start, and clear it when finished.

Author: oop7

src-tauri/src/main.rs

@@ -3,7 +3,7 @@
 use std::collections::HashMap;
 use std::path::Path;
 use std::process::Command;
-use std::sync::{Arc, atomic::{AtomicBool, Ordering}};
+use std::sync::{Arc, atomic::{AtomicBool, AtomicUsize, Ordering}};
 use tauri::command;
 use tokio::sync::Semaphore;
 #[cfg(not(target_os = "windows"))]
@@ -341,6 +341,8 @@ async fn scan_folder(window: Window, state: tauri::State<'_, AppState>, folder_p
     // Process files concurrently with a semaphore to limit parallelism
     let sem = Arc::new(Semaphore::new(8)); // Increased concurrency from 4 to 8
     let mut handles = Vec::new();
+    let total_files = files_to_process.len();
+    let completed_files = Arc::new(AtomicUsize::new(0));
 
     for file_path in files_to_process {
         if state.cancel.load(Ordering::SeqCst) {
@@ -351,14 +353,23 @@ async fn scan_folder(window: Window, state: tauri::State<'_, AppState>, folder_p
         let cancel_flag = state.cancel.clone();
         let file_path_clone = file_path.clone();
         let algorithms_clone = algorithms.clone(); // Clone algorithms for each task
+        let completed_clone = completed_files.clone();
 
         let handle = tokio::spawn(async move {
             // permit is dropped at end of scope to release semaphore
             let _permit = permit;
-            match do_calculate_checksums(win, cancel_flag.clone(), file_path_clone.clone(), algorithms_clone).await {
+            let result = match do_calculate_checksums(win.clone(), cancel_flag.clone(), file_path_clone.clone(), algorithms_clone).await {
                 Ok(checksums) => Ok((file_path_clone, checksums)),
                 Err(e) => Err((file_path_clone, e)),
-            }
+            };
+            
+            let current = completed_clone.fetch_add(1, Ordering::SeqCst) + 1;
+            let _ = win.emit("folder-scan-progress", serde_json::json!({
+                "completed": current,
+                "total": total_files
+            }));
+            
+            result
         });
 
         handles.push(handle);

src/App.tsx

@@ -890,6 +890,26 @@ const FolderScanTab = ({ folderPath, setFolderPath, selectedAlgorithms, handleAl
   const [includeSubfolders, setIncludeSubfolders] = useState(true);
   const [includeHidden, setIncludeHidden] = useState(false);
   const [isScanning, setIsScanning] = useState(false);
+  const [progress, setProgress] = useState<{ completed: number; total: number } | null>(null);
+
+  useEffect(() => {
+    let unlisten: any;
+    (async () => {
+      unlisten = await listen('folder-scan-progress', (event: any) => {
+        const payload = event.payload as any;
+        setProgress({ 
+          completed: payload.completed || 0, 
+          total: payload.total || 0 
+        });
+      });
+    })();
+
+    return () => {
+      if (unlisten && typeof unlisten.then === 'function') {
+        unlisten.then((f: any) => f());
+      }
+    };
+  }, []);
 
   const handleFolderSelect = async () => {
     const selected = await openDialog({
@@ -911,6 +931,7 @@ const FolderScanTab = ({ folderPath, setFolderPath, selectedAlgorithms, handleAl
     }
 
     setIsScanning(true);
+    setProgress({ completed: 0, total: 100 }); // Indeterminate at first, total won't be 100 actually unless 100 files, but we update soon
     setFiles([]);
     try {
       const scannedFiles = await invoke("scan_folder", { 
@@ -924,6 +945,7 @@ const FolderScanTab = ({ folderPath, setFolderPath, selectedAlgorithms, handleAl
       if (e !== "Cancelled") showAlert('Error', `Folder scan failed: ${e}`);
     } finally {
       setIsScanning(false);
+      setProgress(null);
     }
   };
 
@@ -1014,7 +1036,14 @@ const FolderScanTab = ({ folderPath, setFolderPath, selectedAlgorithms, handleAl
             <Button variant="outlined" color="error" onClick={() => invoke('cancel_hashing')}>Cancel</Button>
           )}
         </Box>
-        {isScanning && <LinearProgress sx={{ mt: 2 }} />}
+        {isScanning && progress && (
+          <Box sx={{ mt: 2 }}>
+            <LinearProgress variant={progress.total > 0 ? "determinate" : "indeterminate"} value={progress.total > 0 ? (progress.completed / progress.total) * 100 : 0} />
+            <Typography variant="caption" sx={{ mt: 0.5, display: 'block', textAlign: 'center' }}>
+              {progress.total > 0 ? `${progress.completed} / ${progress.total} files completed (${Math.round((progress.completed / progress.total) * 100)}%)` : 'Scanning...'}
+            </Typography>
+          </Box>
+        )}
 
         <TableContainer component={Paper} sx={{ mt: 2 }}>
             <Table>