drag+drop support

project_manager.py

@@ -108,21 +108,116 @@ class ProjectManager:
     # =========================================================================
     # File & Folder Opening Dialogs
     # =========================================================================
+
+    def is_valid_snirf(self, path: str) -> bool:
+        """Fast header check to verify HDF5/SNIRF signature and ignore corrupt/shadow files."""
+        try:
+            if os.path.getsize(path) < 8:
+                return False
+            with open(path, "rb") as f:
+                return f.read(8) == b"\x89HDF\r\n\x1a\n"
+        except Exception:
+            return False
+        
     def open_file_dialog(self) -> None:
         """Opens dialog to pick a single .snirf file."""
         file_path, _ = QFileDialog.getOpenFileName(
             self.app, "Open File", "", "SNIRF Files (*.snirf);;All Files (*)"
         )
-        if file_path:
-            self._load_files_into_pipeline([os.path.normpath(file_path)])
+        if not file_path:
+            return
+
+        norm_path = os.path.normpath(file_path)
+        filename = os.path.basename(norm_path)
+
+        # 1. Check specifically for macOS shadow files
+        if filename.startswith("._"):
+            QMessageBox.warning(
+                self.app,
+                "Invalid SNIRF File",
+                f"'{filename}' is a macOS system shadow file (Apple Double resource fork), not a actual data file."
+            )
+            return
+
+        # 2. Check for general header validity / corruption
+        if not self.is_valid_snirf(norm_path):
+            QMessageBox.warning(
+                self.app,
+                "Invalid SNIRF File",
+                f"'{filename}' is not a valid SNIRF file or has a corrupted header."
+            )
+            return
+
+        self._load_files_into_pipeline([norm_path])
 
     def open_folder_dialog(self)-> None:
         """Recursively finds all .snirf files in a selected directory."""
         folder_path = QFileDialog.getExistingDirectory(self.app, "Select Folder", "")
-        if folder_path:
-            snirf_files = [os.path.normpath(str(f)) for f in Path(folder_path).rglob("*.snirf")]
-            self._load_files_into_pipeline(snirf_files)
+        if not folder_path:
+            return
 
+        # Automatically filter out shadow files and invalid headers in batch mode
+        snirf_files = [
+            os.path.normpath(str(f))
+            for f in Path(folder_path).rglob("*.snirf")
+            if self.is_valid_snirf(str(f))
+        ]
+
+        if not snirf_files:
+            QMessageBox.information(
+                self.app,
+                "No Valid Files",
+                "No valid .snirf files were found in the selected directory."
+            )
+            return
+
+    def load_dropped_files(self, file_paths: List[str]) -> None:
+        """Public entry point for handling files or folders dropped onto the UI."""
+        if not file_paths:
+            return
+
+        # 1. Single file drop: Give explicit feedback like open_file_dialog
+        if len(file_paths) == 1:
+            norm_path = os.path.normpath(file_paths[0])
+            filename = os.path.basename(norm_path)
+
+            if filename.startswith("._"):
+                QMessageBox.warning(
+                    self.app,
+                    "Invalid SNIRF File",
+                    f"'{filename}' is a macOS system shadow file (Apple Double resource fork), not an actual data file."
+                )
+                return
+
+            if not self.is_valid_snirf(norm_path):
+                QMessageBox.warning(
+                    self.app,
+                    "Invalid SNIRF File",
+                    f"'{filename}' is not a valid SNIRF file or has a corrupted header."
+                )
+                return
+
+            valid_files = [norm_path]
+
+        # 2. Batch drop: Silently filter out shadow/corrupt files like open_folder_dialog
+        else:
+            valid_files = [
+                os.path.normpath(p)
+                for p in file_paths
+                if self.is_valid_snirf(os.path.normpath(p))
+            ]
+
+            if not valid_files:
+                QMessageBox.information(
+                    self.app,
+                    "No Valid Files",
+                    "None of the dropped items were valid .snirf files."
+                )
+                return
+
+        # Delegate to internal pipeline
+        self._load_files_into_pipeline(valid_files)
+        
     def _load_files_into_pipeline(self, file_paths: List[str]) -> None:
         """Loads .snirf files into UI using chunked batches and background workers."""
         app = self.app
@@ -146,8 +241,11 @@ class ProjectManager:
         if not hasattr(app, "metadata_cache"):
             app.metadata_cache = {}
 
-        # Filter out files already in the UI to avoid duplicates
-        new_files = [p for p in file_paths if p not in app.selected_paths]
+        # Filter out duplicates AND non-SNIRF files (including macOS ._ shadow files)
+        new_files = [
+            p for p in file_paths 
+            if p not in app.selected_paths and self.is_valid_snirf(p)
+        ]
         if not new_files:
             return