Add directory drop targets in the file list; fix Copy/Cut/Paste to use the real OS clipboard

Drag-and-drop: directories in the middle file list (list and grid view)
are now drop targets too, same MoveIntoDirectory sidebar bookmarks and
the filetree already use.

Clipboard: Copy/Cut/Paste now goes through Clipboard.set_files/get_files
(the real OS clipboard) instead of private in-process Python state, so
it works between separate SaraFem windows and interoperates with other
apps. Cut-vs-copy has no OS clipboard equivalent, so that one bit lives
in a small ~/.cache/SaraFem/ClipboardMode.txt sidecar every window reads
fresh on pass.

Browser.py

@@ -25,8 +25,8 @@ from Bookmarks import IconChoices as BookmarkIconChoices
 from Bookmarks import IconLabelOverrides
 from Books import ClearSaraTagCache, IsInternalSaraTagFile
 from Core import (
-    AppConfig, ApplyHeightBounds, ChipButtonStyle, DragGroup, ExportSettings, FormatBatchName, ImportSettings,
-    NotificationStyle, Palette, ResizeHandle,
+    AppConfig, ApplyHeightBounds, ChipButtonStyle, DragGroup, ExportSettings, FormatBatchName, GetClipboardMode,
+    ImportSettings, MoveIntoDirectory, NotificationStyle, Palette, ResizeHandle, SetClipboardMode,
 )
 from Editor import EditorView
 from ImageView import ImageView
@@ -282,14 +282,15 @@ class Browser(ft.Row):
         self.MenuOpenedAt = 0.0
         self.PendingMenu: Optional[tuple[Optional[Path], ft.Offset]] = None
 
-        self.ClipboardPaths: list[Path] = []
-        self.ClipboardMode: Optional[str] = None  # "copy" or "cut"
-
         self.Breadcrumbs = ft.Row(spacing=0, wrap=True)
+        # No local disabled/enabled tracking any more — Copy/Cut/Paste live
+        # on the real OS clipboard now (see _DoSetClipboard/_DoPaste), shared
+        # across every SaraFem window and unreadable to check synchronously,
+        # so Paste just always looks clickable and says "Nothing to paste."
+        # if there's genuinely nothing there, same as most apps' Paste.
         self.PasteButton = ft.OutlinedButton(
             content="Paste",
             icon=ft.Icons.CONTENT_PASTE_OUTLINED,
-            disabled=True,
             style=ChipButtonStyle(),
             on_click=lambda e: self._Paste(),
         )
@@ -1101,7 +1102,7 @@ class Browser(ft.Row):
 
         self.EntryTiles[Entry] = _EntryHandle(NameCell, SetSelected)
 
-        return ft.Container(
+        RowControl = ft.Container(
             content=ft.Row(
                 [
                     ft.Draggable(
@@ -1133,6 +1134,19 @@ class Browser(ft.Row):
             ),
             expand=True,
         )
+        if Entry.is_dir():
+            # A directory row is both a drag source (like any other entry, so
+            # it can itself be moved elsewhere) and a drop target (so other
+            # entries can be dropped into it) — same MoveIntoDirectory Sidebar
+            # bookmarks and the filetree already use, just one more place to
+            # drop onto (Features/Major: "drag and drop... directories in
+            # folder you're in in middle").
+            return ft.DragTarget(
+                group=DragGroup,
+                content=RowControl,
+                on_accept=lambda e, dest=Entry: self._OnEntryDroppedInList(e, dest),
+            )
+        return RowControl
 
     def _BuildColumnResizeHandle(self, FieldName: str, Cell: ft.Container) -> ft.Control:
         """Sits between Cell and the next header cell — drags resize Cell's
@@ -1202,7 +1216,7 @@ class Browser(ft.Row):
         self.EntryTiles[Entry] = _EntryHandle(
             Cell, lambda v, C=Cell: setattr(C, "bgcolor", Palette.Surface0 if v else None)
         )
-        return ft.Draggable(
+        GridDraggable = ft.Draggable(
             group=DragGroup,
             data=str(Entry),
             # Right-click applies to the whole Stack (including over the
@@ -1219,6 +1233,15 @@ class Browser(ft.Row):
                 on_secondary_tap_down=lambda e, p=Entry: self._RequestMenu(p, e),
             ),
         )
+        if Entry.is_dir():
+            # Same drop-target treatment as the list view's directory rows —
+            # see _BuildListRow.
+            return ft.DragTarget(
+                group=DragGroup,
+                content=GridDraggable,
+                on_accept=lambda e, dest=Entry: self._OnEntryDroppedInList(e, dest),
+            )
+        return GridDraggable
 
     def _LeadingFor(self, Entry: Path, Size: int = 32):
         if Entry.is_dir():
@@ -1229,6 +1252,20 @@ class Browser(ft.Row):
                 return ft.Image(src=str(ThumbnailPath), width=Size, height=Size, fit=ft.BoxFit.COVER)
         return ft.Icon(ft.Icons.INSERT_DRIVE_FILE_OUTLINED, size=Size, color=Palette.Overlay0)
 
+    def _OnEntryDroppedInList(self, Event: ft.DragTargetEvent, DestinationDir: Path) -> None:
+        """A file/folder dropped onto a directory row/cell in the file list
+        itself — the same MoveIntoDirectory Sidebar's bookmarks and the
+        filetree already use for their own drop targets (Features/Major:
+        "drag and drop... directories in folder you're in in middle")."""
+        SourcePath = Path(Event.src.data)
+        try:
+            MoveIntoDirectory(SourcePath, DestinationDir)
+        except OSError as Error:
+            self._Notify(str(Error))
+            return
+        self._RefreshEntries()
+        self._Notify(f'Moved "{SourcePath.name}" to {DestinationDir.name or DestinationDir}.', Kind="success")
+
     def _MenuItems(self, Entry: Path) -> list[ft.PopupMenuItem]:
         """Shared by the triple-dot button and the right-click context menu —
         they're required to show the same items. Handlers resolve single-vs-
@@ -1408,10 +1445,11 @@ class Browser(ft.Row):
     # --- Clipboard / paste --------------------------------------------------
 
     def _SetClipboard(self, EntryPaths: list[Path], Mode: str) -> None:
-        self.ClipboardPaths = EntryPaths
-        self.ClipboardMode = Mode
-        self.PasteButton.disabled = False
-        self.update()
+        self.page.run_task(self._DoSetClipboard, EntryPaths, Mode)
+
+    async def _DoSetClipboard(self, EntryPaths: list[Path], Mode: str) -> None:
+        await ft.Clipboard().set_files([str(P) for P in EntryPaths])
+        SetClipboardMode(Mode)
 
     def _HandleCopyPath(self, Entry: Optional[Path]) -> None:
         if Entry is None:
@@ -1425,23 +1463,32 @@ class Browser(ft.Row):
         self._Notify(f"Copied {Count} path(s)." if Count > 1 else "Copied path.", Kind="success")
 
     def _Paste(self) -> None:
-        if not self.ClipboardPaths:
-            return
+        self.page.run_task(self._DoPaste)
 
-        Missing = [P for P in self.ClipboardPaths if not P.exists()]
+    async def _DoPaste(self) -> None:
+        # The real OS clipboard (see _DoSetClipboard) — works whether the
+        # files were copied/cut from this same window, a different SaraFem
+        # window (each its own process), or another app entirely. Files
+        # copied from outside SaraFem have no cut/copy flag of their own, so
+        # GetClipboardMode's "copy" default is also the safe one: pasting
+        # never deletes something SaraFem itself didn't mark as cut.
+        Files = await ft.Clipboard().get_files()
+        if not Files:
+            self._Notify("Nothing to paste.")
+            return
+        ClipboardPaths = [Path(F) for F in Files]
+        Mode = GetClipboardMode()
+
+        Missing = [P for P in ClipboardPaths if not P.exists()]
         if Missing:
             self._Notify(f"{Missing[0].name} no longer exists.")
-            self.ClipboardPaths = []
-            self.ClipboardMode = None
-            self.PasteButton.disabled = True
-            self.update()
             return
 
         Failures: list[str] = []
-        for SourcePath in self.ClipboardPaths:
+        for SourcePath in ClipboardPaths:
             Destination = self._UniqueDestination(self.CurrentPath / SourcePath.name)
             try:
-                if self.ClipboardMode == "copy":
+                if Mode == "copy":
                     if SourcePath.is_dir():
                         shutil.copytree(SourcePath, Destination)
                     else:
@@ -1451,11 +1498,10 @@ class Browser(ft.Row):
             except OSError as Error:
                 Failures.append(f"{SourcePath.name}: {Error}")
 
-        if self.ClipboardMode == "cut":
-            self.ClipboardPaths = []
-            self.ClipboardMode = None
-            self.PasteButton.disabled = True
-
+        # No clipboard-clearing after a cut-paste: a stale "cut" pointing at
+        # files that just moved is already handled above (Missing), and
+        # trying to clear a clipboard another window might have since
+        # overwritten would just be racing it for no benefit.
         if Failures:
             self._Notify("Couldn't paste: " + "; ".join(Failures))
 

Core.py

@@ -48,6 +48,28 @@ ActiveFontFamily = BundledFontFamily  # set by ApplyAppearance, read by BuildThe
 CacheDir = Path.home() / ".cache" / "SaraFem"
 ThumbnailCacheDir = CacheDir / "Thumbnails"
 
+# Copy/Cut/Paste uses the real OS clipboard (Clipboard.set_files/get_files —
+# see Browser._DoSetClipboard/_DoPaste) instead of private Python state, so
+# it actually works between two separate SaraFem windows (each its own
+# process) and interoperates with other apps' file managers. The one thing
+# the OS file clipboard has no concept of is a cut-vs-copy flag, so that one
+# bit lives here instead, in a tiny sidecar file every SaraFem window reads
+# fresh on Paste rather than trusting its own possibly-stale local state.
+ClipboardModePath = CacheDir / "ClipboardMode.txt"
+
+
+def SetClipboardMode(Mode: str) -> None:
+    CacheDir.mkdir(parents=True, exist_ok=True)
+    ClipboardModePath.write_text(Mode)
+
+
+def GetClipboardMode() -> str:
+    try:
+        Mode = ClipboardModePath.read_text().strip()
+    except OSError:
+        return "copy"
+    return Mode if Mode in ("copy", "cut") else "copy"
+
 # Config moved from ~/.config/SaraFem/ into a SaraSuite-wide layout so other
 # Sara* programs (SaraTag, SaraView) can eventually read from the same place.
 SharedConfigDir = Path.home() / ".config" / "SaraSuite"