feat: add drag-drop, multi-selection, and context menu for plugins

src/illogical/modules/models.py

@@ -136,10 +136,39 @@ class PluginTableModel(QAbstractTableModel):
 
     def flags(self, index: QModelIndex) -> Qt.ItemFlag:
         base_flags = Qt.ItemFlag.ItemIsEnabled | Qt.ItemFlag.ItemIsSelectable
+        if index.isValid():
+            base_flags |= Qt.ItemFlag.ItemIsDragEnabled
         if index.column() in (COL_CUSTOM_NAME, COL_SHORT_NAME):
             return base_flags | Qt.ItemFlag.ItemIsEditable
         return base_flags
 
+    def mimeTypes(self) -> list[str]:  # noqa: N802
+        return [PLUGIN_MIME_TYPE]
+
+    def mimeData(self, indexes: list[QModelIndex]) -> QMimeData:  # noqa: N802
+        mime_data = QMimeData()
+        if not indexes:
+            return mime_data
+
+        rows = set()
+        for index in indexes:
+            if index.isValid():
+                rows.add(index.row())
+
+        plugin_ids = []
+        for row in sorted(rows):
+            plugin = self.get_plugin(row)
+            if plugin:
+                plugin_ids.append(
+                    f"{plugin.name}|{plugin.manufacturer}|{plugin.type_code}"
+                )
+
+        if plugin_ids:
+            data = "\n".join(plugin_ids)
+            mime_data.setData(PLUGIN_MIME_TYPE, QByteArray(data.encode("utf-8")))
+
+        return mime_data
+
     def setData(  # noqa: N802
         self, index: QModelIndex, value: object, role: int = Qt.ItemDataRole.EditRole
     ) -> bool:
@@ -298,12 +327,14 @@ class CategoryTreeItem:
 
 
 CATEGORY_MIME_TYPE = "application/x-illogical-category"
+PLUGIN_MIME_TYPE = "application/x-illogical-plugin"
 
 
 class CategoryTreeModel(QAbstractItemModel):
     category_changed = Signal()
     error_occurred = Signal(str, str)
     backup_requested = Signal(bool)
+    plugins_dropped = Signal(list, str, bool)
 
     def __init__(self, parent: QObject | None = None) -> None:
         super().__init__(parent)
@@ -443,10 +474,10 @@ class CategoryTreeModel(QAbstractItemModel):
         )
 
     def supportedDropActions(self) -> Qt.DropAction:  # noqa: N802
-        return Qt.DropAction.MoveAction
+        return Qt.DropAction.MoveAction | Qt.DropAction.CopyAction
 
     def mimeTypes(self) -> list[str]:  # noqa: N802
-        return [CATEGORY_MIME_TYPE]
+        return [CATEGORY_MIME_TYPE, PLUGIN_MIME_TYPE]
 
     def mimeData(self, indexes: list[QModelIndex]) -> QMimeData:  # noqa: N802
         mime_data = QMimeData()
@@ -473,6 +504,9 @@ class CategoryTreeModel(QAbstractItemModel):
         column: int,  # noqa: ARG002
         parent: QModelIndex,
     ) -> bool:
+        if data.hasFormat(PLUGIN_MIME_TYPE):
+            return self._handle_plugin_drop(data, parent)
+
         if action != Qt.DropAction.MoveAction:
             return False
         if not data.hasFormat(CATEGORY_MIME_TYPE):
@@ -538,6 +572,27 @@ class CategoryTreeModel(QAbstractItemModel):
         self._rebuild_from_virtual()
         return True
 
+    def _handle_plugin_drop(self, data: QMimeData, parent: QModelIndex) -> bool:
+        from PySide6.QtWidgets import QApplication  # noqa: PLC0415
+
+        if not parent.isValid():
+            return False
+
+        item: CategoryTreeItem = parent.internalPointer()
+        target_category = "" if item.full_path == "Top Level" else item.full_path
+
+        modifiers = QApplication.keyboardModifiers()
+        is_add = bool(modifiers & Qt.KeyboardModifier.ShiftModifier)
+        is_move = not is_add
+
+        raw_data = data.data(PLUGIN_MIME_TYPE).data()
+        plugin_ids = bytes(raw_data).decode("utf-8").split("\n") if raw_data else []
+
+        if plugin_ids:
+            self.plugins_dropped.emit(plugin_ids, target_category, is_move)
+
+        return True
+
     def move_category_up(self, index: QModelIndex) -> bool:
         if not index.isValid() or self._virtual_tree is None or self._logic is None:
             return False
@@ -644,6 +699,10 @@ class CategoryTreeModel(QAbstractItemModel):
             return None
         return index.internalPointer()
 
+    @property
+    def root_item(self) -> CategoryTreeItem:
+        return self._root
+
     def setData(  # noqa: N802
         self, index: QModelIndex, value: object, role: int = Qt.ItemDataRole.EditRole
     ) -> bool:

src/illogical/ui/main_window.py

@@ -20,7 +20,7 @@ from illogical.ui.restore_backup_window import RestoreBackupWindow
 from illogical.ui.sidebar import Sidebar
 
 if TYPE_CHECKING:
-    from logic_plugin_manager import AudioComponent, Logic, SearchResult
+    from logic_plugin_manager import AudioComponent, Category, Logic, SearchResult
     from PySide6.QtGui import QCloseEvent, QKeyEvent, QShowEvent
 
     from illogical.modules.backup_models import (
@@ -138,6 +138,12 @@ class MainWindow(QMainWindow):
         self._backup_service.set_logic(logic)
         self._sidebar.populate(logic)
         self._plugin_table.set_plugins(logic)
+        self._plugin_table.set_category_tree(self._sidebar.category_model)
+        self._sidebar.category_model.plugins_dropped.connect(self._on_plugins_dropped)
+        self._plugin_table.category_assignment_requested.connect(
+            self._on_category_assignment
+        )
+        self._plugin_table.category_removal_requested.connect(self._on_category_removal)
         self._loading_overlay.hide()
         self._plugin_table.focus_table()
 
@@ -201,6 +207,131 @@ class MainWindow(QMainWindow):
                 BackupTrigger.AUTO, "Before category modification"
             )
 
+    def _on_plugins_dropped(
+        self,
+        plugin_ids: list[str],
+        category_path: str,
+        is_move: bool,  # noqa: FBT001
+    ) -> None:
+        if not self._logic:
+            return
+
+        plugins = []
+        for plugin_id in plugin_ids:
+            parts = plugin_id.split("|")
+            if len(parts) == 3:  # noqa: PLR2004
+                name, manufacturer, type_code = parts
+                for plugin in self._logic.plugins.all():
+                    if (
+                        plugin.name == name
+                        and plugin.manufacturer == manufacturer
+                        and plugin.type_code == type_code
+                    ):
+                        plugins.append(plugin)
+                        break
+
+        if plugins:
+            self._assign_plugins_to_category(plugins, category_path, is_move)
+
+    def _on_category_assignment(
+        self,
+        plugins: list[AudioComponent],
+        category_path: str,
+        is_move: bool,  # noqa: FBT001
+    ) -> None:
+        self._assign_plugins_to_category(plugins, category_path, is_move)
+
+    def _on_category_removal(self, plugins: list[AudioComponent]) -> None:
+        if not self._logic or not self._current_category:
+            return
+
+        try:
+            if backup_manager.should_create_auto_backup():
+                backup_manager.create_backup(
+                    BackupTrigger.AUTO,
+                    f"Before removing {len(plugins)} plugin(s) from category",
+                )
+
+            category_path = self._current_category
+            if category_path == "Top Level":
+                category_path = ""
+
+            category = self._logic.categories.get(category_path)
+            if category:
+                for plugin in plugins:
+                    plugin.remove_from_category(category)
+                self._logic.sync_category_plugin_amount(category)
+
+            self._sidebar.populate(self._logic)
+            self._plugin_table.filter_by_category(self._current_category)
+
+        except Exception as e:  # noqa: BLE001
+            QMessageBox.warning(
+                self, "Category Removal Failed", f"Failed to remove plugins: {e}"
+            )
+
+    def _assign_plugins_to_category(
+        self,
+        plugins: list[AudioComponent],
+        category_path: str,
+        is_move: bool,  # noqa: FBT001
+    ) -> None:
+        if not self._logic:
+            return
+
+        try:
+            if backup_manager.should_create_auto_backup():
+                action = "Moving" if is_move else "Assigning"
+                backup_manager.create_backup(
+                    BackupTrigger.AUTO,
+                    f"Before {action.lower()} {len(plugins)} plugin(s) to category",
+                )
+
+            if category_path:
+                category = self._logic.categories.get(category_path)
+                if not category:
+                    category = self._logic.introduce_category(category_path)
+            else:
+                category = self._logic.categories.get("")
+                if not category:
+                    category = self._logic.introduce_category("")
+
+            for plugin in plugins:
+                self._add_plugin_to_category(plugin, category, is_move)
+
+            self._logic.sync_category_plugin_amount(category)
+            self._sidebar.populate(self._logic)
+
+            if self._current_manufacturer:
+                self._plugin_table.filter_by_manufacturer(self._current_manufacturer)
+            else:
+                self._plugin_table.filter_by_category(self._current_category)
+
+        except Exception as e:  # noqa: BLE001
+            QMessageBox.warning(
+                self, "Category Assignment Failed", f"Failed to assign plugins: {e}"
+            )
+
+    def _add_plugin_to_category(
+        self,
+        plugin: AudioComponent,
+        category: Category,
+        is_move: bool,  # noqa: FBT001
+    ) -> None:
+        current_tags = getattr(plugin.tagset, "tags", None)
+        if current_tags is None:
+            plugin.tagset.load()
+            current_tags = plugin.tagset.tags
+
+        if is_move:
+            new_tags = {category.name: "user"}
+        else:
+            new_tags = dict(current_tags)
+            new_tags[category.name] = "user"
+
+        plugin.tagset.set_tags(new_tags)
+        plugin.load()
+
     def _on_search_results(self, results: list[SearchResult]) -> None:
         plugins = [r.plugin for r in results]
         self._plugin_table.filter_by_search_results(

src/illogical/ui/plugin_table.py

@@ -2,11 +2,13 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
-from PySide6.QtCore import Qt, Signal
+from PySide6.QtCore import QItemSelection, QPoint, Qt, QTimer, Signal
+from PySide6.QtGui import QCursor
 from PySide6.QtWidgets import (
     QAbstractItemView,
     QFrame,
     QHeaderView,
+    QMenu,
     QTableView,
     QVBoxLayout,
     QWidget,
@@ -19,14 +21,16 @@ from illogical.modules.models import (
     COL_SHORT_NAME,
     COL_TYPE,
     COL_VERSION,
+    CategoryTreeItem,
+    CategoryTreeModel,
     PluginTableModel,
 )
 from illogical.ui.search_bar import SearchBar
 
 if TYPE_CHECKING:
     from logic_plugin_manager import AudioComponent, Logic
-    from PySide6.QtCore import QModelIndex
+    from PySide6.QtCore import QEvent, QModelIndex
-    from PySide6.QtGui import QKeyEvent, QResizeEvent
+    from PySide6.QtGui import QKeyEvent, QMouseEvent, QResizeEvent
 
 
 KVK_J = 0x26
@@ -35,6 +39,49 @@ KVK_K = 0x28
 
 class _VimTableView(QTableView):
     enter_pressed = Signal()
+    context_menu_requested = Signal(QPoint)
+
+    def __init__(self, parent: QWidget | None = None) -> None:
+        super().__init__(parent)
+        self._anchor_row: int | None = None
+        self.setDragEnabled(True)
+        self.setDragDropMode(QAbstractItemView.DragDropMode.DragOnly)
+        self.setDefaultDropAction(Qt.DropAction.CopyAction)
+        self.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)
+        self.customContextMenuRequested.connect(self._on_context_menu)
+
+    def _on_context_menu(self, pos: QPoint) -> None:
+        if self.selectionModel().hasSelection():
+            self.context_menu_requested.emit(pos)
+
+    def event(self, e: QEvent) -> bool:
+        from PySide6.QtCore import QEvent as QEventType  # noqa: PLC0415
+        from PySide6.QtGui import QKeyEvent as QKeyEventType  # noqa: PLC0415
+
+        if (
+            e.type() == QEventType.Type.ShortcutOverride
+            and isinstance(e, QKeyEventType)
+            and e.key() == Qt.Key.Key_A
+            and e.modifiers() == Qt.KeyboardModifier.ControlModifier
+        ):
+            e.accept()
+            return True
+        return super().event(e)
+
+    def _select_all_rows(self) -> None:
+        row_count = self.model().rowCount()
+        if row_count > 0:
+            top_left = self.model().index(0, 0)
+            bottom_right = self.model().index(
+                row_count - 1, self.model().columnCount() - 1
+            )
+            selection = QItemSelection(top_left, bottom_right)
+            self.selectionModel().select(
+                selection,
+                self.selectionModel().SelectionFlag.ClearAndSelect
+                | self.selectionModel().SelectionFlag.Rows,
+            )
+            self._anchor_row = 0
 
     def _select_row(self, row: int) -> None:
         index = self.model().index(row, 0)
@@ -43,21 +90,106 @@ class _VimTableView(QTableView):
             self.selectionModel().SelectionFlag.ClearAndSelect
             | self.selectionModel().SelectionFlag.Rows,
         )
+        self._anchor_row = row
+
+    def _extend_selection_to(self, row: int) -> None:
+        if self._anchor_row is None:
+            self._anchor_row = self.currentIndex().row()
+
+        start = min(self._anchor_row, row)
+        end = max(self._anchor_row, row)
+
+        self.selectionModel().clear()
+        for r in range(start, end + 1):
+            idx = self.model().index(r, 0)
+            self.selectionModel().select(
+                idx,
+                self.selectionModel().SelectionFlag.Select
+                | self.selectionModel().SelectionFlag.Rows,
+            )
+
+        index = self.model().index(row, 0)
+        self.selectionModel().setCurrentIndex(
+            index, self.selectionModel().SelectionFlag.NoUpdate
+        )
+
+    def mousePressEvent(self, event: QMouseEvent) -> None:  # noqa: N802
+        index = self.indexAt(event.position().toPoint())
+        if not index.isValid():
+            super().mousePressEvent(event)
+            return
+
+        mods = event.modifiers()
+        has_cmd = bool(mods & Qt.KeyboardModifier.ControlModifier)
+        has_shift = bool(mods & Qt.KeyboardModifier.ShiftModifier)
+
+        if has_cmd and not has_shift:
+            self.selectionModel().setCurrentIndex(
+                index,
+                self.selectionModel().SelectionFlag.Toggle
+                | self.selectionModel().SelectionFlag.Rows,
+            )
+            if self._anchor_row is None:
+                self._anchor_row = index.row()
+            event.accept()
+            return
+
+        if has_shift and self._anchor_row is not None:
+            self.selectionModel().clear()
+            start = min(self._anchor_row, index.row())
+            end = max(self._anchor_row, index.row())
+            for r in range(start, end + 1):
+                idx = self.model().index(r, 0)
+                self.selectionModel().select(
+                    idx,
+                    self.selectionModel().SelectionFlag.Select
+                    | self.selectionModel().SelectionFlag.Rows,
+                )
+            self.selectionModel().setCurrentIndex(
+                index, self.selectionModel().SelectionFlag.NoUpdate
+            )
+            event.accept()
+            return
+
+        self._anchor_row = index.row()
+        super().mousePressEvent(event)
 
     def keyPressEvent(self, event: QKeyEvent) -> None:  # noqa: N802
         vk = event.nativeVirtualKey()
         key = event.key()
+        mods = event.modifiers()
+        has_shift = bool(mods & Qt.KeyboardModifier.ShiftModifier)
+        has_alt = bool(mods & Qt.KeyboardModifier.AltModifier)
+        has_ctrl = bool(mods & Qt.KeyboardModifier.ControlModifier)
+
+        if has_ctrl and key == Qt.Key.Key_A:
+            self._select_all_rows()
+            event.accept()
+            return
+
+        if has_alt and key in (Qt.Key.Key_Return, Qt.Key.Key_Enter):
+            self.context_menu_requested.emit(QPoint(0, 0))
+            event.accept()
+            return
 
         if vk == KVK_J or key == Qt.Key.Key_Down:
             current = self.currentIndex()
             if current.row() < self.model().rowCount() - 1:
-                self._select_row(current.row() + 1)
+                new_row = current.row() + 1
+                if has_shift:
+                    self._extend_selection_to(new_row)
+                else:
+                    self._select_row(new_row)
             event.accept()
             return
         if vk == KVK_K or key == Qt.Key.Key_Up:
             current = self.currentIndex()
             if current.row() > 0:
-                self._select_row(current.row() - 1)
+                new_row = current.row() - 1
+                if has_shift:
+                    self._extend_selection_to(new_row)
+                else:
+                    self._select_row(new_row)
             event.accept()
             return
         if key in (Qt.Key.Key_Return, Qt.Key.Key_Enter):
@@ -66,14 +198,28 @@ class _VimTableView(QTableView):
             return
         super().keyPressEvent(event)
 
+    def get_selected_plugins(self) -> list[AudioComponent]:
+        model = self.model()
+        if not isinstance(model, PluginTableModel):
+            return []
+        plugins = []
+        for index in self.selectionModel().selectedRows():
+            plugin = model.get_plugin(index.row())
+            if plugin:
+                plugins.append(plugin)
+        return plugins
+
 
 class PluginTableView(QWidget):
     search_changed = Signal(str)
     plugin_selected = Signal(object)
     edit_requested = Signal(object, int, str)
+    category_assignment_requested = Signal(list, str, bool)
+    category_removal_requested = Signal(list)
 
     def __init__(self, parent: QWidget | None = None) -> None:
         super().__init__(parent)
+        self._category_tree: CategoryTreeModel | None = None
 
         layout = QVBoxLayout(self)
         layout.setContentsMargins(16, 0, 16, 16)
@@ -90,7 +236,7 @@ class PluginTableView(QWidget):
         self._table.setModel(self._model)
         self._table.setAlternatingRowColors(True)
         self._table.setSelectionBehavior(QAbstractItemView.SelectionBehavior.SelectRows)
-        self._table.setSelectionMode(QAbstractItemView.SelectionMode.SingleSelection)
+        self._table.setSelectionMode(QAbstractItemView.SelectionMode.ExtendedSelection)
         self._table.setShowGrid(False)
         self._table.verticalHeader().setVisible(False)
         self._table.horizontalHeader().setStretchLastSection(True)
@@ -138,6 +284,7 @@ class PluginTableView(QWidget):
 
         self._table.selectionModel().currentChanged.connect(self._on_current_changed)
         self._table.enter_pressed.connect(self._on_enter_pressed)
+        self._table.context_menu_requested.connect(self._on_context_menu_requested)
 
     def _on_current_changed(self, current: QModelIndex, _previous: QModelIndex) -> None:
         if current.isValid():
@@ -152,6 +299,137 @@ class PluginTableView(QWidget):
             if plugin:
                 self.plugin_selected.emit(plugin)
 
+    def set_category_tree(self, tree: CategoryTreeModel) -> None:
+        self._category_tree = tree
+
+    def _on_context_menu_requested(self, pos: QPoint) -> None:  # noqa: ARG002
+        plugins = self._table.get_selected_plugins()
+        if not plugins:
+            return
+        self._show_context_menu(plugins)
+
+    def _show_context_menu(self, plugins: list[AudioComponent]) -> None:
+        import pyqt_liquidglass as glass  # noqa: PLC0415
+
+        opts = glass.GlassOptions(corner_radius=10.0)
+
+        def apply_glass_on_show(m: QMenu) -> None:
+            glass.prepare_window_for_glass(m)
+            glass.apply_glass_to_window(m, opts)
+
+        menu = QMenu(self)
+        menu.setStyleSheet(self._get_glass_menu_stylesheet())
+        glass.prepare_window_for_glass(menu)
+
+        assign_menu = menu.addMenu("Assign to")
+        assign_menu.setStyleSheet(self._get_glass_menu_stylesheet())
+        assign_menu.aboutToShow.connect(lambda: apply_glass_on_show(assign_menu))
+        self._build_category_submenu(assign_menu, plugins, is_move=False)
+
+        has_categories = any(p.categories for p in plugins)
+        if has_categories:
+            move_menu = menu.addMenu("Move to")
+            move_menu.setStyleSheet(self._get_glass_menu_stylesheet())
+            move_menu.aboutToShow.connect(lambda: apply_glass_on_show(move_menu))
+            self._build_category_submenu(move_menu, plugins, is_move=True)
+
+            menu.addSeparator()
+            remove_action = menu.addAction("Remove from current category")
+            remove_action.triggered.connect(
+                lambda: self._on_remove_from_category(plugins)
+            )
+
+        menu.popup(QCursor.pos())
+        QTimer.singleShot(0, lambda: glass.apply_glass_to_window(menu, opts))
+
+    def _build_category_submenu(
+        self, menu: QMenu, plugins: list[AudioComponent], *, is_move: bool
+    ) -> None:
+        import pyqt_liquidglass as glass  # noqa: PLC0415
+
+        if self._category_tree is None:
+            return
+
+        def apply_glass_on_show(submenu: QMenu) -> None:
+            glass.prepare_window_for_glass(submenu)
+            opts = glass.GlassOptions(corner_radius=8.0)
+            glass.apply_glass_to_window(submenu, opts)
+
+        def build_from_item(parent_menu: QMenu, item: CategoryTreeItem) -> None:
+            for child in item.children:
+                if child.full_path == "Top Level":
+                    action = parent_menu.addAction("Top Level")
+                    action.triggered.connect(
+                        lambda _=None, p=plugins, m=is_move: self._on_category_action(
+                            p, "", m
+                        )
+                    )
+                elif child.children:
+                    submenu = parent_menu.addMenu(child.name)
+                    submenu.setStyleSheet(self._get_glass_menu_stylesheet())
+                    submenu.aboutToShow.connect(
+                        lambda s=submenu: apply_glass_on_show(s)
+                    )
+
+                    self_action = submenu.addAction(f"{child.name}")
+                    self_action.triggered.connect(
+                        lambda _=None, p=plugins, c=child.full_path, m=is_move: (
+                            self._on_category_action(p, c, m)
+                        )
+                    )
+                    submenu.addSeparator()
+                    build_from_item(submenu, child)
+                else:
+                    action = parent_menu.addAction(child.name)
+                    action.triggered.connect(
+                        lambda _=None, p=plugins, c=child.full_path, m=is_move: (
+                            self._on_category_action(p, c, m)
+                        )
+                    )
+
+        build_from_item(menu, self._category_tree.root_item)
+
+    def _on_category_action(
+        self,
+        plugins: list[AudioComponent],
+        category_path: str,
+        is_move: bool,  # noqa: FBT001
+    ) -> None:
+        self.category_assignment_requested.emit(plugins, category_path, is_move)
+
+    def _on_remove_from_category(self, plugins: list[AudioComponent]) -> None:
+        self.category_removal_requested.emit(plugins)
+
+    def _get_glass_menu_stylesheet(self) -> str:
+        return """
+            QMenu {
+                background: transparent;
+                border: none;
+                border-radius: 10px;
+                padding: 4px 2px;
+            }
+            QMenu::item {
+                padding: 4px 12px 4px 6px;
+                margin: 0px 2px;
+                border-radius: 6px;
+                color: rgba(255, 255, 255, 0.9);
+            }
+            QMenu::item:selected {
+                background-color: rgba(255, 255, 255, 0.15);
+            }
+            QMenu::separator {
+                height: 1px;
+                background: rgba(255, 255, 255, 0.12);
+                margin: 4px 10px;
+            }
+            QMenu::right-arrow {
+                width: 8px;
+                height: 8px;
+                right: 9px;
+                top: -1px;
+            }
+        """
+
     def set_plugins(self, logic: Logic) -> None:
         self._model.set_plugins(logic)
         self._resize_columns()

src/illogical/ui/sidebar.py

@@ -4,7 +4,14 @@ from typing import TYPE_CHECKING
 
 from AppKit import NSColor  # type: ignore[attr-defined]
 from PySide6.QtCore import QModelIndex, QPoint, QRect, Qt, QTimer, Signal
-from PySide6.QtGui import QCursor, QFont
+from PySide6.QtGui import (
+    QCursor,
+    QDragEnterEvent,
+    QDragLeaveEvent,
+    QDragMoveEvent,
+    QDropEvent,
+    QFont,
+)
 from PySide6.QtWidgets import (
     QAbstractItemView,
     QFrame,
@@ -23,6 +30,7 @@ from PySide6.QtWidgets import (
 )
 
 from illogical.modules.models import (
+    PLUGIN_MIME_TYPE,
     CategoryTreeItem,
     CategoryTreeModel,
     ManufacturerFilterProxy,
@@ -50,12 +58,13 @@ class _VimTreeView(QTreeView):
         self.setDragEnabled(True)
         self.setAcceptDrops(True)
         self.setDropIndicatorShown(True)
-        self.setDragDropMode(QAbstractItemView.DragDropMode.InternalMove)
+        self.setDragDropMode(QAbstractItemView.DragDropMode.DragDrop)
         self.setDefaultDropAction(Qt.DropAction.MoveAction)
         self.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)
         self.customContextMenuRequested.connect(self._on_context_menu_requested)
         self._expanded_paths: set[str] = set()
         self.context_menu_path: str | None = None
+        self.drop_target_path: str | None = None
 
     def setModel(self, model: CategoryTreeModel | None) -> None:  # noqa: N802
         old_model = self.model()
@@ -124,6 +133,36 @@ class _VimTreeView(QTreeView):
                 return
         super().mouseDoubleClickEvent(event)
 
+    def dragEnterEvent(self, event: QDragEnterEvent) -> None:  # noqa: N802
+        if event.mimeData().hasFormat(PLUGIN_MIME_TYPE):
+            event.acceptProposedAction()
+        else:
+            super().dragEnterEvent(event)
+
+    def dragMoveEvent(self, event: QDragMoveEvent) -> None:  # noqa: N802
+        index = self.indexAt(event.position().toPoint())
+        if event.mimeData().hasFormat(PLUGIN_MIME_TYPE):
+            if index.isValid():
+                item: CategoryTreeItem = index.internalPointer()
+                self.drop_target_path = item.full_path
+            else:
+                self.drop_target_path = None
+            self.viewport().update()
+            event.acceptProposedAction()
+        else:
+            self.drop_target_path = None
+            super().dragMoveEvent(event)
+
+    def dragLeaveEvent(self, event: QDragLeaveEvent) -> None:  # noqa: N802
+        self.drop_target_path = None
+        self.viewport().update()
+        super().dragLeaveEvent(event)
+
+    def dropEvent(self, event: QDropEvent) -> None:  # noqa: N802
+        self.drop_target_path = None
+        self.viewport().update()
+        super().dropEvent(event)
+
     def keyPressEvent(self, event: QKeyEvent) -> None:  # noqa: N802, C901, PLR0911, PLR0912
         vk = event.nativeVirtualKey()
         key = event.key()
@@ -365,7 +404,11 @@ class _CategoryDelegate(QStyledItemDelegate):
             isinstance(tree_view, _VimTreeView)
             and tree_view.context_menu_path == full_path
         )
-        if is_context_target:
+        is_drop_target = (
+            isinstance(tree_view, _VimTreeView)
+            and tree_view.drop_target_path == full_path
+        )
+        if is_context_target or is_drop_target:
             painter.save()
             path = QPainterPath()
             path.addRoundedRect(option.rect.toRectF(), 4, 4)
@@ -695,6 +738,10 @@ class Sidebar(QWidget):
         self._category_model.build_from_plugins(logic)
         self._manufacturer_model.build_from_plugins(logic)
 
+    @property
+    def category_model(self) -> CategoryTreeModel:
+        return self._category_model
+
     def _clear_selections(self) -> None:
         self._category_tree.clearSelection()
         self._manufacturer_list.clearSelection()