feat(thumbnail grid): arrow key navigation & selection history

src/tagstudio/qt/thumb_grid_layout.py

@@ -2,6 +2,7 @@
 import time
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, override
+from collections import deque
 
 from PySide6.QtCore import QPoint, QRect, QSize
 from PySide6.QtGui import QPixmap
@@ -17,6 +18,27 @@
 if TYPE_CHECKING:
     from tagstudio.qt.ts_qt import QtDriver
 
+#number of selection states to store (for undo/redo selection)
+MAX_HISTORY = 30
+
+def log_selection(method):
+    #decorator to keep a history of selection states
+    def wrapper(self, *args, **kwargs):
+        # Only log if the current state differs from the last
+        if (
+            self._selected
+            and (
+                not self._selection_history
+                or self._selection_history[-1] != self._selected
+            )
+        ):
+            # copy to avoid mutation issues
+            self._selection_history.append(dict(self._selected))
+            if self._undo_selection_history:
+                # clear undo history
+                self._undo_selection_history.clear()
+        return method(self, *args, **kwargs)
+    return wrapper
 
 class ThumbGridLayout(QLayout):
     def __init__(self, driver: "QtDriver", scroll_area: QScrollArea) -> None:
@@ -28,8 +50,12 @@ def __init__(self, driver: "QtDriver", scroll_area: QScrollArea) -> None:
         self._items: list[QLayoutItem] = []
         # Entry.id -> _entry_ids[index]
         self._selected: dict[int, int] = {}
+        self._selection_history:deque[dict[int, int]] = deque(maxlen=MAX_HISTORY)
+        self._undo_selection_history:deque[dict[int, int]] = deque(maxlen=MAX_HISTORY)
         # _entry_ids[index]
         self._last_selected: int | None = None
+        self._is_shift_key_down: bool = False
+        self._shift_select_start: int | None = None
 
         self._entry_ids: list[int] = []
         self._entries: dict[int, Entry] = {}
@@ -43,6 +69,7 @@ def __init__(self, driver: "QtDriver", scroll_area: QScrollArea) -> None:
         self._renderer: ThumbRenderer = ThumbRenderer(self.driver)
         self._renderer.updated.connect(self._on_rendered)
         self._render_cutoff: float = 0.0
+        self._per_row: int = 0
 
         # _entry_ids[StartIndex:EndIndex]
         self._last_page_update: tuple[int, int] | None = None
@@ -52,6 +79,8 @@ def set_entries(self, entry_ids: list[int]):
 
         self._selected.clear()
         self._last_selected = None
+        self._selection_history.clear()
+        self._undo_selection_history.clear()
 
         self._entry_ids = entry_ids
         self._entries.clear()
@@ -83,6 +112,107 @@ def set_entries(self, entry_ids: list[int]):
 
         self._last_page_update = None
 
+    def undo_selection(self):
+        """Loads selection state from history."""
+        if self._selection_history:
+            self._undo_selection_history.append(dict(self._selected))
+            selected = self._selection_history.pop()
+            for id in self._selected:
+                if id not in selected:
+                    self._set_selected(id, value=False)
+            for id in selected:
+                self._set_selected(id)
+                self._last_selected = selected[id]
+            self._selected = selected
+
+
+    def redo_selection(self):
+        """Loads selection state from undo history."""
+        if self._undo_selection_history:
+            self._selection_history.append(dict(self._selected))
+            selected = self._undo_selection_history.pop()
+            for id in self._selected:
+                if id not in selected:
+                    self._set_selected(id, value=False)
+            for id in selected:
+                self._set_selected(id)
+                self._last_selected = selected[id]
+            self._selected = selected
+
+    def handle_shift_key_event(self, is_shift_key_pressed:bool):
+        """Track last_selected and input for shift selecting with directional select."""
+        self._is_shift_key_down = is_shift_key_pressed
+        if is_shift_key_pressed:    
+            self._shift_select_start = self._last_selected
+        else:
+            self._shift_select_start = None
+
+    @log_selection
+    def _enact_directional_select(self,target_index:int):
+        """Common logic for select_next, prev, up, down.
+
+        Handles multi-select (shift+arrow key).
+        """
+        selection_start_index = None
+        if self._is_shift_key_down:
+            #find the multi-select start point
+            if self._shift_select_start is not None:
+                selection_start_index = self._shift_select_start
+            elif self._last_selected is not None:
+                self._shift_select_start = self._last_selected
+                selection_start_index = self._last_selected
+        target_indexes = [target_index]
+        if selection_start_index is not None:
+            #get all indexes from start point to target_index
+            target_indexes = list(
+                range(
+                    min(selection_start_index, target_index),
+                    max(selection_start_index, target_index) + 1
+                )
+            )
+        #update selection
+        selected = {self._entry_ids[i]: i for i in target_indexes}
+        for id in self._selected:
+            if id not in selected:
+                self._set_selected(id, value=False)
+        for id in selected:
+            self._set_selected(id)
+        self._selected = selected
+        self._last_selected = target_index
+        #return selected because this callback is handled in main_window.py (not ts_qt.py)
+        return list(self._selected.keys())
+
+    def select_next(self):
+        target_index = 0
+        if self._last_selected is not None:
+            target_index = min(self._last_selected+1, len(self._entry_ids)-1)
+        return self._enact_directional_select(target_index)
+
+    def select_prev(self):
+        target_index = len(self._entry_ids)-1
+        if self._last_selected is not None:
+            target_index = max(self._last_selected-1, 0)
+        return self._enact_directional_select(target_index)
+
+    def select_up(self):
+        target_index = len(self._entry_ids)-1
+        if self._last_selected is not None:
+            target_index = max(
+                self._last_selected-self._per_row,
+                self._last_selected % self._per_row
+            )
+        return self._enact_directional_select(target_index)
+
+    def select_down(self):
+        target_index = 0
+        if self._last_selected is not None:
+            target_index = min(
+                self._last_selected+self._per_row,
+                len(self._entry_ids)-1
+            )
+        return self._enact_directional_select(target_index)
+
+    @log_selection
     def select_all(self):
         self._selected.clear()
         for index, id in enumerate(self._entry_ids):
@@ -92,6 +222,7 @@ def select_all(self):
         for entry_id in self._entry_items:
             self._set_selected(entry_id)
 
+    @log_selection
     def select_inverse(self):
         selected = {}
         for index, id in enumerate(self._entry_ids):
@@ -107,6 +238,7 @@ def select_inverse(self):
 
         self._selected = selected
 
+    @log_selection
     def select_entry(self, entry_id: int):
         if entry_id in self._selected:
             index = self._selected.pop(entry_id)
@@ -123,6 +255,7 @@ def select_entry(self, entry_id: int):
             self._last_selected = index
             self._set_selected(entry_id)
 
+    @log_selection
     def select_to_entry(self, entry_id: int):
         index = self._entry_ids.index(entry_id)
         if len(self._selected) == 0:
@@ -144,6 +277,7 @@ def select_to_entry(self, entry_id: int):
             self._selected[entry_id] = i
             self._set_selected(entry_id)
 
+    @log_selection
     def clear_selected(self):
         for entry_id in self._entry_items:
             self._set_selected(entry_id, value=False)
@@ -240,7 +374,7 @@ def _size(self, width: int) -> tuple[int, int, int]:
         if width_offset == 0:
             return 0, 0, height_offset
         per_row = int(width / width_offset)
-
+        self._per_row = per_row
         return per_row, width_offset, height_offset
 
     @override

src/tagstudio/qt/ts_qt.py

@@ -429,6 +429,14 @@ def set_open_last_loaded_on_startup(checked: bool):
         self.main_window.menu_bar.select_inverse_action.triggered.connect(
             self.select_inverse_action_callback
         )
+
+        self.main_window.menu_bar.undo_selection_action.triggered.connect(
+            self.undo_selection_action_callback
+        )
+
+        self.main_window.menu_bar.redo_selection_action.triggered.connect(
+            self.redo_selection_action_callback
+        )
 
         self.main_window.menu_bar.clear_select_action.triggered.connect(
             self.clear_select_action_callback
@@ -852,6 +860,20 @@ def add_tags_to_selected_callback(self, tag_ids: list[int]):
         self.main_window.thumb_layout.add_tags(selected, tag_ids)
         self.lib.add_tags_to_entries(selected, tag_ids)
 
+    def undo_selection_action_callback(self):
+        """Undo most recent selection change."""
+        self.main_window.thumb_layout.undo_selection()
+        self.set_clipboard_menu_viability()
+        self.set_select_actions_visibility()
+        self.main_window.preview_panel.set_selection(self.selected, update_preview=True)
+
+    def redo_selection_action_callback(self):
+        """Redo most recent selection undo."""
+        self.main_window.thumb_layout.redo_selection()
+        self.set_clipboard_menu_viability()
+        self.set_select_actions_visibility()
+        self.main_window.preview_panel.set_selection(self.selected, update_preview=True)
+
     def delete_files_callback(self, origin_path: str | Path, origin_id: int | None = None):
         """Callback to send on or more files to the system trash.
 

src/tagstudio/qt/views/main_window.py

@@ -11,7 +11,7 @@
 from PIL import Image, ImageQt
 from PySide6 import QtCore
 from PySide6.QtCore import QMetaObject, QSize, QStringListModel, Qt
-from PySide6.QtGui import QAction, QPixmap
+from PySide6.QtGui import QAction, QPixmap, QKeyEvent
 from PySide6.QtWidgets import (
     QComboBox,
     QCompleter,
@@ -67,6 +67,8 @@ class MainMenuBar(QMenuBar):
     new_tag_action: QAction
     select_all_action: QAction
     select_inverse_action: QAction
+    undo_selection_action: QAction
+    redo_selection_action: QAction
     clear_select_action: QAction
     copy_fields_action: QAction
     paste_fields_action: QAction
@@ -215,6 +217,31 @@ def setup_edit_menu(self):
         self.select_inverse_action.setEnabled(False)
         self.edit_menu.addAction(self.select_inverse_action)
 
+        # Undo Selection
+        self.undo_selection_action = QAction(
+            Translations["select.undo"], self
+        )
+        self.undo_selection_action.setShortcut(
+            QtCore.QKeyCombination(
+                QtCore.Qt.Key.Key_R,
+            )
+        )
+        self.undo_selection_action.setToolTip("R")
+        self.edit_menu.addAction(self.undo_selection_action)
+
+        # Redo Selection
+        self.redo_selection_action = QAction(
+            Translations["select.redo"], self
+        )
+        self.redo_selection_action.setShortcut(
+            QtCore.QKeyCombination(
+                QtCore.Qt.KeyboardModifier(QtCore.Qt.KeyboardModifier.ShiftModifier),
+                QtCore.Qt.Key.Key_R,
+            )
+        )
+        self.redo_selection_action.setToolTip("Shift+R")
+        self.edit_menu.addAction(self.redo_selection_action)
+
         # Clear Selection
         self.clear_select_action = QAction(Translations["select.clear"], self)
         self.clear_select_action.setShortcut(QtCore.Qt.Key.Key_Escape)
@@ -450,6 +477,7 @@ class MainWindow(QMainWindow):
     def __init__(self, driver: "QtDriver", parent: QWidget | None = None) -> None:
         super().__init__(parent)
         self.rm = ResourceManager()
+        self.installEventFilter(self)
 
         # region Type declarations for variables that will be initialized in methods
         # initialized in setup_search_bar
@@ -689,6 +717,37 @@ def setup_status_bar(self):
 
     # endregion
 
+    #keyboard navigation of thumb_layout
+    def eventFilter(self, watched, event):
+        if isinstance(event, QKeyEvent):
+            key = event.key()
+            # KEY RELEASED
+            if event.type() == event.Type.KeyRelease:
+                if key == QtCore.Qt.Key.Key_Shift:
+                    self.thumb_layout.handle_shift_key_event(is_shift_key_pressed=False)
+            # KEY PRESSED
+            else:
+                if key == QtCore.Qt.Key.Key_Shift:
+                    self.thumb_layout.handle_shift_key_event(is_shift_key_pressed=True)
+                elif key == QtCore.Qt.Key.Key_Right:
+                    selected = self.thumb_layout.select_next()
+                    self.preview_panel.set_selection(selected, update_preview=True)
+                    return True
+                elif key == QtCore.Qt.Key.Key_Left:
+                    selected = self.thumb_layout.select_prev()
+                    self.preview_panel.set_selection(selected, update_preview=True)
+                    return True
+                elif key == QtCore.Qt.Key.Key_Up:
+                    selected = self.thumb_layout.select_up()
+                    self.preview_panel.set_selection(selected, update_preview=True)
+                    return True
+                elif key == QtCore.Qt.Key.Key_Down:
+                    selected = self.thumb_layout.select_down()
+                    self.preview_panel.set_selection(selected, update_preview=True)
+                    return True
+        return super().eventFilter(watched, event)
+
+
     def toggle_landing_page(self, enabled: bool):
         if enabled:
             self.entry_scroll_area.setHidden(True)

src/tagstudio/resources/translations/en.json

@@ -254,6 +254,8 @@
     "select.all": "Select All",
     "select.clear": "Clear Selection",
     "select.inverse": "Invert Selection",
+    "select.undo": "Undo Selection",
+    "select.redo": "Redo Selection",
     "settings.clear_thumb_cache.title": "Clear Thumbnail Cache",
     "settings.dateformat.english": "English",
     "settings.dateformat.international": "International",