Configurable slideshow monitor in Settings > General

Dropdown lists all monitors. Default: same as app window.
Select a specific monitor to always open slideshow there.

booru_viewer/gui/app.py

@@ -1111,7 +1111,8 @@ class BooruApp(QMainWindow):
         from .preview import FullscreenPreview
         cols = self._grid._flow.columns
         show_actions = self._stack.currentIndex() != 2
-        self._fullscreen_window = FullscreenPreview(grid_cols=cols, show_actions=show_actions, parent=self)
+        monitor = self._db.get_setting("slideshow_monitor")
+        self._fullscreen_window = FullscreenPreview(grid_cols=cols, show_actions=show_actions, monitor=monitor, parent=self)
         self._fullscreen_window.navigate.connect(self._navigate_fullscreen)
         if show_actions:
             self._fullscreen_window.bookmark_requested.connect(self._bookmark_from_preview)

booru_viewer/gui/preview.py

@@ -30,7 +30,7 @@ class FullscreenPreview(QMainWindow):
     save_toggle_requested = Signal()  # save or unsave depending on state
     closed = Signal()
 
-    def __init__(self, grid_cols: int = 3, show_actions: bool = True, parent=None) -> None:
+    def __init__(self, grid_cols: int = 3, show_actions: bool = True, monitor: str = "", parent=None) -> None:
         super().__init__(parent, Qt.WindowType.Window)
         self.setWindowTitle("booru-viewer — Fullscreen")
         self.setMinimumSize(640, 480)
@@ -84,10 +84,19 @@ class FullscreenPreview(QMainWindow):
 
         from PySide6.QtWidgets import QApplication
         QApplication.instance().installEventFilter(self)
-        # Show on the same monitor as the parent window
+        # Pick target monitor
-        if parent and parent.screen():
+        target_screen = None
-            self.setScreen(parent.screen())
+        if monitor and monitor != "Same as app":
-            self.setGeometry(parent.screen().geometry())
+            for screen in QApplication.screens():
+                label = f"{screen.name()} ({screen.size().width()}x{screen.size().height()})"
+                if label == monitor:
+                    target_screen = screen
+                    break
+        if not target_screen and parent and parent.screen():
+            target_screen = parent.screen()
+        if target_screen:
+            self.setScreen(target_screen)
+            self.setGeometry(target_screen.geometry())
         self.showFullScreen()
 
     def update_state(self, bookmarked: bool, saved: bool) -> None:

booru_viewer/gui/settings.py

@@ -115,6 +115,19 @@ class SettingsDialog(QDialog):
         self._prefetch.setChecked(self._db.get_setting_bool("prefetch_adjacent"))
         form.addRow("", self._prefetch)
 
+        # Slideshow monitor
+        from PySide6.QtWidgets import QApplication
+        self._monitor_combo = QComboBox()
+        self._monitor_combo.addItem("Same as app")
+        for i, screen in enumerate(QApplication.screens()):
+            self._monitor_combo.addItem(f"{screen.name()} ({screen.size().width()}x{screen.size().height()})")
+        current_monitor = self._db.get_setting("slideshow_monitor")
+        if current_monitor:
+            idx = self._monitor_combo.findText(current_monitor)
+            if idx >= 0:
+                self._monitor_combo.setCurrentIndex(idx)
+        form.addRow("Slideshow monitor:", self._monitor_combo)
+
         # File dialog platform (Linux only)
         self._file_dialog_combo = None
         if not IS_WINDOWS:
@@ -664,6 +677,7 @@ class SettingsDialog(QDialog):
         self._db.set_setting("default_score", str(self._default_score.value()))
         self._db.set_setting("preload_thumbnails", "1" if self._preload.isChecked() else "0")
         self._db.set_setting("prefetch_adjacent", "1" if self._prefetch.isChecked() else "0")
+        self._db.set_setting("slideshow_monitor", self._monitor_combo.currentText())
         self._db.set_setting("library_dir", self._library_dir.text().strip())
         self._db.set_setting("max_cache_mb", str(self._max_cache.value()))
         self._db.set_setting("auto_evict", "1" if self._auto_evict.isChecked() else "0")