Use platform-native button layout in dialogs and messageboxes (#3725)

* set button-layout prop in stylesheet

* fix lint

* check for and use non-default layout on linux before falling back

qt/aqt/stylesheets.py

@@ -1,7 +1,7 @@
 # Copyright: Ankitects Pty Ltd and contributors
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-from anki.utils import is_win
+from anki.utils import is_mac, is_win
 from aqt import colors, props
 from aqt.theme import ThemeManager
 
@@ -28,6 +28,19 @@ qlineargradient(
     """
 
 
+def button_layout(tm: ThemeManager):
+    # https://doc.qt.io/qt-6/stylesheet-reference.html#button-layout
+    if is_win:
+        return 0
+    elif is_mac:
+        return 1
+    # on linux, use non-default layout if available
+    if tm._default_button_layout:
+        return tm._default_button_layout
+    # fallback to GnomeLayout
+    return 3
+
+
 class CustomStyles:
     def general(self, tm: ThemeManager) -> str:
         return f"""
@@ -201,6 +214,9 @@ class CustomStyles:
     }}
     QPushButton:flat {{
         border: none;
+    }}
+    QDialogButtonBox {{
+        button-layout: {button_layout(tm)};
     }}
         """
 

qt/aqt/theme.py

@@ -21,6 +21,7 @@ from aqt.qt import (
     QPainter,
     QPalette,
     QPixmap,
+    QStyle,
     QStyleFactory,
     Qt,
     qtmajor,
@@ -62,6 +63,7 @@ class ThemeManager:
     _dark_mode_available: bool | None = None
     _default_style: str | None = None
     _current_widget_style: WidgetStyle | None = None
+    _default_button_layout: int | None = None
 
     def rtl(self) -> bool:
         return is_rtl(anki.lang.current_lang)
@@ -234,6 +236,9 @@ class ThemeManager:
             style = app.style()
             assert style is not None
             self._default_style = style.objectName()
+            self._default_button_layout = style.styleHint(
+                QStyle.StyleHint.SH_DialogButtonLayout
+            )
         self._apply_palette(app)
         self._apply_style(app)
         gui_hooks.theme_did_change()