Use QProxyStyle for TabBarStyle

Closes #812

This does *not* seem to help with the crashes in #5385 or #5124, weirdly
enough, but it still seems simpler, so why not do it.

1 files changed, 14 insertions, 49 deletions

diff --git a/qutebrowser/mainwindow/tabwidget.py b/qutebrowser/mainwindow/tabwidget.py
index b157fc07a..4d447ff48 100644
--- a/qutebrowser/mainwindow/tabwidget.py
+++ b/qutebrowser/mainwindow/tabwidget.py
@@ -26,9 +26,9 @@ from typing import Optional, Dict, Any
 
 from qutebrowser.qt.core import (pyqtSignal, pyqtSlot, Qt, QSize, QRect, QPoint,
                           QTimer, QUrl)
-from qutebrowser.qt.widgets import (QTabWidget, QTabBar, QSizePolicy, QCommonStyle,
+from qutebrowser.qt.widgets import (QTabWidget, QTabBar, QSizePolicy, QProxyStyle,
                              QStyle, QStylePainter, QStyleOptionTab,
-                             QStyleFactory)
+                             QStyleFactory, QCommonStyle)
 from qutebrowser.qt.gui import QIcon, QPalette, QColor
 
 from qutebrowser.utils import qtutils, objreg, utils, usertypes, log
@@ -775,7 +775,7 @@ class Layouts:
     indicator: QRect
 
 
-class TabBarStyle(QCommonStyle):
+class TabBarStyle(QProxyStyle):
 
     """Qt style used by TabBar to fix some issues with the default one.
 
@@ -783,45 +783,10 @@ class TabBarStyle(QCommonStyle):
         - Remove the focus rectangle Ubuntu draws on tabs.
         - Force text to be left-aligned even though Qt has "centered"
           hardcoded.
-
-    Unfortunately PyQt doesn't support QProxyStyle, so we need to do this the
-    hard way...
-
-    Based on:
-
-    https://stackoverflow.com/a/17294081
-    https://code.google.com/p/makehuman/source/browse/trunk/makehuman/lib/qtgui.py
     """
 
     ICON_PADDING = 4
 
-    def __init__(self):
-        """Initialize all functions we're not overriding.
-
-        This simply calls the corresponding function in self._style.
-        """
-        self._style = QStyleFactory.create('Fusion')
-        for method in ['drawComplexControl', 'drawItemPixmap',
-                       'generatedIconPixmap', 'hitTestComplexControl',
-                       'itemPixmapRect', 'itemTextRect', 'polish', 'styleHint',
-                       'subControlRect', 'unpolish', 'drawItemText',
-                       'sizeFromContents', 'drawPrimitive']:
-            setattr(self, method, functools.partial(self._fusion_call, method))
-        super().__init__()
-
-    def _fusion_call(self, method: str, *args: Any) -> Any:
-        """Wrap a call to self._style to log RuntimeErrors.
-
-        WORKAROUND for https://github.com/qutebrowser/qutebrowser/issues/5124
-        """
-        target = getattr(self._style, method)
-        try:
-            return target(*args)
-        except RuntimeError:
-            info = f"self._style.{method}{args}"
-            log.misc.warning(f"Got RuntimeError while calling {info}")
-            raise
-
     def _draw_indicator(self, layouts, opt, p):
         """Draw the tab indicator.
 
@@ -849,7 +814,7 @@ class TabBarStyle(QCommonStyle):
         icon_state = (QIcon.State.On if opt.state & QStyle.StateFlag.State_Selected
                       else QIcon.State.Off)
         icon = opt.icon.pixmap(opt.iconSize, icon_mode, icon_state)
-        self._style.drawItemPixmap(p, layouts.icon, Qt.AlignmentFlag.AlignCenter, icon)
+        self.baseStyle().drawItemPixmap(p, layouts.icon, Qt.AlignmentFlag.AlignCenter, icon)
 
     def drawControl(self, element, opt, p, widget=None):
         """Override drawControl to draw odd tabs in a different color.
@@ -866,7 +831,7 @@ class TabBarStyle(QCommonStyle):
         if element not in [QStyle.ControlElement.CE_TabBarTab, QStyle.ControlElement.CE_TabBarTabShape,
                            QStyle.ControlElement.CE_TabBarTabLabel]:
             # Let the real style draw it.
-            self._style.drawControl(element, opt, p, widget)
+            self.baseStyle().drawControl(element, opt, p, widget)
             return
 
         layouts = self._tab_layout(opt)
@@ -881,15 +846,15 @@ class TabBarStyle(QCommonStyle):
         elif element == QStyle.ControlElement.CE_TabBarTabShape:
             p.fillRect(opt.rect, opt.palette.window())
             self._draw_indicator(layouts, opt, p)
-            # We use super() rather than self._style here because we don't want
+            # We use QCommonStyle rather than self.baseStyle() here because we don't want
             # any sophisticated drawing.
-            super().drawControl(QStyle.ControlElement.CE_TabBarTabShape, opt, p, widget)
+            QCommonStyle.drawControl(self, QStyle.ControlElement.CE_TabBarTabShape, opt, p, widget)
         elif element == QStyle.ControlElement.CE_TabBarTabLabel:
             if not opt.icon.isNull() and layouts.icon.isValid():
                 self._draw_icon(layouts, opt, p)
             alignment = (config.cache['tabs.title.alignment'] |
                          Qt.AlignmentFlag.AlignVCenter | Qt.TextFlag.TextHideMnemonic)
-            self._style.drawItemText(p,
+            self.baseStyle().drawItemText(p,
                                      layouts.text,
                                      int(alignment),
                                      opt.palette,
@@ -917,7 +882,7 @@ class TabBarStyle(QCommonStyle):
                       QStyle.PixelMetric.PM_TabBarScrollButtonWidth]:
             return 0
         else:
-            return self._style.pixelMetric(metric, option, widget)
+            return self.baseStyle().pixelMetric(metric, option, widget)
 
     def subElementRect(self, sr, opt, widget=None):
         """Override subElementRect to use our own _tab_layout implementation.
@@ -942,12 +907,12 @@ class TabBarStyle(QCommonStyle):
             # aligned properly. Otherwise, empty space will be shown after the
             # last tab even though the button width is set to 0
             #
-            # Need to use super() because we also use super() to render
+            # Need to use QCommonStyle here because we also use it to render
             # element in drawControl(); otherwise, we may get bit by
             # style differences...
-            return super().subElementRect(sr, opt, widget)
+            return QCommonStyle.subElementRect(self, sr, opt, widget)
         else:
-            return self._style.subElementRect(sr, opt, widget)
+            return self.baseStyle().subElementRect(sr, opt, widget)
 
     def _tab_layout(self, opt):
         """Compute the text/icon rect from the opt rect.
@@ -994,7 +959,7 @@ class TabBarStyle(QCommonStyle):
             text_rect.adjust(
                 icon_rect.width() + TabBarStyle.ICON_PADDING, 0, 0, 0)
 
-        text_rect = self._style.visualRect(opt.direction, opt.rect, text_rect)
+        text_rect = self.baseStyle().visualRect(opt.direction, opt.rect, text_rect)
         return Layouts(text=text_rect, icon=icon_rect,
                        indicator=indicator_rect)
 
@@ -1029,5 +994,5 @@ class TabBarStyle(QCommonStyle):
 
         icon_top = text_rect.center().y() + 1 - tab_icon_size.height() // 2
         icon_rect = QRect(QPoint(text_rect.left(), icon_top), tab_icon_size)
-        icon_rect = self._style.visualRect(opt.direction, opt.rect, icon_rect)
+        icon_rect = self.baseStyle().visualRect(opt.direction, opt.rect, icon_rect)
         return icon_rect