Qt receive_tab: fix receive_tabs widget on macOS

QTabWidget with "West" tab pos and horizontal text looks completely broken on macOS
(despite looking good on e.g. Ubuntu GNOME and Windows).

The alternative here looks ok on all three OSes.

fixes https://github.com/spesmilo/electrum/issues/7908

electrum/gui/qt/receive_tab.py

@@ -155,7 +155,7 @@ class ReceiveTab(QWidget, MessageBoxMixin, Logger):
 
         from .util import VTabWidget
         self.receive_tabs = VTabWidget()
-        self.receive_tabs.setMinimumHeight(ReceiveTabWidget.min_size.height() + 4) # for margins
+        #self.receive_tabs.setMinimumHeight(ReceiveTabWidget.min_size.height() + 4) # for margins
         self.receive_tabs.addTab(self.receive_URI_widget, read_QIcon("link.png"), _('URI'))
         self.receive_tabs.addTab(self.receive_address_widget, read_QIcon("bitcoin.png"), _('Address'))
         self.receive_tabs.addTab(self.receive_lightning_widget, read_QIcon("lightning.png"), _('Lightning'))
@@ -392,7 +392,7 @@ class ReceiveTab(QWidget, MessageBoxMixin, Logger):
 class ReceiveTabWidget(QWidget):
     min_size = QSize(200, 200)
 
-    def __init__(self, receive_tab: 'ReceiveTab', textedit, qr, help_widget):
+    def __init__(self, receive_tab: 'ReceiveTab', textedit: QWidget, qr: QWidget, help_widget: QWidget):
         self.textedit = textedit
         self.qr = qr
         self.help_widget = help_widget

electrum/gui/qt/util.py

@@ -12,6 +12,7 @@ from functools import partial, lru_cache, wraps
 from typing import (NamedTuple, Callable, Optional, TYPE_CHECKING, Union, List, Dict, Any,
                     Sequence, Iterable, Tuple)
 
+from PyQt5 import QtWidgets, QtCore
 from PyQt5.QtGui import (QFont, QColor, QCursor, QPixmap, QStandardItem, QImage,
                          QPalette, QIcon, QFontMetrics, QShowEvent, QPainter, QHelpEvent)
 from PyQt5.QtCore import (Qt, QPersistentModelIndex, QModelIndex, pyqtSignal,
@@ -24,7 +25,7 @@ from PyQt5.QtWidgets import (QPushButton, QLabel, QMessageBox, QHBoxLayout,
                              QFileDialog, QWidget, QToolButton, QTreeView, QPlainTextEdit,
                              QHeaderView, QApplication, QToolTip, QTreeWidget, QStyledItemDelegate,
                              QMenu, QStyleOptionViewItem, QLayout, QLayoutItem, QAbstractButton,
-                             QGraphicsEffect, QGraphicsScene, QGraphicsPixmapItem)
+                             QGraphicsEffect, QGraphicsScene, QGraphicsPixmapItem, QSizePolicy)
 
 from electrum.i18n import _, languages
 from electrum.util import FileImportFailed, FileExportFailed, make_aiohttp_session, resource_path
@@ -1570,54 +1571,75 @@ class ImageGraphicsEffect(QObject):
         return result
 
 
-# vertical tabs
-# from https://stackoverflow.com/questions/51230544/pyqt5-how-to-set-tabwidget-west-but-keep-the-text-horizontal
-from PyQt5 import QtWidgets, QtCore
-
-class VTabBar(QtWidgets.QTabBar):
-
-    def tabSizeHint(self, index):
-        s = QtWidgets.QTabBar.tabSizeHint(self, index)
-        s.transpose()
-        return s
-
-    def paintEvent(self, event):
-        painter = QtWidgets.QStylePainter(self)
-        opt = QtWidgets.QStyleOptionTab()
-
-        for i in range(self.count()):
-            self.initStyleOption(opt, i)
-            painter.drawControl(QtWidgets.QStyle.CE_TabBarTabShape, opt)
-            painter.save()
-
-            s = opt.rect.size()
-            s.transpose()
-            r = QtCore.QRect(QtCore.QPoint(), s)
-            r.moveCenter(opt.rect.center())
-            opt.rect = r
-
-            c = self.tabRect(i).center()
-            painter.translate(c)
-            painter.rotate(90)
-            painter.translate(-c)
-            painter.drawControl(QtWidgets.QStyle.CE_TabBarTabLabel, opt);
-            painter.restore()
-
-
-class VTabWidget(QtWidgets.QTabWidget):
-    def __init__(self, *args, **kwargs):
-        QtWidgets.QTabWidget.__init__(self, *args, **kwargs)
-        self.setTabBar(VTabBar(self))
-        self.setTabPosition(QtWidgets.QTabWidget.West)
-
+class SquareTabWidget(QtWidgets.QTabWidget):
     def resizeEvent(self, e):
         # keep square aspect ratio when resized
         size = e.size()
-        w = self.tabBar().width() + size.height()
+        w = size.height()
+        w += self.tabBar().width() if self.tabBar().isVisible() else 0
         self.setFixedWidth(w)
         return super().resizeEvent(e)
 
 
+class VTabWidget(QWidget):
+    """QtWidgets.QTabWidget alternative with "West" tab positions and horizontal tab-text."""
+    def __init__(self):
+        QWidget.__init__(self)
+
+        hbox = QHBoxLayout()
+        self.setLayout(hbox)
+        hbox.setContentsMargins(0, 0, 0, 0)
+        hbox.setSpacing(0)
+
+        self._tabs_vbox = tabs_vbox = QVBoxLayout()
+        self._tab_btns = []  # type: List[QPushButton]
+        tabs_vbox.setContentsMargins(0, 0, 0, 0)
+        tabs_vbox.setSpacing(0)
+
+        _tabs_vbox_outer_w = QWidget()
+        _tabs_vbox_outer = QVBoxLayout()
+        _tabs_vbox_outer_w.setLayout(_tabs_vbox_outer)
+        _tabs_vbox_outer_w.setSizePolicy(QSizePolicy(QSizePolicy.Maximum, _tabs_vbox_outer_w.sizePolicy().verticalPolicy()))
+        _tabs_vbox_outer.setContentsMargins(0, 0, 0, 0)
+        _tabs_vbox_outer.setSpacing(0)
+        _tabs_vbox_outer.addLayout(tabs_vbox)
+        _tabs_vbox_outer.addStretch(1)
+
+        self.content_w = content_w = SquareTabWidget()
+        content_w.setStyleSheet("QTabBar::tab {height: 0px;}")  # TODO Linux/mac: still insufficient to rm top padding...
+        content_w.tabBar().hide()
+
+        hbox.addStretch(1)
+        hbox.addWidget(_tabs_vbox_outer_w)
+        hbox.addWidget(content_w)
+
+        self.currentChanged = content_w.currentChanged
+        self.currentIndex = content_w.currentIndex
+
+    def addTab(self, widget: QWidget, icon: QIcon, text: str):
+        btn = QPushButton(icon, text)
+        btn.setCheckable(True)
+        btn.setSizePolicy(QSizePolicy.Preferred, btn.sizePolicy().verticalPolicy())
+
+        def on_btn_click():
+            self.content_w.setCurrentIndex(idx)
+            for btn2 in self._tab_btns:
+                if btn2 != btn:
+                    btn2.setChecked(False)
+        btn.clicked.connect(on_btn_click)
+        idx = len(self._tab_btns)
+        self._tab_btns.append(btn)
+
+        self._tabs_vbox.addWidget(btn)
+        self.content_w.addTab(widget, "")
+
+    def setTabIcon(self, idx: int, icon: QIcon):
+        self._tab_btns[idx].setIcon(icon)
+
+    def setCurrentIndex(self, idx: int):
+        self._tab_btns[idx].click()
+
+
 class QtEventListener(EventListener):
 
     qt_callback_signal = QtCore.pyqtSignal(tuple)