[Python] Make a mouse-slide border between the tab bar and the contents of the tab

I want to make a QTabWidget with horizontal tabs placed on the left, so that you can change the width of the tab bar with the mouse. To do this, I placed the qtabwidget on the right panel of the qsplitter, and the tabbar from this widget on the left. In general, everything works. But! In QTabWidget, a place is allocated for the tab bar, which is drawn elsewhere. I'm asking for help on how to change the behavior of QTabWidget so that it doesn't have a place for the tab bar. I've been thinking about what to write in the paintEvent method. I even got into the Qt source code, but I didn't figure it out, I just figured out that QStackedWidget is used to store widgets, but it can't be extracted outside.

import sys
from PySide2.QtWidgets import (
QApplication,
QMainWindow,
QSplitter,
QLabel,
QTabWidget,
QTabBar,
QStylePainter,
)
from PySide2 import QtWidgets
from PySide2 import QtCore
from PySide2 import QtGui
from PySide2.QtGui import QPainter, QPaintEvent
from PySide2.QtWidgets import QProxyStyle, QStyle


class TabBar(QTabBar):
def tabSizeHint(self, index):
s = 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 TabWidget(QtWidgets.QTabWidget):
def __init__(self, *args, **kwargs):
QtWidgets.QTabWidget.__init__(self, *args, **kwargs)
self.setTabBar(TabBar(self))
self.setTabPosition(QtWidgets.QTabWidget.West)


if __name__ == "__main__":
app = QApplication()
mainwindow = QMainWindow()
splitter = QSplitter()
tab_widget = TabWidget()
tab_widget.addTab(QLabel("Tab one"), "Tab one")
tab_widget.addTab(QLabel("Tab two"), "Tab two tab two")
l_widget = QtWidgets.QWidget()
l_layaout = QtWidgets.QVBoxLayout()
l_widget.setLayout(l_layaout)
l_layaout.addWidget(tab_widget.tabBar())
splitter.addWidget(l_widget)
splitter.addWidget(tab_widget)
mainwindow.setCentralWidget(splitter)
mainwindow.showMaximized()
sys.exit(app.exec_())



Or maybe there is another way to make a border that can be changed with the mouse.

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