pyqt5 tabwidget vertical tab horizontal text alignment left

Question

Since pyqt doesn't have horizontal text in vertical tab option, I followed this link to make it happen. I wanted to have icons on the left and then text after icon and different color for selected tab text, inactive tabs text. Below code gets it done almost. The only problem is text alignment is center. I tried changing tabRect.center() but changing it with left and top or right etc is making it crash.

The commented code which I got from this link gets me left alignment but it didn't have icons which I added. But in that I am unable to change text color of inactive tabs.

I am new to python and I am unable to find a solution for this. I tried this as well link but this only sets background color. tried using this option as well setTabTextColor link but it didn't work for some reason. been trying from 2 days.

Whenever I try to set text color using stylesheet with commented code, the "color" option won't work in stylesheet. any ideas on how to get this done? thanks

from PyQt5 import QtCore, QtGui, QtWidgets

class TabBar(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()

        # for i in range(self.count()):
        #     self.initStyleOption(opt, i)
        #     c = self.tabRect(i)
        #     c.moveLeft(35)
        #     painter.drawControl(QtWidgets.QStyle.CE_TabBarTabShape, opt)
        #     # painter.setPen(QColor(255, 255, 255))
        #     painter.drawText(c, QtCore.Qt.AlignVCenter | QtCore.Qt.TextDontClip, self.tabText(i))
        #     if i == 0:
        #         painter.drawImage(QtCore.QRectF(8, 8, 20, 20), QtGui.QImage("images/logo.png"))
        #     if i == 1:
        #         painter.drawImage(QtCore.QRectF(8, 44, 20, 20), QtGui.QImage("images/data.png"))
        #     if i == 2:
        #         painter.drawImage(QtCore.QRectF(8, 82, 20, 20), QtGui.QImage("images/browse.png"))
        #     if i == 3:
        #         painter.drawImage(QtCore.QRectF(8, 120, 20, 20), QtGui.QImage("images/off.png"))
        #     if i == 4:
        #         painter.drawImage(QtCore.QRectF(8, 158, 20, 20), QtGui.QImage("images/cal.png"))
        #     if i == 5:
        #         painter.drawImage(QtCore.QRectF(8, 196, 20, 20), QtGui.QImage("images/fol.png"))
        #     if i == 6:
        #         painter.drawImage(QtCore.QRectF(8, 232, 20, 20), QtGui.QImage("images/exc.png"))
        # painter.end()


class TabWidget(QtWidgets.QTabWidget):
    def __init__(self, *args, **kwargs):
        QtWidgets.QTabWidget.__init__(self, *args, **kwargs)
        self.setTabBar(TabBar(self))
        self.setTabPosition(QtWidgets.QTabWidget.West)

Answer 1

The solution is to use a QProxyStyle to redirect text painting:

from PyQt5 import QtCore, QtGui, QtWidgets


class TabBar(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 TabWidget(QtWidgets.QTabWidget):
    def __init__(self, *args, **kwargs):
        QtWidgets.QTabWidget.__init__(self, *args, **kwargs)
        self.setTabBar(TabBar(self))
        self.setTabPosition(QtWidgets.QTabWidget.West)

class ProxyStyle(QtWidgets.QProxyStyle):
    def drawControl(self, element, opt, painter, widget):
        if element == QtWidgets.QStyle.CE_TabBarTabLabel:
            ic = self.pixelMetric(QtWidgets.QStyle.PM_TabBarIconSize)
            r = QtCore.QRect(opt.rect)
            w =  0 if opt.icon.isNull() else opt.rect.width() + self.pixelMetric(QtWidgets.QStyle.PM_TabBarIconSize)
            r.setHeight(opt.fontMetrics.width(opt.text) + w)
            r.moveBottom(opt.rect.bottom())
            opt.rect = r
        QtWidgets.QProxyStyle.drawControl(self, element, opt, painter, widget)

if __name__ == '__main__':
    import sys

    app = QtWidgets.QApplication(sys.argv)
    QtWidgets.QApplication.setStyle(ProxyStyle())
    w = TabWidget()
    w.addTab(QtWidgets.QWidget(), QtGui.QIcon("zoom.png"), "ABC")
    w.addTab(QtWidgets.QWidget(), QtGui.QIcon("zoom-in.png"), "ABCDEFGH")
    w.addTab(QtWidgets.QWidget(), QtGui.QIcon("zoom-out.png"), "XYZ")

    w.resize(640, 480)
    w.show()

    sys.exit(app.exec_())

Answer 2

In case you have previously designed any tab in QtDesigner. For example, I have designed this tab in QtDesigner:

Now I have generated the py file from the ui file, and the UI file, looks like this:

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'tabwidget.ui'
#
# Created by: PyQt5 UI code generator 5.13.2
#
# WARNING! All changes made in this file will be lost!


from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName("gridLayout")
        self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
        self.tabWidget.setObjectName("tabWidget")
        self.tab = QtWidgets.QWidget()
        self.tab.setObjectName("tab")
        self.gridLayout_2 = QtWidgets.QGridLayout(self.tab)
        self.gridLayout_2.setObjectName("gridLayout_2")
        self.pushButton_reach = QtWidgets.QPushButton(self.tab)
        self.pushButton_reach.setObjectName("pushButton_reach")
        self.gridLayout_2.addWidget(self.pushButton_reach, 1, 1, 1, 1)
        self.label = QtWidgets.QLabel(self.tab)
        self.label.setAlignment(QtCore.Qt.AlignCenter)
        self.label.setObjectName("label")
        self.gridLayout_2.addWidget(self.label, 0, 1, 1, 1)
        self.tabWidget.addTab(self.tab, "")
        self.tab_2 = QtWidgets.QWidget()
        self.tab_2.setObjectName("tab_2")
        self.tabWidget.addTab(self.tab_2, "")
        self.gridLayout.addWidget(self.tabWidget, 0, 0, 1, 1)
        self.pushButton_addoptions = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_addoptions.setObjectName("pushButton_addoptions")
        self.gridLayout.addWidget(self.pushButton_addoptions, 1, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        self.tabWidget.setCurrentIndex(0)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.pushButton_reach.setText(_translate("MainWindow", "I am here"))
        self.label.setText(_translate("MainWindow", "Gotcha!"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab), _translate("MainWindow", "First Tab"))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_2), _translate("MainWindow", "Second Tab"))
        self.pushButton_addoptions.setText(_translate("MainWindow", "ADD options"))

And from eyllanesc's answer I figured out how to add tabs vertically and I added the pre-existing First-Tab to my modified tabwidget as follows:

import sys
from PyQt5.QtWidgets import QMainWindow, QApplication
from PyQt5 import QtGui, QtWidgets, QtCore
import tabwidget


# new additions
class TabBar(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 TabWidget(QtWidgets.QTabWidget):
#     def __init__(self, *args, **kwargs):
#         QtWidgets.QTabWidget.__init__(self, *args, **kwargs)
#         self.setTabBar(TabBar(self))
#         self.setTabPosition(QtWidgets.QTabWidget.West)

# new additions


class app_window(QMainWindow):
    def __init__(self):
        super().__init__()
        self.ui = tabwidget.Ui_MainWindow()
        self.ui.setupUi(self)
        # self.ui.tabWidget = TabWidget()
        self.ui.tabWidget.setTabBar(TabBar(self.ui.tabWidget))
        self.ui.tabWidget.setTabPosition(self.ui.tabWidget.West)
        self.ui.tabWidget.insertTab(0, self.ui.tab, "My tab")
        self.ui.pushButton_reach.clicked.connect(self.display)
        self.show()

    def display(self):
        print("reached")
        self.close()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = app_window()
    w.show()
    sys.exit(app.exec_())

Now my windows look like this:

I hope this will clear many people's problem who directly just want to recreate their tabwidget vertically!

Answer 3

I couldn't get working the first answer with only text (not icons) because my text get cut. And even if I was able to run the second answer I think it isn't clear. So here is my answer:
This code defines VerticalTabWidget class using second answer's code :

import sys
from PyQt5.QtWidgets import *
from PyQt5 import QtGui, QtWidgets, QtCore

class TabBar(QTabBar):
    def tabSizeHint(self, index):
        s = QTabBar.tabSizeHint(self, index)
        s.transpose()
        return s

    def paintEvent(self, event):
        painter = QStylePainter(self)
        opt = QStyleOptionTab()

        for i in range(self.count()):
            self.initStyleOption(opt, i)
            painter.drawControl(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(QStyle.CE_TabBarTabLabel, opt)
            painter.restore()

class VerticalTabWidget(QTabWidget):
    def __init__(self, *args, **kwargs):
        QTabWidget.__init__(self, *args, **kwargs)
        self.setTabBar(TabBar())
        self.setTabPosition(QtWidgets.QTabWidget.West)

class app_window(QMainWindow):
    def __init__(self):
        super().__init__()

        tabs = VerticalTabWidget()
        tabs.addTab(QWidget(), "First Tab")
        tabs.addTab(QWidget(), "Second Tab")
        tabs.addTab(QWidget(), "Third Tab")

        self.setCentralWidget(tabs)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = app_window()
    w.show()
    sys.exit(app.exec_())

You can just copy the TabBar and VerticalTabWidget classes into your code and use VerticalTabWidget as any QTabWidget .