Change color of QTabWidget tab's

Question

I want to customize a QTabWidget, so that every tab has it's own background color. I know, that this cannot be done with stylesheets, so I subclassed QTabBar and changed it's paintEvent. Then, I replaced the default QTabBar of QTabWidget with my own implementation. However, the background color of the tabs doesn't change. Does anybody know what I am missing?

Here is a small demo application which illustrates my problem:

from PyQt4 import QtGui 

import sys

class coloredTabBar(QtGui.QTabBar):
    def __init__(self, parent = None):
        QtGui.QTabBar.__init__(self, parent)

    def paintEvent(self, event):
        p = QtGui.QStylePainter(self)
        painter = QtGui.QPainter(self)
        for index in range(self.count()): #for all tabs
            tab = QtGui.QStyleOptionTabV3() #create styled tab
            self.initStyleOption(tab, index) #initialize with default values
            #change background color to red
            tab.palette.setColor(QtGui.QPalette.Base, QtGui.QColor(255, 0, 0)) 
            p.drawControl(QtGui.QStyle.CE_TabBarTab, tab) #draw tab


class coloredTabWidget(QtGui.QTabWidget):
    def __init__(self, parent = None):
        QtGui.QTabWidget.__init__(self, parent)

        coloredTabs = coloredTabBar()
        self.setTabBar(coloredTabs) #replace default tabBar with my own implementation

if __name__ == "__main__":     
    app = QtGui.QApplication(sys.argv)

    tabWidget = coloredTabWidget()

    tabWidget.addTab(QtGui.QWidget(), "Hello")
    tabWidget.addTab(QtGui.QWidget(), "World")

    tabWidget.show()

    sys.exit(app.exec_())

Kind Regards

Bernhard

user2494129 user2494129 · Accepted Answer · 2014-03-24T10:30:59

Okay, I think I got something. It is not the prettiest thing, but it does the trick.

If anyone has a better idea on how to solve this problem...let me know.

from PyQt4 import QtGui 
from PyQt4 import QtCore

import sys

class coloredTabBar(QtGui.QTabBar):
    def __init__(self, parent = None):
        QtGui.QTabBar.__init__(self, parent)

    def paintEvent(self, event):
        p = QtGui.QStylePainter(self)
        painter = QtGui.QPainter(self)
        painter.save()
        for index in range(self.count()): #for all tabs

            tabRect = self.tabRect(index)
            tabRect.adjust(-1, 3, -1, -1) #ajust size of every tab (make it smaller)
            if index == 0: #make first tab red 
                color = QtGui.QColor(255, 0, 0)
            elif index == 1: #make second tab yellow
                color = QtGui.QColor(255, 255, 0)
            else: #make all other tabs blue
                color = QtGui.QColor(0, 0, 255)
            if index == self.currentIndex(): #if it's the selected tab
                color = color.lighter(130) #highlight the selected tab with a 30% lighter color
                tabRect.adjust(0, -3, 0, 1) #increase height of selected tab and remove bottom border


            brush = QtGui.QBrush(color)
            painter.fillRect(tabRect, brush)

            painter.setPen(QtGui.QPen(QtGui.QColor(QtCore.Qt.black))) #black pen (for drawing the text)
            painter.drawText(tabRect, QtCore.Qt.AlignVCenter | QtCore.Qt.AlignHCenter,
                             self.tabText(index))

            painter.setPen(QtGui.QPen(QtGui.QColor(QtCore.Qt.gray))) #gray pen (for drawing the border)
            painter.drawRect(tabRect)
        painter.restore()

class coloredTabWidget(QtGui.QTabWidget):
    def __init__(self, parent = None):
        QtGui.QTabWidget.__init__(self, parent)

        coloredTabs = coloredTabBar()
        self.setTabBar(coloredTabs) #replace default tabBar with my own implementation

if __name__ == "__main__":     
    app = QtGui.QApplication(sys.argv)

    tabWidget = coloredTabWidget()

    tabWidget.addTab(QtGui.QWidget(), "Tab 1")
    tabWidget.addTab(QtGui.QWidget(), "Tab 2")
    tabWidget.addTab(QtGui.QWidget(), "Tab 3")
    tabWidget.addTab(QtGui.QWidget(), "Tab 4")

    tabWidget.show()

    sys.exit(app.exec_())

Change color of QTabWidget tab's

2 Answers