I have a QtTabWidget with 1 (or 2) widgets (my main page widget) hanging off of it like:
330 for i in range(1):
331 win = MainWindow()
332 tabs.addTab(win, QIcon('running.png'), "Test-%d" % i)
333 tabs.show()
334 print("tab count = %d" % tabs.count())
AFAIK, 'tabs' is now a parent to 'win'. I also have a tool bar with a "Add Tab" and "Remove Tab". The remove/quit handler is working and is like
254 # ----------------------- quitHandler() ------------------------
255 def quitHandler(self):
256 if ( self.parentWidget().count() == 1 ):
257 self.statusBar.setText('I am the last one, you can not kill me ....')
258 return
259 tab = self.parentWidget().currentWidget()
260 self.close()
261 self.parentWidget().removeWidget(tab)
262
But my "Add Tab" handler written as
263 # ----------------------- newTabHandler() ------------------------
264 def newTabHandler(self):
265 count = self.parentWidget().count()
266 if ( count > 10 ):
267 self.statusBar.setText('I only support 10 tabs ....')
268 return
269 win = MainWindow()
270 self.parentWidget().addWidget(win)
271 self.parentWidget().show()
272 print(self.parentWidget().count())
is not rendering the new tab. But I see that tab count is increasing .. here is the log
medi@medi:~/proto/python/d1> ./utg
tab count = 1
2
3
4
5
Help is appreciated.
As requested, here is a minimal code to show the problem statement:
1 #!/usr/bin/python3
2
3 import sys
4 import os
5
6 from PyQt5 import (QtCore, QtWidgets, QtGui)
7 from PyQt5.QtGui import (QIcon)
8 from PyQt5.QtWidgets import (QMainWindow, QPushButton, QLabel, QLineEdit, QTextEdit)
9 from PyQt5.QtWidgets import (QWidget, QHBoxLayout, QVBoxLayout, QGroupBox, QGridLayou t)
10 from PyQt5.QtWidgets import (QFormLayout, QSizePolicy, QAction, QToolBar)
11 from PyQt5.QtCore import (QSize, QProcess)
12
13 class MainWindow(QMainWindow):
14 def __init__(self):
15 super().__init__()
16 self.setWindowTitle('tabs mgmnt test')
17 self.setGeometry(50, 50, 600, 600)
18
19 self.toolbar = QToolBar('My Main Tool Bar')
20 self.addToolBar(self.toolbar)
21 newTabAct = QAction('New Tab', self)
22 self.toolbar.addAction(newTabAct)
23 newTabAct.triggered.connect(self.newTabHandler)
24
25 # ----------------------- newTabHandler() ------------------------
26 def newTabHandler(self):
27 print("before new tab, tab-count = %d" % self.parentWidget().count() )
28 win = MainWindow()
29 self.parentWidget().addWidget(win)
30 self.parentWidget().show()
31 print("after new tab, tab-count = %d" % self.parentWidget().count() )
32
33 # ================================= main() ==========================
34 if (__name__ == "__main__"):
35 app = QtWidgets.QApplication(sys.argv)
36 tabs = QtWidgets.QTabWidget()
37 win = MainWindow()
38 tabs.addTab(win, "Tab-1" )
39 tabs.show()
40 sys.exit ( app.exec_() )
41
As seen, in main() and line 36 I create a QTabWidget and a window and hang the window to tabs.So I believe, 'tabs' is parent and 'win' is a child. Then the 'newTabHandler()' on line 26 should add another tab to tabs. But this method is an instance method of MainWindow and does not see 'tabs' which is local to main(). So I traverse the parent-child relation via parentWidget(). Also note that the print() statements on line 27 and 31 are reporting correct tab count. But I do not see the new tab rendered. Maybe I am missing a show() against some object. which I do on line 30. Yet no rendering of new tab and I only see one tab, the one created in main().
To understand the problem you must print the parentWidget() in newTabHandler:
def newTabHandler(self):
print(self.parentWidget())
and you will notice that every time you try to add a tab you get:
<PyQt5.QtWidgets.QStackedWidget object at 0x7f3e4e2680d0>
<PyQt5.QtWidgets.QStackedWidget object at 0x7f3e4e2680d0>
<PyQt5.QtWidgets.QStackedWidget object at 0x7f3e4e2680d0>
...
So parentWidget() is not the QTabWidget but a QStackedWidget.
Explanation:
A QTabWidget is a QTabBar + QStackedWidget, and every time you add a widget using addTab() the widget is added to the QStackedWidget and a new tab is created in the QTabBar, so accordingly the parent of the widget is the QStackedWidget.
Solution:
Considering the above, the solution is to use the parentWidget() of the QStackedWidget which is the QTabWidget, or in the code that you provide as the QTabWidget is the window then use the window() method:
def newTabHandler(self):
tab_widget = self.parentWidget().parentWidget()
# QStackedWidget QTabWidget
# or
# tab_widget = self.window()
print(tab_widget)
count = tab_widget.count()
win = MainWindow()
tab_widget.addTab(win, "Tab-{}".format(count + 1))