Delete Qt Layout manager - Printable Version

Delete Qt Layout manager - Printable Version

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+--- Thread: Delete Qt Layout manager (/thread-31937.html)

Delete Qt Layout manager - deanhystad - Jan-10-2021

I cannot find a way to change the layout manager for a Qt widget. In the code below I first set the layout manager to a horizontal box layout and then try to set it to a grid layout. From the output you can see that the layout remains a horizontal box layou

import sys
import PySide6.QtWidgets as QtWidgets

class Test(QtWidgets.QWidget):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setLayout(QtWidgets.QHBoxLayout())
        self.setLayout(QtWidgets.QGridLayout())
        print(self.layout())

QtWidgets.QApplication(sys.argv)
Test()

Output:
<PySide6.QtWidgets.QHBoxLayout(0x1731138e8a0) at 0x000001731242AA00>

Qt documentation says you have to delete the old layout before setting a new layout. So I tried the code below which gives me a syntax error on line 9 saying "Cannot delete function call".

class Test(QtWidgets.QWidget):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setLayout(QtWidgets.QHBoxLayout())
        del self.layout()
        print(self.layout())

So I use a local variable to reference the layout widget and tried again.

class Test(QtWidgets.QWidget):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setLayout(QtWidgets.QHBoxLayout())
        temp = self.layout()
        delete temp
        print(self.layout())

This code runs, but it does not remove the layout widget. I still get the QHBoxLayout when printing self.layout()

Does anyone have an idea how I can replace the existing layout?

RE: Delete Qt Layout manager - Axel_Erfurt - Jan-10-2021

You should define different Layouts and use QMainWindow

for example

import sys
import PyQt5.QtWidgets as QtWidgets
 
class Test(QtWidgets.QMainWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.layout = QtWidgets.QVBoxLayout()
        self.btn1 = QtWidgets.QPushButton("HLayout")
        self.btn1.clicked.connect(self.setLayoutH)
        self.btn2 = QtWidgets.QPushButton("GLayout")
        self.btn2.clicked.connect(self.setLayoutG)
        self.layout.addWidget(self.btn1)
        self.layout.addWidget(self.btn2)
        w = QtWidgets.QWidget()
        w.setLayout(self.layout)
        self.setCentralWidget(w)
        

    def setLayoutG(self):        
        # gridlayout
        gridlayout = QtWidgets.QGridLayout()
        btn1 = QtWidgets.QPushButton("HLayout")
        gridlayout.addWidget(btn1)
        btn1.clicked.connect(self.setLayoutH)
        self.cwg = QtWidgets.QWidget()
        self.cwg.setLayout(gridlayout)        
        self.setCentralWidget(self.cwg)
        
    def setLayoutH(self):
        # hlayout
        hlayout = QtWidgets.QHBoxLayout()
        btn2 = QtWidgets.QPushButton("GLayout")
        btn2.clicked.connect(self.setLayoutG)
        hlayout.addWidget(btn2)
        self.editor = QtWidgets.QTextEdit()
        hlayout.addWidget(self.editor)
        self.cwh = QtWidgets.QWidget()
        self.cwh.setLayout(hlayout)
        self.setCentralWidget(self.cwh)

if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    win = Test()
    win.setGeometry(0, 0, 400, 200)
    win.setWindowTitle("MyApp" + "[*]")
    win.show()
    sys.exit(app.exec_())

RE: Delete Qt Layout manager - deanhystad - Jan-10-2021

I'm not doing this for a main window, otherwise that would be a great idea.