[FIXED] Can't write to QTextBrowser when calling function from another file

Issue

I have a python plugin where the main.py file displays a QTextBrowser and writes some text. This works fine.

I wrote a second file anotherFile.py which identifies the same QTextBrowser but cannot write any text to it. Perhaps it needs to take ownership, I'm not sure?

Here is the code used:

# main.py #
from Example_dockwidget import ExampleDockWidget
from anotherFile import anotherClass

class Example:
    def __init__(self, iface):
        self.iface = iface

    def function(self):
        self.dockwidget = ExampleDockWidget()
        self.dockwidget.show()

        textBrowser = self.dockwidget.textBrowser
        #textBrowser.setText('This works!')
        a = anotherClass(self)
        a.anotherFunction()

---

# anotherFile.py #
from Example_dockwidget import ExampleDockWidget

class anotherClass:
    def __init__(self, iface):
        self.iface = iface
        self.dockwidget = ExampleDockWidget()

    def anotherFunction(self):
        textBrowser = self.dockwidget.textBrowser
        textBrowser.setText('This does not work!')
        print 'Why?'

---

# Example_dockwidget.py #
FORM_CLASS, _ = uic.loadUiType(os.path.join(
    os.path.dirname(__file__), 'Example_dockwidget_base.ui'))

class ExampleDockWidget(QtGui.QDockWidget, FORM_CLASS):
    def __init__(self, parent=None):
        super(ExampleDockWidget, self).__init__(parent)
        self.setupUi(self)

Solution

Your two classes both create their own ExampleDockWidget. Only one of them is shown (has its show method called) but there are two.

So it's not surprising that text sent to one does not appear on the other. You need to arrange for your anotherClass object to obtain a reference to the other ExampleDockWidget so it can share the same one.

Answered By - strubbly