Programm crashes when textBrowser get's called from other class

levoxtrip

So I'm building a GUI in pyqt.

I have a class Ui_MainWindow(object): where my textBrowser is in

I also have a stream class where a videocapture get's streamed and some object detection

I want that everytime an object gets detected that the label get's appended in the textBrowser

But everytime I call textBrowser in my second class the programm crashes.

Thx in advance

class Ui_MainWindow(object):
def setupUi(self, MainWindow):
    
    ...
    self.textBrowser = QtWidgets.QTextBrowser(self.centralwidget)
    self.textBrowser.setMinimumSize(QtCore.QSize(860, 640))
    self.textBrowser.setObjectName("textBrowser")
    self.gridLayout.addWidget(self.textBrowser, 0, 1, 1, 1, QtCore.Qt.AlignHCenter|QtCore.Qt.AlignVCenter)
    ...

class Stream(QThread):
    ...
    for i in objects:
    textBrowser.append(i)

SGaist

Hi and welcome to devnet,

You are breaking the main rule: do not manipulate GUI element from any other thread than the GUI thread.

levoxtrip

Hey thx for answer.
You have any idea how I can achieve it on another way?

mrjj

Hi
You have to use the signal from the thread

like
for i in objects:
emit AppendThis(i);

(not sure its excact python syntax ;)

and then in MainWindow or other class that has the browser
you connect this new signal to a slot and in that slot
you do

textBrowser.append(i)

levoxtrip

@mrjj said in Programm crashes when textBrowser get's called from other class:

new signal to a slot and in that slot

ok that sounds good. I'll try tha

levoxtrip

Man thx a lot for your help! Really appreciate it