How To Resize Qlabels To Fit Contents In Qscrollarea

This issue is specific to PyQt5, but C++ Qt5 answers are fine too. Within a QScrollArea with fixed width and variable height, I have a QVBoxLayout that contains QLabels. These QLab

Solution 1:

This can be solved quite simply by using the addStretch method of the layout that contains the news items:

classNewsList(QtWidgets.QScrollArea):def__init__(self, parent=None):
        ...    
        layout = QtWidgets.QVBoxLayout()
        layout.setContentsMargins(5, 5, 5, 5)
        layout.setSpacing(5)
        layout.setAlignment(QtCore.Qt.AlignTop)
        # add a stretchable space to the bottom of the layout
        layout.addStretch(1)

    defappend_message(self, text):
        ...
        # set the size policy of the label
        new_item.setSizePolicy(
            QtWidgets.QSizePolicy.Preferred,
            QtWidgets.QSizePolicy.MinimumExpanding)
        # insert the label before the spacer        
        layout = self.news_widget.layout()
        layout.insertWidget(layout.count() - 1, new_item)

The spacer pushes the labels upwards, which stops them streching to take up the available space. Using the stretch-factor argument of addStretch ensures that the spacer always takes precedence over the other items in the layout.