Setting the scroll bar to the bottom on PyQt5 (using scrollArea and a gridLayout)

Question

I have a QScrollArea with a QGridLayout within. This said QGridLayout is filled with buttons on a 100x100 grid. I want the vertical scrollbar to start on the bottom instead of the top. I've searched online how to do it, but nothing worked so far.

import sys
from PyQt5 import QtWidgets


class IndicSelectWindow(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super(IndicSelectWindow, self).__init__(parent=parent)
        self.resize(500, 400)
        self.layout = QtWidgets.QHBoxLayout(self)
        self.scrollArea = QtWidgets.QScrollArea(self)
        self.scrollArea.setWidgetResizable(True)
        self.scrollAreaWidgetContents = QtWidgets.QWidget()
        self.gridLayout = QtWidgets.QGridLayout(self.scrollAreaWidgetContents)
        self.scrollArea.setWidget(self.scrollAreaWidgetContents)
        self.layout.addWidget(self.scrollArea)

        for i in range(100):
            for j in range(100):
                self.gridLayout.addWidget(QtWidgets.QPushButton(), i, j)



if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    w = IndicSelectWindow()
    w.show()
    sys.exit(app.exec_())

Edit: Trying to explain better - I need to scroll to the bottom so when I open the window, the scrollbar is at the bottom and not at the top.

What I have tried:

x = self.scrollArea.verticalScrollBar().maximum()
self.scrollArea.verticalScrollBar().setValue(x)

and

x = self.scrollArea.verticalScrollBar().maximum()
self.scrollArea.verticalScrollBar().setSliderPosition(x)

Answer 1

The problem is that the scrollbar geometry is updated when:

• The widget is set to the QScrollArea.
• The QScrollArea is made visible.
• The size of the QScrollArea changes.
• The widget size changes if it is visible.

So when placing the widget first and then the buttons, the QScrollArea is not notified of it, so there are 2 solutions:

• Move the scrollbar an instant after showing.

      for i in range(100):
          for j in range(100):
              self.gridLayout.addWidget(QtWidgets.QPushButton(), i, j)
      QtCore.QTimer.singleShot(0, self.handle_timeout)
  
  def handle_timeout(self):
      x = self.scrollArea.verticalScrollBar().maximum()
      self.scrollArea.verticalScrollBar().setValue(x)
  

• Set the widget to the QScrollArea after the buttons were placed.

  class IndicSelectWindow(QtWidgets.QDialog):
      def __init__(self, parent=None):
          super(IndicSelectWindow, self).__init__(parent=parent)
          self.resize(500, 400)
          self.layout = QtWidgets.QHBoxLayout(self)
          self.scrollArea = QtWidgets.QScrollArea(self)
          self.scrollArea.setWidgetResizable(True)
          self.scrollAreaWidgetContents = QtWidgets.QWidget()
          self.gridLayout = QtWidgets.QGridLayout(self.scrollAreaWidgetContents)
  
          self.layout.addWidget(self.scrollArea)
          for i in range(100):
              for j in range(100):
                  self.gridLayout.addWidget(QtWidgets.QPushButton(), i, j)
  
          self.scrollArea.setWidget(self.scrollAreaWidgetContents)
          x = self.scrollArea.verticalScrollBar().maximum()
          self.scrollArea.verticalScrollBar().setValue(x)