How to enable autoscroll in Qtableview like in Qtextedit?

Question

I'm using QtableView and QStandardItemModel to display logs on GUI to maintain proper spacing and filter logs. I created model and inserted data into it. Used QSortFilterProxyModel for filter strings.

self.tableView = QtGui.QTableView(self)
self.model = QtGui.QStandardItemModel(self)
self.proxy = QtGui.QSortFilterProxyModel(self)
self.proxy.setSourceModel(self.model)
self.tableView.setModel(self.proxy)

In a sec, nearly 100 logs are expected and should be shown on GUI. When new logs are appended, the view isn't auto scrolling and the slider stays only at the top. It doesn't give live feel for logging and user need to scroll manually to the end. So to overcome this, i used following syntax,

self.model.rowsInserted.connect(lambda: QtCore.QTimer.singleShot(5, self.tableView.scrollToBottom))

It gives live feel for logs, but the slider remains always in bottom and i'm not able to scroll up to see previous logs. Whenever i try to move the slider, it immediately comes down to bottom again. So this syntax doesn't meet my requirement. In QTextEdit, auto scrolling is proper and user friendly. I want the same scenario here on QtableView. Is there any alternative for auto scrolling which resembles like QTextEdit ?

Answer 1

To get the required behaviour, you can auto-scroll only when the previous scroll position is at the bottom. That way, whenever the user scrolls away from the bottom, auto-scrolling will be disabled; but when they scroll back to the bottom, auto-scrolling will be re-enabled. (NB: to quickly re-enable auto-scroll, right-click the scrollbar and select "Bottom" from the context menu).

Here is a simple demo:

from PyQt4 import QtCore, QtGui

class Window(QtGui.QWidget):
    def __init__(self):
        super(Window, self).__init__()
        self.table = QtGui.QTableView(self)
        self.model = QtGui.QStandardItemModel(self)
        self.table.setModel(self.model)
        layout = QtGui.QVBoxLayout(self)
        layout.addWidget(self.table)
        self._scroll = True
        self.model.rowsAboutToBeInserted.connect(self.beforeInsert)
        self.model.rowsInserted.connect(self.afterInsert)

    def beforeInsert(self):
        vbar = self.table.verticalScrollBar()
        self._scroll = vbar.value() == vbar.maximum()

    def afterInsert(self):
        if self._scroll:
            self.table.scrollToBottom()

    def addRow(self):
        self.model.appendRow([QtGui.QStandardItem(c) for c in 'ABC'])

if __name__ == '__main__':

    app = QtGui.QApplication([''])
    window = Window()
    window.setGeometry(500, 50, 400, 300)
    window.show()
    timer = QtCore.QTimer()
    timer.timeout.connect(window.addRow)
    timer.start(200)
    app.exec_()