[FIXED] Value based gridlines / divider in QTableView

Issue

I have a QTableView, which I feed with data from ODBC/SQL, where I sort the values firstly in "Team" and in "Person":

Team	Person	RO
A	PA	11111
A	PB	11112
A	PC	11113
B	PD	11114
B	PE	11115
C	PF	11116

In the QTableView I know, that I can set the gridline via

tableWidget.setShowGrid(False)
tableWidget.setStyleSheet('QTableView::item {border-right: 1px solid #d6d9dc;}')

But I want to make a thick line between different "Teams", so between Person PC/PD and PE/PF should be a thick horizontal seperator on the full row.

How to do that? - I searched the web and dont find anything...

I thought I cloud do it with

QtCore.QAbstractTableModel

but I dont find a Role to give another borderline.

Thanks

Solution

A possible solution could be to override the paint event of the table and draw the "thicker" lines based on the data. For optimization reasons, the rows of those lines can be "cached", so that the only computation needed for painting is to get the coordinates for the lines.

The code below will give the following result:

class TableSplitLines(QTableWidget):
    linesDirty = False
    penWidth = 3
    referenceColumn = 0
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.splitLines = []
        self.itemChanged.connect(self.markDirty)

    def markDirty(self):
        if not self.linesDirty:
            self.linesDirty = True
            self.update()

    def updateLines(self):
        '''
        Create a list of rows that correspond to the last rows that have common
        and contiguous values for the choosen column
        '''
        self.splitLines.clear()
        last = None
        for row in range(self.rowCount()):
            first = self.item(row, self.referenceColumn)
            if first is None:
                value = None
            else:
                value = first.text()
            if row == 0:
                last = value
            elif value != last:
                self.splitLines.append(row)
                last = value
        self.linesDirty = False

    def paintEvent(self, event):
        if self.linesDirty:
            self.updateLines()

        if self.splitLines:
            # get the right edge of the last visible column
            hHeader = self.horizontalHeader()
            lastSection = -1
            for i in range(self.columnCount()):
                logical = hHeader.logicalIndex(i)
                if not hHeader.isSectionHidden(logical):
                    lastSection = logical

            right = min(self.viewport().width(), 
                hHeader.sectionPosition(lastSection)
                + hHeader.sectionSize(lastSection)
                - hHeader.offset() 
            )

            extent = self.penWidth // 2 + 1
            top = event.rect().y() - extent
            bottom = event.rect().bottom() + extent

            # get the grid color from the current style
            opt = QStyleOption()
            opt.initFrom(self)
            gridColor = QColor.fromRgb(
                self.style().styleHint(
                    QStyle.SH_Table_GridLineColor, opt, self
                ) & 0xffffff)

            qp = QPainter(self.viewport())
            qp.setPen(QPen(gridColor, self.penWidth, cap=Qt.FlatCap))

            # draw lines as long as they're included in the event rect
            vHeader = self.verticalHeader()
            offset = vHeader.offset() + 1
            for row in self.splitLines:
                y = vHeader.sectionPosition(row) - offset
                if y < top:
                    continue
                elif y > bottom:
                    break
                qp.drawLine(0, y, right, y)

        # call the base implementation
        super().paintEvent(event)

Note: the 0xffffffff mask is caused by the fact that the value returned by styleHint() is an unsigned int, but due to the dynamic typing of Python it can be interpreted as a signed (so, possibly negative).

Answered By - musicamante