Determine Line Count for Certain Font w WordWrap at Runtime

rhb327

I have a function called from QML, where QML passes a TableView index, column width and the string in question. I want to determine the line count so I can then dynamically determine the row height which the TableView rowDegate will use.

Here's some of the interaction from QML. When I click the row and I'm in the expanded state I want to combine text in columns 2 & 3 and then show that in column 3. I also need to dynamically determine the height of this combined text.

 rowDelegate: Rectangle {
                id: tvRowDelegate
                height: 65
                width: parent.width

                state: ((sqlELmodel.getExpanded(styleData.row)) ? "expanded" : "collapsed")
                states: [
                    State {
                        name: "collapsed"
                        PropertyChanges { target: tvRowDelegate; height: 65; }
                    },
                    State {
                        name: "expanded"
                        PropertyChanges { target: tvRowDelegate; height: (sqlELmodel.getExpandedSL(styleData.row) === 0) ? 100 : (27*(sqlELmodel.getExpandedSL(styleData.row)) < 100) ? 100 : 27*(sqlELmodel.getExpandedSL(styleData.row)); }
                    }
                ]
                MouseArea {
                    anchors.fill: parent
                    onClicked: {
                        var cTxt
                        cTxt = sqlELmodel.combineColumns(styleData.row, 2, 3)
                        sqlELmodel.setExpandedSL(styleData.row, col3.width, cTxt)
                        sqlELmodel.setExpanded(styleData.row, !sqlELmodel.getExpanded(styleData.row))
                        timerRow = styleData.row
                        sqlELmodel.refresh()
                        eventLogView.positionViewAtRow(timerRow, ListView.Beginning)
                    }
                }
            }

This is a C++ object that runs all of my queries for the TableView QML object. I've added a QPlainTextEdit member (pte) and in the constructor I set some defaults so I don't have to do this for every call to setExpandedSL() which will be called as rows are rendered.

SqlQueryModel::SqlQueryModel(QObject* parent) : QSqlQueryModel(parent) {
    connect(&futureWatcher, SIGNAL(finished()), this, SLOT(valDone()));
    setValidate(false);

    // In constructor increase performance
    QFont viewFont("NotoSans", 19, QFont::Normal);
    viewFont.setPixelSize(19);
    pte.setFont(viewFont);
    pte.setAttribute(Qt::WA_DontShowOnScreen);
    pte.setWordWrapMode(QTextOption::WordWrap);
}

Here's the real issue. The show() call works in Win10 just fine but fails on my embedded target and I have no idea why.

void SqlQueryModel::setExpandedSL(int idx, int w, QString str) {
    // Save the visual number of lines
    pte.setFixedWidth(w);
    pte.setPlainText(str);
    pte.show();

#ifdef VERBOSITY_HIGH
    qDebug() << "Exp line cnt: " << pte.document()->documentLayout()->documentSize().height();
#endif

    ExpandedStrLen[idx] = pte.document()->documentLayout()->documentSize().height();
}

I've tried alternates like pte.repaint(), pte.update(), pte.viewport()->... and pte.layout()->...

Any thoughts on what might cause the call to show() to hang or another way to force the layout to update so I can get the text line count for the font (constructor set) and word wrap mode I've set?

Thanks,
-Rich