we have use qt TableView like sample source. but the memory was leaked.

[liuyang]

we have use qt TableView like sample source. but the memory was leaked.
please support us to prevent the memory leaks.
Entry QML:Screen.qml

c++ sample source:
1)display
beginRemoveRows(QModelIndex(), 0, 0);
for (i = - 1; i >= 0; --i)
{
m_inputPointList.removeAt(i);
}
endRemoveRows();
beginInsertRows(QModelIndex(), 0, loopCnt-1);
for(i = 0 ; i < loopCnt; ++i){
......
m_inputPointList.append(point);
}
endInsertRows();
2) data refresh
beginRemoveRows(QModelIndex(), 0, rowCount() - 1);
for (i = m_inputPointList.count() - 1; i >= 0; --i)
{

        m_inputPointList.removeAt(i);
    }
    endRemoveRows();
    beginInsertRows(QModelIndex(), 0, loopCnt-1);
    for(i = 0 ; i < loopCnt; ++i){
       ......
        m_inputPointList.append(point);
    }
    endInsertRows();

3. nondisplay
   beginRemoveRows(QModelIndex(), 0, rowCount() - 1);
   for (i = m_inputPointList.count() - 1; i >= 0; --i)
   {

        m_inputPointList.removeAt(i);
    }
    endRemoveRows();
   

[cheezus]

@liuyang Are you aware of how memory leaks are created in JavaScript? It's subtly different than in C++. Think of objects in JavaScript like shared_ptr in C++: as long as you have a reference to the object, it will not be garbage collected.

[liuyang]

@cheezus we've confirmed that there is not memory leak on c++ side.

can you tell me how to attach files.
the sample source is listed folloing.
please tell me the reason of leak.

MyTableView.qml
import QtQuick 2.5
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.4
import ...

MyItem {
id: myTableView

/* テーブルビュー */
property QtObject tableViewStyle: QtObject {
    //common
    property real opacity: 1.0
    property int fontPixelSize: Style.basicFont.pixelSize
    property int leftMargin: 8
    property int rightMargin: 8

    //header
    property int headerBorderWidth: 0
    property int headerInsideBorderWidth: 1
    property color headerInsideBorderColor: Style.basicColorStyle.gray5
    property color headerBgColor: Style.basicColorStyle.darkblue
    property int headerRowHeight: 28
    property color headerFontColor: Style.basicColorStyle.white

    //body
    property color bodyBgColor: Style.basicColorStyle.white
    property color bodyBgStripeColor: Style.basicColorStyle.peerblue
    property color bodySelectedBgColor: Style.basicColorStyle.lightblue
    property int bodyRowHeight: 30
    property int bodyBorderWidth: 1
    property color bodyBorderColor: Style.basicColorStyle.gray2
    property color bodySelectedBorderColor: Style.basicColorStyle.blue
    property int bodyInsideBorderWidth: 1
    property color bodyInsideBorderColor: Style.basicColorStyle.gray3
    property color bodyFontColor: Style.basicColorStyle.black
    property color itemBgColor: "transparent"

    //drag
    property color dropAreaColor: Style.basicColorStyle.lightblue
    property color dropAreaBorderColor: Style.basicColorStyle.vividblue
    property int dropAreaBorderWidth: 2
}

property Component customItemDelegate: null

property var displayItem: null
property bool dragDropEnable: false
property string dropKey: "dropKey"
property bool resizeable: false
property bool verticalScroll: false
property var expansionTitle: null
/* 一ページに表示可能の最大行数、verticalScroll=false時無視する */
property int showRowCount: 10
property alias currentRow: tableView.currentRow
readonly property alias rowCount: tableView.rowCount
property alias onfocus: tableView.focus

/* 上位エレメントへ通知 */
signal rowMoved(int from, int to);
signal rowSelected(int rowIndex);

enabled: displayItem === null ? true : displayItem.enabled
visible: displayItem === null ? true : displayItem.visible

property int resizeColIndex: 0

property real resizeColBasicWidth

signal resizeColumnWidth(real addWidth)

onResizeColumnWidth: {
    if(resizeable === true)
    {
        if(tableView.isExistColumn(resizeColIndex) === true &&
                tableView.getColumn(resizeColIndex).width + addWidth > myTableView.resizeColBasicWidth)
        {
            tableView.getColumn(resizeColIndex).width += addWidth;
        }
    }
}

function addColumn(column) {
    return tableView.addColumn(column);
}

function insertColumn(index, column) {
    return tableView.insertColumn(index, column);
}

/* 指定する行をテーブルの先頭に表示する。 */
function positionTableRowAtTop(row)
{
    //rowは-1より大きい、かつ、TableViewの行数より小さいの場合は、
    //パラメータrowで指定したテーブル行をmyTableViewの先頭に表示する。
    if(row > -1 && row < tableView.rowCount)
    {
        tableView.positionViewAtRow(row,ListView.Beginning);
    }
}

[liuyang]

@cheezus
QML sample source url:https://bugreports.qt.io/browse/QTBUG-53509

[cheezus]

@liuyang I'm saying that JavaScript "leaks" ind ifferent ways than C++. If you do not know how JavaScript leaks, you should learn that first.

[liuyang]

@cheezus
JavaScipt source doesn't leak now.but QML side still leaks.please .