How do I delete the current QTreeWidget element correctly?

[Christian Ehrlicher]

@Helg1980 said in How do I delete the current QTreeWidget element correctly?:

The result was disappointing:

Why? There is only one leak which should interest you:

==2615== by 0x159CCB: SelectPreset::SelectPreset(QWidget*) (selectpreset.cpp:28)

The rest are no real 'leaks' and can be ignored.

[Helg1980]

Here is a part of the text where there may be an error:

SelectPreset::SelectPreset(QWidget *parent) :
    QDialog(parent),
    ui_selectpreset(new Ui::SelectPreset)
{
    ui_selectpreset->setupUi(this);
    ui_selectpreset->treeWidget->clear();
    int n =  _preset_table[0].size();
    int m = _preset_table.size();
    QString type;
    QColor color;
    color.setRgba(qRgb(120, 120, 150));
    QFont font;
    font.setBold(true);
    QTreeWidgetItem *item = new QTreeWidgetItem();    //    line 28  -  deleted this line
    for (int i = 0; i < n; i++) {
        type = _preset_table[23][i];
        if (type == "TopLewelItem") {
            QTreeWidgetItem *root = new QTreeWidgetItem();
            root->setText(0, _preset_table[0][i]);
            ui_selectpreset->treeWidget->addTopLevelItem(root);
            ui_selectpreset->treeWidget->setCurrentItem(root);
            root->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsEditable);
            root->setFont(0, font);
            root->setForeground(0, color);
        };
        if (type == "ChildItem") {
            item = ui_selectpreset->treeWidget->currentItem();   // replaced with: QTreeWidgetItem *item =  ....
            QTreeWidgetItem *child = new QTreeWidgetItem();
            for (int j = 0; j < 23; j++) {
                child->setText(j, _preset_table[j][i]);
            };
            child->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsEditable);
            item->addChild(child);
        };
    };
    item = ui_selectpreset->treeWidget->topLevelItem(pos_top)->child(pos_cld);   // replaced with: QTreeWidgetItem *item =  ....
    ui_selectpreset->treeWidget->setCurrentItem(item);
    std::cout << n << " x " << m << std::endl; // Table size
    ui_selectpreset->treeWidget->expandAll();
    for (int i=1; i<=24; i++) {
        ui_selectpreset->treeWidget->hideColumn(i);
    };
    QAction *addsection = new QAction(tr("Add section"), this);
    QAction *addpreset = new QAction(tr("Add new preset"), this);
    connect(addsection, &QAction::triggered, this, &SelectPreset::add_section);
    connect(addpreset, &QAction::triggered, this, &SelectPreset::add_preset);
    QMenu* menu = new QMenu(this);
    menu->addAction(addsection);
    menu->addAction(addpreset);
    menu->setStyleSheet("QMenu {background-color: rgb(5, 20, 25);} "
                        "QMenu::item {background-color: transparent;} "
                        "QMenu::item:selected {background-color: rgb(5, 40, 45);}");
    ui_selectpreset->actionAdd_preset->setMenu(menu);
}

[JonB]

@Helg1980 said in How do I delete the current QTreeWidget element correctly?:

QTreeWidgetItem *item = new QTreeWidgetItem(); // line 28

So, as the valgrind tells you, in all cases you do not use/overwrite this newed item without using it. Hence the leak.

[Helg1980]

This post is deleted!

[JonB]

@Helg1980
So I see. So now has that leak gone away? That's all you are looking to resolve.

[Helg1980]

It looks like the error has disappeared. I don't work very well with valgrind yet. So I understand that I only need to search for lines where there are links to my files.

==7099== HEAP SUMMARY:
==7099==     in use at exit: 571,790 bytes in 7,682 blocks
==7099==   total heap usage: 833,977 allocs, 826,295 frees, 5,575,110,174 bytes allocated
==7099== 
==7099== 24 bytes in 1 blocks are definitely lost in loss record 94 of 561
==7099==    at 0x483A77F: malloc (vg_replace_malloc.c:307)
==7099==    by 0xDE61E5E: XextCreateExtension (in /usr/lib/libXext.so.6.4.0)
==7099==    by 0x1074014B: ???
==7099==    by 0x1073775C: ???
==7099==    by 0x10662091: ??? (in /usr/lib/qt/plugins/xcbglintegrations/libqxcb-glx-integration.so)
==7099==    by 0xA28C084: QXcbWindow::create() (in /usr/lib/libQt5XcbQpa.so.5.15.1)
==7099==    by 0xA27A746: QXcbIntegration::createPlatformWindow(QWindow*) const (in /usr/lib/libQt5XcbQpa.so.5.15.1)
==7099==    by 0x5842F26: QWindowPrivate::create(bool, unsigned long long) (in /usr/lib/libQt5Gui.so.5.15.1)
==7099==    by 0x51F78A7: QWidgetPrivate::create() (in /usr/lib/libQt5Widgets.so.5.15.1)
==7099==    by 0x51F7E20: QWidget::create(unsigned long long, bool, bool) (in /usr/lib/libQt5Widgets.so.5.15.1)
==7099==    by 0x520551B: QWidgetPrivate::setVisible(bool) (in /usr/lib/libQt5Widgets.so.5.15.1)
==7099==    by 0x117E3F: main (main.cpp:10)
==7099== 
==7099== 160 bytes in 1 blocks are possibly lost in loss record 372 of 561
==7099==    at 0x483A77F: malloc (vg_replace_malloc.c:307)
==7099==    by 0x60A8595: QObjectPrivate::addConnection(int, QObjectPrivate::Connection*) (in /usr/lib/libQt5Core.so.5.15.1)
==7099==    by 0x60AC9DE: QObjectPrivate::connectImpl(QObject const*, int, QObject const*, void**, QtPrivate::QSlotObjectBase*, Qt::ConnectionType, int const*, QMetaObject const*) (in /usr/lib/libQt5Core.so.5.15.1)
==7099==    by 0x60ACEB5: QObject::connectImpl(QObject const*, void**, QObject const*, void**, QtPrivate::QSlotObjectBase*, Qt::ConnectionType, int const*, QMetaObject const*) (in /usr/lib/libQt5Core.so.5.15.1)
==7099==    by 0xA3D1BBD: QDBusConnectionInterface::QDBusConnectionInterface(QDBusConnection const&, QObject*) (in /usr/lib/libQt5DBus.so.5.15.1)
==7099==    by 0xA3CEB3A: ??? (in /usr/lib/libQt5DBus.so.5.15.1)
==7099==    by 0xA3CFD13: ??? (in /usr/lib/libQt5DBus.so.5.15.1)
==7099==    by 0x60AB7E1: QObject::event(QEvent*) (in /usr/lib/libQt5Core.so.5.15.1)
==7099==    by 0x607ECAF: QCoreApplication::notifyInternal2(QObject*, QEvent*) (in /usr/lib/libQt5Core.so.5.15.1)
==7099==    by 0x60817D2: QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (in /usr/lib/libQt5Core.so.5.15.1)
==7099==    by 0x60D8303: ??? (in /usr/lib/libQt5Core.so.5.15.1)
==7099==    by 0x6A2CBFB: g_main_context_dispatch (in /usr/lib/libglib-2.0.so.0.6600.0)
==7099== 
==7099== 302 (256 direct, 46 indirect) bytes in 1 blocks are definitely lost in loss record 414 of 561
==7099==    at 0x483A77F: malloc (vg_replace_malloc.c:307)
==7099==    by 0xA38F9E2: ??? (in /usr/lib/libfontconfig.so.1.12.0)
==7099==    by 0xA3902E4: ??? (in /usr/lib/libfontconfig.so.1.12.0)
==7099==    by 0xA391BEB: ??? (in /usr/lib/libfontconfig.so.1.12.0)
==7099==    by 0xA399E59: ??? (in /usr/lib/libfontconfig.so.1.12.0)
==7099==    by 0xA5309E7: ??? (in /usr/lib/libexpat.so.1.6.11)
==7099==    by 0xA52EDDC: ??? (in /usr/lib/libexpat.so.1.6.11)
==7099==    by 0xA532620: ??? (in /usr/lib/libexpat.so.1.6.11)
==7099==    by 0xA5348CB: XML_ParseBuffer (in /usr/lib/libexpat.so.1.6.11)
==7099==    by 0xA397024: ??? (in /usr/lib/libfontconfig.so.1.12.0)
==7099==    by 0xA397657: ??? (in /usr/lib/libfontconfig.so.1.12.0)
==7099==    by 0xA397713: ??? (in /usr/lib/libfontconfig.so.1.12.0)
==7099== 
==7099== LEAK SUMMARY:
==7099==    definitely lost: 280 bytes in 2 blocks
==7099==    indirectly lost: 46 bytes in 2 blocks
==7099==      possibly lost: 160 bytes in 1 blocks
==7099==    still reachable: 571,284 bytes in 7,675 blocks
==7099==                       of which reachable via heuristic:
==7099==                         newarray           : 4,264 bytes in 1 blocks
==7099==         suppressed: 20 bytes in 2 blocks
==7099== Reachable blocks (those to which a pointer was found) are not shown.
==7099== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==7099== 
==7099== Use --track-origins=yes to see where uninitialised values come from
==7099== For lists of detected and suppressed errors, rerun with: -s
==7099== ERROR SUMMARY: 80 errors from 80 contexts (suppressed: 0 from 0)

[JonB]

@Helg1980
Are you running valgrind yourself with those command-line arguments? I run it from inside Qt Creator, from the menu item. I (Ubuntu 20.04) always get exactly 32 leaks, which with the default of the checkbox which says something about "don't report system ones" being checked, are always suppressed, so I don't see them. Any genuine ones from my own code are then the only ones reported.

[Helg1980]

This post is deleted!

[Helg1980]

Here's what valgrind QtCreator gives me. There are 35 errors in total.

160 bytes in 1 blocks are possibly lost in loss record 6,742 of 8,837
  in Ui_MainWindow::setupUi(QMainWindow*) in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/build-cine_encoder-Desktop-Debug/ui_mainwindow.h:556
  1: malloc in /build/valgrind/src/valgrind-3.16.1/coregrind/m_replacemalloc/vg_replace_malloc.c:307
  2: QObjectPrivate::addConnection(int, QObjectPrivate::Connection*) in /usr/lib/libQt5Core.so.5.15.1
  3: /usr/lib/libQt5Core.so.5.15.1
  4: QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType) in /usr/lib/libQt5Core.so.5.15.1
  5: /usr/lib/libQt5Widgets.so.5.15.1
  6: Ui_MainWindow::setupUi(QMainWindow*) in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/build-cine_encoder-Desktop-Debug/ui_mainwindow.h:556
  7: MainWindow::MainWindow(QWidget*) in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/cine-encoder-3.0/app/mainwindow.cpp:71
  8: main in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/cine-encoder-3.0/app/main.cpp:9
288 bytes in 1 blocks are possibly lost in loss record 7,317 of 8,837
  in Ui_MainWindow::setupUi(QMainWindow*) in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/build-cine_encoder-Desktop-Debug/ui_mainwindow.h:556
  1: malloc in /build/valgrind/src/valgrind-3.16.1/coregrind/m_replacemalloc/vg_replace_malloc.c:307
  2: QObjectPrivate::addConnection(int, QObjectPrivate::Connection*) in /usr/lib/libQt5Core.so.5.15.1
  3: /usr/lib/libQt5Core.so.5.15.1
  4: QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType) in /usr/lib/libQt5Core.so.5.15.1
  5: /usr/lib/libQt5Widgets.so.5.15.1
  6: Ui_MainWindow::setupUi(QMainWindow*) in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/build-cine_encoder-Desktop-Debug/ui_mainwindow.h:556
  7: MainWindow::MainWindow(QWidget*) in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/cine-encoder-3.0/app/mainwindow.cpp:71
  8: main in /run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/cine-encoder-3.0/app/main.cpp:9

[VRonin]

All looks good to me, only false positives left

[Helg1980]

Thanks!

I'm still confused by these lines, I don't know what to do with it:

QCssParser::parseColorValue: Specified color without alpha value but alpha given: 'rgb 27, 29, 35, 0'
QCssParser::parseColorValue: Specified color without alpha value but alpha given: 'rgb 27, 29, 35, 0'
kf.kio.core: We got some errors while running testparm "Error loading services."
kf.kio.core: We got some errors while running 'net usershare info'
kf.kio.core: "Can't load /etc/samba/smb.conf - run testparm to debug it\n"
kf.kio.widgets.kdirmodel: No node found for item that was just removed: QUrl("file:///run/media/helg/GOODRAM-SDB/QtCreatorProjects/CineEncoder/build-cine_encoder-Desktop-Debug/Makefile")

[Christian Ehrlicher]

@Helg1980 said in How do I delete the current QTreeWidget element correctly?:

QCssParser::parseColorValue: Specified color without alpha value but alpha given: 'rgb 27, 29, 35, 0'

You have a css somewhere which defines a wrong color rgb value.