Crash in takeChild() while deleting a QTreeWidgetItem

LAXMIU

ModelForm.cpp
@
#include "ModelForm.h"

ModelForm::ModelForm( QWidget* parent, Qt::WFlags fl):QWidget( parent, fl )
{
modelTree=new QTreeWidget;
QGridLayout *mainLayout = new QGridLayout;
QVBoxLayout *VLayout = new QVBoxLayout;
VLayout->setMargin(0);
mainLayout->setMargin(0);
VLayout->addWidget(modelTree,0);
mainLayout->addLayout(VLayout, 0,0);
setLayout(mainLayout);
_delegate = NULL;
globalModels = NULL;

_delegate = new ModelFormDelegate(modelTree,modelTree,this);
modelTree->setItemDelegate(_delegate);
modelTree->setColumnCount(3);
modelTree->header()->resizeSection(CHECKBOXCOL,60);
modelTree->header()->resizeSection(FILENAMECOL,400);
modelTree->header()->setResizeMode(FILENAMECOL, QHeaderView::Stretch);
modelTree->header()->setResizeMode(CHECKBOXCOL, QHeaderView::Interactive);
modelTree->header()->setResizeMode(SECTIONCOL, QHeaderView::Interactive);
modelTree->header()->setStretchLastSection(false);
modelTree->setContextMenuPolicy(Qt::CustomContextMenu);
modelTree->setSelectionMode(QAbstractItemView::ExtendedSelection);
modelTree->setTextElideMode(Qt::ElideLeft);
modelTree->setEditTriggers(QAbstractItemView::AllEditTriggers);

modelTree->setTabKeyNavigation(true);

QStringList labels;
labels << "" << "Model File" << "Section";
modelTree->setHeaderLabels(labels);

 resetModelForm();
       
 connect( _delegate, SIGNAL( addModelFilesSignal(const QStringList&) ),
   this, SLOT(  addModelFilesSlot(const QStringList&) ) );
 connect( modelTree, SIGNAL( itemChanged(QTreeWidgetItem *, int) ),
   this, SLOT(  itemChanged(QTreeWidgetItem *,int) ) );
 connect(this, SIGNAL(deleteRow(QTreeWidgetItem*, int)), this, SLOT(deleteRowSlot(QTreeWidgetItem*, int)));

 if (!parent) show();

}

bool ModelForm::event(QEvent *event)
{
if(event->type() == QEvent::Leave) {
QTreeWidgetItem *item = modelTree->currentItem();
if(item != NULL){
int col = modelTree->currentColumn();
ModelFileEditor *fileEdit = qobject_cast<ModelFileEditor *>(modelTree->itemWidget(item,col));
QLineEdit *lineEdit = qobject_cast<QLineEdit *>(modelTree->itemWidget(item,col));
if(fileEdit){
if(item->text(col) != fileEdit->lineEdit->text()){
item->setText(col,fileEdit->lineEdit->text());
}
}
else if(lineEdit){
if(item->text(col) != lineEdit->text()){
item->setText(col,lineEdit->text());
}
}
}
}
return QWidget::event(event);
}

void ModelForm::resetModelForm() {
modelTree->clearSelection();
QTreeWidgetItem* current = modelTree->currentItem();
if(current) {
modelTree->closePersistentEditor(current,FILENAMECOL);
}
modelTree->clear();
globalModels = new QTreeWidgetItem;
modelTree->blockSignals(true);
globalModels->setText(BLOCKCOL,GLOBALBLOCKNAME);
globalModels->setFlags(Qt::ItemIsEnabled|Qt::ItemIsUserCheckable);
modelTree->blockSignals(false);
modelTree->addTopLevelItem(globalModels);
addBlankRow(globalModels);
}

void ModelForm::addBlankRow(QTreeWidgetItem* item) {
QTreeWidgetItem* chItem = new QTreeWidgetItem;

item->addChild(chItem);
modelTree->expandItem(item);
modelTree->blockSignals(true);
chItem->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsDragEnabled | Qt::ItemIsEditable);
chItem->setCheckState(CHECKBOXCOL,Qt::Unchecked);
chItem->setText(FILENAMECOL,QString(EMPTYROWTEXT));
modelTree->blockSignals(false);
}

QTreeWidgetItem* ModelForm::getBlockItem( QString blockName) {
if(QString::compare(QString(GLOBALBLOCKNAME),blockName) == 0) {
return globalModels;
} else {
int itemCount = modelTree->topLevelItemCount();
for(int i=0; i<itemCount;i++) {
if(QString::compare(modelTree->topLevelItem(i)->text(BLOCKCOL),blockName) == 0) {
return modelTree->topLevelItem(i);
}
}
}
return NULL;
}
void ModelForm::itemChanged( QTreeWidgetItem * item,int col) {
if(col == FILENAMECOL) {
QString file = item->text(FILENAMECOL);
if(item->parent() != NULL) {
QTreeWidgetItem* p = item->parent();
int index = p->indexOfChild(item);
if((index == p->childCount() -1) && (file != QString(EMPTYROWTEXT))) {
if(file.isEmpty()){
modelTree->blockSignals(true);
item->setText(FILENAMECOL,QString(EMPTYROWTEXT));
modelTree->blockSignals(false);
}
else {
item->setFlags(item->flags()|Qt::ItemIsSelectable);
item->setCheckState(CHECKBOXCOL,Qt::Checked);
addBlankRow(p);
}
} else if( index != p->childCount() -1 && (file.isEmpty() || file == QString(EMPTYROWTEXT))) {
// delete this row
emit deleteRow(p, index);
}
}
}
}

//Modified below function so that files are inserted instead of adding it at last.
void ModelForm::addModelFilesSlot(const QStringList& paths){
QTreeWidgetItem* curItem = NULL;
curItem = modelTree->currentItem();
int curCol = modelTree->currentColumn();
// if curItem is not toplevel item
if(curItem && (curCol !=-1) && (modelTree->indexOfTopLevelItem(curItem) == -1)) {
QTreeWidgetItem* parent = curItem->parent();
if(parent){
int childIndex = parent->indexOfChild(curItem);
for (int i = 0; i < paths.size(); ++i) {
QTreeWidgetItem* child = new QTreeWidgetItem();
child->setFlags(Qt::ItemIsSelectable|Qt::ItemIsUserCheckable |
Qt::ItemIsEnabled | Qt::ItemIsDragEnabled | Qt::ItemIsEditable);
child->setCheckState(CHECKBOXCOL,Qt::Checked);
child->setText(FILENAMECOL,(paths.at(i)));
parent->insertChild(((childIndex+1)+i), child);
}
}
}
}

void ModelForm::deleteRowSlot(QTreeWidgetItem* item , int index) {
QTimer::singleShot(1, this, SLOT(deleteCurrent()));
}
@

[edit: highlight added / Denis Kormalev]

LAXMIU

@
void ModelForm::deleteCurrent() {
QList<QTreeWidgetItem *> itemList = modelTree->selectedItems();
modelTree->blockSignals(true);
for(int i= 0; i <itemList.size(); i++) {
if(itemList.at(i) != NULL && itemList.at(i)->parent() != NULL) {
QTreeWidgetItem *c=itemList.at(i);
QTreeWidgetItem p = c->parent();
c= p->takeChild(p->indexOfChild(c));
delete c;
if( modelTree->isItemExpanded(p)) {
modelTree->collapseItem(p);
modelTree->expandItem(p);
}
}
}
modelTree->blockSignals(false);
//now select the current item
QTreeWidgetItem curItem = modelTree->currentItem();
if(curItem){
modelTree->setItemSelected(curItem, true);
}
}
@

[edit: highlight added / Denis Kormalev]

LAXMIU

ModelFormDelegate.cpp
@
#include <QtGui/QtGui>

#include "ModelFormDelegate.h"
#include "ModelForm.h"

QString ModelFileEditor::lastFilePath = NULL;

ModelFileEditor::ModelFileEditor( QWidget* parent, ModelForm* qwidget, Qt::WFlags fl )
:QWidget( parent, fl ), _parent(qwidget)
{
lineEdit = new QLineEdit;
lineEdit->setFrame(FALSE);
btn = new QPushButton(QString(" ... "));
QHBoxLayout *mainLayout = new QHBoxLayout;
mainLayout->setMargin(0);
mainLayout->setSpacing(0);
mainLayout->addWidget(lineEdit,5);
mainLayout->addWidget(btn,0);
mainLayout->addSpacing(5);
setLayout(mainLayout);
connect(lineEdit, SIGNAL(editingFinished()), this, SIGNAL(editingFinished()));
connect(lineEdit, SIGNAL(editingFinished()), this, SLOT(editingFinishedSlot()));
connect(lineEdit, SIGNAL(textChanged(const QString &) ),this, SLOT(textChangedSlot( const QString &)));
this->setFocusProxy(lineEdit);
setTabOrder(lineEdit,btn);
}

void ModelFileEditor::editingFinishedSlot() {
f(lineEdit) {
if((lineEdit->text() != QString(EMPTYROWTEXT)) && (lineEdit->text() != QString(""))) {

QString temp(FILESTR);

temp.append(lineEdit->text());
temp.append(NOTEXIST);
lineEdit->setToolTip(temp);
}
}
}

void ModelFileEditor::textChangedSlot( const QString & text){
if(lineEdit){
lineEdit->setToolTip(text);
}
editingFinishedSlot();
}

ModelFormDelegate::ModelFormDelegate(QObject *parent)
: QItemDelegate(parent),m_view(NULL){}

ModelFormDelegate::ModelFormDelegate(QObject *parent, QAbstractItemView *aiv,ModelForm *qwidget)
: QItemDelegate(parent),m_view(aiv),_parent(qwidget){}

void ModelFormDelegate::paint(QPainter *painter,
const QStyleOptionViewItem &option,
const QModelIndex &index) const
{
int col = index.column();
int row = index.row();
int pRow = index.parent().row();
if (index.isValid() && !index.parent().isValid()) {
QModelIndex index2(index.sibling(index.row(),0));
QStyleOptionViewItem sovi(option);
sovi.rect=QRect(0, option.rect.y(),
painter->viewport().width(),
option.rect.height());
if(m_view)
sovi.rect.setX(m_view->visualRect(index2).x());
QItemDelegate::paint(painter,sovi,index2);
} else {
int rows = -1;
if(m_view)
{
rows = qobject_cast<QTreeWidget *>(m_view)->topLevelItem(pRow)->childCount();
}
QModelIndex lastRowIndex(index.sibling(rows-1,col));
QModelIndex lastColIndex(index.sibling(row,2));
int w = option.rect.width();
int h = option.rect.height();
if(index == lastRowIndex)
{
h= h-1;
}
if(index == lastColIndex)
{
w= w-1;
}
QItemDelegate::paint(painter, option, index);
painter->setPen(QColor(Qt::lightGray));
QRect myrect(option.rect.x(),option.rect.y(),w,h);
painter->drawRect(myrect);
}
}
QWidget *ModelFormDelegate::createEditor(QWidget parent,
const QStyleOptionViewItem & / option */,
const QModelIndex &index) const
{
int col = index.column();

if( !index.parent().isValid()) return NULL;

if(col == 2 ) { // section
QLineEdit *lineEdit = new QLineEdit(parent);
connect( lineEdit, SIGNAL(editingFinished()), this , SLOT(emitCommitData()));
return lineEdit;
} else if(col == 0 ){// checkBox
return NULL;
} else if(col == 3 ){// push button for browser
QPushButton * pushButton = new QPushButton(QString("..."),parent);
connect(pushButton, SIGNAL(clicked()), this, SLOT(emitCommitData()));
return pushButton;
} else if(col == 1 ){ //file
ModelFileEditor *fileEdit = new ModelFileEditor(parent,_parent);
connect(fileEdit, SIGNAL(editingFinished()), this, SLOT(emitCommitData()));
connect(fileEdit, SIGNAL(addModelFiles(const QStringList&)), this, SLOT(addModelFiles(const QStringList&)));
return fileEdit;
} else {
return NULL;
}
return NULL;
}

void ModelFormDelegate::setEditorData(QWidget *editor,
const QModelIndex &index) const
{
int col = index.column();
if(col == 2 ) {
QLineEdit *lineEdit = qobject_cast<QLineEdit *>(editor);
if( !lineEdit) {
return;
}
if((lineEdit->text())!= (index.model()->data(index).toString())) {
lineEdit->setText(index.model()->data(index).toString());
lineEdit->selectAll();
}

} else if(col == 1 ){
ModelFileEditor *fileEdit = qobject_cast<ModelFileEditor *>(editor);
if (!fileEdit) {
return;
}
if ((fileEdit->lineEdit->text())!= (index.model()->data(index).toString())) {
fileEdit->lineEdit->setText(index.model()->data(index).toString());
}
fileEdit->lineEdit->selectAll();

} else if(col == 3 ){
QPushButton *btn = qobject_cast<QPushButton *>(editor);
if (!btn)
return;
}
}

void ModelFormDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,
const QModelIndex &index) const
{
int col = index.column();
if(col == 2 ) {
QLineEdit *lineEdit = qobject_cast<QLineEdit *>(editor);
if( !lineEdit) {
return;
}
model->setData(index, lineEdit->text());

} else if(col == 1 ){
ModelFileEditor *fileEdit = qobject_cast<ModelFileEditor *>(editor);
if (!fileEdit) {
return;
}
model->setData(index, fileEdit->lineEdit->text());
} else if(col == 3 ){
QPushButton *btn = qobject_cast<QPushButton *>(editor);
if (!btn)
return;
model->setData(index, true);
}
}

void ModelFormDelegate::addModelFiles(const QStringList& files)
{
emit addModelFilesSignal(files);
}
@

[edit: highlight added / Denis Kormalev]

tobias.hunger

Could you please use the code tags to format your code sections? It is hardly readable the way it is printed now!

thorbjorn

This might have something to do with @modelTree->blockSignals(true);@, which I guess could cause the view not to be entirely aware of the child removals, but I'm not sure. In any case this forum is not the proper place to report bugs, you should use "http://bugreports.qt.nokia.com/":http://bugreports.qt.nokia.com/ for that.

LAXMIU

LAXMIU

Hi,
I tried removing blockSignals from the deleteCurrent functionality , but it did not work out.

Thanks, Laxmi

LAXMIU

LAXMIU

DenisKormalev

LAXMIU, I've added highlighting to your code, please don't forget to use it by yourself in future :)

alexander

why do you use takeChild()?
try only delete item

@void ModelForm::deleteCurrent() {
QList<QTreeWidgetItem *> itemList = modelTree->selectedItems();
for(int i= 0; i <itemList.size(); i++) {
if(itemList.at(i) != NULL && itemList.at(i)->parent() != NULL) {
QTreeWidgetItem *c=itemList.at(i);
QTreeWidgetItem p = c->parent();
delete c;
}
}
//now select the current item
QTreeWidgetItem curItem = modelTree->currentItem();
if(curItem){
modelTree->setItemSelected(curItem, true);
}
}@

LAXMIU

Hi Alexander,

I tried removing takeChild too, the crash now coming in the destructor of QTreeWidgetItem as follows:

#0 0x00270823 in QPersistentModelIndex::operator QModelIndex const& ()
from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtCore.so.4
#1 0x0120539f in QAbstractItemView::updateEditorGeometries () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#2 0x011f6dd2 in QAbstractItemViewPrivate::_q_rowsRemoved () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#3 0x0123deaa in QTreeViewPrivate::rowsRemoved () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#4 0x0123e4eb in QTreeView::rowsAboutToBeRemoved () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#5 0x01202865 in QAbstractItemView::qt_metacall () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#6 0x012492ba in QTreeView::qt_metacall () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#7 0x0128212a in QTreeWidget::qt_metacall () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#8 0x00291583 in QMetaObject::activate () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtCore.so.4
#9 0x002921e2 in QMetaObject::activate () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtCore.so.4
#10 0x002cb7ff in QAbstractItemModel::rowsAboutToBeRemoved () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtCore.so.4
#11 0x00272965 in QAbstractItemModel::beginRemoveRows () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtCore.so.4
#12 0x0127f4c6 in QTreeModel::beginRemoveItems () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#13 0x0127f6b0 in QTreeWidgetItem::~QTreeWidgetItem () from /net/ciclnx11d/export/home/laxmi/PERFORCE/DEL/lnx86/tools/Qt/32bit/lib/libQtGui.so.4
#14 0x0804c7da in ModelForm::deleteCurrent (this=0x857ff60) at ModelForm.cpp:179

LAXMIU

[quote author="Denis Kormalev" date="1285753913"]LAXMIU, I've added highlighting to your code, please don't forget to use it by yourself in future :)[/quote]

Hi Denis,
Please let me know the procedure/steps of highlighting the code. I really don't know. I am new to this forum. I could not either find any icon above for doing so.

Thanks andregards,
Laxmi

? This user is from outside of this forum

just enclose only your code with the @ tag ... one before and one after your code :)

tobias.hunger

LAXMIU: ... or just mark the code with your mouse and click on the second icon from the right (the one with the tooltip "Code").

tobias.hunger

This thread kind of reminds me of computer magazines in the early 80ties...

DenisKormalev

[quote author="Tobias Hunger" date="1286270859"]This thread kind of reminds me of computer magazines in the early 80ties...[/quote]

A lot of code and small amount of text?:)

LAXMIU

I have removed unnecessary repetition of code from the thread.
Hopefully its readable now.

Thanks,
Laxmi

? This user is from outside of this forum

ok laxmi, I copied all the code and tried on Qt 4.7, no crashes ... any specific reason you are still on Qt 4.5.x ?

LAXMIU

Thanks a lot Chetan,

We have migrated from 4.4.1 to 4.5.3 in one of our product releases. Hopefully, we will be getting the latest Qt version attached for our next product release.

May I get any pointer that its actually a bug in Qt 4.5.3?
Have you been able to reproduce the crash in Qt 4.5.3? (If thats available with you)

Thanks,
Laxmi