How to check/uncheck all the items in a QTreeWidget?

[qlands]

Hi,

I'm using QT Creator to develop an small application. I have a QTreeWidget in the UI and I use the following code to populated:

QTreeWidgetItem *mainhh = new QTreeWidgetItem(this->ui->treetables);
    mainhh->setText(0, tr("Main Table"));
    QStringList lista;
    //Move the items to the list
    lista << tr("Sub-table 1");
    lista << tr("Sub-table 2");
    lista << tr("Sub-table 3");
    //Many more items ........
    //Add the list of subtables as a children of Main Table
    new QTreeWidgetItem(mainhh,lista,0);
   //Many more parent nodes and childs.......
  this->ui->treetables->expandAll(); //Expand the tree

QTreeWidgetItem *mainhh = new QTreeWidgetItem(this->ui->treetables);
    mainhh->setText(0, tr("Main Table"));
    QStringList lista;
    //Move the items to the list
    lista << tr("Sub-table 1");
    lista << tr("Sub-table 2");
    lista << tr("Sub-table 3");
    //Many more items ........
    //Add the list of subtables as a children of Main Table
    new QTreeWidgetItem(mainhh,lista,0);
   //Many more parent nodes and childs.......
  this->ui->treetables->expandAll(); //Expand the tree

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The code works fine but how can I check/uncheck all the items after I have fulled populated the tree e.g., by clicking a button called "Check/Uncheck all". I guess I need to set some flags and properties to each items with something like:

setFlags(Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled);
  setCheckState(Qt::Unchecked); //or QT::Checked

setFlags(Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled);
  setCheckState(Qt::Unchecked); //or QT::Checked

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But.... I don't know how to go through all the items in the tree to set those properties and flags to each item.

Many thanks,
QLands

[wysota]

Can't you do it while populating the tree?

[qlands]

Well... Yes I can but I still need to implement a "Check/Uncheck all" button. And for this I would like to use a FOR statement. For example, if I use a QListWidget is can implement the code really easy with:

for (pos =0; pos <= this->ui->lsttables->count()-1; pos++)
    {
        this->ui->lsttables->item(pos)->setFlags(Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled);
        this->ui->lsttables->item(pos)->setCheckState(Qt::Unchecked);
    }

for (pos =0; pos <= this->ui->lsttables->count()-1; pos++)
    {
        this->ui->lsttables->item(pos)->setFlags(Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled);
        this->ui->lsttables->item(pos)->setCheckState(Qt::Unchecked);
    }

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But, with a QTreeWidget, I have no clue how to do it.

Thanks.

[wysota]

void checkSubTree(QTreeWidgetItem *item, Qt::CheckState st){
  item->setCheckState(0, st);
  for(int i=0;i<item->childCount();i++)
    checkSubTree(item->child(i), st);
}
 
for(int i=0;i<tree->topLevelItemCount();i++){
  checkSubTree(tree->topLevelItem(i), Qt::Checked);
}

void checkSubTree(QTreeWidgetItem *item, Qt::CheckState st){
  item->setCheckState(0, st);
  for(int i=0;i<item->childCount();i++)
    checkSubTree(item->child(i), st);
}

for(int i=0;i<tree->topLevelItemCount();i++){
  checkSubTree(tree->topLevelItem(i), Qt::Checked);
}

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Be warned it might be very slow for many items. A model-based approach should be much faster (apart when using QStandardItemModel).

[qlands]

Brilliant...

Thanks a lot.

[jialrs]

maybe you can use a QList<QTreeWidgetItem *> to store all the point of all the item object , and just use a for loop to check/uncheck , this will be more faster and just use a little of memory .....