how can i get the QTreeWidgetItem from its itemWidget?

opengpu2

how can i get the QTreeWidgetItem from its itemWidget?
i use setItemWidget to add a QPushButton on a column of QTreeWidgetItem, and in the QPushButton's clicked slot i want to gef the related QTreeWidgetItem.
is there any good way to do this?
thank you!

Paul Colby

The documentation for QTreeViewWidget::setItemWidget says:

Note: The tree takes ownership of the widget.

So, can probably do something like:

QTreeViewWidget * const treeViewWidget = qobject_cast<QTreeViewWidget *>(parent());
Q_CHECK_PTR(treeViewWidget);

Cheers.

opengpu2

thank you , but i want the related QTreeWidgetItem not QTreeWidget...

Paul Colby

Oops. Sorry... didn't read carefully enough :)

Which class is implementing the slot that the QPushButton::clicked signal is connected to? A custom QTreeWidget or QTreeWidgetItem?

How are you adding the QPushButton instances to the QTreeWidget?

opengpu2

@Paul-Colby use setItemWidget to add a QPushButton.
i want to get the related QTreeWidgetItem in the QPushButton's clicked slot, because there are some custom data stored in the other column of the QTreeWidgetItem which using setData().

Paul Colby

@opengpu2 said:

i want to get the related QTreeWidgetItem in the QPushButton's clicked slot

QPushButton doesn't have a clicked slot - it has a clicked signal. So you have to connect that signal to a slot somewhere. Depending on where you want to encapsulate the logic, that slot could be on a custom QTreeWidget, QTreeWidgetItem, or QPushButton.

For example, using a slot in a custom QTreeWidget (pseudo code only):

// in header: QMap<QPushButton *, QTreeWidgetItem *> buttonItemMap;

void MyTreeWidget::MyTreeWidget() : QTreeWidget() {
    QTreeWidgetItem * item = new QTreeWidgetItem(this);
    QPushButton * button = new QPushButton(this);
    buttonItemMap.insert(button, item);
    connect(button, SIGNAL(clicked()), myTreeWidget, SLOT(buttonClicked));
    myTreeWidget->setItemWidget(item , 0, button);
}

void MyTreeWidget::buttonClicked() {
    QPushButton * const button = qobject_cast<QPushButton *>(sender());
    QT_CHECK_PTR(button)
    QTreeWidgetItem * const item = map.at(button);
    QT_CHECK_PTR(item)
    // do what you want with 'item'.
}

Using a slot in a custom QTreeWidgetItem (pseudo code only):

void MyClass::wherever() {
    MyTreeWidgetItem * myTreeWidgetItem = new QTreeWidgetItem;
    QPushButton * button = new QPushButton(this);
    connect(button, SIGNAL(clicked()), myTreeWidgetItem, SLOT(buttonClicked));
    treeWidget->setItemWidget(myTreeWidgetItem , 0, button);
}

MyTreeWidgetItem::buttonClicked() {
    // do whatever you want with 'this'.
}

Using a slot in a custom QPushButton (pseudo code only):

void MyClass::wherever() {
    QTreeWidgetItem * item = new QTreeWidgetItem;
    MyPushButton * myButton = new MyPushButton(this);
    myButton->setItem(item);
    connect(myButton, SIGNAL(clicked()), myTreeWidgetItem, SLOT(onClicked));
    treeWidget->setItemWidget(item , 0, button);
}

void MyPushButton::setItem(QTreeWidgetItem * item) {
    this->item = item;
}

// Note, this is a new onClicked function, not the base class' clicked signal.
// Alternatively, you could probably override QPushButton::onMouseUp?
void MyPushButton::onClicked() {
    // do whatever you want with this->item.
}

Again, it depends on where it makes most sense to have your logic that uses the item, but the custom QTreeWidgetItem is likely to be the most logical otherwise a custom QTreeWidget. The custom QPushButton is likely to be wrong approach I think.

Also, note in the QTreeWidget::setItemWidget documentation says:

This function should only be used to display static content in the place of a tree widget item. If you want to display custom dynamic content or implement a custom editor widget, use QTreeView and subclass QItemDelegate instead.

I suspect that a QPushButton would not be considered static content, and you might need to be using a delegate instead.

Cheers.

opengpu2

@Paul-Colby thank you very much!
actually i want to add a button like this pic below, the 2nd and 3th column, which is checkable.
http://help.autodesk.com/cloudhelp/2015/ENU/3DSMax/images/GUID-251FA108-D677-470F-85AB-F1CF690EC4C0.png

opengpu2

thank you
i did use delegate to edit a QTreeWidgetItem.
howerver, i donnot know how to use delegate to add 2 buttons before the original QTreeWidgetItem and its icon...
and i want to react the signals of the 2 buttons...