ReImplement showPopup for my QComboBOx

[ber0y]

Hi,

I think that the problem is easy, but i don't know how to process for this:
I just want to reimplement QComboBox::showPopup() in my new class that inherit from QComboBox, but I want to reuse the given code and just add one line.
I can't because:

`QComboBoxPrivate* QComboBox::d_func()' is private
mycombobox.cpp:24: error: within this context
mycombobox.cpp:31: error: invalid use of undefined type `struct QAbstractItemView'
d:/Outils/Qt/qt/qt/include/QtGui/../../src/gui/itemviews/qabstractitemdelegate.h:59: error: forward declaration of `struct QAbstractItemView'
mycombobox.cpp:31: error: invalid use of undefined type `struct QComboBoxPrivate'
d:/Outils/Qt/qt/qt/include/QtGui/../../src/gui/widgets/qcombobox.h:60: error: forward declaration of `struct QComboBoxPrivate'
mycombobox.cpp:32: error: `QItemSelectionModel' has not been declared
mycombobox.cpp:32: error: `ClearAndSelect' was not declared in this scope
mycombobox.cpp:33: error: invalid use of undefined type `struct QComboBoxPrivate'
...

My code:

#include <QComboBox>
class MyComboBox : public QComboBox
{
public:
    MyComboBox (QWidget *parent);
    virtual void showPopup();
};
 
/*!
    Displays the list of items in the combobox. If the list is empty
    then the no items will be shown.
    If you reimplement this function to show a custom pop-up, make
    sure you call hidePopup() to reset the internal state.
*/
void MyComboBox::showPopup()
{
   // i just try this part of the code
    Q_D(QComboBox);
    if (count() <= 0)
        return;
 
    QStyle * const style = this->style();
 
    view()->selectionModel()->setCurrentIndex(d->currentIndex,
                                              QItemSelectionModel::ClearAndSelect);
 
    QComboBoxPrivateContainer* container = d->viewContainer();
 
    /* ... */

#include <QComboBox>
class MyComboBox : public QComboBox
{
public:
    MyComboBox (QWidget *parent);
    virtual void showPopup();
};

/*!
    Displays the list of items in the combobox. If the list is empty
    then the no items will be shown.
    If you reimplement this function to show a custom pop-up, make
    sure you call hidePopup() to reset the internal state.
*/
void MyComboBox::showPopup()
{
   // i just try this part of the code
    Q_D(QComboBox);
    if (count() <= 0)
        return;

    QStyle * const style = this->style();

    view()->selectionModel()->setCurrentIndex(d->currentIndex,
                                              QItemSelectionModel::ClearAndSelect);

    QComboBoxPrivateContainer* container = d->viewContainer();
    
    /* ... */

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How could i reuse the code for this method please ?

Thanks.

[nish]

you can not use it.

[wysota]

In general you can't. You should use QComboBox::view() and QComboBox::setView() instead.

[ber0y]

In general you can't. You should use QComboBox::view() and QComboBox::setView() instead.

Thanks !!!

I just use view() :

void MyComboBox::showPopup()
{
    view()->move(view()->x(), view()->y() - view()->height()/2);
    QComboBox::showPopup();
}

void MyComboBox::showPopup()
{
    view()->move(view()->x(), view()->y() - view()->height()/2);
    QComboBox::showPopup();
}

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I reimplement the method becasue I would like to show the items 1, 2 and 3 in a view above the QComboBox button, and the items 4, 5 and 6 below the button in a other view.
How could i do that ? : create two QListWidget and separate the QComboBox view in the two QListWidget ?

Thanks again

[wysota]

I think all you need to do is to move the popup up (change its geometry) using something like:

view()->window()->move(...);

view()->window()->move(...);

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[sedi]

It's an old thread, but the problem is still there. I needed some time to see the obvious: you have to call the base class "showPopup" before moving the popup item. This works well:

void MyQComboBox::showPopup() {
    QComboBox::showPopup();
    QWidget *popup = this->findChild<QFrame*>();
    popup->move(popup->x(),popup->y()-this->height()-popup->height());
}

void MyQComboBox::showPopup() {
    QComboBox::showPopup();
    QWidget *popup = this->findChild<QFrame*>();
    popup->move(popup->x(),popup->y()-this->height()-popup->height());
}

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