All QStyleOptionButton in listview sunken when clicking one of them

[jiveaxe]

HI, I have the following strange behaviour: I created a QListView whose elements are delegates. The delegate contains a button implemented this way:

void ItemDelegate::paint ( QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    ...
    QStyleOptionButton button;
    button.rect = buttonRect;
    button.features |= QStyleOptionButton::Flat;
    button.state = _state | QStyle::State_Enabled;
    QApplication::style()->drawControl(QStyle::CE_PushButton, &button, painter);
    ...
}
 
bool ItemDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index)
{
    if( event->type() == QEvent::MouseButtonPress ||
        event->type() == QEvent::MouseButtonRelease ) {
    } else {
         _state = QStyle::State_Raised;
        return true;
    }
 
    ...
    QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event);
    if( !buttonRect.contains( mouseEvent->pos()) ) {
        _state = QStyle::State_Raised;
        return true;
    }
 
    if( event->type() == QEvent::MouseButtonPress) {
        _state = QStyle::State_Sunken;
    } else if( event->type() == QEvent::MouseButtonRelease) {
        _state = QStyle::State_Raised;
        // call slot
    }
}

void ItemDelegate::paint ( QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    ...
    QStyleOptionButton button;
    button.rect = buttonRect;
    button.features |= QStyleOptionButton::Flat;
    button.state = _state | QStyle::State_Enabled;
    QApplication::style()->drawControl(QStyle::CE_PushButton, &button, painter);
    ...
}

bool ItemDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index)
{
    if( event->type() == QEvent::MouseButtonPress ||
        event->type() == QEvent::MouseButtonRelease ) {
    } else {
         _state = QStyle::State_Raised;
        return true;
    }

    ...
    QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event);
    if( !buttonRect.contains( mouseEvent->pos()) ) {
        _state = QStyle::State_Raised;
        return true;
    }

    if( event->type() == QEvent::MouseButtonPress) {
        _state = QStyle::State_Sunken;
    } else if( event->type() == QEvent::MouseButtonRelease) {
        _state = QStyle::State_Raised;
        // call slot
    }
}

To copy to clipboard, switch view to plain text mode 

It works fine except that the first time (after starting the application) I click any button, all buttons show the State_Sunken; all others clicks, after the first one, are normals: only the clicked button show the sunken/raised effect.

Do you have any explaination for this?

Very thanks.

[ChrisW67]

Where is buttonrect defined/coming from?

The items in the view are all drawn by the same, single delegate (i.e. the list view items are not delegates). If buttonrect is kept state then then painting will be confused.

[jiveaxe]

Here the code (the same for paint() and editorEvent()):

QRect buttonRect;
buttonRect.setX(option.rect.width() - buttonSize - margin);
buttonRect.setY(option.rect.y() + (option.rect.height()/2 - buttonSize/2));
buttonRect.setWidth(buttonSize);
buttonRect.setHeight(buttonSize);

QRect buttonRect;
buttonRect.setX(option.rect.width() - buttonSize - margin);
buttonRect.setY(option.rect.y() + (option.rect.height()/2 - buttonSize/2));
buttonRect.setWidth(buttonSize);
buttonRect.setHeight(buttonSize);

To copy to clipboard, switch view to plain text mode 

I omitted it in first post because, I thought, not significant.

[ChrisW67]

And _state? If this is a member variable then that single _state is used when rendering any of the items the view needs to paint.

[jiveaxe]

_state is effectively a member variable:

QStyle::State _state;

QStyle::State _state;

To copy to clipboard, switch view to plain text mode 

but if this is the problem, why the behaviour happens only on very first click and not in next?

[ChrisW67]

Are you initialising _state to QStyle::State_Raised in the constructor ?

[jiveaxe]

This is my constructor:

ItemDelegate::ItemDelegate(QObject *parent) :
    QAbstractItemDelegate(parent)
{
    _state =  QStyle::State_Enabled;
}

ItemDelegate::ItemDelegate(QObject *parent) :
    QAbstractItemDelegate(parent)
{
    _state =  QStyle::State_Enabled;
}

To copy to clipboard, switch view to plain text mode 

Thanks for your patience

[jiveaxe]

I solved changing approach; I'm not using anymore _state member but int _currRow to track clicked button; here it is a sample code:

ItemDelegate::ItemDelegate(QObject *parent) :
    QAbstractItemDelegate(parent)
{
    _currRow = -1;
}
 
void ItemDelegate::paint ( QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    if (!index.isValid())
        return;
 
    QApplication::style()->drawPrimitive(QStyle::PE_PanelItemViewItem, &option, painter, 0);
 
    ...
 
    QStyleOptionButton button;
    button.rect = buttonRect;
    button.features |= QStyleOptionButton::Flat;
 
    if(_currRow == index.row())
        button.state = QStyle::State_Sunken | QStyle::State_Enabled;
    else
        button.state = QStyle::State_Raised | QStyle::State_Enabled;
 
    QApplication::style()->drawControl(QStyle::CE_PushButton, &button, painter);
}
 
bool ItemDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index)
{
    Q_UNUSED(model)
 
    if( event->type() != QEvent::MouseButtonPress &&
        event->type() != QEvent::MouseButtonRelease ) {
        return true;
    }
 
    if( event->type() == QEvent::MouseButtonPress)
        _currRow = index.row();
    else
        _currRow = -1;
 
    ...
 
    QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event);
    if( !buttonRect.contains( mouseEvent->pos()) ) {
        return true;
    }
 
    if( event->type() == QEvent::MouseButtonRelease) {
        // call slot
    }
 
    return true;
}

ItemDelegate::ItemDelegate(QObject *parent) :
    QAbstractItemDelegate(parent)
{
    _currRow = -1;
}

void ItemDelegate::paint ( QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    if (!index.isValid())
        return;

    QApplication::style()->drawPrimitive(QStyle::PE_PanelItemViewItem, &option, painter, 0);

    ...

    QStyleOptionButton button;
    button.rect = buttonRect;
    button.features |= QStyleOptionButton::Flat;

    if(_currRow == index.row())
        button.state = QStyle::State_Sunken | QStyle::State_Enabled;
    else
        button.state = QStyle::State_Raised | QStyle::State_Enabled;

    QApplication::style()->drawControl(QStyle::CE_PushButton, &button, painter);
}

bool ItemDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index)
{
    Q_UNUSED(model)

    if( event->type() != QEvent::MouseButtonPress &&
        event->type() != QEvent::MouseButtonRelease ) {
        return true;
    }

    if( event->type() == QEvent::MouseButtonPress)
        _currRow = index.row();
    else
        _currRow = -1;

    ...

    QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event);
    if( !buttonRect.contains( mouseEvent->pos()) ) {
        return true;
    }

    if( event->type() == QEvent::MouseButtonRelease) {
        // call slot
    }

    return true;
}

To copy to clipboard, switch view to plain text mode 

Thanks ChrisW67 for your time.