CODEWITHSUNDEEP
c++qt
Vladimir Gamalyan
Vladimir Gamalyan

Reputation: 255

How to get currentIndex of QListView in QStyledItemDelegate::paint()

I defined pure virtual method QStyledItemDelegate::paint as:

void FooViewDelegate::paint( QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    bool selected = option.state & QStyle::State_Selected;
    // ...
    // drawing code
}

But I cant't figure how to know is the drawing item current or no (The same item as from QListView::currentIndex()).

Upvotes: 4

Views: 1675

Answers (3)

Jruv
Jruv

Reputation: 1598

The parent of the delegate is the view, you can directly obtain the current index from the view.

void FooViewDelegate::paint( QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    bool selected = index == parent()->currentIndex();
}

Upvotes: 1

Dmitry Sazonov
Dmitry Sazonov

Reputation: 8994

Qt MVC is not designed for such usecases, because, theoretically, delegate should not know, what view you are using (it may be QListView or QTableView).

So, a "good way" is to keep this information inside your delegate (because model may be used by sevaral views). Fox example (pseudo-code):

class FooViewDelegate : ...
{
private:
  QModelIndex _currentIndex;

  void connectToView( QAbstractItemView *view )
  {
    connect( view, &QAbstractItemView::currentChanged, this, &FooViewDelegate ::onCurrentChanged );
  }

  void onCurrentChanged( const QModelIndex& current, const QModelIndex& prev )
  {
    _currentIndex = current;
  }

public:
    void paint( QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
    {
        bool selected = index == _currentIndex;
        // ...
        // drawing code
    }

}

Upvotes: 1

Kuba hasn't forgotten Monica
Kuba hasn't forgotten Monica

Reputation: 98445

You're along the right track:

auto current = option.state & QStyle::State_HasFocus;

The item with focus is the current item.

Upvotes: 0

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