问题
I want to fire QAbstractItemView::doubleClicked
slot programaticaly for an item that has specific text. I want to do this using QAbstractItemView
class and not it's implementations if possible.
This task boils down to looping over items and comparing strings. But I cannot find any method that would give me all QModelIndex
es. The only method that gives any QModelIndex
without parameters is QAbstractItemView::rootIndex
. But when I look into QModelIndex
docs, I again cannot see a way to access it's children and siblings.
So how to access all QModelIndex
es in QAbstractItemView
?
回答1:
The indexes are provided by the model, not by the view. The view provides the rootIndex()
to indicate what node in the model it considers as root; it might be an invalid index. Otherwise it has nothing to do with the data. You have to traverse the model itself - you can get it from view->model()
.
Here's a depth-first walk through a model:
void iterate(const QModelIndex & index, const QAbstractItemModel * model,
const std::function<void(const QModelIndex&, int)> & fun,
int depth = 0)
{
if (index.isValid())
fun(index, depth);
if (!model->hasChildren(index) || (index.flags() & Qt::ItemNeverHasChildren)) return;
auto rows = model->rowCount(index);
auto cols = model->columnCount(index);
for (int i = 0; i < rows; ++i)
for (int j = 0; j < cols; ++j)
iterate(model->index(i, j, index), model, fun, depth+1);
}
The functor fun
gets invoked for every item in the model, starting at root and going in depth-row-column order.
E.g.
void dumpData(QAbstractItemView * view) {
iterate(view->rootIndex(), view->model(), [](const QModelIndex & idx, int depth){
qDebug() << depth << ":" << idx.row() << "," << idx.column() << "=" << idx.data();
});
}
来源:https://stackoverflow.com/questions/39153835/how-to-loop-over-qabstractitemview-indexes