Postings by Michael in January 2010
How to customize your view with delegates
The usual way in Qt, when an item view wants to render itself, is to ask the item model for everything, layout, style and the actual data. Storing view-specific layout information in the model itself means that views and models can always only exist in a 1:1 relationship. The logical conclusion: If you need to share a model between different views, you will probably have to add proxy models for each view. I wasn't satisfied with that idea, so I continued to research QStyledItemDelegates. They ...
Fragile API and invalid iterators
For the Miniature project I sometimes need to iterate over all graphics items in a QGraphicsScene, or more precisely, all items of a specific parent item, the chess board itself. For that, I use the QGraphicsItem::childItems() API. However, when used with STL-style iterators you have to be careful, since value types of that form can easily break the iterator idiom:
for (QList<QGraphicsItem *>::iterator iter = parent_item->childItems().begin();
iter != parent_item->childItems().end();
++iter)
{
...
