crash when loading a lot of photos

[Kicer86]

When nodes are expanded and huge directory is added - PhotoBroom crashes at some point

[Kicer86]

The problem is with Qt's view model architecture:
it is not easy to create reliable link between view's and model's item (http://qt-project.org/forums/viewthread/51259/).

Ideas for fixing it:

• using QPersistentModelIndex. drawbacks: It looks that each model change will case update of all QPersistenModelIndex objects.
• introduce own model - view architecture. Model can inherit from QAbstractItemModel, but will have to introduce two funcitons: IndexFromId and IdFromIndex where Index would be QModelIndex and Id some uniq id of item (pointer for example). Such approch would allow model to be used by default views, but the ImagesTreeView used in PhotoBrooum would have to introduce brand new view class (not inheriting from QAbstractItemView)

[Kicer86]

Approach no 1 used.