Hi! I have certain design problem, which I cannot solve elegantly. Maybe you know some good design patterns for this kind of tasks.
Task: We have a model which has two kinds of objects: groups and elements. Groups can hold other groups (subgroups) and elements. It's a simple directory tree, for example. We would like to display it in a tree view (which sound good for this kind of model). What is more required, for groups and elements there are different sets of operations, which should be available under right click. For example for group, there should be operations: 'add element' and 'add group', and for element there should be 'change properties'. Do you know any smart way to achieve this? The simplest way is to ask for the class and display operations accordingly. But from the first day with OO programming I have heard, that asking for class is wrong. But I can hardly see any easy and more maintainable solution for this problem. Could you help me with this? -- Filip Gruszczyński -- http://mail.python.org/mailman/listinfo/python-list
