||There are two dialog deals with data. Both are DecTreeData class's descendants:
It has the same structure of working:
1. Get the version from dialog
2. Fill the version into the window (column name, types, etc.)
3. Check some conditions and let user to set another things (typically choose some column for special purposes, type some name of new column etc.]
Then if the user click OK button, the values from dialog is saved into class's variables. Then it can be used by other methods for working with it.