Common Open and Save File Dialog

In OS/2 there is a default filter of All Files that cannot be removed from the Type of File combination box. In Windows, there is no default filter. If a Win32 developer adds one or more filters (including, perhaps, an All Files filter), the Type of File combination box will still have All Files as a choice.

But, if a developer does add one or more filters, there is no way to have the OS/2 All Files filter come up as the default selection. Developers should be cautioned not to remove the All Files entry if they want the option of selecting it as their default choice.

The actual filtering mechanism also behaves quite a bit differently in OS/2:

• In Win32, filtering is centralized, and the current filter can be changed in two different ways:

  • By typing a filter in the File Name edit box (using wild card characters)
    
  • By selecting a filter from the List Files Of Type combination box
  
  In OS/2, the filtering is based on an intersection (or union if the proper flag is set) of the contents of the File Name field and the filter currently selected in the Type of File combination box. This might seem awkward to Windows programmers because an intersection of a file name of *.txt and a filter of *.hlp will not display anything (even if txt and hlp files exist) and a file name of *.* and a filter of *.hlp will display only hlp files.
  
  In Win32, if a filter is selected from the List Files of Type list and the File Name field currently contains wild card characters, then the File Name field will be updated with the selected filter string.

  For example, if File Name contains *.txt or shell.?pp and the user selects List Files of Type filter of All Files (*.*), then File Name will be set to *.*.

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