Select All

[VisualAlf]

It seems there is some counterintuitive / unconsistent behavior...

1. When editing a cell:
   a. Optionsbutton/Select All has no function (although it's enabled). (Ctrl-A however selects the Text within the TextBox, which is quite standard).
   b. Optionsbutton/Deselect All, however, deselects everything and terminates the editing.

2. Whatever selection is active, it is unselected when we click into any column header for sorting/filtering. We could argue that filtering could change the selected Set. But IMHO it should not cancel the complete selection.

   As a side-note I noticed that the AdvancedCollectionView does not alter the SelectedItem (et al.). It does clear the
   selection-set, but in the end it will reselect the original value.

3. When IsReadonly=True and OptionsButton is hidden
   a. in Single-Mode, selection jumps to Line 1 after (Select All)-Click. [It seems somewhat contradictionary to have SINGLE row selection but also a select ALL. So, maybe we could/should suppress this function in this case.]
   b. in Extended-Mode, there is no way to unselect (except toggle sort/filter or Ctrl-Shft-A). Nor can you select a specific line after all lines are selected.

[w-ahmad]

Thank you, @VisualAlf, for the thorough investigation of the functionality. I will try to implement these suggestions in v1.3.0.