Autocomplete text control (and its problems)

[Sjors]

I needed a text control that anticipates what the user wants to type (like in most browsers, office programs and cell-phones) by creating an ever shrinking dropdown list as the user types. I couldn't find one for wxWidgets, so I decided to try to make one. I'm a beginner in both C++ and wxWidgets, but I managed to get something working. It's on my
homepage and everyone may feel free to use, modify and copy it.
Here is a screenshot of demo application that uses it:


As I also mention on my homepage there are several problems with it:

- (part of) the code is not very elegant
- it is possible for any part of the program to use the help classes (AutocompleteListCtrlPart for the listcontrol and AutocompleteTimerPart). I'm not actually sure if this is a problem, but they are quite specifically designed to be used by the AutocompleteTextCtrl
- I don't know how to handle the tab order of a program; if you press <Tab>, the demonstration program won't jump to another control. I'm not sure if this is something that has to be built into the AutocompleteTextCtrl class or is normally handled some other way.
- if you select a random text (not in the list) and start typing you override the selected text. At the first letter you type there won't be a listcontrol visibible, because the control still sees the original text. It will work fine at the next keypress.
- when a user decides to focus on some other control the listbox part disappears (using a function triggered by a KillFocus event that runs

[Jasper]

Did you consider using a combobox? I think this would solve at least a few problems.

[Jorg]

No I think Sjors is on to something. You don't want to see that ugly dropdown all the time and I am not sure if all OS'es react the same to auto completion when it comes it a combobox.

I will download your source and comment on some parts when I find the time. If the dropdown can get a border and scroll features then I think we have something that is worth for the wxWidgets contrib in the future. Maybe you can create a modaless dialog for your selection, without any borders and project a wxListBox on there which is updated when the user types. This might be easier...

In any way, it is always nice to see people create new stuff that extends wxWidgets.

- Jorgen

[upCASE]

Hi!
I think using wxWindow::PopupMenu and creating the list in a menu would solve some problems and improve the look & feel. A problem would be that if the list is too long the menu might get very big.
Another, maybe better way, would be to use a scrolled window.

This is just my first thought, I didn't look into the sources. If you want me too I could have a look at it this weekend (when I hopefully get my internet access back at home )

[raboof]

Did you consider using a combobox? I think this would solve at least a few problems.

I gave that a quick shot, see http://bzzt.net/~arnouten/wxautocombobox

on wxGTK, the SetSelection() doesn't apprear to be working quite right. any ideas?

[leio]

In my opinion this should simply be implemented natively.
gtk+ has it, I'm quite sure others have it aswell.