Reinstate wxDIRCTRL_SHOW_FILTERS flag

[wojdyr]

It was discussed on wx-dev, that wxDIRCTRL_SHOW_FILTERS flag can be removed. I left the flag for compatibility, but it is unused now.
The only case when the new behaviour is not compatibile with the previous version is when wxDIRCTRL_SHOW_FILTERS is _not_ specified, but given filter is not empty. In this case filters will be shown now.

[vadz]

I've applied the patch to HEAD, thanks. I've changed it slightly to avoid the addition of m_filterStyle member variable: instead I've moved the style detection to wxDirFilterListCtrl itself.

[vadz]

Oops, forgot to close it.

[troelsk]

Where is the discussion, why is this flag removed?
Because, it generally makes no sense with this combobox below the file/folder view, a combobox which may have only == one single == item in it, eg "All Files(*.*)"; a combobox with only one item is rather bad UI, please allow the flags to hide the combobox back.

[vadz]

I don't remember what happened 6 years ago but I think the idea was that you wouldn't use filters at all if you don't actually use them, i.e. use just "All files" one. Is there any problem with doing this?

[troelsk]

The issue is clearly seen in the widgets sample. In the sample, using dirctrl:
If you want to see files too, not only folders, you click "All files". And get a useless one-item combobox. This combobox may be acceptable in a sample but is no good in a user app.

[vadz]

But if you just don't configure filters at all, wouldn't it go away? I.e. isn't it just a bug in the sample?

[troelsk]

No, I get it also in my user app, and see no way of getting rid of it. The very same app compiled against wx28 displays no combobox (unless wxDIRCTRL_SHOW_FILTERS is specified).

[troelsk]

Revert

[troelsk]

Added patch

[troelsk]

Never mind. Clearing the filter put there by DialogBlocks ("All *.*") made the combobox go away. Not sure about the wisdom in removing the flag though (and was unable to find the wxdev thread with the reasoning)

[vadz]

What do the other think, should we restore wxDIRCTRL_SHOW_FILTERS or not? Does anybody else think it would be useful to have it? When in doubt, I'd probably prefer to restore it to avoid breaking compatibility.

[ericj]

In general i think it's better to have more control than less.

+1 to restore from me.

[VZ]

(In [73621]) Restore wxDIRCTRL_SHOW_FILTERS flag of wxDirCtrl.

Closes #8572.