bug#69662: 30.0.50; PGTK Window system supports drag-and-drop but doesn't define x-begin-drag

["Björn Bidar via Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: 69662@debbugs.gnu.org
>> Date: Sat, 09 Mar 2024 18:55:34 +0800
>> From:  Po Lu via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> Björn Bidar <bjorn.bidar@thaodan.de> writes:
>> 
>> > I noticed when investigating why drag and drop wasn't working
>> > in my setup that pgtk doesn't define `x-begin-drag' but defines
>> > functions for drag and drop support.
>> > That x-begin-drag isn't present breaks `dnd-begin-text-drag` and friend.
>> >
>> > 1. Build Emacs with at least --with-pgtk
>> > 2. Call `dnd-begin-text-drag'
>> > 3. Error
>> 
>> As I've explained elsewhere, GTK's limitations and corner-cutting poses
>> special difficulties for drag-and-drop implementations, for which reason
>> I decided against implementing that for the PGTK build myself.  Patches
>> will, as ever, be appreciated.
>
> What does this mean in practice, though?  Does it mean drag-and-drop
> doesn't work at all in the PGTK builds?  Or only some aspects of that
> don't work?  We should at least document the limitations.
>
> Thanks.

I also wonder why does it not work in Emacs while other GTK applications
don't have the same issue?

There must be ways around the issue.