[Gambas-user] Drag and drop inconsistent across toolkits

[Benoît Minisini]

Le 17/10/2014 16:29, Tobias Boege a écrit :
> Hi,
>
> there is a project attached which tries to implement some drag and drop. The
> archive has gb.qt4 as graphical component but let me start with its behaviour
> under gb.gui:
>
>   - drag from SourceLabel und SourceTextBox and drop on Destination work,
>   - if I do three drag and drops: (i) from SourceLabel, (ii) from
>     SourceTextBox, (iii) from SourceLabel again, I get an error "Undergoing
>     drag". At step (ii) I see a warning in the console:
>
>       (DragData:2084): GLib-GObject-WARNING **: gsignal.c:2580: instance '0x14170a0' has no handler with id '138'
>
> When I change the component to gb.qt4, I get the following:
>
>   - drag from SourceTextBox does not work automatically anymore, I have to
>     code it myself (losing the ability to select text in it),
>   - no errors or warnings.
>
> The project is from another Gambas user and on his system (don't know what
> it is -- does it matter?), the project with gb.gui does:
>
>   - drag from SourceTextBox works automatically, drag from SourceLabel
>     doesn't work, even when coded (as in the attached project).
>
> Is there anything I can say to him about this?
>

I have started to fix drag and drop in gb.gtk and gb.gtk3.

Normally, your example should work as expected both with gb.gtk and gb.gtk3.

The fix may have a bad side effect with automatic mouse grabs on button 
press in gb.gtk3. People will tell me.

As for gb.qt4, I don't understand why dnd is not automatic anymore with 
TextBox. If you replace the TextBox by a TextArea, it works. I noticed 
that behaviour in some other textboxes (QLineEdit Qt4 widget) in KDE 
programs, but not all!

There is also a bug I couldn't reproduce at will with gb.qt4: If, in 
your example, I repeatedly and alternatively drag from the Label and 
from the TextBox, I can make the destination widget disappear and the 
program crash.

Regards,

-- 
Benoît Minisini