[Lazarus] GTK2: Drag files to other applications (to the file manager, Thunar, Nautilus, etc)

[Hans-Peter Diettrich]

Bernd schrieb:
> I am making progress. The handle is indeed a PGTKWidget but there are
> always multiple widgets nested inside each other, for example a
> TButton is really a GTKLabel inside a GTKButton inside a GTKEventBox,
> so I have to recursively go through all the child widgets and set up
> drag&drop for them all.

Please clarify what you *really* want to achieve. DragDrop of *files* is 
very different from DragDrop of *components*.

Dragging *controls* worked for me off the shelf, on both Win32 and Gtk2 
widgetsets.

Dragging *files* across applications is a matter of the platform, 
requiring different procedures for *sending* and *receiving*. I don't 
see how the widgetset is involved here, at least on Windows the related 
messages (WM_DROPFILES) are sent to the control *Handle*. Similarly 
sending files must be invoked by an event of a control, again fully 
independent from the used widgetset. The code for actually sending files 
depends on the platform, dunno whether there exists a common API already 
in the FCL/LCL.

DoDi