Re: DnD

[Owen Taylor <otaylor redhat com>]

Robert Roebling <roebling@ruf.uni-freiburg.de> writes:

> Owen Taylor wrote:
> 
> > The new DND code simply uses strings (X atoms in particular)
> > to convey target types.
> > 
> > The standard we use for the format of those strings
> > is MIME types.
> > 
> > So, "image/png" is very much a good type to use.
> > so would by "application/x-my-cool-spreadsheat-document"
> 
> OK. The format of selection data is always identified
> by an atom for the target "image/png" and by a 
> selection atom. Is the latter always GDK_SELECTION_STRING
> for non-standard types? I couldnīt find anything
> like GDK_SELECTION_BINARY.

If we are talking about selections (not DND) -

You can have multiple selections, each identified by
an atom. There are predefined atoms GDK_SELECTION_PRIMARY
and GDK_SELECTION_SECONDARY.

The data in the selection can be retrieved in various
formats, called targets, also identified by atom.
There are a couple of predefined atoms:

  GDK_TARGET_BITMAP = 5,
  GDK_TARGET_COLORMAP = 7,
  GDK_TARGET_DRAWABLE = 17,
  GDK_TARGET_PIXMAP = 20,
  GDK_TARGET_STRING = 31

(defined by X) but you can use any string.


For DND, there is no conception of multiple selections.
Data types are again represented by atoms:

You might use a targets table that looked like:

  static GtkTargetEntry drag_types[] =
  {
    { "text/uri-list", 0, TARGET_URI_LIST },
    { "_NETSCAPE_URL", 0, TARGET_URL }
  };

Or whatever.

Regards,
                                        Owen