Re: GtkToolbar drag and drop

[Marco Pesenti Gritti <marco gnome org>]

On Thu, 2003-10-16 at 11:24, Soeren Sandmann wrote:
> Marco Pesenti Gritti <marco gnome org> writes:
> 
> > 1 Keep the throbber visible at the end of the toolbar, after the
> > overflow menu arrow. I think this is a strong requirement, being a form
> > of feedback and not a faster way to access a function available from the
> > menubar.
> > 2 Have an efficient way of achieve user tasks (add spinner to a toolbar,
> > remove spinner from a toolbar, move spinner from a toolbar to another).
> > 3 Keep the user model the simpler is possible
> 
> Sorry about taking so long to get back to this. How does this sound:
> 
>         - get rid of GtkToolItem::pack_end as it's only useful for
>           spinners.
> 
>         - add a new gtk_toolbar_set_end_item() that inserts a tool
>           item in spinner position. This function could take NULL for
>           the new tool item in which case the existing item, if any,
>           would be removed.
> 
>         - Change gtk_toolbar_get_drop_position() to be:
> 
>            gboolean gtk_toolbar_get_drop_position (GtkToolbar *toolbar, 
>                                                     int         x
>                                                     int         y,
>                                                     int        *pos)
> 
>           that would return TRUE if the indicated (x, y) corresonds to
>           a valid drop location. In that case, 
> 
>                if *pos is non-negative, indicates the position where 
>                the new item should be inserted. 
> 
>                If *pos is negative, indicates that the new item should 
>                be added to the end of the toolbar.
> 
>           This function only indicates the "spinner" position as
>           as valid drop target if the toolbar doesn't have a tool item
>           in that position already.
>         
>         - add API 
> 
>                 gtk_toolbar_highlight_drop_location (GtkToolbar *toolbar,
>                                                      int         x,
>                                                      int         y,
>                                                      GtkToolItem *new_item)
> 
>                 gtk_toolbar_unhighlight_drop_position (GtkToolbar *);
> 
>           that would [un]highlight corresponding position on the
>           toolbar.
> 
> This API achieves:
> 
>         - ability to have zero or one spinners on the toolbar
> 
>         - good feedback on drag and drop.
> 
>         - some simplification of the gtktoolbar.c and gtktoolitem.c
> 
>         - expanding spacers can be added later if we decide it's a
>           good idea (which I still think it might be).

I like the proposal, it seem simple and quite flexible.

> The sacrifice is the ability to have more than one tool item in
> spinner position, which is acceptable in my opinion.

I agree that the sacrifice is acceptable.

> The following is a sketch of how the toolbar editor would work:
> 

We discussed it on irc. My feeling is that requiring the spinner to be
dragged at the end of the toolbar to be added (refusing the drag if it's
not there), is bad for usability. I'm convinced it would be hard to find
out for users.
I see two possible ways to handle it, not sure which is the better one.

1 Accept the drag on the whole toolbar, highlight the toolbar border,
and put the spinner in the last position.
2 Accept the drag on the whole toolbar, highlight the position where the
spinner is dragged. Put the spinner as last item, aligned on the right,
if it has been dragged in last position. Put it in the middle of other
items, like a normal item, if it was dragged somewhere else.

Marco