Re: Combo box investigation + proposed new API

[Havoc Pennington <hp redhat com>]

Kristian Rietveld <kristian planet nl> writes: 
> I used the HBox derivation in the new GtkComboBox, because the old
> GtkCombo and the GtkComboBox of Gnumeric also use the HBox
> derivation. Which is the best widget to derive GtkComboBox from?
>

Just GtkContainer I think.
 
> + <new_widget_to_derive_GtkComboBox_from>
>   + GtkComboBox
>     + GtkComboBoxGrid
>        + GtkComboBoxPixbuf
>

I don't think the Pixbuf version is needed, really (it would just call
gtk_image_new_from_pixbuf() for you, which seems not worth its own
widget).
 
> Should the GtkComboBox base class also use GtkTreeView? I had in mind that
> the base class only supplies functions to add the popdown and entry
> widgets. The GtkComboBoxGrid won't be using the GtkTreeView, only the
> GtkComboBoxText will.
>

Yes. What I'm saying is that if you want to do something custom (use a
tree view other than the standard one GtkComboBoxText provides) you
can simply use GtkComboBox directly.
 
> gtk_combo_box_text_set_pattern_matching(): sets the pattern matching on or
> off. So it'll try to match an entry in the list while you're typing.
>

Does this mean Internet Explorer-style autocompletion? If so I'd call
it autocomplete rather than pattern_matching.

Most likely part of the support for that has to be done in GtkEntry, I
would envision something like an "autocomplete" signal on GtkEntry
maybe.
 
> think it's better rename the function to:
> 
> void     gtk_combo_box_text_select ( GtkComboBoxText *cboxtext,
> 				     const gchar *string );
> 

Yep, the signal-emitting function should match the signal name.
 
> For the function which will get all the strings from the popdown I
> propose:
> 
> const gchar **gtk_combo_box_text_get_strings ( GtkComboBoxText *cboxtext
> );
>

I would instead return an allocated copy of the array, or an allocated
list. If you do const gchar** you're locked into an implementation
that stores the strings as an array.
 
> This function came from the original GtkCombo, it seems to disable the
> activation of the ComboBox. I think we should ditch this function,
> because we're able to {en,dis}able to combo box by setting the arrow
> sensitive or insensitive.
>

Seems sensible to me. (Or you can just set the whole combo
insensitive, I don't know why you'd set just the arrow.)
 
> If I've collected all feedback on this headers, I'll post edited ones. If
> those will be ok, I'll start implementing.
>

Expect additional comments from various people throughout the
implementation process. ;-) But I think getting started implementing
should be fine; I'd say people agree on the basic structure with a
GtkComboBox base widget, with text and grid subclasses.

Havoc