Re: How to draw GtkCellRendererCombo in (inside) a custom cell renderer?

[Vivien Malerba <vmalerba gmail com>]

On 6 June 2012 09:51, Osmo Antero <osmoma gmail com> wrote:

> Hello,
> I wanted to study the GtkCellRendererCombo so I added it directly to the
> treeview (as column).
> The combobox is initially hidden, only the "text" value is shown.
> The combo becomes visible after user clicks or double-clicks the column in
> the row.
>
> Unfortunately the click event does not work (or pass through) when the
> GtkCellRendererCombo is baked inside a custom-renderer class. Therefore it
> simply shows the "text" value, the combo-list itself is not accessible or
> visible.
>
> This might explain why GTK3 has NO renderer for very common type of
> widgets, like GtkButton.
> There is no GtkCellRendererButton class because it cannot handle the
> events.
>
> I may need to use the low-level painting functions directly, like
> gtk_paint_arrow(...)
> gtk_paint_shadow(...)
> gtk_paint_box(...)
> And somehow calculate the co-ordinates for click-events.
>
> Ref: http://developer.gnome.org/gtk3/3.4/GtkStyle.html
>
> All comments are welcome.
> // Osmo Antero
>
> /*
> Adding GtkCellRendererCombo directly (as column) to the treeview, just to
> study its behaviour.
>
> GtkTreeStore *store = gtk_tree_store_new(NUM_COLS,
>                               G_TYPE_INT,
>                               G_TYPE_POINTER,
>                               G_TYPE_STRING); // <-- combo "text" field
> ...
>
> // Combo cell renderer (directly as column)
> renderer = gtk_cell_renderer_combo_new();
>
> GtkTreeIter iter;
> GtkListStore *combo_store = gtk_list_store_new (1, G_TYPE_STRING);
> gtk_list_store_append(combo_store, &iter);
> gtk_list_store_set(combo_store, &iter, 0, "First Item", -1);
> gtk_list_store_append(combo_store, &iter);
> gtk_list_store_set(combo_store, &iter, 0, "Second Item", -1);
>
> g_object_set (renderer, "editable", FALSE,
>                        "has-entry", TRUE,
>                        "model", combo_store,
>                        "text-column", 0,
>                        NULL);
>
> col = gtk_tree_view_column_new();
> gtk_tree_view_column_pack_start (col, renderer, TRUE);
> gtk_tree_view_column_add_attribute(col, renderer, "text", COL_2);
> gtk_tree_view_column_set_title (col, "Combo");
> gtk_tree_view_append_column(GTK_TREE_VIEW(tv),col);
> */
>
>
> On Tue, Jun 5, 2012 at 8:38 PM, Osmo Antero <osmoma gmail com> wrote:
>
> > Hello,
> > I want to create my own cell-renderer for a treeview widget.
> > This custom cell will contain a text string and a combobox with some
> > values.
> > So my custom cell (row) contains both GtkCellRendererText and
> > GtkCellRendererCombo widgets.
> >
> > The cell renderer works well that it displays the text string, but the
> > combobox is *invisible*.
> >
> > In cell-renderer.c, I carefully get the size of the combobox:
> >     gtk_cell_renderer_get_preferred_size(p->combo_renderer, widget, NULL,
> > &size);
> >     combo_area.width = size.width;
> >     combo_area.height = size.height;
> >
> > And then render it to cell with:
> >     combo_area.x = title_area.x + title_area.width + GUI_PAD;
> >     combo_area.y = fill_area.y + (fill_area.height - combo_area.height
> )/2;
> >     gtk_cell_renderer_render(p->combo_renderer, window, widget,
> > background_area, &combo_area, flags);
> >
> > See the render_row(...) function in "cell-renderer.c" file.
> > But the p->combo_renderer (of type GtkCellRendererCombo) will not show
> up.
> > The treeview row should display:
> >  "Node 1-0 text  [Combobox with values]"
> >  "Node 1-1 text [Combobox with values]"
> >  "Node 1-2 text [Combobox with values]"
> > ...
> > What could be wrong with my code?
> >
> > Here is a complete example of this:
> > http://www.futuredesktop.org/tmp/Test6.tar.gz
> >
> > Use the "m.sh" script to compile it:
> > $ ./m.sh
> >
> > Then run:
> > $ ./main
> >
> > You should see this:
> > http://bildr.no/view/1197967
I've implemented a custom combo in a cell renderer for Libgda, see the code
at
http://git.gnome.org/browse/libgda/tree/libgda-ui/data-entries/gdaui-data-cell-renderer-combo.c
and specifically the  gdaui_data_cell_renderer_combo_start_editing() method.

Hope it helps you,
regards

Vivien