At Thu, 01 Mar 2012 16:25:56 -0300, Diogo F. S. Ramos wrote: > Experimenting with different codes, I get the impression that a panel%, > using gtk_container_add(), can hold only one child. So, my idea is to > create subclasses of panel% and each of these will have a new GtkWidget > inside. > > Unfortunately my new objects do not show if I add them to a panel% but > they make an appearance inside a frame%.
I think the problem in the example below is the outer panel `pan'. It's an instance of `panel%', which implements no layout. As a result, the `label%' and `message%' are stacked up. Make `pan' a `vertical-panel%', instead. Then, when you resize the window, you'll see "GtkLabel". If you set the minimum height of the panel in `label%', then you won't have to resize to see "GtkLabel". > Below there is a code example of my proposed technique and the ninja > class (under certain weather conditions) label%, which is redundant > because of message% but illustrates my point. The object `message' > appears, but not `label'. > > For the record, I'm using Racket 5.1.3. > > #lang racket/gui > > (require racket/class) > (require ffi/unsafe) > > (define win (new frame% (label "hello, world"))) > (define pan (new panel% (parent win))) > (define gtk-label-new (get-ffi-obj "gtk_label_new" #f (_fun _string -> > _pointer))) > (define gtk-container-add (get-ffi-obj "gtk_container_add" #f (_fun _pointer > _pointer -> _void))) > (define gtk-widget-show (get-ffi-obj "gtk_widget_show" #f (_fun _pointer -> > _void))) > > (define label% > (class panel% > (init parent text) > (super-new (parent parent)) > (define ptr (gtk-label-new text)) > (gtk-container-add (send this get-client-handle) ptr) > (gtk-widget-show ptr))) > > (define label (new label% > (text "GtkLabel") > (parent pan))) > (define message (new message% > (label "Message") > (parent pan))) > > (send label show #t) > (send win show #t) > > -- > Diogo F. S. Ramos ____________________ Racket Users list: http://lists.racket-lang.org/users
