Re: (severe) performance issues

["David J. Andruczyk" <djandruczyk yahoo com>]

I added your code, and it DOES stop the display from resizing
widgets when the labels display small values,  but it DOES NOT drop
cpu usage at all.  so internally GTK+ is still going something with
regards to the labels.
If I comment out gtk_label_set_text() in my code cpu usage drops
from 45% to 4%.  (dual cpu AMD 2.1Ghz, 3GB ram)


--- jcupitt gmail com wrote:

> On 3/26/07, David J. Andruczyk <djandruczyk yahoo com> wrote:
> > I think the resizing is the culprit.  I was tempted to use
> > gtk_entries instead as you can assign them fixed size in
> > charactors, which is easier to handle differences in font size.
> 
> You can do that with a label too. Measure the size of the string
> "8",
> then call gtk_widget_set_size_request() to lock the label to 10
> (for
> example) 8s across by 1 8 down.
> 
> I do this with:
> 
> --------------------
> /* Calculate the bounding box for a string rendered with a
> widget's default
>  * font. Set geo to a rect with 0,0 positioned on the left-hand
> baseline.
>  */
> void
> get_geo( GtkWidget *widget, const char *text, Rect *geo )
> {
>         PangoLayout *layout;
>         int width, height;
> 
>         layout = gtk_widget_create_pango_layout( widget, text );
>         pango_layout_get_pixel_size( layout, &width, &height );
>         g_object_unref( layout );
> 
>         /* FIXME ... we left/top to 0 for now.
>          */
>         geo->width = width;
>         geo->height = height;
>         geo->left = 0;
>         geo->top = 0;
> }
> 
> /* Set a widget to a fixed size ... width in characters.
>  */
> void
> set_fixed( GtkWidget *widget, int nchars )
> {
>         Rect geo;
> 
>         get_geo( widget, "8", &geo );
>         gtk_widget_set_size_request( widget, geo.width * nchars,
> geo.height );
> }
> ------------
> 
> John
> 


-- David J. Andruczyk


 
____________________________________________________________________________________
We won't tell. Get more on shows you hate to love 
(and love to hate): Yahoo! TV's Guilty Pleasures list.
http://tv.yahoo.com/collections/265