Re: [patch] GtkMainThread.c calculate the dpi value in case ofgtk-xft-dpi can't

[Thomas Fitzsimmons <fitzsim at redhat dot com>]

On Fri, 2004-06-25 at 17:24, Andreas Tobler wrote:
> Hi,
> currently if we build the awt peers with recent gtk/pango packages we 
> run into troubles if gtk-xft-dpi can't calculate a reasonable value. 
> Then it returns -1 as default value and we end up with a bogus value for 
>   dpi_conversion_factor.
> 
> The attached patch fixes this. Tested on darwin-7.4.0 with the TestAWT.java.
> 

Hi Andreas,

Thanks for tracking this down.

> Ok on main?
> 
> Andreas
> 
> 2004-06-25  Andreas Tobler  <a.tobler@schweiz.ch>
> 
> 	* jni/gtk-peer/gnu_java_awt_peer_gtk_GtkMainThread.c
> 	(init_dpi_conversion_factor): Check for int_dpi < 0 in case gtk-xft-dpi
> 	can no calculate the right value.
> 	(dpi_changed_cb): Mark *pspec as unsused.
> 
> 
> 
> ______________________________________________________________________
> Index: jni/gtk-peer/gnu_java_awt_peer_gtk_GtkMainThread.c
> ===================================================================
> RCS file: /cvs/gcc/gcc/libjava/jni/gtk-peer/gnu_java_awt_peer_gtk_GtkMainThread.c,v
> retrieving revision 1.13
> diff -u -r1.13 gnu_java_awt_peer_gtk_GtkMainThread.c
> --- jni/gtk-peer/gnu_java_awt_peer_gtk_GtkMainThread.c	17 Jun 2004 23:43:16 -0000	1.13
> +++ jni/gtk-peer/gnu_java_awt_peer_gtk_GtkMainThread.c	25 Jun 2004 21:10:01 -0000
> @@ -231,9 +231,13 @@
>      {
>        int int_dpi;
>        g_object_get (settings, "gtk-xft-dpi", &int_dpi, NULL);
> +      /* If int_dpi == -1 gtk-xft-dpi returns the default value. So we
> +	 have to do approximate calculation here.  The value is 1024 * dots.
> +	 We take 96 for dots.  */
> +      if (int_dpi < 0)  int_dpi = 98304;
>        dpi_conversion_factor = PANGO_SCALE * 72.0 / (int_dpi / PANGO_SCALE);

Can we split this into an if-else statement where we set
dpi_conversion_factor to PANGO_SCALE * 72.0 / 96.0 or to the result of
the current calculation if int_dpi is meaninful?  (I know this is the
value I said on IRC, but I was just "roughing it in" -- I'd rather not
have this magic number in the code ;-)

With these changes, this can go in.

Thanks again,
Tom

>        g_signal_connect (settings, "notify::gtk-xft-dpi",
> -                        G_CALLBACK (dpi_changed_cb), NULL);
> +			G_CALLBACK (dpi_changed_cb), NULL);
>      }
>    else
>      /* Approximate. */
> @@ -242,7 +246,7 @@
>  
>  static void
>  dpi_changed_cb (GtkSettings  *settings,
> -                GParamSpec   *pspec)
> +		GParamSpec *pspec __attribute__((unused)))
>  {
>    int int_dpi;
>    g_object_get (settings, "gtk-xft-dpi", &int_dpi, NULL);