RE: Working with embedded images with GResource, GdkPixbuf and GtkWidget

[Alessandro Francesconi <misterbirra hotmail it>]

Thanks, but for gdk-pixbuf-new-from-data I need to know size and properties of the original image… it’s an 
information that I find very difficult to obtain. Is there a simpler way?



About gdk-pixbuf-new-from-file, for some reasons the images are embedded, so i can’t use it.



Regards,

Ale



________________________________
From: Joël Krähemann <jkraehemann gmail com>
Sent: Sunday, November 11, 2018 8:29:37 PM
To: misterbirra hotmail it
Cc: gtk-app-devel-.
Subject: Re: Working with embedded images with GResource, GdkPixbuf and GtkWidget

Hi,

First you create a GdkPixbuf:

https://developer.gnome.org/gdk-pixbuf/stable/gdk-pixbuf-Image-Data-in-Memory.html#gdk-pixbuf-new-from-data

then set the property of about dialog:

https://developer.gnome.org/gtk2/stable/GtkAboutDialog.html#GtkAboutDialog--logo

g_object_set(your_about_dialog,
  "logo", your_pixbuf,
  NULL);

Why don't you use just following?

https://developer.gnome.org/gdk-pixbuf/stable/gdk-pixbuf-File-Loading.html#gdk-pixbuf-new-from-file

Bests,
Joël

On Sun, Nov 11, 2018 at 6:23 PM Alessandro Francesconi
<misterbirra hotmail it> wrote:
> Hello,
>
>
>
> I need to show some images inside my GTK+ 2.32 application so I decided to embed them using GResource 
> compiler.
>
> I’ve prepared an XML file like this:
>
>
>
> <?xml version="1.0" encoding="UTF-8"?>
>
> <gresources>
>
>   <gresource prefix="/myapp/icons">
>
>     <file preprocess="to-pixdata">logo.png</file>
>    <…..>
>
>   </gresource>
>
> </gresources>
>
>
>
> And after “glib-compile-resources.exe --target=icons.c --generate icons.xml”, I correctly have a .c file 
> with images encoded inside.
>
>
>
> Problem here: i need that images to be shown in About dialog (gtk_show_about_dialog) and buttons 
> (gtk_button_set_image). As far as I know, to accomplish this I have to create GdkPixbuf (for 
> gtk_about_dialog_set_logo) and GtkWidget (for gtk_button_set_image). I tried with this code but got some 
> issues (see the comments):
>
>
>
> -----------
>
>     GResource* icons = icons_get_resource();
>
>     GBytes* data = g_resource_lookup_data(icons, path, G_RESOURCE_LOOKUP_FLAGS_NONE, NULL);
>
>     gsite size = g_bytes_get_size(data); // <-- this works since I have no errors and the size is > 0, so I 
> expect data to be ok
>
>
>
>     // now I need to create a GdkPixbuf, is that the correct way?
>
>     GError* e = NULL;
>
>     GdkPixbuf* pixbuf;
>
>     pixbuf = gdk_pixbuf_new_from_inline(g_bytes_get_size(data), data, FALSE, &e);
>     // error here! Message is “Image header corrupt”
>
>
>
>     // if worked… I’d continue by also getting the GtkWidget image with:
>     GtkWidget* image;
>
>     image = gtk_image_new_from_pixbuf(pixbuf);
>
> -----------
>
>
>
> I can’t really understand how Pixbuf expects from the GResource data… also i read in the docs that 
> “gdk_pixbuf_new_from_inline has been deprecated since version 2.32 and should not be used in newly-written 
> code. Use GResource instead.”… so what’s the correct way to create Pixbuf for About boxes and GdkWidgets 
> for image button?
>
>
>
> Thanks for the support
>
> Alessandro
>
>
>
> _______________________________________________
> gtk-app-devel-list mailing list
> gtk-app-devel-list gnome org
> https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list