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<?xml version="1.0"?>
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
]>
<chapter id="gtk-migrating-GtkColorButton">
<title>Migrating from GnomeColorPicker to GtkColorButton</title>
<para>
Since version 2.6, GTK+ provides the #GtkColorButton
widget as a replacement for the <structname>GnomeColorPicker</structname>
widget in the libgnomeui library.
</para>
<para>
Porting an application from <structname>GnomeColorPicker</structname> to
<structname>GtkColorButton</structname> is very simple.
<structname>GtkColorButton</structname> doesn't support dithering
(since it is rarely needed on modern hardware), and it doesn't have
setters and getters to set the color from floating point or integer
components. So instead of
<informalexample><programlisting>
guint red, green, blue, alpha;
/* ... */
gnome_color_picker_set_i8 (color_picker, red, green, blue, alpha);
</programlisting></informalexample>
you have to write
<informalexample><programlisting>
GdkColor color;
color.red = red << 8;
color.green = green << 8;
color.blue = blue << 8;
gtk_color_button_set_color (color_picker, &color);
gtk_color_button_set_alpha (color_picker, alpha << 8);
</programlisting></informalexample>
and similarly for the setters taking other number formats. For
<function>gnome_color_picker_set_i16()</function> no conversion is needed,
for <function>gnome_color_picker_set_d()</function>, you need to convert
the color components like this:
<informalexample><programlisting>
color.red = (guint16) (red * 65535.0 + 0.5);
color.green = (guint16) (green * 65535.0 + 0.5);
color.blue = (guint16) (blue * 65535.0 + 0.5);
</programlisting></informalexample>
</para>
</chapter>
<!--
Local variables:
mode: sgml
sgml-parent-document: ("gtk-docs.sgml" "book" "part" "chapter")
End:
-->
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