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GtkObject::get_arg

mixed get_arg(string arg_name);

In most cases where you are likely to need to know the content of an argument, there will be a get method in place which is basically a wrapper for get_arg() . This is good, because there is, unfortunately, no way to know for certain the name of the argument to pass to this function without looking at GTK+ source. A brief tutorial on making sense of what you see there follows.

An individual widget's arguments are initialized as a set of enumerated values at the beginning of the c file relating to that object. For example, in gtklabel.c in GTK 1.2.10 you will see this directly after the includes:

enum {
  ARG_0,
  ARG_LABEL,
  ARG_PATTERN,
  ARG_JUSTIFY,
  ARG_WRAP
};

Around a hundred lines later, these argument types are defined as they are added to the widget, in the class_init function:

gtk_object_add_arg_type ("GtkLabel::label", 
                                 GTK_TYPE_STRING, 
                                 GTK_ARG_READWRITE, 
                                 ARG_LABEL);
gtk_object_add_arg_type ("GtkLabel::pattern", 
                                 GTK_TYPE_STRING, 
                                 GTK_ARG_READWRITE, 
                                 ARG_PATTERN);
gtk_object_add_arg_type ("GtkLabel::justify", 
                                 GTK_TYPE_JUSTIFICATION, 
                                 GTK_ARG_READWRITE, 
                                 ARG_JUSTIFY);
gtk_object_add_arg_type ("GtkLabel::wrap", 
                                 GTK_TYPE_BOOL, 
                                 GTK_ARG_READWRITE, 
                                 ARG_WRAP);

This gives you the name (in quotes) that you are looking for, the type of data that the argument will consist of, the fact that it is writeable (always), and the name of the original enumerated value to bind this information to.

For get_arg() , all you really need is the part that is in quotes, which can be surmised by looking at the initial enums. The datatype may, however, be useful information if you need to set an argument and have no other means of doing so than set_arg() .

The way you would access this is as follows:

<?php

$label = &new GtkLabel('This is an argumentative label');
$arg = $label->get_arg('GtkLabel::label');
echo $arg."\n";

?>