ParamSpec

Object Hierarchy:

GLib.ParamSpec GLib.ParamSpec GLib.ParamSpec

Description:

[ CCode ( get_value_function = "g_value_get_param" , param_spec_function = "g_param_spec_param" , ref_function = "g_param_spec_ref" , set_value_function = "g_value_set_param" , take_value_function = "g_value_take_param" , type_id = "G_TYPE_PARAM" , unref_function = "g_param_spec_unref" ) ]
public class ParamSpec

`GParamSpec` encapsulates the metadata required to specify parameters, such as `GObject` properties.

Parameter names

A property name consists of one or more segments consisting of ASCII letters and digits, separated by either the `-` or `_` character. The first character of a property name must be a letter. These are the same rules as for signal naming (see [func@GObject.signal_new]).

When creating and looking up a `GParamSpec`, either separator can be used, but they cannot be mixed. Using `-` is considerably more efficient, and is the ‘canonical form’. Using `_` is discouraged.

Example: Object-introspection:

public class MyObject : Object {
	public int myprop1 { get; set; }
	public int myprop2 { get; set; }
	public int myprop3 { get; set; }
}

public static int main (string[] args) {
	// Output:
	//  ``myprop1``
	//  ``myprop2``
	//  ``myprop3``
	Type type = typeof (MyObject);
	ObjectClass ocl = (ObjectClass) type.class_ref ();
	foreach (ParamSpec spec in ocl.list_properties ()) {
		print ("%s\n", spec.get_name ());
	}

	// Output: ``nick: myprop1``
	unowned ParamSpec? spec = ocl.find_property ("myprop1"); 
	print ("nick: %s\n", spec.get_nick ());

	return 0;
}

valac --pkg gobject-2.0 GLib.ObjectClass.vala

All known sub-classes:

Namespace: GLib
Package: gobject-2.0

Content:

Static methods:

Creation methods:

Methods:

  • public unowned ParamSpec @ref ()
    Increments the reference count of this.
  • public virtual void finalize ()
    The instance finalization function (optional), should chain up to the finalize method of the parent class.
  • public unowned string get_blurb ()
    Get the short description of a ParamSpec.
  • public unowned Value? get_default_value ()
    Gets the default value of this as a pointer to a Value.
  • public unowned string get_name ()
    Get the name of a ParamSpec.
  • public Quark get_name_quark ()
    Gets the GQuark for the name.
  • public unowned string get_nick ()
    Get the nickname of a ParamSpec.
  • public void* get_qdata (Quark quark)
    Gets back user data pointers stored via set_qdata.
  • public unowned ParamSpec get_redirect_target ()
    If the paramspec redirects operations to another paramspec, returns that paramspec.
  • public unowned ParamSpec ref_sink ()
    Convenience function to ref and sink a ParamSpec.
  • public void set_qdata (Quark quark, void* data)
    Sets an opaque, named pointer on a ParamSpec.
  • public void set_qdata_full (Quark quark, void* data, DestroyNotify destroy)
    This function works like set_qdata, but in addition, a `void (*destroy) (gpointer)` function may be specified which is called with data as argument when the this is finalized, or the data is being overwritten by a call to set_qdata with the same quark.
  • public void set_value_default (ref Value value)
    Sets value to its default value as specified in pspec .
  • public void sink ()
    The initial reference count of a newly created ParamSpec is 1, even though no one has explicitly called @ref on it yet.
  • public void* steal_qdata (Quark quark)
    Gets back user data pointers stored via set_qdata and removes the data from this without invoking its destroy function (if any was set).
  • public void unref ()
    Decrements the reference count of a this.
  • public bool value_convert (Value src_value, ref Value dest_value, bool strict_validation)
    Transforms src_value into dest_value if possible, and then validates dest_value, in order for it to conform to pspec.
  • public virtual bool value_defaults (Value value)
    Checks whether value contains the default value as specified in pspec.
  • public bool value_is_valid (Value value)
    Return whether the contents of value comply with the specifications set out by pspec.
  • public virtual bool value_validate (Value value)
    Ensures that the contents of value comply with the specifications set out by pspec.
  • public virtual int values_cmp (Value value1, Value value2)
    Compares value1 with value2 according to pspec, and return -1, 0 or +1, if value1 is found to be less than, equal to or greater than value2, respectively.

Fields: