Gtk::Filter Class Reference

Filtering items. More...

#include <gtkmm/filter.h>

Inheritance diagram for Gtk::Filter:

Public Types
enum class	Match {   SOME ,   NONE ,   ALL }
enum class	Change {   DIFFERENT ,   LESS_STRICT ,   MORE_STRICT }

Public Member Functions
	Filter (Filter &&src) noexcept
Filter &	operator= (Filter &&src) noexcept
	~Filter () noexcept override
GtkFilter *	gobj ()
	Provides access to the underlying C GObject.
const GtkFilter *	gobj () const
	Provides access to the underlying C GObject.
GtkFilter *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
bool	match (const Glib::RefPtr< Glib::ObjectBase > &item)
	Checks if the given item is matched by the filter or not.
Match	get_strictness ()
	Gets the known strictness of filters.
Glib::SignalProxy< void(Change)>	signal_changed ()

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Protected Member Functions
	Filter ()
void	changed (Change change=Change::DIFFERENT)
	Notifies all users of the filter that it has changed.
virtual bool	match_vfunc (const Glib::RefPtr< Glib::ObjectBase > &item)
virtual Match	get_strictness_vfunc ()

Related Symbols
(Note that these are not member symbols.)
Glib::RefPtr< Gtk::Filter >	wrap (GtkFilter *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

Filtering items.

A Gtk::Filter object describes the filtering to be performed by a Gtk::FilterListModel.

The model will use the filter to determine if it should include items or not by calling match() for each item and only keeping the ones that the function returns true for.

Filters may change what items they match through their lifetime. In that case, they will emit the signal_changed() signal to notify that previous filter results are no longer valid and that items should be checked again via match().

GTK provides various pre-made filter implementations for common filtering operations. These filters often include properties that can be linked to various widgets to easily allow searches.

However, in particular for large lists or complex search methods, it is also possible to subclass Gtk::Filter and provide one's own filter.

See also

Gtk::FilterListModel

Since gtkmm 3.98:

Member Enumeration Documentation

Change

enum class Gtk::Filter::Change

strong

Enumerator
DIFFERENT	The filter change cannot be described with any of the other enumeration values.
LESS_STRICT	The filter is less strict than it was before: All items that it used to return true for still return true, others now may, too.
MORE_STRICT	The filter is more strict than it was before: All items that it used to return false for still return false, others now may, too.

Match

enum class Gtk::Filter::Match

strong

Enumerator
SOME	The filter matches some items, Gtk::Filter::match() may return true or false.
NONE	The filter does not match any item, Gtk::Filter::match() will always return false.
ALL	The filter matches all items, Gtk::Filter::match() will alays return true.

Constructor & Destructor Documentation

Filter() [1/2]

Gtk::Filter::Filter ( Filter &&  src )

noexcept

~Filter()

Gtk::Filter::~Filter ( )

overridenoexcept

Filter() [2/2]

Gtk::Filter::Filter ( )

protected

Member Function Documentation

changed()

void Gtk::Filter::changed ( Change  change = Change::DIFFERENT )

protected

Notifies all users of the filter that it has changed.

This emits the signal_changed() signal. Users of the filter should then check items again via match().

Depending on the change parameter, not all items need to be changed, but only some. Refer to the Gtk::Filter::Change documentation for details.

This function is intended for implementers of Gtk::Filter subclasses and should not be called from other functions.

Parameters

change

How the filter changed.

get_strictness()

Match Gtk::Filter::get_strictness

(

)

Gets the known strictness of filters.

If the strictness is not known, Gtk::Filter::Match::SOME is returned.

This value may change after emission of the signal_changed() signal.

This function is meant purely for optimization purposes, filters can choose to omit implementing it, but Gtk::FilterListModel uses it.

Returns

The strictness of self.

get_strictness_vfunc()

virtual Match Gtk::Filter::get_strictness_vfunc ( )

protectedvirtual

get_type()

static GType Gtk::Filter::get_type ( )

static

Get the GType for this class, for use with the underlying GObject type system.

gobj() [1/2]

GtkFilter * Gtk::Filter::gobj ( )

inline

Provides access to the underlying C GObject.

gobj() [2/2]

const GtkFilter * Gtk::Filter::gobj ( ) const

inline

Provides access to the underlying C GObject.

gobj_copy()

GtkFilter * Gtk::Filter::gobj_copy

(

)

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

match()

bool Gtk::Filter::match

(

const Glib::RefPtr< Glib::ObjectBase > &

item

)

Checks if the given item is matched by the filter or not.

Parameters

item	The item to check.

Returns

true if the filter matches the item and a filter model should keep it, false if not.

match_vfunc()

virtual bool Gtk::Filter::match_vfunc ( const Glib::RefPtr< Glib::ObjectBase > &  item )

protectedvirtual

operator=()

Filter & Gtk::Filter::operator= ( Filter &&  src )

noexcept

signal_changed()

Glib::SignalProxy< void(Change)> Gtk::Filter::signal_changed

(

)

Slot Prototype:

void on_my_changed(Change change)

Flags: Run Last

Emitted whenever the filter changed.

Users of the filter should then check items again via Gtk::Filter::match().

Gtk::FilterListModel handles this signal automatically.

Depending on the change parameter, not all items need to be checked, but only some. Refer to the Gtk::Filter::Change documentation for details.

Parameters

change

How the filter changed.

Friends And Related Symbol Documentation

wrap()

Glib::RefPtr< Gtk::Filter > wrap ( GtkFilter *  object, bool  take_copy = false  )

related

A Glib::wrap() method for this object.

Parameters

object	The C instance.
take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns

A C++ instance that wraps this C instance.