gtkmm  4.8.0
Public Member Functions | Static Public Member Functions | Protected Member Functions | Related Functions | List of all members
Gtk::SelectionModel Class Reference

An extension of the list model interface that handles selections. More...

#include <gtkmm/selectionmodel.h>

Inheritance diagram for Gtk::SelectionModel:
Inheritance graph
[legend]

Public Member Functions

 SelectionModel (SelectionModel && src) noexcept
 
SelectionModeloperator= (SelectionModel && src) noexcept
 
 ~SelectionModel () noexcept override
 
GtkSelectionModel * gobj ()
 Provides access to the underlying C GObject. More...
 
const GtkSelectionModel * gobj () const
 Provides access to the underlying C GObject. More...
 
bool is_selected (guint position) const
 Checks if the given item is selected. More...
 
Glib::RefPtr< const Bitsetget_selection () const
 Gets the set containing all currently selected items in the model. More...
 
Glib::RefPtr< const Bitsetget_selection (guint position, guint n_items) const
 Gets the set of selected items in a range. More...
 
bool select_item (guint position, bool unselect_rest)
 Requests to select an item in the model. More...
 
bool unselect_item (guint position)
 Requests to unselect an item in the model. More...
 
bool select_range (guint position, guint n_items, bool unselect_rest)
 Requests to select a range of items in the model. More...
 
bool unselect_range (guint position, guint n_items)
 Requests to unselect a range of items in the model. More...
 
bool select_all ()
 Requests to select all items in the model. More...
 
bool unselect_all ()
 Requests to unselect all items in the model. More...
 
bool set_selection (const Glib::RefPtr< const Bitset > & selected, const Glib::RefPtr< const Bitset > & mask)
 Make selection changes. More...
 
Glib::SignalProxy< void(guint, guint)> signal_selection_changed ()
 

Static Public Member Functions

static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...
 

Protected Member Functions

 SelectionModel ()
 You should derive from this class to use it. More...
 
void selection_changed (guint position, guint n_items)
 Helper function for implementations of Gtk::SelectionModel. More...
 
virtual bool is_selected_vfunc (guint position) const
 
virtual Glib::RefPtr< const Bitsetget_selection_vfunc (guint position, guint n_items)
 
virtual bool select_item_vfunc (guint position, bool unselect_rest)
 
virtual bool unselect_item_vfunc (guint position)
 
virtual bool select_range_vfunc (guint position, guint n_items, bool unselect_rest)
 
virtual bool unselect_range_vfunc (guint position, guint n_items)
 
virtual bool select_all_vfunc ()
 
virtual bool unselect_all_vfunc ()
 
virtual bool set_selection_vfunc (const Glib::RefPtr< const Bitset > & selected, const Glib::RefPtr< const Bitset > & mask)
 

Related Functions

(Note that these are not member functions.)

Glib::RefPtr< Gtk::SelectionModelwrap (GtkSelectionModel * object, bool take_copy=false)
 A Glib::wrap() method for this object. More...
 

Detailed Description

An extension of the list model interface that handles selections.

Gtk::SelectionModel is an interface that extends the Gio::ListModel interface by adding support for selections. This support is then used by widgets using list models to add the ability to select and unselect various items.

GTK provides default implementations of the common selection modes such as Gtk::SingleSelection, so you will only need to implement this interface if you want detailed control about how selections should be handled.

A Gtk::SelectionModel supports a single boolean per row indicating if a row is selected or not. This can be queried via is_selected(). When the selected state of one or more rows changes, the model will emit signal_selection_changed() by calling the selection_changed() method. The positions given in that signal may have their selection state changed, though that is not a requirement.
If new items added to the model via Gio::ListModel::signal_items_changed() are selected or not is up to the implementation.

Additionally, the interface can expose functionality to select and unselect items. If these functions are implemented, GTK's list widgets will allow users to select and unselect items. However, Gtk::SelectionModels are free to only implement them partially or not at all. In that case the widgets will not support the unimplemented operations.

When selecting or unselecting is supported by a model, the return values of the selection functions do NOT indicate if selection or unselection happened. They are only meant to indicate complete failure, like when this mode of selecting is not supported by the model. Selections may happen asynchronously, so the only reliable way to find out when an item was selected is to listen to the signals that indicate selection.

See also
Gio::ListModel, Gtk::SingleSelection
Since gtkmm 3.96:

Constructor & Destructor Documentation

◆ SelectionModel() [1/2]

Gtk::SelectionModel::SelectionModel ( )
protected

You should derive from this class to use it.

◆ SelectionModel() [2/2]

Gtk::SelectionModel::SelectionModel ( SelectionModel &&  src)
noexcept

◆ ~SelectionModel()

Gtk::SelectionModel::~SelectionModel ( )
overridenoexcept

Member Function Documentation

◆ add_interface()

static void Gtk::SelectionModel::add_interface ( GType  gtype_implementer)
static

◆ get_selection() [1/2]

Glib::RefPtr<const Bitset> Gtk::SelectionModel::get_selection ( ) const

Gets the set containing all currently selected items in the model.

This function may be slow, so if you are only interested in single item, consider using is_selected() or if you are only interested in a few, consider get_selection_in_range().

Returns
A Gtk::Bitset containing all the values currently selected in model. If no items are selected, the bitset is empty. The bitset must not be modified.

◆ get_selection() [2/2]

Glib::RefPtr<const Bitset> Gtk::SelectionModel::get_selection ( guint  position,
guint  n_items 
) const

Gets the set of selected items in a range.

This function is an optimization for get_selection() when you are only interested in part of the model's selected state. A common use case is in response to the signal_selection_changed() signal.

Parameters
positionStart of the queired range.
n_itemsNumber of items in the queried range.
Returns
A Gtk::Bitset that matches the selection state for the given range with all other values being undefined. The bitset must not be modified.

◆ get_selection_vfunc()

virtual Glib::RefPtr<const Bitset> Gtk::SelectionModel::get_selection_vfunc ( guint  position,
guint  n_items 
)
protectedvirtual

◆ get_type()

static GType Gtk::SelectionModel::get_type ( )
static

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

◆ gobj() [1/2]

GtkSelectionModel* Gtk::SelectionModel::gobj ( )
inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GtkSelectionModel* Gtk::SelectionModel::gobj ( ) const
inline

Provides access to the underlying C GObject.

◆ is_selected()

bool Gtk::SelectionModel::is_selected ( guint  position) const

Checks if the given item is selected.

Parameters
positionThe position of the item to query.
Returns
true if the item is selected.

◆ is_selected_vfunc()

virtual bool Gtk::SelectionModel::is_selected_vfunc ( guint  position) const
protectedvirtual

◆ operator=()

SelectionModel& Gtk::SelectionModel::operator= ( SelectionModel &&  src)
noexcept

◆ select_all()

bool Gtk::SelectionModel::select_all ( )

Requests to select all items in the model.

Returns
true if this action was supported and no fallback should be tried. This does not mean that all items are now selected.

◆ select_all_vfunc()

virtual bool Gtk::SelectionModel::select_all_vfunc ( )
protectedvirtual

◆ select_item()

bool Gtk::SelectionModel::select_item ( guint  position,
bool  unselect_rest 
)

Requests to select an item in the model.

Parameters
positionThe position of the item to select.
unselect_restWhether previously selected items should be unselected.
Returns
true if this action was supported and no fallback should be tried. This does not mean the item was selected.

◆ select_item_vfunc()

virtual bool Gtk::SelectionModel::select_item_vfunc ( guint  position,
bool  unselect_rest 
)
protectedvirtual

◆ select_range()

bool Gtk::SelectionModel::select_range ( guint  position,
guint  n_items,
bool  unselect_rest 
)

Requests to select a range of items in the model.

Parameters
positionThe first item to select.
n_itemsThe number of items to select.
unselect_restWhether previously selected items should be unselected.
Returns
true if this action was supported and no fallback should be tried. This does not mean the range was selected.

◆ select_range_vfunc()

virtual bool Gtk::SelectionModel::select_range_vfunc ( guint  position,
guint  n_items,
bool  unselect_rest 
)
protectedvirtual

◆ selection_changed()

void Gtk::SelectionModel::selection_changed ( guint  position,
guint  n_items 
)
protected

Helper function for implementations of Gtk::SelectionModel.

Call this when a the selection changes to emit the signal_selection_changed() signal.

Parameters
positionThe first changed item.
n_itemsThe number of changed items.

◆ set_selection()

bool Gtk::SelectionModel::set_selection ( const Glib::RefPtr< const Bitset > &  selected,
const Glib::RefPtr< const Bitset > &  mask 
)

Make selection changes.

This is the most advanced selection updating method that allows the most fine-grained control over selection changes. If you can, you should try the simpler versions, as implementations are more likely to implement support for those.

Requests that the selection state of all positions set in mask be updated to the respective value in the selected bitmask.

In pseudocode, it would look something like this:

[C example ellipted]

mask and selected must not be modified. They may refer to the same bitset, which would mean that every item in the set should be selected.

Parameters
selectedBitmask specifying if items should be selected or unselected.
maskBitmask specifying which items should be updated.
Returns
true if this action was supported and no fallback should be tried. This does not mean that all items were updated according to the inputs.

◆ set_selection_vfunc()

virtual bool Gtk::SelectionModel::set_selection_vfunc ( const Glib::RefPtr< const Bitset > &  selected,
const Glib::RefPtr< const Bitset > &  mask 
)
protectedvirtual

◆ signal_selection_changed()

Glib::SignalProxy<void(guint, guint)> Gtk::SelectionModel::signal_selection_changed ( )
Slot Prototype:
void on_my_selection_changed(guint position, guint n_items)

Flags: Run Last

Emitted when the selection state of some of the items in model changes.

Note that this signal does not specify the new selection state of the items, they need to be queried manually. It is also not necessary for a model to change the selection state of any of the items in the selection model, though it would be rather useless to emit such a signal.

Parameters
positionThe first item that may have changed.
n_itemsNumber of items with changes.

◆ unselect_all()

bool Gtk::SelectionModel::unselect_all ( )

Requests to unselect all items in the model.

Returns
true if this action was supported and no fallback should be tried. This does not mean that all items are now unselected.

◆ unselect_all_vfunc()

virtual bool Gtk::SelectionModel::unselect_all_vfunc ( )
protectedvirtual

◆ unselect_item()

bool Gtk::SelectionModel::unselect_item ( guint  position)

Requests to unselect an item in the model.

Parameters
positionThe position of the item to unselect.
Returns
true if this action was supported and no fallback should be tried. This does not mean the item was unselected.

◆ unselect_item_vfunc()

virtual bool Gtk::SelectionModel::unselect_item_vfunc ( guint  position)
protectedvirtual

◆ unselect_range()

bool Gtk::SelectionModel::unselect_range ( guint  position,
guint  n_items 
)

Requests to unselect a range of items in the model.

Parameters
positionThe first item to unselect.
n_itemsThe number of items to unselect.
Returns
true if this action was supported and no fallback should be tried. This does not mean the range was unselected.

◆ unselect_range_vfunc()

virtual bool Gtk::SelectionModel::unselect_range_vfunc ( guint  position,
guint  n_items 
)
protectedvirtual

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gtk::SelectionModel > wrap ( GtkSelectionModel *  object,
bool  take_copy = false 
)
related

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

Parameters
objectThe C instance.
take_copyFalse 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.