Gtk.SectionModel

Implementations:

Gtk.FilterListModel, Gtk.FlattenListModel, Gtk.MapListModel, Gtk.MultiSelection, Gtk.NoSelection, Gtk.SingleSelection, Gtk.SliceListModel, Gtk.SortListModel

Methods

	get_section (position)
	sections_changed (position, n_items)

Virtual Methods

do_get_section (position)

Properties

None

Signals

Name	Short Description
sections-changed	Emitted when the start-of-section state of some of the items in model changes.

Fields

None

Class Details

class Gtk.SectionModel

Bases:

GObject.GInterface

Structure:

Gtk.SectionModelInterface

GtkSectionModel is an interface that adds support for sections to list models.

A GtkSectionModel groups successive items into so-called sections. List widgets like GtkListView and GtkGridView then allow displaying section headers for these sections by installing a header factory.

Many GTK list models support sections inherently, or they pass through the sections of a model they are wrapping.

When the section groupings of a model change, the model will emit the [signal`Gtk`.SectionModel::sections-changed] signal by calling the [method`Gtk`.SectionModel.sections_changed] function. All sections in the given range then need to be queried again. The [signal`Gio`.ListModel::items-changed] signal has the same effect, all sections in that range are invalidated, too.

New in version 4.12.

get_section(position)

Parameters:

position (int) – the position of the item to query

Returns:

out_start:

the position of the first item in the section

out_end:

the position of the first item not part of the section anymore.

Return type:

(out_start: int, out_end: int)

Query the section that covers the given position. The number of items in the section can be computed by out_end - out_start.

If the position is larger than the number of items, a single range from n_items to GObject.G_MAXUINT will be returned.

New in version 4.12.

sections_changed(position, n_items)

Parameters:

• position (int) – the first changed item

• n_items (int) – the number of changed items

This function emits the [signal`Gtk`.SectionModel::sections-changed] signal to notify about changes to sections.

It must cover all positions that used to be a section start or that are now a section start. It does not have to cover all positions for which the section has changed.

The [signal`Gio`.ListModel::items-changed] implies the effect of the [signal`Gtk`.SectionModel::sections-changed] signal for all the items it covers.

It is recommended that when changes to the items cause section changes in a larger range, that the larger range is included in the emission of the [signal`Gio`.ListModel::items-changed] instead of emitting two signals.

New in version 4.12.

do_get_section(position) virtual

Parameters:

position (int) – the position of the item to query

Returns:

out_start:

the position of the first item in the section

out_end:

the position of the first item not part of the section anymore.

Return type:

(out_start: int, out_end: int)

Query the section that covers the given position. The number of items in the section can be computed by out_end - out_start.

If the position is larger than the number of items, a single range from n_items to GObject.G_MAXUINT will be returned.

New in version 4.12.

Signal Details

Gtk.SectionModel.signals.sections_changed(section_model, position, n_items)

Signal Name:

sections-changed

Flags:

RUN_LAST

Parameters:

• section_model (Gtk.SectionModel) – The object which received the signal

• position (int) – The first item that may have changed

• n_items (int) – number of items with changes

Emitted when the start-of-section state of some of the items in model changes.

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

The [signal`Gio`.ListModel::items-changed] implies the effect of the [signal`Gtk`.SectionModel::sections-changed] signal for all the items it covers.

New in version 4.12.