Struct ListItemFactory

pub struct ListItemFactory { /* private fields */ }

A ListItemFactory creates widgets for the items taken from a GListModel.

This is one of the core concepts of handling list widgets such as ListView or GridView.

The ListItemFactory is tasked with creating widgets for items taken from the model when the views need them and updating them as the items displayed by the view change.

A view is usually only able to display anything after both a factory and a model have been set on the view. So it is important that you do not skip this step when setting up your first view.

Because views do not display the whole list at once but only a few items, they only need to maintain a few widgets at a time. They will instruct the ListItemFactory to create these widgets and bind them to the items that are currently displayed.

As the list model changes or the user scrolls to the list, the items will change and the view will instruct the factory to bind the widgets to those new items.

The actual widgets used for displaying those widgets is provided by you.

When the factory needs widgets created, it will create a ListItem and hand it to your code to set up a widget for. This list item will provide various properties with information about what item to display and provide you with some opportunities to configure its behavior. See the ListItem documentation for further details.

Various implementations of ListItemFactory exist to allow you different ways to provide those widgets. The most common implementations are BuilderListItemFactory which takes a Builder .ui file and then creates widgets and manages everything automatically from the information in that file and SignalListItemFactory which allows you to connect to signals with your own code and retain full control over how the widgets are setup and managed.

A ListItemFactory is supposed to be final - that means its behavior should not change and the first widget created from it should behave the same way as the last widget created from it. If you intend to do changes to the behavior, it is recommended that you create a new ListItemFactory which will allow the views to recreate its widgets.

Once you have chosen your factory and created it, you need to set it on the view widget you want to use it with, such as via ListView::set_factory(). Reusing factories across different views is allowed, but very uncommon.

Implements

[trait@glib::ObjectExt]

GLib type: GObject with reference counted clone semantics.

Implementations

impl ListItemFactory

pub const NONE: Option<&'static ListItemFactory> = None

Trait Implementations

impl Clone for ListItemFactory

fn clone(&self) -> Self

Makes a clone of this shared reference.

This increments the strong reference count of the object. Dropping the object will decrement it again.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ListItemFactory

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for ListItemFactory

type ParamSpec = ParamSpecObject

type SetValue = ListItemFactory

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, ListItemFactory>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for ListItemFactory

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Hashes the memory address of this object.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for ListItemFactory

fn cmp(&self, other: &Self) -> Ordering

Comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl ParentClassIs for ListItemFactory

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for ListItemFactory

fn eq(&self, other: &OT) -> bool

Equality for two GObjects.

Two GObjects are equal if their memory addresses are equal.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for ListItemFactory

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

Partial comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for ListItemFactory

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for ListItemFactory

impl IsA<ListItemFactory> for BuilderListItemFactory

impl IsA<ListItemFactory> for SignalListItemFactory