Struct gtk4::ListItemFactory [−][src]
pub struct ListItemFactory(_);Expand description
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 Implementations
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Returns the type identifier of Self.
Auto Trait Implementations
impl RefUnwindSafe for ListItemFactory
impl !Send for ListItemFactory
impl !Sync for ListItemFactory
impl Unpin for ListItemFactory
impl UnwindSafe for ListItemFactory
Blanket Implementations
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T. Read more
Upcasts an object to a reference of its superclass or interface T. Read more
Tries to downcast to a subclass or interface implementor T. Read more
Tries to downcast to a reference of its subclass or interface implementor T. Read more
Tries to cast to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Casts to T unconditionally. Read more
Casts to &T unconditionally. Read more
Returns true if the object is an instance of (can be cast to) T.
pub fn set_property<'a, N, V>(
&self,
property_name: N,
value: V
) -> Result<(), BoolError> where
N: Into<&'a str>,
V: ToValue,
pub fn set_property_from_value<'a, N>(
&self,
property_name: N,
value: &Value
) -> Result<(), BoolError> where
N: Into<&'a str>,
pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value)]
) -> Result<(), BoolError>
pub fn has_property<'a, N>(&self, property_name: N, type_: Option<Type>) -> bool where
N: Into<&'a str>,
pub fn find_property<'a, N>(&self, property_name: N) -> Option<ParamSpec> where
N: Into<&'a str>,
Safety Read more
Safety Read more
Safety Read more
Safety Read more
pub fn connect<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value> + Send + Sync,
Same as connect but takes a SignalId instead of a signal name.
pub fn connect_local<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value>,
Same as connect_local but takes a SignalId instead of a signal name.
pub unsafe fn connect_unsafe<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: Fn(&[Value]) -> Option<Value>,
Same as connect_unsafe but takes a SignalId instead of a signal name.
Emit signal by signal id.
Same as emit but takes Value for the arguments.
Emit signal by its name.
Same as emit_by_name but takes Value for the arguments.
Emit signal with details by signal id.
Same as emit_with_details but takes Value for the arguments.
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync,
pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec),
pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec),
pub fn bind_property<'a, O, N, M>(
&'a self,
source_property: N,
target: &'a O,
target_property: M
) -> BindingBuilder<'a> where
O: ObjectType,
N: Into<&'a str>,
M: Into<&'a str>,
Returns a SendValue clone of self.