Struct slint::MapModel

pub struct MapModel<M, F> { /* private fields */ }

Provides rows that are generated by a map function based on the rows of another Model

When the other Model is updated, the MapModel is updated accordingly.

Generic parameters:

• M the type of the wrapped Model.
• F the map function.

Example

Here we have a VecModel holding rows of a custom type Name. It is then mapped into a MapModel of SharedStrings

#[derive(Clone)]
struct Name {
    first: String,
    last: String,
}

let model = VecModel::from(vec![
    Name { first: "Hans".to_string(), last: "Emil".to_string() },
    Name { first: "Max".to_string(), last: "Mustermann".to_string() },
    Name { first: "Roman".to_string(), last: "Tisch".to_string() },
]);

let mapped_model = MapModel::new(model, |n|
    slint::format!("{}, {}", n.last, n.first)
);

assert_eq!(mapped_model.row_data(0).unwrap(), SharedString::from("Emil, Hans"));
assert_eq!(mapped_model.row_data(1).unwrap(), SharedString::from("Mustermann, Max"));
assert_eq!(mapped_model.row_data(2).unwrap(), SharedString::from("Tisch, Roman"));

Alternatively you can use the shortcut ModelExt::map.

let mapped_model = VecModel::from(vec![
    Name { first: "Hans".to_string(), last: "Emil".to_string() },
    Name { first: "Max".to_string(), last: "Mustermann".to_string() },
    Name { first: "Roman".to_string(), last: "Tisch".to_string() },
])
.map(|n| slint::format!("{}, {}", n.last, n.first));

If you want to modify the underlying VecModel you can give it a Rc of the MapModel:

let model = Rc::new(VecModel::from(vec![
    Name { first: "Hans".to_string(), last: "Emil".to_string() },
    Name { first: "Max".to_string(), last: "Mustermann".to_string() },
    Name { first: "Roman".to_string(), last: "Tisch".to_string() },
]));

let mapped_model = MapModel::new(model.clone(), |n|
    slint::format!("{}, {}", n.last, n.first)
);

model.set_row_data(1, Name { first: "Minnie".to_string(), last: "Musterfrau".to_string() });

assert_eq!(mapped_model.row_data(0).unwrap(), SharedString::from("Emil, Hans"));
assert_eq!(mapped_model.row_data(1).unwrap(), SharedString::from("Musterfrau, Minnie"));
assert_eq!(mapped_model.row_data(2).unwrap(), SharedString::from("Tisch, Roman"));

Implementations

impl<M, F, T, U> MapModel<M, F>where
    M: 'static + Model<Data = T>,
    F: 'static + Fn(T) -> U,

pub fn new(model: M, map_function: F) -> MapModel<M, F>

Trait Implementations

impl<M, F, T, U> Model for MapModel<M, F>where
    M: 'static + Model<Data = T>,
    F: 'static + Fn(T) -> U,

type Data = U

The model data: A model is a set of row and each row has this data

fn row_count(&self) -> usize

The amount of row in the model

fn row_data(&self, row: usize) -> Option<<MapModel<M, F> as Model>::Data>

Returns the data for a particular row. This function should be called with row < row_count().

fn model_tracker(&self) -> &dyn ModelTracker

The implementation should return a reference to its ModelNotify field.

fn as_any(&self) -> &(dyn Any + 'static)

Return something that can be downcast’ed (typically self)

fn set_row_data(&self, _row: usize, _data: Self::Data)

Sets the data for a particular row.

fn iter(&self) -> ModelIterator<'_, Self::Data> where
    Self: Sized,

Returns an iterator visiting all elements of the model.