pub trait IntoVar<T: VarValue> {
// Required method
fn into_var(self) -> Var<T>;
}Expand description
A value-to-var conversion that consumes the value.
Every Var<T> implements this to convert to itself, every VarValue implements this to
convert to a const_var.
This trait is used by most properties, it allows then to accept literal values, variables and context variables
all with a single signature. Together with Var<T> this gives properties great flexibility of usage. Widget
when blocks also use IntoVar<T> to support changing the property value depending on the widget state.
Value types can also manually implement this to support a shorthand literal syntax for when they are used in properties,
this converts the shorthand value like a tuple into the actual value type and wraps it into a variable, usually const_var.
Value types can implement the trait multiple times to support different shorthand syntaxes.