Struct relm4::prelude::DynamicIndex

source ·
pub struct DynamicIndex { /* private fields */ }
Expand description

A dynamic index that updates automatically when items are shifted inside a factory container.

For example a FactoryVecDeque has an insert method that allows users to insert data at arbitrary positions. If we insert at the front all following widgets will be moved by one which would invalidate their indices. To allow widgets in a factory container to send messages with valid indices this type ensures that the indices is always up to date.

Never send an index as usize but always as DynamicIndex to the update function because messages can be queued up and stale by the time they are handled.

DynamicIndex is a smart pointer so cloning will work similar to std::rc::Rc and will create a pointer to the same data.

In short: only call current_index from the update function where you actually need the index as usize.

Implementations§

Get the current index number.

This value is updated by the factory container and might change after each update function.

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
This method tests for self and other values to be equal, and is used by ==.
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Returns the position. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Returns the position. Read more
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more