pub enum MessageDirection {
    ToWidget,
    FromWidget,
}
Expand description

Message direction allows you to distinguish from where message has came from. Often there is a need to find out who created a message to respond properly. Imagine that we have a NumericUpDown input field for a property and we using some data source to feed data into input field. When we change something in the input field by typing, it creates a message with new value. On other hand we often need to put new value in the input field from some code, in this case we again creating a message. But how to understand from which “side” message has came from? Was it filled in by user and we should create a command to change value in the data source, or it was created from syncing code just to pass new value to UI? This problem solved by setting a direction to a message. Also it solves another problem: often we need to respond to a message only if it did some changes. In this case at first we fire a message with ToWidget direction, widget catches it and checks if changes are needed and if so, it “rethrows” message with direction FromWidget. Listeners are “subscribed” to FromWidget messages only and won’t respond to ToWidget messages.

Variants§

§

ToWidget

Used to indicate a request for changes in a widget.

§

FromWidget

Used to indicate response from widget if anything has actually changed.

Implementations§

Reverses direction.

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
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. 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.
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
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
Casts self to a &dyn Any

Returns the argument unchanged.

Calls U::from(self).

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

The alignment of pointer.
The type for initializers.
Initializes a with the given initializer. Read more
Dereferences the given pointer. Read more
Mutably dereferences the given pointer. Read more
Drops the object pointed to by the given pointer. Read more
Should always be Self
The inverse inclusion map: attempts to construct self from the equivalent element of its superset. Read more
Checks if self is actually part of its subset T (and can be converted to it).
Use with care! Same as self.to_subset but without any property checks. Always succeeds.
The inclusion map: converts self to the equivalent element of its superset.
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.