View source code
Display the source code in std/signals.d from which this page was generated on
github.
Improve this page
Quickly fork, edit online, and submit a pull request for this page.
Requires a signed-in GitHub account. This works well for small changes.
If you'd like to make larger changes you may want to consider using
local clone.
Page wiki
View or edit the community-maintained wiki page associated with this page.
Template std.signals.Signal
Mixin to create a signal within a class object.
Different signals can be added to a class by naming the mixins.
Arguments
template Signal(T1...);
Functions
| Function name | Description |
|---|---|
| connect | Add a slot to the list of slots to be called when emit() is called.
|
| disconnect | Remove a slot from the list of slots to be called when emit() is called.
|
| emit | Call each of the connected slots, passing the argument(s) i to them.
|
Aliases
| Alias name | Description |
|---|---|
| slot_t | A slot is implemented as a delegate.
The slot_t is the type of the delegate.
The delegate must be to an instance of a class or an interface
to a class instance.
Delegates to struct instances or nested functions must not be
used as slots.
|
Example
import std.signals; import std.stdio; class Observer { // our slot void watch(string msg, int i) { writefln("Observed msg '%s' and value %s", msg, i); } } class Foo { int value() { return _value; } int value(int v) { if (v != _value) { _value = v; // call all the connected slots with the two parameters emit("setting new value", v); } return v; } // Mix in all the code we need to make Foo into a signal mixin Signal!(string, int); private : int _value; } void main() { Foo a = new Foo; Observer o = new Observer; a.value = 3; // should not call o.watch() a.connect(&o.watch); // o.watch is the slot a.value = 4; // should call o.watch() a.disconnect(&o.watch); // o.watch is no longer a slot a.value = 5; // so should not call o.watch() a.connect(&o.watch); // connect again a.value = 6; // should call o.watch() destroy(o); // destroying o should automatically disconnect it a.value = 7; // should not call o.watch() }
which should print:
Observed msg 'setting new value' and value 4 Observed msg 'setting new value' and value 6