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| -rwxr-xr-x | vala.html.markdown | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/vala.html.markdown b/vala.html.markdown index a0fbc5c1..237d4a15 100755 --- a/vala.html.markdown +++ b/vala.html.markdown @@ -279,6 +279,29 @@ public class Calculator : GLib.Object { var calc1 = new Calculator.with_name("Temp"); var calc2 = new Calculator.model("TI-84"); +// Signals (a.k.a. events or event listeners) are a way to execute multiple +// methods with the same signature at the same time. + +public class SignalDemo : GLib.Object { + public signal void sig_demo(int sig_demo_int); // Must be public + + public static int main(string[] args) { + // main method; program does not compile without it + var sig_demo_class = new SignalDemo(); // New instance of class + + sig_demo_class.sig_demo.connect((ob, sig_int) => { // Lambda used as handler + stdout.printf("%d\n", sig_int); // "ob" is object on which it is emitted + }); + + sig_demo_class.sig_demo(27); // Signal is emitted + + return 0; + } +} + +// You may use the connect() method and attach as many handlers as you'd like. +// They'll all run when the signal is emitted. + ``` * More Vala documentation can be found [here](https://valadoc.org/). * Read about building GUIs with GTK+ and Vala [here](http://archive.is/7C7bw). |