From 3665c36d276f7209ed09a93dc2e08d2e34a393c0 Mon Sep 17 00:00:00 2001
From: Norayr Chilingarian <norayr@arnet.am>
Date: Wed, 27 May 2015 02:56:52 +0400
Subject: [PATCH] added events example.

---
 src/test/events/README.md |  7 +++++
 src/test/events/clb.Mod   | 55 +++++++++++++++++++++++++++++++++++++++
 src/test/events/makefile  |  4 +++
 3 files changed, 66 insertions(+)
 create mode 100644 src/test/events/README.md
 create mode 100644 src/test/events/clb.Mod
 create mode 100644 src/test/events/makefile

diff --git a/src/test/events/README.md b/src/test/events/README.md
new file mode 100644
index 00000000..32729f67
--- /dev/null
+++ b/src/test/events/README.md
@@ -0,0 +1,7 @@
+**events example in oberon**
+
+Just a simple example which helps to explain how events are implemented, what is callback procedure, and how easy it is.
+
+Some languages simplify programmer's work, hide details, so that it's not obvious to him what's going on when he defines it's own OnSomething function.
+
+Callbacks are common when dealing with gui events like OnClick but they can be used with any events. I guess code is simple enough, it doesn't need explanation.
diff --git a/src/test/events/clb.Mod b/src/test/events/clb.Mod
new file mode 100644
index 00000000..218b82b7
--- /dev/null
+++ b/src/test/events/clb.Mod
@@ -0,0 +1,55 @@
+MODULE clb;
+
+IMPORT Console;
+
+TYPE OnSomething = PROCEDURE (x, y : INTEGER);
+
+PROCEDURE ProcessEvents(x, y : INTEGER; onsomething : OnSomething);
+
+BEGIN
+
+IF onsomething # NIL THEN onsomething(x, y)
+ELSE
+   Console.String("didn't happen"); Console.Ln
+END;
+
+END ProcessEvents;
+
+
+PROCEDURE OnEvent(x, y : INTEGER);
+
+BEGIN
+
+Console.String("event happened"); Console.Ln
+
+END OnEvent;
+
+PROCEDURE OnEvent2(x, y : INTEGER);
+
+BEGIN
+
+Console.String("happened"); Console.Ln
+
+END OnEvent2;
+
+PROCEDURE Something;
+VAR onsmth : OnSomething;
+
+BEGIN
+
+   onsmth := NIL;
+   ProcessEvents(0, 0, onsmth);
+
+   onsmth := OnEvent;
+   ProcessEvents(0, 0, onsmth);
+
+END Something;
+
+BEGIN
+   Something;
+(*
+ProcessEvents(0, 0, NIL);
+ProcessEvents(0, 0, OnEvent);
+ProcessEvents(0, 0, OnEvent2);
+*)
+END clb.
diff --git a/src/test/events/makefile b/src/test/events/makefile
new file mode 100644
index 00000000..b2f73828
--- /dev/null
+++ b/src/test/events/makefile
@@ -0,0 +1,4 @@
+
+
+all:
+	/opt/voc/bin/voc -M clb.Mod