From a7fd0f20297f3ebbc8009a9fa9f5c71e6a3dd16c Mon Sep 17 00:00:00 2001
From: Camil Staps
Date: Fri, 21 Aug 2015 14:33:40 +0200
Subject: Tut 10.4.2 Resetting the counter

---
 tut10_4_2.icl | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 tut10_4_2.icl

diff --git a/tut10_4_2.icl b/tut10_4_2.icl
new file mode 100644
index 0000000..58d9f26
--- /dev/null
+++ b/tut10_4_2.icl
@@ -0,0 +1,40 @@
+module tut10_4_2
+
+// ********************************************************************************
+// Clean tutorial example program.
+//
+// This program defines a Controls component that implements a manually settable
+// counter. A receiver is used to add a reset option.
+// ********************************************************************************
+
+import StdEnv, StdIO
+
+Start :: *World -> *World
+Start world = startIO NDI Void initialise [] world
+where
+    initialise pst
+    # (displayId, pst)  = accPIO openId pst
+    # (resetId, pst)    = accPIO openRId pst
+    # (error, pst)      = openDialog Void (dialog displayId resetId) pst
+    | error <> NoError  = abort "Counter could not open Dialog."
+    | otherwise         = pst
+
+dialog displayId resetId = Dialog "Counter" (counter :+: resetButton) [WindowClose (noLS closeProcess)]
+where
+    counter = { newLS = initcount,
+                newDef = LayoutControl (EditControl (toString initcount) (PixelWidth (hmm 50.0)) 1 [ControlId displayId, ControlSelectState Unable] :+:
+                                        ButtonControl "-" [ControlFunction (count(-1)), ControlWidth (PixelWidth (hmm 25.0)), ControlPos (BelowPrev, zero)] :+:
+                                        ButtonControl "+" [ControlFunction (count  1 ), ControlWidth (PixelWidth (hmm 25.0))] :+:
+                                        Receiver resetId reset [])
+                                       [ControlPos (Center, zero), ControlHMargin 0 0, ControlVMargin 0 0, ControlItemSpace 0 0] }
+    where
+        initcount = 0
+
+        count :: Int (Int, PSt .l) -> (Int, PSt .l)
+        count dx (count, pst) = (count + dx, appPIO (setControlText displayId (toString (count+dx))) pst)
+
+        reset :: m (Int, PSt .l) -> (Int, PSt .l)
+        reset _ (_, pst) = (initcount, appPIO (setControlText displayId (toString initcount)) pst)
+
+    resetButton = ButtonControl "Reset" [ControlFunction (noLS (snd o syncSend resetId undef)), ControlPos (Center, zero)]
+
-- 
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