Initial data commit

Task/GUI-component-interaction/Haskell/gui-component-interaction-1.hs

@@ -0,0 +1,26 @@
+import Graphics.UI.WX
+import System.Random
+
+main :: IO ()
+main = start $ do
+    frm   <- frame [text := "Interact"]
+    fld   <- textEntry frm [text := "0", on keyboard := checkKeys]
+    inc   <- button frm [text := "increment", on command := increment fld]
+    ran   <- button frm [text := "random", on command := (randReplace fld frm)]
+    set frm [layout := margin 5 $ floatCentre $ column 2
+            [centre $ widget fld, row 2 [widget inc, widget ran]]]
+
+increment :: Textual w => w -> IO ()
+increment field = do
+    val <- get field text
+    when ((not . null) val) $ set field [text := show $ 1 + read val]
+
+checkKeys :: EventKey -> IO ()
+checkKeys (EventKey key _ _) =
+    when (elem (show key) $ "Backspace" : map show [0..9]) propagateEvent
+
+randReplace :: Textual w => w -> Window a -> IO ()
+randReplace field frame = do
+    answer <- confirmDialog frame "Random" "Generate a random number?" True
+    when answer $ getStdRandom (randomR (1,100)) >>= \num ->
+                  set field [text := show (num :: Int)]