add an example program to test input event handling: vty-event-echo

test/EventEcho.hs

@@ -0,0 +1,42 @@
+module Main where
+
+import Graphics.Vty
+
+import Control.Applicative
+import Control.Arrow
+import Control.Monad.RWS
+
+import Data.Sequence (Seq, (<|) )
+import qualified Data.Sequence as Seq
+import Data.Foldable
+
+event_buffer_size = 1000
+
+type App = RWST Vty () (Seq String) IO
+
+main = do
+    vty <- mkVty
+    _ <- execRWST vty_interact vty Seq.empty
+    shutdown vty
+
+vty_interact :: App ()
+vty_interact = do
+    update_display
+    done <- handle_next_event
+    unless done vty_interact
+
+update_display :: App ()
+update_display = do
+    let info = string def_attr "Press ESC to exit."
+    event_log <- foldMap (string def_attr) <$> get
+    let pic = pic_for_layers [info,event_log]
+    vty <- ask
+    liftIO $ update vty pic
+
+handle_next_event = ask >>= liftIO . next_event >>= handle_event
+    where
+        handle_event (EvKey KEsc []) = return True
+        handle_event e               = do
+            modify $ (<|) (show e) >>> Seq.take event_buffer_size
+            return False
+

vty.cabal

@@ -561,6 +561,25 @@ executable vty-interactive-terminal-test
                        utf8-string >= 0.3 && < 0.4,
                        vector >= 0.7
 
+executable vty-event-echo
+  main-is:             EventEcho.hs
+  hs-source-dirs:      test
+
+  default-language:    Haskell2010
+  default-extensions:  ScopedTypeVariables
+
+  build-depends:       vty,
+                       base >= 4 && < 5,
+                       array >= 0.4 && < 2.0,
+                       bytestring,
+                       containers,
+                       lens,
+                       mtl >= 1.1.1.0 && < 2.2,
+                       parallel >= 2.2 && < 3.3,
+                       text >= 0.11.3,
+                       utf8-string >= 0.3 && < 0.4,
+                       vector >= 0.7
+
 executable vty-rouge
   main-is:             Rouge.hs
   hs-source-dirs:      test