qnd input impl with slow spinning

src/net/torvald/tsvm/VMGUI.kt

@@ -46,7 +46,7 @@ class VMGUI(val appConfig: LwjglApplicationConfiguration) : ApplicationAdapter()
 
         vm.printStream = gpu.getPrintStream()
         vm.errorStream = gpu.getErrorStream()
-        //inputStream = gpu.getInputStream()
+        vm.inputStream = gpu.getInputStream()
 
         // TEST PRG
         vmRunner = VMRunnerFactory(vm, "js")
@@ -267,10 +267,7 @@ println("");
 print("C:\\\\>");
 
 while (true) {
-    var mx = vm.peek(-33) + vm.peek(-34) * 256;
-    var my = vm.peek(-35) + vm.peek(-36) * 256;
-    println("mx: "+mx+", my: "+my);
-    graphics.plotPixel(mx, my, (mx + my) % 255);
+    print(String.fromCharCode(vm.readKey()));
 }
     """.trimIndent()
 

src/net/torvald/tsvm/VMJSR223Delegate.kt

@@ -22,6 +22,7 @@ class VMJSR223Delegate(val vm: VM) {
         vm.printStream.write((s + '\n').toByteArray())
     }
 
+    fun readKey() = vm.inputStream.read()
 }
 
 class VMSerialDebugger(val vm: VM) {

src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt

@@ -413,7 +413,27 @@ class GraphicsAdapter(val vm: VM, val lcdMode: Boolean = false) : GlassTty(Compa
     }
 
     override fun getInputStream(): InputStream {
-        TODO("Not yet implemented")
+        try {
+            return INPUTSTREAM_INSTANCE
+        }
+        catch (e: UninitializedPropertyAccessException) {
+            INPUTSTREAM_INSTANCE = object : InputStream() {
+
+                override fun read(): Int {
+                    var key: Byte
+                    do {
+                        Thread.sleep(4L) // if spinning rate is too fast, this function fail.
+                        // Possible cause: Input event handling of GDX is done on separate thread
+                        key = vm.getIO().mmio_read(37L)!!
+                    } while (key == (-1).toByte())
+
+                    println("[stdin] key = $key")
+                    return key.toInt().and(255)
+                }
+            }
+
+            return INPUTSTREAM_INSTANCE
+        }
     }
 
     override fun dispose() {

src/net/torvald/tsvm/peripheral/IOSpace.kt

@@ -67,8 +67,10 @@ class IOSpace(val vm: VM) : PeriBase, InputProcessor {
     }
 
     override fun keyTyped(p0: Char): Boolean {
-        keyboardBuffer.appendTail(p0.toByte())
-        println("[IO] Key typed: $p0")
+        try {
+            keyboardBuffer.appendTail(p0.toByte())
+        }
+        catch (e: StackOverflowError) { /* if stack overflow, simply stop reading more keys */ }
         return true
     }