examples: add keyboard-input example

Signed-off-by: Lilis Iskandar <lilis@veand.co>

examples/keyboard-input/keyboard-input.go

@@ -0,0 +1,94 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/veandco/go-sdl2/sdl"
+)
+
+func run() (err error) {
+	var window *sdl.Window
+
+	if err = sdl.Init(sdl.INIT_EVERYTHING); err != nil {
+		return
+	}
+	defer sdl.Quit()
+
+	window, err = sdl.CreateWindow("Input", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, 800, 600, sdl.WINDOW_SHOWN)
+	if err != nil {
+		return
+	}
+	defer window.Destroy()
+
+	running := true
+	for running {
+		for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
+			switch t := event.(type) {
+			case *sdl.QuitEvent:
+				running = false
+			case *sdl.KeyboardEvent:
+				keyCode := t.Keysym.Sym
+				keys := ""
+
+				// Modifier keys
+				switch t.Keysym.Mod {
+				case sdl.KMOD_LALT:
+					keys += "Left Alt"
+				case sdl.KMOD_LCTRL:
+					keys += "Left Control"
+				case sdl.KMOD_LSHIFT:
+					keys += "Left Shift"
+				case sdl.KMOD_LGUI:
+					keys += "Left Meta or Windows key"
+				case sdl.KMOD_RALT:
+					keys += "Right Alt"
+				case sdl.KMOD_RCTRL:
+					keys += "Right Control"
+				case sdl.KMOD_RSHIFT:
+					keys += "Right Shift"
+				case sdl.KMOD_RGUI:
+					keys += "Right Meta or Windows key"
+				case sdl.KMOD_NUM:
+					keys += "Num Lock"
+				case sdl.KMOD_CAPS:
+					keys += "Caps Lock"
+				case sdl.KMOD_MODE:
+					keys += "AltGr Key"
+				}
+
+				if keyCode < 10000 {
+					if keys != "" {
+						keys += " + "
+					}
+
+					// If the key is held down, this will fire
+					if t.Repeat > 0 {
+						keys += string(keyCode) + " repeating"
+					} else {
+						if t.State == sdl.RELEASED {
+							keys += string(keyCode) + " released"
+						} else if t.State == sdl.PRESSED {
+							keys += string(keyCode) + " pressed"
+						}
+					}
+
+				}
+
+				if keys != "" {
+					fmt.Println(keys)
+				}
+			}
+		}
+
+		sdl.Delay(16)
+	}
+
+	return
+}
+
+func main() {
+	if err := run(); err != nil {
+		os.Exit(1)
+	}
+}