Support for meta and hyper keys added

Support for the compose key has also been added but it's just the
button code for now, no support for actually composing stuff.
There are plans for that in a fixme.

backend.go

@@ -17,7 +17,7 @@ type Backend interface {
 	// Whatever the application draws from within this event handler must be
 	// the first thing that appears on-screen.
 	//
-	// The OnResize evnt handler must run whenever the window is resized.
+	// The OnResize event handler must run whenever the window is resized.
 	// The backend must push updates to the screen after OnResize has been
 	// run.
 	//
@@ -45,8 +45,8 @@ type Backend interface {
 	Draw ()
 }
 
-// BackendFactory should completely initialize a backend, and return it. If
-// anything goes wrong, it should stop, clean up any resources and return an
+// BackendFactory must completely initialize a backend, and return it. If
+// anything goes wrong, it must stop, clean up any resources and return an
 // error so another backend can be chosen.
 type BackendFactory func (
 	application *Application,

backends/x/unicode.go

@@ -1,5 +1,6 @@
 package x
 
+import "fmt"
 import "unicode"
 import "github.com/jezek/xgb/xproto"
 import "github.com/jezek/xgbutil/keybind"
@@ -36,10 +37,15 @@ var buttonCodeTable = map[xproto.Keysym] stone.Button {
 	0xFFE2: stone.KeyRightShift,
 	0xFFE3: stone.KeyLeftControl,
 	0xFFE4: stone.KeyRightControl,
+
+	0xFFE7: stone.KeyLeftMeta,
+	0xFFE8: stone.KeyRightMeta,
 	0xFFE9: stone.KeyLeftAlt,
 	0xFFEA: stone.KeyRightAlt,
 	0xFFEB: stone.KeyLeftSuper,
 	0xFFEC: stone.KeyRightSuper,
+	0xFFED: stone.KeyLeftHyper,
+	0xFFEE: stone.KeyRightHyper,
 	
 	0xFFFF: stone.KeyDelete,
 	
@@ -55,6 +61,14 @@ var buttonCodeTable = map[xproto.Keysym] stone.Button {
 	0xFFC7: stone.KeyF10,
 	0xFFC8: stone.KeyF11,
 	0xFFC9: stone.KeyF12,
+
+	// TODO: send this whenever a compose key, dead key, etc is pressed,
+	// and then send the resulting character while witholding the key
+	// presses that were used to compose it. As far as the program is
+	// concerned, a magical key with the final character was pressed and the
+	// KeyDead key is just so that the program might provide some visual
+	// feedback to the user while input is being waited for.
+	0xFF20: stone.KeyDead,
 }
 
 func (backend *Backend) keycodeToButton (
@@ -84,7 +98,7 @@ func (backend *Backend) keycodeToButton (
 		symbol3 = symbol1
 	case symbol3 == 0 && symbol4 == 0:
 		symbol3 = symbol1
-		symbol2 = symbol2
+		symbol4 = symbol2
 	case symbol4 == 0:
 		symbol4 = 0
 	}
@@ -124,6 +138,8 @@ func (backend *Backend) keycodeToButton (
 	var selectedKeysym xproto.Keysym
 	var selectedRune   rune
 
+	fmt.Printf("AAA\t%X\t%X\t%X\t%X\n", symbol1, symbol2, symbol3, symbol4)
+	
 	// big ol list in the middle
 	switch {
 	// FIXME: take into account numlock

examples/printbuttons/main.go

@@ -0,0 +1,41 @@
+package main
+
+import "os"
+import "image"
+import _ "image/png"
+import "git.tebibyte.media/sashakoshka/stone"
+import _ "git.tebibyte.media/sashakoshka/stone/backends/x"
+
+var application = &stone.Application { }
+
+func main () {
+	application.SetTitle("press any key")
+	application.SetSize(8, 1)
+
+	iconFile16, err := os.Open("assets/scaffold16.png")
+	if err != nil { panic(err) }
+	icon16, _, err := image.Decode(iconFile16)
+	if err != nil { panic(err) }
+	iconFile16.Close()
+	iconFile32, err := os.Open("assets/scaffold32.png")
+	if err != nil { panic(err) }
+	icon32, _, err := image.Decode(iconFile32)
+	if err != nil { panic(err) }
+	iconFile16.Close()
+	
+	application.SetIcon([]image.Image { icon16, icon32 })
+	
+	application.OnPress(onPress)
+	application.OnRelease(onRelease)
+	
+	err = application.Run()
+	if err != nil { panic(err) }
+}
+
+func onPress (button stone.Button) {
+	println("press", button)
+}
+
+func onRelease (button stone.Button) {
+	println("release", button)
+}

input.go

@@ -33,10 +33,14 @@ const (
 	KeyRightShift   Button = 21
 	KeyLeftControl  Button = 22
 	KeyRightControl Button = 23
-	KeyLeftAlt      Button = 24
-	KeyRightAlt     Button = 25	
-	KeyLeftSuper    Button = 26
-	KeyRightSuper   Button = 27
+	KeyLeftMeta     Button = 24
+	KeyRightMeta    Button = 25
+	KeyLeftAlt      Button = 26
+	KeyRightAlt     Button = 27	
+	KeyLeftSuper    Button = 28
+	KeyRightSuper   Button = 29
+	KeyLeftHyper    Button = 30
+	KeyRightHyper   Button = 31
 	
 	KeyDelete       Button = 127
 	
@@ -67,6 +71,8 @@ const (
 	KeyF10 Button = 153
 	KeyF11 Button = 154
 	KeyF12 Button = 155
+	
+	KeyDead Button = 156
 )
 
 // Printable returns whether or not the character could show up on screen. If