app,io/key: introduce keys for directional navigation

This change adds key.NameUp/Down/Left/Right and maps the Android TV
remote directional keys to them. As a side-effect a key.InputOp can
now receive directional keys (and block their focus movement).

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/os_android.go

@@ -867,8 +867,6 @@ func (w *window) draw(env *C.JNIEnv, sync bool) {
 	}
 }
 
-type keyMapper func(devId, keyCode C.int32_t) rune
-
 func runInJVM(jvm *C.JavaVM, f func(env *C.JNIEnv)) {
 	if jvm == nil {
 		panic("nil JVM")
@@ -908,6 +906,14 @@ func convertKeyCode(code C.jint) (string, bool) {
 		n = key.NameAlt
 	case C.AKEYCODE_META_LEFT, C.AKEYCODE_META_RIGHT:
 		n = key.NameSuper
+	case C.AKEYCODE_DPAD_UP:
+		n = key.NameUp
+	case C.AKEYCODE_DPAD_DOWN:
+		n = key.NameDown
+	case C.AKEYCODE_DPAD_LEFT:
+		n = key.NameLeft
+	case C.AKEYCODE_DPAD_RIGHT:
+		n = key.NameRight
 	default:
 		return "", false
 	}
@@ -917,19 +923,9 @@ func convertKeyCode(code C.jint) (string, bool) {
 //export Java_org_gioui_GioView_onKeyEvent
 func Java_org_gioui_GioView_onKeyEvent(env *C.JNIEnv, class C.jclass, handle C.jlong, keyCode, r C.jint, pressed C.jboolean, t C.jlong) {
 	w := cgo.Handle(handle).Value().(*window)
-	if pressed == C.JNI_TRUE {
-		switch keyCode {
-		case C.AKEYCODE_DPAD_UP:
-			w.callbacks.MoveFocus(router.FocusUp)
-		case C.AKEYCODE_DPAD_DOWN:
-			w.callbacks.MoveFocus(router.FocusDown)
-		case C.AKEYCODE_DPAD_LEFT:
-			w.callbacks.MoveFocus(router.FocusLeft)
-		case C.AKEYCODE_DPAD_RIGHT:
-			w.callbacks.MoveFocus(router.FocusRight)
-		case C.AKEYCODE_DPAD_CENTER:
-			w.callbacks.ClickFocus()
-		}
+	if pressed == C.JNI_TRUE && keyCode == C.AKEYCODE_DPAD_CENTER {
+		w.callbacks.ClickFocus()
+		return
 	}
 	if n, ok := convertKeyCode(keyCode); ok {
 		state := key.Release

app/window.go

@@ -506,10 +506,6 @@ func (c *callbacks) SetEditorSnippet(r key.Range) {
 	c.Event(key.SnippetEvent(r))
 }
 
-func (c *callbacks) MoveFocus(dir router.FocusDirection) {
-	c.w.moveFocus(dir, c.d)
-}
-
 func (w *Window) moveFocus(dir router.FocusDirection, d driver) {
 	if w.queue.q.MoveFocus(dir) {
 		w.queue.q.RevealFocus(w.viewport)
@@ -851,6 +847,14 @@ func (w *Window) processEvent(d driver, e event.Event) {
 				w.moveFocus(router.FocusForward, d)
 			case e.Name == key.NameTab && e.Modifiers == key.ModShift:
 				w.moveFocus(router.FocusBackward, d)
+			case e.Name == key.NameUp && e.Modifiers == 0:
+				w.moveFocus(router.FocusUp, d)
+			case e.Name == key.NameDown && e.Modifiers == 0:
+				w.moveFocus(router.FocusDown, d)
+			case e.Name == key.NameLeft && e.Modifiers == 0:
+				w.moveFocus(router.FocusLeft, d)
+			case e.Name == key.NameRight && e.Modifiers == 0:
+				w.moveFocus(router.FocusRight, d)
 			}
 		}
 		w.updateCursor(d)

io/key/key.go

@@ -219,6 +219,10 @@ const (
 	NameF10            = "F10"
 	NameF11            = "F11"
 	NameF12            = "F12"
+	NameUp             = "Up"
+	NameDown           = "Down"
+	NameLeft           = "Left"
+	NameRight          = "Right"
 )
 
 // Contain reports whether m contains all modifiers