From 2b477eef5a43d4cb077f2fc0abd9d29457aafc4c Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Mon, 23 May 2016 02:44:28 +0900
Subject: [PATCH] mobile: Introduce EventDispatcher to reduce glue code

---
 examples/mobile/main_mobile.go | 23 ++++-------------------
 mobile/run.go                  | 27 ++++++++++++++++++++-------
 2 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/examples/mobile/main_mobile.go b/examples/mobile/main_mobile.go
index 4f4bf3bd7..acd1d566a 100644
--- a/examples/mobile/main_mobile.go
+++ b/examples/mobile/main_mobile.go
@@ -29,25 +29,10 @@ import (
 	"github.com/hajimehoshi/ebiten/mobile"
 )
 
-func Start() error {
-	mobile.Start(example.Update, example.ScreenWidth, example.ScreenHeight, 2, "Mobile (Ebiten Demo)")
-	return nil
-}
+// EventDispacher must be redeclared and exported so that this is available on the Java/Objective-C side.
 
-func Render() error {
-	return mobile.Render()
-}
+type EventDispatcher mobile.EventDispatcher
 
-// TODO: So many glue codes: Can I reduce those?
-
-func TouchDown(x, y int) {
-	mobile.TouchDown(x, y)
-}
-
-func TouchUp(x, y int) {
-	mobile.TouchUp(x, y)
-}
-
-func TouchMove(x, y int) {
-	mobile.TouchMove(x, y)
+func Start() (EventDispatcher, error) {
+	return mobile.Start(example.Update, example.ScreenWidth, example.ScreenHeight, 2, "Mobile (Ebiten Demo)")
 }
diff --git a/mobile/run.go b/mobile/run.go
index 6141b00b7..8ece510a9 100644
--- a/mobile/run.go
+++ b/mobile/run.go
@@ -26,22 +26,35 @@ import (
 
 var chError <-chan error
 
+type EventDispatcher interface {
+	SetScreenSize(width, height int)
+	SetScreenScale(scale int)
+	Render() error
+	TouchDown(x, y int)
+	TouchUp(x, y int)
+	TouchMove(x, y int)
+}
+
 // Start starts the game and returns immediately.
 //
 // Different from ebiten.Run, this invokes only the game loop and not the main (UI) loop.
-func Start(f func(*ebiten.Image) error, width, height, scale int, title string) {
+func Start(f func(*ebiten.Image) error, width, height, scale int, title string) (EventDispatcher, error) {
 	chError = ebiten.RunWithoutMainLoop(f, width, height, scale, title)
+	return &eventDispatcher{}, nil
 }
 
-func SetScreenSize(width, height int) {
+type eventDispatcher struct {
+}
+
+func (e *eventDispatcher) SetScreenSize(width, height int) {
 	ui.CurrentUI().SetScreenSize(width, height)
 }
 
-func SetScreenScale(scale int) {
+func (e *eventDispatcher) SetScreenScale(scale int) {
 	ui.CurrentUI().SetScreenScale(scale)
 }
 
-func Render() error {
+func (e *eventDispatcher) Render() error {
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
 
@@ -51,14 +64,14 @@ func Render() error {
 	return ui.Render(chError)
 }
 
-func TouchDown(x, y int) {
+func (e *eventDispatcher) TouchDown(x, y int) {
 	ui.TouchDown(x, y)
 }
 
-func TouchUp(x, y int) {
+func (e *eventDispatcher) TouchUp(x, y int) {
 	ui.TouchUp(x, y)
 }
 
-func TouchMove(x, y int) {
+func (e *eventDispatcher) TouchMove(x, y int) {
 	ui.TouchMove(x, y)
 }