From d0fce2a2dbcec0e2e0bfcbae56106c8a9ee61a21 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Tue, 11 Feb 2020 22:14:41 +0900
Subject: [PATCH] mobile/ebitenmobileview: Refactoring

---
 mobile/ebitenmobileview/game.go               | 54 -------------------
 .../ebitenmobileview/{funcs.go => mobile.go}  | 44 +++++++++------
 2 files changed, 29 insertions(+), 69 deletions(-)
 delete mode 100644 mobile/ebitenmobileview/game.go
 rename mobile/ebitenmobileview/{funcs.go => mobile.go} (73%)

diff --git a/mobile/ebitenmobileview/game.go b/mobile/ebitenmobileview/game.go
deleted file mode 100644
index 7bc738e29..000000000
--- a/mobile/ebitenmobileview/game.go
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2019 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build android ios
-
-package ebitenmobileview
-
-import (
-	"sync"
-
-	"github.com/hajimehoshi/ebiten"
-)
-
-var theState state
-
-type state struct {
-	game ebiten.Game
-
-	delayedLayout func()
-
-	errorCh <-chan error
-
-	// m is a mutex required for each function.
-	// For example, on Android, Update can be called from a different thread:
-	// https://developer.android.com/reference/android/opengl/GLSurfaceView.Renderer
-	m sync.Mutex
-}
-
-func SetGame(game ebiten.Game) {
-	theState.m.Lock()
-	defer theState.m.Unlock()
-
-	theState.game = game
-
-	if theState.delayedLayout != nil {
-		theState.delayedLayout()
-		theState.delayedLayout = nil
-	}
-}
-
-func (s *state) isRunning() bool {
-	return s.errorCh != nil
-}
diff --git a/mobile/ebitenmobileview/funcs.go b/mobile/ebitenmobileview/mobile.go
similarity index 73%
rename from mobile/ebitenmobileview/funcs.go
rename to mobile/ebitenmobileview/mobile.go
index f5de1d342..67ac324ac 100644
--- a/mobile/ebitenmobileview/funcs.go
+++ b/mobile/ebitenmobileview/mobile.go
@@ -27,25 +27,42 @@ import "C"
 
 import (
 	"runtime"
+	"sync"
 
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/internal/uidriver/mobile"
 )
 
+var theState state
+
+type state struct {
+	game ebiten.Game
+
+	errorCh <-chan error
+
+	// m is a mutex required for each function.
+	// For example, on Android, Update can be called from a different thread:
+	// https://developer.android.com/reference/android/opengl/GLSurfaceView.Renderer
+	m sync.Mutex
+}
+
+func (s *state) isRunning() bool {
+	return s.game != nil && s.errorCh != nil
+}
+
+func SetGame(game ebiten.Game) {
+	theState.m.Lock()
+	defer theState.m.Unlock()
+
+	if theState.game != nil {
+		panic("ebitenmobileview: SetGame cannot be called twice or more")
+	}
+	theState.game = game
+}
+
 func Layout(viewWidth, viewHeight float64) {
 	theState.m.Lock()
 	defer theState.m.Unlock()
-	layout(viewWidth, viewHeight)
-}
-
-func layout(viewWidth, viewHeight float64) {
-	if theState.game == nil {
-		// It is fine to override the existing function since only the last layout result matters.
-		theState.delayedLayout = func() {
-			layout(viewWidth, viewHeight)
-		}
-		return
-	}
 
 	mobile.Get().SetOutsideSize(viewWidth, viewHeight)
 	if !theState.isRunning() {
@@ -54,16 +71,13 @@ func layout(viewWidth, viewHeight float64) {
 }
 
 func Update() error {
+	// Lock the OS thread since graphics functions (GL) must be called on this thread.
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
 
 	theState.m.Lock()
 	defer theState.m.Unlock()
 
-	return update()
-}
-
-func update() error {
 	if !theState.isRunning() {
 		// start is not called yet, but as update can be called from another thread, it is OK. Just ignore
 		// this.