ui: Use events in the game loop

internal/ui/event.go

@@ -0,0 +1,21 @@
+// Copyright 2016 Hajime Hoshi
+//
+// 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.
+
+package ui
+
+type CloseEvent struct {
+}
+
+type RenderEvent struct {
+}

internal/ui/ui_glfw.go

@@ -196,7 +196,14 @@ func (u *UserInterface) pollEvents() error {
 	return currentInput.update(u.window, u.windowScale())
 }
 
-func (u *UserInterface) Update() error {
+func (u *UserInterface) Update() (interface{}, error) {
+	shouldClose := false
+	u.runOnMainThread(func() {
+		shouldClose = u.window.ShouldClose()
+	})
+	if shouldClose {
+		return CloseEvent{}, nil
+	}
 	var ferr error
 	u.runOnMainThread(func() {
 		if err := u.pollEvents(); err != nil {
@@ -215,7 +222,10 @@ func (u *UserInterface) Update() error {
 			}
 		}
 	})
-	return ferr
+	if ferr != nil {
+		return nil, ferr
+	}
+	return RenderEvent{}, nil
 }
 
 func (u *UserInterface) Terminate() {
@@ -226,14 +236,6 @@ func (u *UserInterface) Terminate() {
 	u.funcs = nil
 }
 
-func (u *UserInterface) IsClosed() bool {
-	r := false
-	u.runOnMainThread(func() {
-		r = u.window.ShouldClose()
-	})
-	return r
-}
-
 func (u *UserInterface) SwapBuffers() {
 	u.runOnMainThread(func() {
 		u.swapBuffers()

internal/ui/ui_js.go

@@ -83,19 +83,15 @@ func vsync() {
 	<-ch
 }
 
-func (u *UserInterface) Update() error {
+func (u *UserInterface) Update() (interface{}, error) {
 	currentInput.UpdateGamepads()
-	return nil
+	return RenderEvent{}, nil
 }
 
 func (u *UserInterface) Terminate() {
 	// Do nothing.
 }
 
-func (u *UserInterface) IsClosed() bool {
-	return false
-}
-
 func (u *UserInterface) SwapBuffers() {
 	vsync()
 	for !shown() {

run.go

@@ -204,16 +204,17 @@ func run(f func(*Image) error, width, height, scale int, title string) error {
 	beforeForUpdate := n
 	beforeForFPS := n
 	for {
-		// TODO: setSize should be called after swapping buffers?
 		if err := currentRunContext.updateScreenSize(graphicsContext); err != nil {
 			return err
 		}
-		if err := ui.CurrentUI().Update(); err != nil {
+		e, err := ui.CurrentUI().Update()
+		if err != nil {
 			return err
 		}
-		if ui.CurrentUI().IsClosed() {
+		switch e.(type) {
+		case ui.CloseEvent:
 			return nil
-		}
+		case ui.RenderEvent:
 			now := ui.Now()
 			// If beforeForUpdate is too old, we assume that screen is not shown.
 			if int64(5*time.Second/FPS) < now-beforeForUpdate {
@@ -245,6 +246,9 @@ func run(f func(*Image) error, width, height, scale int, title string) error {
 				beforeForFPS = now
 				frames = 0
 			}
+		default:
+			panic("not reach")
+		}
 	}
 }