uidriver/mobile: Refactoring

internal/graphicsdriver/opengl/context_mobile.go

@@ -73,7 +73,10 @@ type contextImpl struct {
 	worker mgl.Worker
 }
 
-func (c *context) doWork(chDone <-chan struct{}) error {
+// doWork consumes the queued GL tasks.
+//
+// doWork is called only on gomobile-bind.
+func (c *context) doWork(done <-chan struct{}) error {
 	if c.worker == nil {
 		panic("opengl: worker must be initialized but not")
 	}
@@ -84,7 +87,7 @@ loop:
 		select {
 		case <-workAvailable:
 			c.worker.DoWork()
-		case <-chDone:
+		case <-done:
 			break loop
 		}
 	}

internal/graphicsdriver/opengl/driver_mobile.go

@@ -20,8 +20,8 @@ import (
 	"golang.org/x/mobile/gl"
 )
 
-func (d *Driver) DoWork(chDone <-chan struct{}) error {
+func (d *Driver) DoWork(done <-chan struct{}) error {
-	return d.context.doWork(chDone)
+	return d.context.doWork(done)
 }
 
 func (d *Driver) Init() {

internal/uidriver/mobile/ui.go

@@ -37,9 +37,14 @@ import (
 
 var (
 	glContextCh = make(chan gl.Context)
-	renderCh    = make(chan struct{})
+
-	renderChEnd = make(chan struct{})
+	// renderCh recieves when updating starts.
-	theUI       = &UserInterface{}
+	renderCh = make(chan struct{})
+
+	// renderEndCh receives when updating finishes.
+	renderEndCh = make(chan struct{})
+
+	theUI = &UserInterface{}
 )
 
 func init() {
@@ -62,7 +67,7 @@ func (u *UserInterface) Render(chError <-chan error) error {
 	case err := <-chError:
 		return err
 	case renderCh <- struct{}{}:
-		return opengl.Get().DoWork(renderChEnd)
+		return opengl.Get().DoWork(renderEndCh)
 	case <-time.After(500 * time.Millisecond):
 		// This function must not be blocked. We need to break for timeout.
 		return nil
@@ -127,7 +132,7 @@ func (u *UserInterface) appMain(a app.App) {
 				continue
 			}
 			renderCh <- struct{}{}
-			<-renderChEnd
+			<-renderEndCh
 			a.Publish()
 			a.Send(paint.Event{})
 		case touch.Event:
@@ -253,7 +258,7 @@ render:
 	context.ResumeAudio()
 
 	defer func() {
-		renderChEnd <- struct{}{}
+		renderEndCh <- struct{}{}
 	}()
 
 	if err := context.Update(func() {