graphicsdriver/opengl: Use context.Context when possible

internal/graphicsdriver/opengl/context_mobile.go

@@ -17,6 +17,7 @@
 package opengl
 
 import (
+	stdcontext "context"
 	"errors"
 	"fmt"
 
@@ -76,7 +77,7 @@ type contextImpl struct {
 // doWork consumes the queued GL tasks.
 //
 // doWork is called only on gomobile-bind.
-func (c *context) doWork(done <-chan struct{}) error {
+func (c *context) doWork(context stdcontext.Context) {
 	if c.worker == nil {
 		panic("opengl: worker must be initialized but not")
 	}
@@ -87,11 +88,10 @@ loop:
 		select {
 		case <-workAvailable:
 			c.worker.DoWork()
-		case <-done:
+		case <-context.Done():
 			break loop
 		}
 	}
-	return nil
 }
 
 func (c *context) reset() error {

internal/graphicsdriver/opengl/driver_mobile.go

@@ -17,11 +17,13 @@
 package opengl
 
 import (
+	stdcontext "context"
+
 	"golang.org/x/mobile/gl"
 )
 
-func (d *Driver) DoWork(done <-chan struct{}) error {
-	return d.context.doWork(done)
+func (d *Driver) DoWork(context stdcontext.Context) {
+	d.context.doWork(context)
 }
 
 func (d *Driver) Init() {

internal/uidriver/mobile/ui.go

@@ -17,6 +17,7 @@
 package mobile
 
 import (
+	"context"
 	"errors"
 	"image"
 	"runtime"
@@ -71,7 +72,13 @@ func (u *UserInterface) Render(chError <-chan error) error {
 	}
 
 	renderCh <- struct{}{}
-	return opengl.Get().DoWork(renderEndCh)
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		<-renderEndCh
+		cancel()
+	}()
+	opengl.Get().DoWork(ctx)
+	return nil
 }
 
 type UserInterface struct {