apps/gophers: split main into App and UI and add BenchmarkUI

Signed-off-by: Elias Naur <mail@eliasnaur.com>

apps/gophers/main_test.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"image"
+	"testing"
+	"time"
+
+	"gioui.org/ui"
+	"gioui.org/ui/input"
+	"gioui.org/ui/layout"
+)
+
+type queue struct{}
+
+type config struct{}
+
+func BenchmarkUI(b *testing.B) {
+	invalidate := func() {}
+	fetch := func(_ string) {}
+	u := newUI(invalidate, fetch)
+	ops := new(ui.Ops)
+	q := new(queue)
+	c := new(config)
+	cs := layout.RigidConstraints(image.Point{800, 600})
+	for i := 0; i < b.N; i++ {
+		ops.Reset()
+		u.Layout(c, q, ops, cs)
+	}
+}
+
+func (queue) Next(k input.Key) (input.Event, bool) {
+	return nil, false
+}
+
+func (config) Now() time.Time {
+	return time.Now()
+}
+
+func (config) Px(v ui.Value) int {
+	return int(v.V + .5)
+}