Add vendor

Specifically because I want to modify a dependency

vendor/golang.org/x/mobile/app/shiny.go

@@ -0,0 +1,83 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+package app
+
+import (
+	"log"
+
+	"golang.org/x/exp/shiny/driver/gldriver"
+	"golang.org/x/exp/shiny/screen"
+	"golang.org/x/mobile/event/lifecycle"
+	"golang.org/x/mobile/event/mouse"
+	"golang.org/x/mobile/event/touch"
+	"golang.org/x/mobile/gl"
+)
+
+func main(f func(a App)) {
+	gldriver.Main(func(s screen.Screen) {
+		w, err := s.NewWindow(nil)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer w.Release()
+
+		theApp.glctx = nil
+		theApp.worker = nil // handled by shiny
+
+		go func() {
+			for range theApp.publish {
+				res := w.Publish()
+				theApp.publishResult <- PublishResult{
+					BackBufferPreserved: res.BackBufferPreserved,
+				}
+			}
+		}()
+
+		donec := make(chan struct{})
+		go func() {
+			// close the donec channel in a defer statement
+			// so that we could still be able to return even
+			// if f panics.
+			defer close(donec)
+
+			f(theApp)
+		}()
+
+		for {
+			select {
+			case <-donec:
+				return
+			default:
+				theApp.Send(convertEvent(w.NextEvent()))
+			}
+		}
+	})
+}
+
+func convertEvent(e interface{}) interface{} {
+	switch e := e.(type) {
+	case lifecycle.Event:
+		if theApp.glctx == nil {
+			theApp.glctx = e.DrawContext.(gl.Context)
+		}
+	case mouse.Event:
+		te := touch.Event{
+			X: e.X,
+			Y: e.Y,
+		}
+		switch e.Direction {
+		case mouse.DirNone:
+			te.Type = touch.TypeMove
+		case mouse.DirPress:
+			te.Type = touch.TypeBegin
+		case mouse.DirRelease:
+			te.Type = touch.TypeEnd
+		}
+		return te
+	}
+	return e
+}