chore: vendor clipboard into go package

packages/tui/clipboard/clipboard_ios.go

@@ -0,0 +1,80 @@
+// Copyright 2021 The golang.design Initiative Authors.
+// All rights reserved. Use of this source code is governed
+// by a MIT license that can be found in the LICENSE file.
+//
+// Written by Changkun Ou <changkun.de>
+
+//go:build ios
+
+package clipboard
+
+/*
+#cgo CFLAGS: -x objective-c
+#cgo LDFLAGS: -framework Foundation -framework UIKit -framework MobileCoreServices
+
+#import <stdlib.h>
+void clipboard_write_string(char *s);
+char *clipboard_read_string();
+*/
+import "C"
+import (
+	"bytes"
+	"context"
+	"time"
+	"unsafe"
+)
+
+func initialize() error { return nil }
+
+func read(t Format) (buf []byte, err error) {
+	switch t {
+	case FmtText:
+		return []byte(C.GoString(C.clipboard_read_string())), nil
+	case FmtImage:
+		return nil, errUnsupported
+	default:
+		return nil, errUnsupported
+	}
+}
+
+// SetContent sets the clipboard content for iOS
+func write(t Format, buf []byte) (<-chan struct{}, error) {
+	done := make(chan struct{}, 1)
+	switch t {
+	case FmtText:
+		cs := C.CString(string(buf))
+		defer C.free(unsafe.Pointer(cs))
+
+		C.clipboard_write_string(cs)
+		return done, nil
+	case FmtImage:
+		return nil, errUnsupported
+	default:
+		return nil, errUnsupported
+	}
+}
+
+func watch(ctx context.Context, t Format) <-chan []byte {
+	recv := make(chan []byte, 1)
+	ti := time.NewTicker(time.Second)
+	last := Read(t)
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				close(recv)
+				return
+			case <-ti.C:
+				b := Read(t)
+				if b == nil {
+					continue
+				}
+				if bytes.Compare(last, b) != 0 {
+					recv <- b
+					last = b
+				}
+			}
+		}
+	}()
+	return recv
+}