implement requested changes

app/os_macos.go

@@ -10,9 +10,9 @@ import (
 	"image"
 	"io"
 	"mime"
+	"os"
 	"path/filepath"
 	"runtime"
-	"strings"
 	"time"
 	"unicode"
 	"unicode/utf8"
@@ -572,8 +572,8 @@ func gio_onExternalDrop(view C.CFTypeRef, path *C.char) {
 
 	w.w.Event(transfer.DataEvent{
 		Type: mime,
-		Open: func() io.ReadCloser {
-			return io.NopCloser(strings.NewReader(fileUrl))
+		Open: func() (io.ReadCloser, error) {
+			return os.Open(fileUrl)
 		},
 	})
 }

io/router/pointer.go

@@ -858,9 +858,9 @@ func (q *pointerQueue) deliverTransferDataEvent(p *pointerInfo, events *handlerE
 	transferIdx := len(q.transfers)
 	events.Add(p.dataTarget, transfer.DataEvent{
 		Type: src.offeredMime,
-		Open: func() io.ReadCloser {
+		Open: func() (io.ReadCloser, error) {
 			q.transfers[transferIdx] = nil
-			return src.data
+			return src.data, nil
 		},
 	})
 	q.transfers = append(q.transfers, src.data)

io/router/router.go

@@ -183,10 +183,15 @@ func (q *Router) Queue(events ...event.Event) bool {
 		case clipboard.Event:
 			q.cqueue.Push(e, &q.handlers)
 		case transfer.DataEvent:
-			for tag, handler := range q.pointer.queue.handlers {
-				for _, mimeType := range (*handler).targetMimes {
-					if mimeType == e.Type {
-						q.handlers.Add(tag, e)
+			pq := &q.pointer.queue
+			for _, h := range pq.hitTree {
+				if h.tag != nil {
+					targetMimes := pq.handlers[h.tag].targetMimes
+					for _, mimeType := range targetMimes {
+						if mimeType == e.Type {
+							q.handlers.Add(h.tag, e)
+							break
+						}
 					}
 				}
 			}

io/transfer/transfer.go

@@ -103,7 +103,7 @@ type DataEvent struct {
 	Type string
 	// Open returns the transfer data. It is only valid to call Open in the frame
 	// the DataEvent is received. The caller must close the return value after use.
-	Open func() io.ReadCloser
+	Open func() (io.ReadCloser, error)
 }
 
 func (DataEvent) ImplementsEvent() {}