We now set the target atom properly

backends/x/event.go

@@ -245,7 +245,17 @@ func (window *window) handleSelectionNotify (
 	// Follow:
 	// https://tronche.com/gui/x/icccm/sec-2.html#s-2.4
 	if window.selectionRequest == nil { return }
-	die := func (err error) { window.selectionRequest(nil, err) }
+	die := func (err error) {
+		window.selectionRequest(nil, err)
+		window.selectionRequest = nil
+	}
+
+	// If the property argument is None, the conversion has been refused.
+	// This can mean either that there is no owner for the selection, that
+	// the owner does not support the conversion implied by the target, or
+	// that the server did not have sufficient space to accommodate the
+	// data.
+	if event.Property == 0 { die(nil); return }
 
 	// When using GetProperty to retrieve the value of a selection, the
 	// property argument should be set to the corresponding value in the

backends/x/window.go

@@ -290,7 +290,10 @@ func (window *window) Paste (accept data.Mime, callback func (io.Reader, error))
 	// Follow:
 	// https://tronche.com/gui/x/icccm/sec-2.html#s-2.4
 
-	die := func (err error) { callback(nil, err) }
+	die := func (err error) {
+		window.selectionRequest = nil
+		callback(nil, err)
+	}
 	if window.selectionRequest != nil {
 		// TODO: add the request to a queue and take care of it when the
 		// current selection has completed
@@ -299,8 +302,10 @@ func (window *window) Paste (accept data.Mime, callback func (io.Reader, error))
 
 	selectionName := "CLIPBOARD"
 	propertyName  := "TOMO_SELECTION"
-	// TODO: change based on mime type
-	targetName    := "TEXT"
+	targetName    := accept.String()
+	if accept == data.M("text", "plain") {
+		targetName = "UTF8_STRING"
+	}
 
 	// get atoms
 	selectionAtom, err := xprop.Atm(window.backend.connection, selectionName)

data/data.go

@@ -16,6 +16,16 @@ type Mime struct {
 	Type, Subtype string
 }
 
+// M is shorthand for creating a MIME type.
+func M (ty, subtype string) Mime {
+	return Mime { ty, subtype }
+}
+
+// String returns the string representation of the MIME type.
+func (mime Mime) String () string {
+	return mime.Type + "/" + mime.Subtype
+}
+
 var MimePlain = Mime { "text", "plain" }
 
 var MimeFile = Mime { "text", "uri-list" }

examples/clipboard/main.go

@@ -26,16 +26,24 @@ func run () {
 	pasteButton := basicElements.NewButton("Paste")
 	pasteButton.SetIcon(theme.IconPaste)
 
-	clipboardCallback := func (clipboard io.Reader, err error) {		
+	clipboardCallback := func (clipboard io.Reader, err error) {
 		if err != nil {
 			popups.NewDialog (
 				popups.DialogKindError,
 				window,
 				"Error",
-				"No text data in clipboard:\n" + err.Error())
+				"Cannot get clipboard:\n" + err.Error())
+			return 
+		}
+		
+		if clipboard == nil {
+			popups.NewDialog (
+				popups.DialogKindError,
+				window,
+				"Clipboard Empty",
+				"No text data in clipboard")
 			return 
 		}
-
 
 		text, _ := io.ReadAll(clipboard)
 		tomo.Do (func () {