Implement system UI Clipboard

Author: pas2k

flutter/flutter.go

@@ -170,6 +170,17 @@ func (flu *EngineOpenGL) EngineSendPlatformMessage(Message PlatformMessage) Resu
 	return (Result)(res)
 }
 
+func (flu *EngineOpenGL) EngineSendPlatformMessageResponse(respondTo *PlatformMessage, respondWith []byte) Result {
+
+	res := C.FlutterEngineSendPlatformMessageResponse(
+		flu.Engine,
+		(*C.FlutterPlatformMessageResponseHandle)(respondTo.ResponseHandle),
+		(*C.uchar)(C.CBytes(respondWith)),
+		C.ulong(len(respondWith)))
+
+	return (Result)(res)
+}
+
 // EngineFlushPendingTasksNow flush tasks on a  message loop not controlled by the Flutter engine.
 // deprecated soon.
 func EngineFlushPendingTasksNow() {

flutter/flutter_proxy.go

@@ -28,6 +28,7 @@ func proxy_on_platform_message(message *C.FlutterPlatformMessage, userPointer un
 
 		FlutterPlatformMessage.Message = messageContent
 		FlutterPlatformMessage.Channel = C.GoString(message.channel)
+		FlutterPlatformMessage.ResponseHandle = (*platformMessageResponseHandle)(message.response_handle)
 		if message.response_handle == nil {
 			fmt.Println("==================== NIL")
 		}

flutter/message.go

@@ -18,6 +18,10 @@ const (
 	TextInputClientSet    = "TextInput.setClient"
 	TextInputClientClear  = "TextInput.clearClient"
 	TextInputSetEditState = "TextInput.setEditingState"
+
+	// platform
+	ClipboardSetData = "Clipboard.setData"
+	ClipboardGetData = "Clipboard.getData"
 )
 
 // Message is the json content of a PlatformMessage
@@ -44,3 +48,7 @@ type ArgsEditingState struct {
 	ComposingBase          int    `json:"composingBase"`
 	ComposingExtent        int    `json:"composingExtent"`
 }
+
+type ArgsClipboardSetData struct {
+	Text string `json:"text"`
+}

gutter.go

@@ -323,6 +323,31 @@ func onPlatformMessage(platMessage flutter.PlatformMessage, window unsafe.Pointe
 		default:
 			// log.Printf("unhandled text input method: %#v\n", platMessage.Message)
 		}
+	} else if platMessage.Channel == flutter.PlatformChannel {
+		switch message.Method {
+		case flutter.ClipboardSetData:
+			newClipboard := flutter.ArgsClipboardSetData{}
+			json.Unmarshal(message.Args, &newClipboard)
+			windows.SetClipboardString(newClipboard.Text)
+		case flutter.ClipboardGetData:
+			requestedMime := ""
+			json.Unmarshal(message.Args, &requestedMime)
+			if requestedMime == "text/plain" {
+				flutterOGL := *(*flutter.EngineOpenGL)(windows.GetUserPointer())
+				clipText, _ := windows.GetClipboardString()
+
+				retBytes, _ := json.Marshal([]struct {
+					Text string `json:"text"`
+				}{{clipText}})
+
+				flutterOGL.EngineSendPlatformMessageResponse(&platMessage, retBytes)
+			} else {
+				// log.Printf("Don't know how to acquire type #v from the clipboard", requestedMime)
+			}
+
+		default:
+			// log.Printf("unhandled platform method: %#v\n", platMessage.Message)
+		}
 	}
 
 	return true