forward messages only when connected.

Signed-off-by: Akos Kitta <kittaakos@typefox.io>

arduino-ide-extension/src/browser/monitor/monitor-connection.ts

@@ -3,7 +3,7 @@ import { Emitter, Event } from '@theia/core/lib/common/event';
 // import { ConnectionStatusService } from '@theia/core/lib/browser/connection-status-service';
 import { MessageService } from '@theia/core/lib/common/message-service';
 import { FrontendApplicationStateService } from '@theia/core/lib/browser/frontend-application-state';
-import { MonitorService, MonitorConfig, MonitorError, Status } from '../../common/protocol/monitor-service';
+import { MonitorService, MonitorConfig, MonitorError, Status, MonitorReadEvent } from '../../common/protocol/monitor-service';
 import { BoardsServiceClientImpl } from '../boards/boards-service-client-impl';
 import { Port, Board, BoardsService, AttachedSerialBoard, AttachedBoardsChangeEvent } from '../../common/protocol/boards-service';
 import { MonitorServiceClientImpl } from './monitor-service-client-impl';
@@ -44,11 +44,19 @@ export class MonitorConnection {
      */
     protected _autoConnect: boolean = false;
     protected readonly onConnectionChangedEmitter = new Emitter<MonitorConnection.State | undefined>();
-
+    /**
-    readonly onConnectionChanged: Event<MonitorConnection.State | undefined> = this.onConnectionChangedEmitter.event;
+     * This emitter forwards all read events **iff** the connection is established.
+     */
+    protected readonly onReadEmitter = new Emitter<MonitorReadEvent>();
 
     @postConstruct()
     protected init(): void {
+        // Forward the messages from the board **iff** connected.
+        this.monitorServiceClient.onRead(event => {
+            if (this.connected) {
+                this.onReadEmitter.fire(event);
+            }
+        });
         this.monitorServiceClient.onError(async error => {
             let shouldReconnect = false;
             if (this.state) {
@@ -140,9 +148,11 @@ export class MonitorConnection {
                 return disconnectStatus;
             }
         }
+        console.info(`>>> Creating serial monitor connection for ${Board.toString(config.board)} on port ${Port.toString(config.port)}...`);
         const connectStatus = await this.monitorService.connect(config);
         if (Status.isOK(connectStatus)) {
             this.state = { config };
+            console.info(`<<< Serial monitor connection created for ${Board.toString(config.board, { useFqbn: false })} on port ${Port.toString(config.port)}.`);
         }
         this.onConnectionChangedEmitter.fire(this.state);
         return Status.isOK(connectStatus);
@@ -152,7 +162,7 @@ export class MonitorConnection {
         if (!this.state) { // XXX: we user `this.state` instead of `this.connected` to make the type checker happy. 
             return Status.OK;
         }
-        console.log('>>> Disposing existing monitor connection before establishing a new one...');
+        console.log('>>> Disposing existing monitor connection...');
         const status = await this.monitorService.disconnect();
         if (Status.isOK(status)) {
             console.log(`<<< Disposed connection. Was: ${MonitorConnection.State.toString(this.state)}`);
@@ -179,6 +189,14 @@ export class MonitorConnection {
         });
     }
 
+    get onConnectionChanged(): Event<MonitorConnection.State | undefined> {
+        return this.onConnectionChangedEmitter.event;
+    }
+
+    get onRead(): Event<MonitorReadEvent> {
+        return this.onReadEmitter.event;
+    }
+
     protected async handleBoardConfigChange(boardsConfig: BoardsConfig.Config): Promise<void> {
         if (this.autoConnect) {
             if (this.boardsServiceClient.canUploadTo(boardsConfig, { silent: false })) {

arduino-ide-extension/src/browser/monitor/monitor-widget.tsx

@@ -81,7 +81,9 @@ export class MonitorWidget extends ReactWidget {
     }
 
     protected onUpdateRequest(msg: Message): void {
-        if (!this.closing) {
+        // TODO: `this.isAttached`
+        // See: https://github.com/eclipse-theia/theia/issues/6704#issuecomment-562574713
+        if (!this.closing && this.isAttached) {
             super.onUpdateRequest(msg);
         }
     }
@@ -160,7 +162,7 @@ export class MonitorWidget extends ReactWidget {
             <div className='body'>
                 <SerialMonitorOutput
                     monitorModel={this.monitorModel}
-                    monitorServiceClient={this.monitorServiceClient}
+                    monitorConnection={this.monitorConnection}
                     clearConsoleEvent={this.clearOutputEmitter.event} />
             </div>
         </div>;
@@ -251,8 +253,8 @@ export class SerialMonitorSendInput extends React.Component<SerialMonitorSendInp
 
 export namespace SerialMonitorOutput {
     export interface Props {
-        readonly monitorServiceClient: MonitorServiceClientImpl;
         readonly monitorModel: MonitorModel;
+        readonly monitorConnection: MonitorConnection;
         readonly clearConsoleEvent: Event<void>;
     }
     export interface State {
@@ -287,7 +289,7 @@ export class SerialMonitorOutput extends React.Component<SerialMonitorOutput.Pro
         this.scrollToBottom();
         let chunk = '';
         this.toDisposeBeforeUnmount.pushAll([
-            this.props.monitorServiceClient.onRead(({ data }) => {
+            this.props.monitorConnection.onRead(({ data }) => {
                 chunk += data;
                 const eolIndex = chunk.indexOf('\n');
                 if (eolIndex !== -1) {