TraceServer: Show error messages beside logging it

While still logging errors to the console, also show them to the user as
actual messages, for explicit UX purposes.

Such error messages show as sticky, thus each has to be closed by the
user. These messages are likely more useful when [1] below isn't
installed alongside this extension. Meaning, when [1]'s provided server
status bar item isn't present to show similar statuses.

[1] https://github.com/eclipse-cdt-cloud/vscode-trace-extension

Contributes to fixing #8.

Signed-off-by: Marco Miller <marco.miller@ericsson.com>

Author: marco-miller

src/trace-server.ts

@@ -22,7 +22,7 @@ export class TraceServer {
         const server = spawn(this.getPath(from), this.getArgs(from));
 
         if (!server.pid) {
-            console.error(prefix + ' startup' + suffix);
+            this.showError(prefix + ' startup' + suffix);
             return;
         }
         this.server = server;
@@ -56,9 +56,9 @@ export class TraceServer {
                     const message = prefix + ' stopping' + suffix;
                     treeKill(pid, error => {
                         if (error) {
-                            console.error(message);
+                            this.showError(message);
                         } else {
-                            id = setTimeout(() => console.error(message), millis);
+                            id = setTimeout(() => this.showError(message), millis);
                         }
                     });
                 }
@@ -140,7 +140,7 @@ export class TraceServer {
                         break;
                     }
                     if (timeout) {
-                        console.error(prefix + ' startup timed-out after ' + millis + 'ms.');
+                        this.showError(prefix + ' startup timed-out after ' + millis + 'ms.');
                         this.stopOrReset(context);
                         break;
                     }
@@ -149,6 +149,11 @@ export class TraceServer {
         );
     }
 
+    private showError(message: string) {
+        console.error(message);
+        vscode.window.showErrorMessage(message);
+    }
+
     private showStatus(started: boolean) {
         if (started) {
             vscode.window.showInformationMessage(prefix + ': Started.');