Polish the audiosource example

- Use a QWidget instead of a QMainWindow since no QMainWindow
  functionality is used and the controls are wrongly parented
- Change the update signal of AudioInfo to levelChanged(level),
  removing the need for a lamba
- Streamline the code

Change-Id: Ic03a5414ee5da4841532ad23db112d0594f458e5
Reviewed-by: Doris Verria <doris.verria@qt.io>
(cherry picked from commit a71362d9ef7098c1d7869b3768a0990a61474980)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/examples/multimedia/audiosource/main.cpp b/examples/multimedia/audiosource/main.cpp
index 1f6ae63a6..e45c2bd67 100644
--- a/examples/multimedia/audiosource/main.cpp
+++ b/examples/multimedia/audiosource/main.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
@@ -48,17 +48,17 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets>
-
 #include "audiosource.h"
 
+#include <QtWidgets/QApplication>
+
 int main(int argv, char **args)
 {
     QApplication app(argv, args);
-    app.setApplicationName("Audio Source Test");
+    QCoreApplication::setApplicationName("Audio Source Test");
 
     InputTest input;
     input.show();
 
-    return app.exec();
+    return QCoreApplication::exec();
 }