Improve pingpong example

The following adjustments were done:

- Use new Qt connect syntax
- Add QLoggingCatergory enablers (easy to enable by uncommenting)
- Makes the UI more robust to High vs Low DPI issues

Change-Id: Iad99a67ac375de828883b4add99d440f7a6994c6
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

4 files changed, 32 insertions, 21 deletions

diff --git a/examples/bluetooth/pingpong/assets/Dialog.qml b/examples/bluetooth/pingpong/assets/Dialog.qml
index 2a332715..53be3eaa 100644
--- a/examples/bluetooth/pingpong/assets/Dialog.qml
+++ b/examples/bluetooth/pingpong/assets/Dialog.qml
@@ -42,7 +42,7 @@ import QtQuick 2.0
 
 Rectangle {
     width: parent.width/2
-    height: 100
+    height: message.implicitHeight*2
     z: 50
     border.width: 2
     border.color: "#363636"
diff --git a/examples/bluetooth/pingpong/assets/Menu.qml b/examples/bluetooth/pingpong/assets/Menu.qml
index b7516262..09eabb36 100644
--- a/examples/bluetooth/pingpong/assets/Menu.qml
+++ b/examples/bluetooth/pingpong/assets/Menu.qml
@@ -47,17 +47,18 @@ Rectangle {
 
     Rectangle {
         width: parent.width
-        height: 70
+        height: headerText.implicitHeight *1.2
         border.width: 1
         border.color: "#363636"
         radius: 5
 
         Text {
+            id: headerText
             horizontalAlignment: Text.AlignHCenter
             verticalAlignment: Text.AlignVCenter
             anchors.fill: parent
             text: "Welcome to PingPong Game \n Please select an option"
-            font.pixelSize: 20
+            font.pointSize: 20
             elide: Text.ElideMiddle
             color: "#363636"
         }
@@ -67,10 +68,11 @@ Rectangle {
         id: startServer
         anchors.centerIn: parent
         width: parent.width/2
-        height: parent.height/5
+        height: startServerText.implicitHeight*5
         color: "#363636"
 
         Text {
+            id: startServerText
             horizontalAlignment: Text.AlignHCenter
             verticalAlignment: Text.AlignVCenter
             anchors.fill: parent
@@ -95,10 +97,11 @@ Rectangle {
         anchors.top: startServer.bottom
         anchors.topMargin: 10
         width: parent.width/2
-        height: parent.height/5
+        height: startClientText.implicitHeight*5
         color: "#363636"
 
         Text {
+            id: startClientText
             horizontalAlignment: Text.AlignHCenter
             verticalAlignment: Text.AlignVCenter
             anchors.fill: parent
diff --git a/examples/bluetooth/pingpong/main.cpp b/examples/bluetooth/pingpong/main.cpp
index d2a84440..b6430248 100644
--- a/examples/bluetooth/pingpong/main.cpp
+++ b/examples/bluetooth/pingpong/main.cpp
@@ -41,10 +41,13 @@
 #include <QQmlContext>
 #include <QGuiApplication>
 #include <QQmlApplicationEngine>
+#include <QLoggingCategory>
 #include "pingpong.h"
 
+
 int main(int argc, char *argv[])
 {
+    //QLoggingCategory::setFilterRules(QStringLiteral("qt.bluetooth* = true"));
     QGuiApplication app(argc, argv);
     PingPong pingPong;
     QQmlApplicationEngine engine;
diff --git a/examples/bluetooth/pingpong/pingpong.cpp b/examples/bluetooth/pingpong/pingpong.cpp
index 58d5ff2f..d893f64c 100644
--- a/examples/bluetooth/pingpong/pingpong.cpp
+++ b/examples/bluetooth/pingpong/pingpong.cpp
@@ -49,7 +49,7 @@ PingPong::PingPong():
     m_showDialog(false), m_role(0), m_proportionX(0), m_proportionY(0), m_serviceFound(false)
 {
     m_timer = new QTimer(this);
-    connect(m_timer, SIGNAL(timeout()), this, SLOT(update()));
+    connect(m_timer, &QTimer::timeout, this, &PingPong::update);
 }
 
 PingPong::~PingPong()
@@ -233,9 +233,10 @@ void PingPong::startServer()
     setMessage(QStringLiteral("Starting the server"));
     //! [Starting the server]
     m_serverInfo = new QBluetoothServer(QBluetoothServiceInfo::RfcommProtocol, this);
-    connect(m_serverInfo, SIGNAL(newConnection()), this, SLOT(clientConnected()));
-    connect(m_serverInfo, SIGNAL(error(QBluetoothServer::Error)),
-            this, SLOT(serverError(QBluetoothServer::Error)));
+    connect(m_serverInfo, &QBluetoothServer::newConnection,
+            this, &PingPong::clientConnected);
+    connect(m_serverInfo, QOverload<QBluetoothServer::Error>::of(&QBluetoothServer::error),
+            this, &PingPong::serverError);
     const QBluetoothUuid uuid(serviceUuid);
 
     m_serverInfo->listen(uuid, QStringLiteral("PingPong server"));
@@ -251,11 +252,12 @@ void PingPong::startClient()
     //! [Searching for the service]
     discoveryAgent = new QBluetoothServiceDiscoveryAgent(QBluetoothAddress());
 
-    connect(discoveryAgent, SIGNAL(serviceDiscovered(QBluetoothServiceInfo)),
-            this, SLOT(addService(QBluetoothServiceInfo)));
-    connect(discoveryAgent, SIGNAL(finished()), this, SLOT(done()));
-    connect(discoveryAgent, SIGNAL(error(QBluetoothServiceDiscoveryAgent::Error)),
-            this, SLOT(serviceScanError(QBluetoothServiceDiscoveryAgent::Error)));
+    connect(discoveryAgent, &QBluetoothServiceDiscoveryAgent::serviceDiscovered,
+            this, &PingPong::addService);
+    connect(discoveryAgent, &QBluetoothServiceDiscoveryAgent::finished,
+            this, &PingPong::done);
+    connect(discoveryAgent, QOverload<QBluetoothServiceDiscoveryAgent::Error>::of(&QBluetoothServiceDiscoveryAgent::error),
+            this, &PingPong::serviceScanError);
 #ifdef Q_OS_ANDROID //see QTBUG-61392
     if (QtAndroid::androidSdkVersion() >= 23)
         discoveryAgent->setUuidFilter(QBluetoothUuid(androidUuid));
@@ -284,10 +286,13 @@ void PingPong::clientConnected()
     if (!socket)
         return;
     socket->setParent(this);
-    connect(socket, SIGNAL(readyRead()), this, SLOT(readSocket()));
-    connect(socket, SIGNAL(disconnected()), this, SLOT(clientDisconnected()));
-    connect(socket, SIGNAL(error(QBluetoothSocket::SocketError)),
-            this, SLOT(socketError(QBluetoothSocket::SocketError)));
+    connect(socket, &QBluetoothSocket::readyRead,
+            this, &PingPong::readSocket);
+    connect(socket, &QBluetoothSocket::disconnected,
+            this, &PingPong::clientDisconnected);
+    connect(socket, QOverload<QBluetoothSocket::SocketError>::of(&QBluetoothSocket::error),
+            this, &PingPong::socketError);
+
     //! [Initiating server socket]
     setMessage(QStringLiteral("Client connected."));
 
@@ -334,9 +339,9 @@ void PingPong::addService(const QBluetoothServiceInfo &service)
     socket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol);
     socket->connectToService(service);
 
-    connect(socket, SIGNAL(readyRead()), this, SLOT(readSocket()));
-    connect(socket, SIGNAL(connected()), this, SLOT(serverConnected()));
-    connect(socket, SIGNAL(disconnected()), this, SLOT(serverDisconnected()));
+    connect(socket, &QBluetoothSocket::readyRead, this, &PingPong::readSocket);
+    connect(socket, &QBluetoothSocket::connected, this, &PingPong::serverConnected);
+    connect(socket, &QBluetoothSocket::disconnected, this, &PingPong::serverDisconnected);
     //! [Connecting the socket]
     m_serviceFound = true;
 }