Polish the btscanner example

- Use Qt 5 connection syntax
- Use a QDialogButtonBox instead of a single button in the service dialog
- Forward-declare the UI classes
- Streamline code

Pick-to: 6.2
Change-Id: I30db78043a8e3a62ea10223252a59b8415296e55
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

6 files changed, 97 insertions, 120 deletions

diff --git a/examples/bluetooth/btscanner/device.cpp b/examples/bluetooth/btscanner/device.cpp
index bf882265..33e29e07 100644
--- a/examples/bluetooth/btscanner/device.cpp
+++ b/examples/bluetooth/btscanner/device.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 QtBluetooth module of the Qt Toolkit.
@@ -50,49 +50,57 @@
 
 #include "device.h"
 #include "service.h"
+#include "ui_device.h"
 
 #include <qbluetoothaddress.h>
 #include <qbluetoothdevicediscoveryagent.h>
 #include <qbluetoothlocaldevice.h>
+
 #include <QMenu>
 #include <QDebug>
 
-DeviceDiscoveryDialog::DeviceDiscoveryDialog(QWidget *parent)
-:   QDialog(parent), localDevice(new QBluetoothLocalDevice),
+static QColor colorForPairing(QBluetoothLocalDevice::Pairing pairing)
+{
+    return pairing == QBluetoothLocalDevice::Paired
+           || pairing == QBluetoothLocalDevice::AuthorizedPaired
+           ? QColor(Qt::green) : QColor(Qt::red);
+}
+
+DeviceDiscoveryDialog::DeviceDiscoveryDialog(QWidget *parent) :
+    QDialog(parent),
+    localDevice(new QBluetoothLocalDevice),
     ui(new Ui_DeviceDiscovery)
 {
     ui->setupUi(this);
 
-    /*
-     * In case of multiple Bluetooth adapters it is possible to set adapter
-     * which will be used. Example code:
-     *
-     * QBluetoothAddress address("XX:XX:XX:XX:XX:XX");
-     * discoveryAgent = new QBluetoothDeviceDiscoveryAgent(address);
-     *
-     **/
+    // In case of multiple Bluetooth adapters it is possible to set the adapter
+    // to be used. Example code:
+    //
+    // QBluetoothAddress address("XX:XX:XX:XX:XX:XX");
+    // discoveryAgent = new QBluetoothDeviceDiscoveryAgent(address);
 
     discoveryAgent = new QBluetoothDeviceDiscoveryAgent();
 
-    connect(ui->scan, SIGNAL(clicked()), this, SLOT(startScan()));
+    connect(ui->scan, &QAbstractButton::clicked, this, &DeviceDiscoveryDialog::startScan);
 
-    connect(discoveryAgent, SIGNAL(deviceDiscovered(QBluetoothDeviceInfo)),
-            this, SLOT(addDevice(QBluetoothDeviceInfo)));
-    connect(discoveryAgent, SIGNAL(finished()), this, SLOT(scanFinished()));
+    connect(discoveryAgent, &QBluetoothDeviceDiscoveryAgent::deviceDiscovered,
+            this, &DeviceDiscoveryDialog::addDevice);
+    connect(discoveryAgent, &QBluetoothDeviceDiscoveryAgent::finished,
+            this, &DeviceDiscoveryDialog::scanFinished);
 
-    connect(ui->list, SIGNAL(itemActivated(QListWidgetItem*)),
-            this, SLOT(itemActivated(QListWidgetItem*)));
+    connect(ui->list, &QListWidget::itemActivated,
+            this, &DeviceDiscoveryDialog::itemActivated);
 
-    connect(localDevice, SIGNAL(hostModeStateChanged(QBluetoothLocalDevice::HostMode)),
-            this, SLOT(hostModeStateChanged(QBluetoothLocalDevice::HostMode)));
+    connect(localDevice, &QBluetoothLocalDevice::hostModeStateChanged,
+            this, &DeviceDiscoveryDialog::hostModeStateChanged);
 
     hostModeStateChanged(localDevice->hostMode());
     // add context menu for devices to be able to pair device
     ui->list->setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(ui->list, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(displayPairingMenu(QPoint)));
-    connect(localDevice, SIGNAL(pairingFinished(QBluetoothAddress,QBluetoothLocalDevice::Pairing))
-        , this, SLOT(pairingDone(QBluetoothAddress,QBluetoothLocalDevice::Pairing)));
-
+    connect(ui->list, &QWidget::customContextMenuRequested,
+            this, &DeviceDiscoveryDialog::displayPairingMenu);
+    connect(localDevice, &QBluetoothLocalDevice::pairingFinished,
+            this, &DeviceDiscoveryDialog::pairingDone);
 }
 
 DeviceDiscoveryDialog::~DeviceDiscoveryDialog()
@@ -102,19 +110,14 @@ DeviceDiscoveryDialog::~DeviceDiscoveryDialog()
 
 void DeviceDiscoveryDialog::addDevice(const QBluetoothDeviceInfo &info)
 {
-    QString label = QString("%1 %2").arg(info.address().toString()).arg(info.name());
-    QList<QListWidgetItem *> items = ui->list->findItems(label, Qt::MatchExactly);
-    if (items.empty()) {
+    const QString label = info.address().toString() + u' ' + info.name();
+    const auto items = ui->list->findItems(label, Qt::MatchExactly);
+    if (items.isEmpty()) {
         QListWidgetItem *item = new QListWidgetItem(label);
         QBluetoothLocalDevice::Pairing pairingStatus = localDevice->pairingStatus(info.address());
-        if (pairingStatus == QBluetoothLocalDevice::Paired || pairingStatus == QBluetoothLocalDevice::AuthorizedPaired )
-            item->setForeground(QColor(Qt::green));
-        else
-            item->setForeground(QColor(Qt::black));
-
+        item->setForeground(colorForPairing(pairingStatus));
         ui->list->addItem(item);
     }
-
 }
 
 void DeviceDiscoveryDialog::startScan()
@@ -130,10 +133,8 @@ void DeviceDiscoveryDialog::scanFinished()
 
 void DeviceDiscoveryDialog::itemActivated(QListWidgetItem *item)
 {
-    QString text = item->text();
-
-    int index = text.indexOf(' ');
-
+    const QString text = item->text();
+    const auto index = text.indexOf(' ');
     if (index == -1)
         return;
 
@@ -162,19 +163,10 @@ void DeviceDiscoveryDialog::on_power_clicked(bool clicked)
 
 void DeviceDiscoveryDialog::hostModeStateChanged(QBluetoothLocalDevice::HostMode mode)
 {
-    if (mode != QBluetoothLocalDevice::HostPoweredOff)
-        ui->power->setChecked(true);
-    else
-       ui->power->setChecked( false);
-
-    if (mode == QBluetoothLocalDevice::HostDiscoverable)
-        ui->discoverable->setChecked(true);
-    else
-        ui->discoverable->setChecked(false);
-
-    bool on = !(mode == QBluetoothLocalDevice::HostPoweredOff);
-
+    ui->power->setChecked(mode != QBluetoothLocalDevice::HostPoweredOff);
+    ui->discoverable->setChecked(mode == QBluetoothLocalDevice::HostDiscoverable);
 
+    const bool on = mode != QBluetoothLocalDevice::HostPoweredOff;
     ui->scan->setEnabled(on);
     ui->discoverable->setEnabled(on);
 }
@@ -189,7 +181,7 @@ void DeviceDiscoveryDialog::displayPairingMenu(const QPoint &pos)
     QListWidgetItem *currentItem = ui->list->currentItem();
 
     QString text = currentItem->text();
-    int index = text.indexOf(' ');
+    const auto index = text.indexOf(' ');
     if (index == -1)
         return;
 
@@ -200,19 +192,11 @@ void DeviceDiscoveryDialog::displayPairingMenu(const QPoint &pos)
         localDevice->requestPairing(address, QBluetoothLocalDevice::Unpaired);
     }
 }
-void DeviceDiscoveryDialog::pairingDone(const QBluetoothAddress &address, QBluetoothLocalDevice::Pairing pairing)
+void DeviceDiscoveryDialog::pairingDone(const QBluetoothAddress &address,
+                                        QBluetoothLocalDevice::Pairing pairing)
 {
-    QList<QListWidgetItem *> items = ui->list->findItems(address.toString(), Qt::MatchContains);
-
-    if (pairing == QBluetoothLocalDevice::Paired || pairing == QBluetoothLocalDevice::AuthorizedPaired ) {
-        for (int var = 0; var < items.count(); ++var) {
-            QListWidgetItem *item = items.at(var);
-            item->setForeground(QColor(Qt::green));
-        }
-    } else {
-        for (int var = 0; var < items.count(); ++var) {
-            QListWidgetItem *item = items.at(var);
-            item->setForeground(QColor(Qt::red));
-        }
-    }
+    const auto items = ui->list->findItems(address.toString(), Qt::MatchContains);
+    const QColor color = colorForPairing(pairing);
+    for (auto *item : items)
+        item->setForeground(color);
 }
diff --git a/examples/bluetooth/btscanner/device.h b/examples/bluetooth/btscanner/device.h
index 15082141..0bad0361 100644
--- a/examples/bluetooth/btscanner/device.h
+++ b/examples/bluetooth/btscanner/device.h
@@ -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 QtBluetooth module of the Qt Toolkit.
@@ -51,14 +51,15 @@
 #ifndef DEVICE_H
 #define DEVICE_H
 
-#include "ui_device.h"
-
 #include <qbluetoothlocaldevice.h>
 
 #include <QDialog>
 
 QT_FORWARD_DECLARE_CLASS(QBluetoothDeviceDiscoveryAgent)
 QT_FORWARD_DECLARE_CLASS(QBluetoothDeviceInfo)
+QT_FORWARD_DECLARE_CLASS(QListWidgetItem)
+
+QT_FORWARD_DECLARE_CLASS(Ui_DeviceDiscovery)
 
 QT_USE_NAMESPACE
 
diff --git a/examples/bluetooth/btscanner/main.cpp b/examples/bluetooth/btscanner/main.cpp
index 156f02ad..4752a11d 100644
--- a/examples/bluetooth/btscanner/main.cpp
+++ b/examples/bluetooth/btscanner/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 QtBluetooth module of the Qt Toolkit.
@@ -59,11 +59,7 @@ int main(int argc, char *argv[])
     QApplication app(argc, argv);
 
     DeviceDiscoveryDialog d;
-    QObject::connect(&d, SIGNAL(accepted()), &app, SLOT(quit()));
-    d.show();
-
-    app.exec();
-
+    d.exec();
     return 0;
 }
 
diff --git a/examples/bluetooth/btscanner/service.cpp b/examples/bluetooth/btscanner/service.cpp
index 12e8bd2b..51cb19a1 100644
--- a/examples/bluetooth/btscanner/service.cpp
+++ b/examples/bluetooth/btscanner/service.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Copyright (C) 2013 BlackBerry Limited. All rights reserved.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -50,6 +50,7 @@
 ****************************************************************************/
 
 #include "service.h"
+#include "ui_service.h"
 
 #include <qbluetoothaddress.h>
 #include <qbluetoothservicediscoveryagent.h>
@@ -68,14 +69,12 @@ ServiceDiscoveryDialog::ServiceDiscoveryDialog(const QString &name,
     QBluetoothLocalDevice localDevice;
     QBluetoothAddress adapterAddress = localDevice.address();
 
-    /*
-     * In case of multiple Bluetooth adapters it is possible to
-     * set which adapter will be used by providing MAC Address.
-     * Example code:
-     *
-     * QBluetoothAddress adapterAddress("XX:XX:XX:XX:XX:XX");
-     * discoveryAgent = new QBluetoothServiceDiscoveryAgent(adapterAddress);
-     */
+    // In case of multiple Bluetooth adapters it is possible to
+    // set which adapter will be used by providing MAC Address.
+    // Example code:
+    //
+    // QBluetoothAddress adapterAddress("XX:XX:XX:XX:XX:XX");
+    // discoveryAgent = new QBluetoothServiceDiscoveryAgent(adapterAddress);
 
     discoveryAgent = new QBluetoothServiceDiscoveryAgent(adapterAddress);
 
@@ -83,9 +82,10 @@ ServiceDiscoveryDialog::ServiceDiscoveryDialog(const QString &name,
 
     setWindowTitle(name);
 
-    connect(discoveryAgent, SIGNAL(serviceDiscovered(QBluetoothServiceInfo)),
-            this, SLOT(addService(QBluetoothServiceInfo)));
-    connect(discoveryAgent, SIGNAL(finished()), ui->status, SLOT(hide()));
+    connect(discoveryAgent, &QBluetoothServiceDiscoveryAgent::serviceDiscovered,
+            this, &ServiceDiscoveryDialog::addService);
+    connect(discoveryAgent, &QBluetoothServiceDiscoveryAgent::finished,
+            ui->status, &QWidget::hide);
 
     discoveryAgent->start();
 }
diff --git a/examples/bluetooth/btscanner/service.h b/examples/bluetooth/btscanner/service.h
index 93d1e12b..1c6a7867 100644
--- a/examples/bluetooth/btscanner/service.h
+++ b/examples/bluetooth/btscanner/service.h
@@ -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 QtBluetooth module of the Qt Toolkit.
@@ -51,7 +51,6 @@
 #ifndef SERVICE_H
 #define SERVICE_H
 
-#include "ui_service.h"
 
 #include <QDialog>
 
@@ -59,6 +58,8 @@ QT_FORWARD_DECLARE_CLASS(QBluetoothAddress)
 QT_FORWARD_DECLARE_CLASS(QBluetoothServiceInfo)
 QT_FORWARD_DECLARE_CLASS(QBluetoothServiceDiscoveryAgent)
 
+QT_FORWARD_DECLARE_CLASS(Ui_ServiceDiscovery)
+
 QT_USE_NAMESPACE
 
 class ServiceDiscoveryDialog : public QDialog
diff --git a/examples/bluetooth/btscanner/service.ui b/examples/bluetooth/btscanner/service.ui
index 68ebc5dc..4ca12ee0 100644
--- a/examples/bluetooth/btscanner/service.ui
+++ b/examples/bluetooth/btscanner/service.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>400</width>
-    <height>300</height>
+    <width>539</width>
+    <height>486</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -25,50 +25,45 @@
     </widget>
    </item>
    <item>
-    <layout class="QHBoxLayout" name="horizontalLayout">
-     <item>
-      <spacer name="horizontalSpacer">
-       <property name="orientation">
-        <enum>Qt::Horizontal</enum>
-       </property>
-       <property name="sizeHint" stdset="0">
-        <size>
-         <width>40</width>
-         <height>20</height>
-        </size>
-       </property>
-      </spacer>
-     </item>
-     <item>
-      <widget class="QPushButton" name="close">
-       <property name="text">
-        <string>Close</string>
-       </property>
-      </widget>
-     </item>
-    </layout>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Close</set>
+     </property>
+    </widget>
    </item>
   </layout>
  </widget>
- <tabstops>
-  <tabstop>list</tabstop>
-  <tabstop>close</tabstop>
- </tabstops>
  <resources/>
  <connections>
   <connection>
-   <sender>close</sender>
-   <signal>clicked()</signal>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
    <receiver>ServiceDiscovery</receiver>
    <slot>accept()</slot>
    <hints>
     <hint type="sourcelabel">
-     <x>350</x>
-     <y>277</y>
+     <x>396</x>
+     <y>457</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>535</x>
+     <y>443</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>ServiceDiscovery</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>339</x>
+     <y>464</y>
     </hint>
     <hint type="destinationlabel">
-     <x>237</x>
-     <y>269</y>
+     <x>535</x>
+     <y>368</y>
     </hint>
    </hints>
   </connection>