QtNetwork (examples) - update secure socket client example

This patch contains:

- some cosmetic changes to  make example look more like
  modern C++;
- UI initialization code and SSL signals handling were split
  into separate member-functions;
- useless checks 'if (socket)' were deleted;
- widget's minimum size is now fixed + font size
  in 'CertInfo' dialog increased to make it readable.

Change-Id: I7aadb78896832a989494d280d6da0635045f948c
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

examples/network/securesocketclient/certificateinfo.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
@@ -57,8 +57,8 @@ CertificateInfo::CertificateInfo(QWidget *parent)
     form = new Ui_CertificateInfo;
     form->setupUi(this);
 
-    connect(form->certificationPathView, SIGNAL(currentIndexChanged(int)),
+    connect(form->certificationPathView, QOverload<int>::of(&QComboBox::currentIndexChanged),
-            this, SLOT(updateCertificateInfo(int)));
+            this, &CertificateInfo::updateCertificateInfo);
 }
 
 CertificateInfo::~CertificateInfo()
@@ -68,25 +68,23 @@ CertificateInfo::~CertificateInfo()
 
 void CertificateInfo::setCertificateChain(const QList<QSslCertificate> &chain)
 {
-    this->chain = chain;
+    certificateChain = chain;
 
     form->certificationPathView->clear();
-
+    for (int i = 0; i < certificateChain.size(); ++i) {
-    for (int i = 0; i < chain.size(); ++i) {
+        const QSslCertificate &cert = certificateChain.at(i);
-        const QSslCertificate &cert = chain.at(i);
         form->certificationPathView->addItem(tr("%1%2 (%3)").arg(!i ? QString() : tr("Issued by: "))
                                              .arg(cert.subjectInfo(QSslCertificate::Organization).join(QLatin1Char(' ')))
                                              .arg(cert.subjectInfo(QSslCertificate::CommonName).join(QLatin1Char(' '))));
     }
-
     form->certificationPathView->setCurrentIndex(0);
 }
 
 void CertificateInfo::updateCertificateInfo(int index)
 {
     form->certificateInfoView->clear();
-    if (index >= 0 && index < chain.size()) {
+    if (index >= 0 && index < certificateChain.size()) {
-        const QSslCertificate &cert = chain.at(index);
+        const QSslCertificate &cert = certificateChain.at(index);
         QStringList lines;
         lines << tr("Organization: %1").arg(cert.subjectInfo(QSslCertificate::Organization).join(QLatin1Char(' ')))
               << tr("Subunit: %1").arg(cert.subjectInfo(QSslCertificate::OrganizationalUnitName).join(QLatin1Char(' ')))
@@ -101,9 +99,7 @@ void CertificateInfo::updateCertificateInfo(int index)
               << tr("Issuer Locality: %1").arg(cert.issuerInfo(QSslCertificate::LocalityName).join(QLatin1Char(' ')))
               << tr("Issuer State/Province: %1").arg(cert.issuerInfo(QSslCertificate::StateOrProvinceName).join(QLatin1Char(' ')))
               << tr("Issuer Common Name: %1").arg(cert.issuerInfo(QSslCertificate::CommonName).join(QLatin1Char(' ')));
-        foreach (QString line, lines)
+        for (const auto &line : lines)
             form->certificateInfoView->addItem(line);
-    } else {
-        form->certificateInfoView->clear();
     }
 }

examples/network/securesocketclient/certificateinfo.h

@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
@@ -51,8 +51,9 @@
 #ifndef CERTIFICATEINFO_H
 #define CERTIFICATEINFO_H
 
-#include <QtWidgets/QDialog>
+#include <QDialog>
-#include <QtNetwork/QSslCertificate>
+#include <QList>
+#include <QSslCertificate>
 
 QT_BEGIN_NAMESPACE
 class Ui_CertificateInfo;
@@ -62,7 +63,7 @@ class CertificateInfo : public QDialog
 {
     Q_OBJECT
 public:
-    CertificateInfo(QWidget *parent = 0);
+    explicit CertificateInfo(QWidget *parent = nullptr);
     ~CertificateInfo();
 
     void setCertificateChain(const QList<QSslCertificate> &chain);
@@ -71,8 +72,8 @@ private slots:
     void updateCertificateInfo(int index);
 
 private:
-    Ui_CertificateInfo *form;
+    Ui_CertificateInfo *form = nullptr;
-    QList<QSslCertificate> chain;
+    QList<QSslCertificate> certificateChain;
 };
 
 #endif

examples/network/securesocketclient/certificateinfo.ui

@@ -42,7 +42,7 @@
     <widget class="QListWidget" name="certificateInfoView">
      <property name="font">
       <font>
-       <pointsize>8</pointsize>
+       <pointsize>10</pointsize>
       </font>
      </property>
      <property name="wordWrap">

examples/network/securesocketclient/main.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
@@ -50,6 +50,9 @@
 
 #include <QApplication>
 #include <QMessageBox>
+#include <QtNetwork>
+
+QT_REQUIRE_CONFIG(ssl);
 
 #include "sslclient.h"
 
@@ -61,7 +64,7 @@ int main(int argc, char **argv)
 
     if (!QSslSocket::supportsSsl()) {
         QMessageBox::information(0, "Secure Socket Client",
-                                 "This system does not support OpenSSL.");
+                                 "This system does not support SSL/TLS.");
         return -1;
     }
 

examples/network/securesocketclient/securesocketclient.pro

@@ -1,3 +1,5 @@
+requires(qtHaveModule(network))
+
 HEADERS   += certificateinfo.h \
              sslclient.h
 SOURCES   += certificateinfo.cpp \

examples/network/securesocketclient/sslclient.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
@@ -50,29 +50,17 @@
 
 #include "certificateinfo.h"
 #include "sslclient.h"
+
 #include "ui_sslclient.h"
 #include "ui_sslerrors.h"
 
-#include <QtWidgets/QScrollBar>
+#include <QtCore>
-#include <QtWidgets/QStyle>
-#include <QtWidgets/QToolButton>
-#include <QtWidgets/QMessageBox>
-#include <QtNetwork/QSslCipher>
 
 SslClient::SslClient(QWidget *parent)
-    : QWidget(parent), socket(0), padLock(0), executingDialog(false)
+    : QWidget(parent)
 {
-    form = new Ui_Form;
+    setupUi();
-    form->setupUi(this);
+    setupSecureSocket();
-    form->hostNameEdit->setSelection(0, form->hostNameEdit->text().size());
-    form->sessionOutput->setHtml(tr("&lt;not connected&gt;"));
-
-    connect(form->hostNameEdit, SIGNAL(textChanged(QString)),
-            this, SLOT(updateEnabledState()));
-    connect(form->connectButton, SIGNAL(clicked()),
-            this, SLOT(secureConnect()));
-    connect(form->sendButton, SIGNAL(clicked()),
-            this, SLOT(sendData()));
 }
 
 SslClient::~SslClient()
@@ -82,17 +70,15 @@ SslClient::~SslClient()
 
 void SslClient::updateEnabledState()
 {
-    bool unconnected = !socket || socket->state() == QAbstractSocket::UnconnectedState;
+    const bool unconnected = socket->state() == QAbstractSocket::UnconnectedState;
-
     form->hostNameEdit->setReadOnly(!unconnected);
     form->hostNameEdit->setFocusPolicy(unconnected ? Qt::StrongFocus : Qt::NoFocus);
-
     form->hostNameLabel->setEnabled(unconnected);
     form->portBox->setEnabled(unconnected);
     form->portLabel->setEnabled(unconnected);
     form->connectButton->setEnabled(unconnected && !form->hostNameEdit->text().isEmpty());
 
-    bool connected = socket && socket->state() == QAbstractSocket::ConnectedState;
+    const bool connected = socket->state() == QAbstractSocket::ConnectedState;
     form->sessionOutput->setEnabled(connected);
     form->sessionInput->setEnabled(connected);
     form->sessionInputLabel->setEnabled(connected);
@@ -101,20 +87,6 @@ void SslClient::updateEnabledState()
 
 void SslClient::secureConnect()
 {
-    if (!socket) {
-        socket = new QSslSocket(this);
-        connect(socket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),
-                this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));
-        connect(socket, SIGNAL(encrypted()),
-                this, SLOT(socketEncrypted()));
-        connect(socket, SIGNAL(error(QAbstractSocket::SocketError)),
-                this, SLOT(socketError(QAbstractSocket::SocketError)));
-        connect(socket, SIGNAL(sslErrors(QList<QSslError>)),
-                this, SLOT(sslErrors(QList<QSslError>)));
-        connect(socket, SIGNAL(readyRead()),
-                this, SLOT(socketReadyRead()));
-    }
-
     socket->connectToHostEncrypted(form->hostNameEdit->text(), form->portBox->value());
     updateEnabledState();
 }
@@ -125,20 +97,18 @@ void SslClient::socketStateChanged(QAbstractSocket::SocketState state)
         return;
 
     updateEnabledState();
+
     if (state == QAbstractSocket::UnconnectedState) {
+        form->sessionInput->clear();
         form->hostNameEdit->setPalette(QPalette());
         form->hostNameEdit->setFocus();
         form->cipherLabel->setText(tr("<none>"));
-        if (padLock)
+        padLock->hide();
-            padLock->hide();
     }
 }
 
 void SslClient::socketEncrypted()
 {
-    if (!socket)
-        return;                 // might have disconnected already
-
     form->sessionOutput->clear();
     form->sessionInput->setFocus();
 
@@ -146,36 +116,12 @@ void SslClient::socketEncrypted()
     palette.setColor(QPalette::Base, QColor(255, 255, 192));
     form->hostNameEdit->setPalette(palette);
 
-    QSslCipher ciph = socket->sessionCipher();
+    const QSslCipher cipher = socket->sessionCipher();
-    QString cipher = QString("%1, %2 (%3/%4)").arg(ciph.authenticationMethod())
+    const QString cipherInfo = QString("%1, %2 (%3/%4)").arg(cipher.authenticationMethod())
-                     .arg(ciph.name()).arg(ciph.usedBits()).arg(ciph.supportedBits());;
+                                       .arg(cipher.name()).arg(cipher.usedBits())
-    form->cipherLabel->setText(cipher);
+                                       .arg(cipher.supportedBits());;
-
+    form->cipherLabel->setText(cipherInfo);
-    if (!padLock) {
+    padLock->show();
-        padLock = new QToolButton;
-        padLock->setIcon(QIcon(":/encrypted.png"));
-#ifndef QT_NO_CURSOR
-        padLock->setCursor(Qt::ArrowCursor);
-#endif
-        padLock->setToolTip(tr("Display encryption details."));
-
-        int extent = form->hostNameEdit->height() - 2;
-        padLock->resize(extent, extent);
-        padLock->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Ignored);
-
-        QHBoxLayout *layout = new QHBoxLayout(form->hostNameEdit);
-        layout->setMargin(form->hostNameEdit->style()->pixelMetric(QStyle::PM_DefaultFrameWidth));
-        layout->setSpacing(0);
-        layout->addStretch();
-        layout->addWidget(padLock);
-
-        form->hostNameEdit->setLayout(layout);
-
-        connect(padLock, SIGNAL(clicked()),
-                this, SLOT(displayCertificateInfo()));
-    } else {
-        padLock->show();
-    }
 }
 
 void SslClient::socketReadyRead()
@@ -185,7 +131,7 @@ void SslClient::socketReadyRead()
 
 void SslClient::sendData()
 {
-    QString input = form->sessionInput->text();
+    const QString input = form->sessionInput->text();
     appendString(input + '\n');
     socket->write(input.toUtf8() + "\r\n");
     form->sessionInput->clear();
@@ -193,7 +139,12 @@ void SslClient::sendData()
 
 void SslClient::socketError(QAbstractSocket::SocketError)
 {
+    if (handlingSocketError)
+        return;
+
+    handlingSocketError = true;
     QMessageBox::critical(this, tr("Connection error"), socket->errorString());
+    handlingSocketError = false;
 }
 
 void SslClient::sslErrors(const QList<QSslError> &errors)
@@ -201,10 +152,10 @@ void SslClient::sslErrors(const QList<QSslError> &errors)
     QDialog errorDialog(this);
     Ui_SslErrors ui;
     ui.setupUi(&errorDialog);
-    connect(ui.certificateChainButton, SIGNAL(clicked()),
+    connect(ui.certificateChainButton, &QPushButton::clicked,
-            this, SLOT(displayCertificateInfo()));
+            this, &SslClient::displayCertificateInfo);
 
-    foreach (const QSslError &error, errors)
+    for (const auto &error : errors)
         ui.sslErrorList->addItem(error.errorString());
 
     executingDialog = true;
@@ -219,10 +170,69 @@ void SslClient::sslErrors(const QList<QSslError> &errors)
 
 void SslClient::displayCertificateInfo()
 {
-    CertificateInfo *info = new CertificateInfo(this);
+    CertificateInfo info;
-    info->setCertificateChain(socket->peerCertificateChain());
+    info.setCertificateChain(socket->peerCertificateChain());
-    info->exec();
+    info.exec();
-    info->deleteLater();
+}
+
+void SslClient::setupUi()
+{
+    if (form)
+        return;
+
+    form = new Ui_Form;
+    form->setupUi(this);
+    form->hostNameEdit->setSelection(0, form->hostNameEdit->text().size());
+    form->sessionOutput->setHtml(tr("&lt;not connected&gt;"));
+
+    connect(form->hostNameEdit, SIGNAL(textChanged(QString)),
+            this, SLOT(updateEnabledState()));
+    connect(form->connectButton, SIGNAL(clicked()),
+            this, SLOT(secureConnect()));
+    connect(form->sendButton, SIGNAL(clicked()),
+            this, SLOT(sendData()));
+
+    padLock = new QToolButton;
+    padLock->setIcon(QIcon(":/encrypted.png"));
+    connect(padLock, SIGNAL(clicked()), this, SLOT(displayCertificateInfo()));
+
+#if QT_CONFIG(cursor)
+    padLock->setCursor(Qt::ArrowCursor);
+#endif
+    padLock->setToolTip(tr("Display encryption details."));
+
+    const int extent = form->hostNameEdit->height() - 2;
+    padLock->resize(extent, extent);
+    padLock->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Ignored);
+
+    QHBoxLayout *layout = new QHBoxLayout(form->hostNameEdit);
+    layout->setMargin(form->hostNameEdit->style()->pixelMetric(QStyle::PM_DefaultFrameWidth));
+    layout->setSpacing(0);
+    layout->addStretch();
+    layout->addWidget(padLock);
+
+    form->hostNameEdit->setLayout(layout);
+    padLock->hide();
+}
+
+void SslClient::setupSecureSocket()
+{
+    if (socket)
+        return;
+
+    socket = new QSslSocket(this);
+
+    connect(socket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),
+            this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));
+    connect(socket, SIGNAL(encrypted()),
+            this, SLOT(socketEncrypted()));
+    connect(socket, SIGNAL(error(QAbstractSocket::SocketError)),
+            this, SLOT(socketError(QAbstractSocket::SocketError)));
+    connect(socket, SIGNAL(sslErrors(QList<QSslError>)),
+            this, SLOT(sslErrors(QList<QSslError>)));
+    connect(socket, SIGNAL(readyRead()),
+            this, SLOT(socketReadyRead()));
+
 }
 
 void SslClient::appendString(const QString &line)

examples/network/securesocketclient/sslclient.h

@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
@@ -51,13 +51,13 @@
 #ifndef SSLCLIENT_H
 #define SSLCLIENT_H
 
-#include <QtWidgets/QWidget>
+#include <QtNetwork>
-#include <QtNetwork/QAbstractSocket>
+
-#include <QtNetwork/QSslSocket>
+QT_REQUIRE_CONFIG(ssl);
+
+#include <QtWidgets>
 
 QT_BEGIN_NAMESPACE
-class QSslSocket;
-class QToolButton;
 class Ui_Form;
 QT_END_NAMESPACE
 
@@ -65,7 +65,7 @@ class SslClient : public QWidget
 {
     Q_OBJECT
 public:
-    SslClient(QWidget *parent = 0);
+    explicit SslClient(QWidget *parent = nullptr);
     ~SslClient();
 
 private slots:
@@ -80,12 +80,15 @@ private slots:
     void displayCertificateInfo();
 
 private:
+    void setupUi();
+    void setupSecureSocket();
     void appendString(const QString &line);
 
-    QSslSocket *socket;
+    QSslSocket *socket = nullptr;
-    QToolButton *padLock;
+    QToolButton *padLock = nullptr;
-    Ui_Form *form;
+    Ui_Form *form = nullptr;
-    bool executingDialog;
+    bool handlingSocketError = false;
+    bool executingDialog = false;
 };
 
 #endif

examples/network/securesocketclient/sslclient.ui

@@ -10,6 +10,12 @@
     <height>320</height>
    </rect>
   </property>
+  <property name="minimumSize">
+   <size>
+    <width>343</width>
+    <height>320</height>
+   </size>
+  </property>
   <property name="windowTitle">
    <string>Secure Socket Client</string>
   </property>
@@ -114,8 +120,8 @@
       <string>&lt;!DOCTYPE HTML PUBLIC &quot;-//W3C//DTD HTML 4.0//EN&quot; &quot;http://www.w3.org/TR/REC-html40/strict.dtd&quot;&gt;
 &lt;html&gt;&lt;head&gt;&lt;meta name=&quot;qrichtext&quot; content=&quot;1&quot; /&gt;&lt;style type=&quot;text/css&quot;&gt;
 p, li { white-space: pre-wrap; }
-&lt;/style&gt;&lt;/head&gt;&lt;body style=&quot; font-family:'MS Shell Dlg 2'; font-size:8.25pt; font-weight:400; font-style:normal;&quot;&gt;
+&lt;/style&gt;&lt;/head&gt;&lt;body style=&quot; font-family:'.SF NS Text'; font-size:13pt; font-weight:400; font-style:normal;&quot;&gt;
-&lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-family:'Sans Serif'; font-size:9pt;&quot;&gt;&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+&lt;p style=&quot;-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-family:'Sans Serif'; font-size:9pt;&quot;&gt;&lt;br /&gt;&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
      </property>
     </widget>
    </item>