SimpleTextViewer: Revamp the example

Fix const correctness.
Fix code formatting.
Fix error message on crash.
Use initializer lists in c'tors.
Limit the start assistant timeout to 3 seconds, like it's done for
termination.

Change-Id: Idfafa35834fba725b03d80e6252be8ac3eaf489f
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit cbcd71aeac7c092c52de3d55f0f303d1cf4cab65)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

7 files changed, 39 insertions, 56 deletions

diff --git a/examples/assistant/simpletextviewer/assistant.cpp b/examples/assistant/simpletextviewer/assistant.cpp
index 69e9b2d06..5b6b0bba4 100644
--- a/examples/assistant/simpletextviewer/assistant.cpp
+++ b/examples/assistant/simpletextviewer/assistant.cpp
@@ -10,8 +10,6 @@
 #include <QMessageBox>
 #include <QStandardPaths>
 
-Assistant::Assistant() = default;
-
 //! [0]
 Assistant::~Assistant()
 {
@@ -36,7 +34,7 @@ void Assistant::showDocumentation(const QString &page)
 }
 //! [1]
 
-QString documentationDirectory()
+static QString documentationDirectory()
 {
     QStringList paths;
 #ifdef SRCDIR
@@ -50,18 +48,18 @@ QString documentationDirectory()
         if (QFileInfo::exists(path))
             return path;
     }
-    return QString();
+    return {};
 }
 
 //! [2]
 bool Assistant::startAssistant()
 {
     if (m_process.isNull()) {
-        m_process.reset(new QProcess());
+        m_process.reset(new QProcess);
         QObject::connect(m_process.data(), &QProcess::finished,
                          m_process.data(), [this](int exitCode, QProcess::ExitStatus status) {
-                             this->finished(exitCode, status);
-                         });
+            finished(exitCode, status);
+        });
     }
 
     if (m_process->state() != QProcess::Running) {
@@ -78,15 +76,15 @@ bool Assistant::startAssistant()
             return false;
         }
 
-        QStringList args{QLatin1String("-collectionFile"),
-                         collectionDirectory + QLatin1String("/simpletextviewer.qhc"),
-                         QLatin1String("-enableRemoteControl")};
+        const QStringList args{QLatin1String("-collectionFile"),
+                    collectionDirectory + QLatin1String("/simpletextviewer.qhc"),
+                    QLatin1String("-enableRemoteControl")};
 
         m_process->start(app, args);
 
-        if (!m_process->waitForStarted()) {
+        if (!m_process->waitForStarted(3000)) {
             showError(tr("Unable to launch Qt Assistant (%1): %2")
-                              .arg(QDir::toNativeSeparators(app), m_process->errorString()));
+                      .arg(QDir::toNativeSeparators(app), m_process->errorString()));
             return false;
         }
     }
@@ -96,16 +94,14 @@ bool Assistant::startAssistant()
 
 void Assistant::showError(const QString &message)
 {
-    QMessageBox::critical(QApplication::activeWindow(),
-                          tr("Simple Text Viewer"), message);
+    QMessageBox::critical(QApplication::activeWindow(), tr("Simple Text Viewer"), message);
 }
 
 void Assistant::finished(int exitCode, QProcess::ExitStatus status)
 {
     const QString stdErr = QString::fromLocal8Bit(m_process->readAllStandardError());
-    if (status != QProcess::NormalExit) {
-        showError(tr("Assistant crashed: ").arg(stdErr));
-    } else if (exitCode != 0) {
+    if (status != QProcess::NormalExit)
+        showError(tr("Assistant crashed: %1").arg(stdErr));
+    else if (exitCode != 0)
         showError(tr("Assistant exited with %1: %2").arg(exitCode).arg(stdErr));
-    }
 }
diff --git a/examples/assistant/simpletextviewer/assistant.h b/examples/assistant/simpletextviewer/assistant.h
index 9c881f93c..1cbc8b9e2 100644
--- a/examples/assistant/simpletextviewer/assistant.h
+++ b/examples/assistant/simpletextviewer/assistant.h
@@ -9,13 +9,11 @@
 #include <QScopedPointer>
 #include <QString>
 
-
 class Assistant
 {
     Q_DECLARE_TR_FUNCTIONS(Assistant)
 
 public:
-    Assistant();
     ~Assistant();
     void showDocumentation(const QString &file);
 
diff --git a/examples/assistant/simpletextviewer/findfiledialog.cpp b/examples/assistant/simpletextviewer/findfiledialog.cpp
index 78087a3e0..7dccfb074 100644
--- a/examples/assistant/simpletextviewer/findfiledialog.cpp
+++ b/examples/assistant/simpletextviewer/findfiledialog.cpp
@@ -20,9 +20,9 @@
 //! [0]
 FindFileDialog::FindFileDialog(TextEdit *editor, Assistant *assistant)
     : QDialog(editor)
+    , currentEditor(editor)
+    , currentAssistant(assistant)
 {
-    currentAssistant = assistant;
-    currentEditor = editor;
 //! [0]
 
     createButtons();
@@ -42,8 +42,8 @@ FindFileDialog::FindFileDialog(TextEdit *editor, Assistant *assistant)
 
 void FindFileDialog::browse()
 {
-    QString currentDirectory = directoryComboBox->currentText();
-    QString newDirectory = QFileDialog::getExistingDirectory(this,
+    const QString currentDirectory = directoryComboBox->currentText();
+    const QString newDirectory = QFileDialog::getExistingDirectory(this,
                                tr("Select Directory"), currentDirectory);
     if (!newDirectory.isEmpty()) {
         directoryComboBox->addItem(QDir::toNativeSeparators(newDirectory));
@@ -61,12 +61,12 @@ void FindFileDialog::help()
 
 void FindFileDialog::openFile()
 {
-    auto item  = foundFilesTree->currentItem();
+    QTreeWidgetItem *item = foundFilesTree->currentItem();
     if (!item)
         return;
 
-    QString fileName = item->text(0);
-    QString path = QDir(directoryComboBox->currentText()).filePath(fileName);
+    const QString fileName = item->text(0);
+    const QString path = QDir(directoryComboBox->currentText()).filePath(fileName);
 
     currentEditor->setContents(path);
     close();
@@ -75,8 +75,7 @@ void FindFileDialog::openFile()
 void FindFileDialog::update()
 {
     findFiles();
-    buttonBox->button(QDialogButtonBox::Open)->setEnabled(
-            foundFilesTree->topLevelItemCount() > 0);
+    buttonBox->button(QDialogButtonBox::Open)->setEnabled(foundFilesTree->topLevelItemCount() > 0);
 }
 
 void FindFileDialog::findFiles()
@@ -84,9 +83,9 @@ void FindFileDialog::findFiles()
     QString wildCard = fileNameComboBox->currentText();
     if (!wildCard.endsWith('*'))
         wildCard += '*';
-    QRegularExpression filePattern(QRegularExpression::wildcardToRegularExpression(wildCard));
+    const QRegularExpression filePattern(QRegularExpression::wildcardToRegularExpression(wildCard));
 
-    QDir directory(directoryComboBox->currentText());
+    const QDir directory(directoryComboBox->currentText());
 
     const QStringList allFiles = directory.entryList(QDir::Files | QDir::NoSymLinks);
     QStringList matchingFiles;
@@ -102,10 +101,8 @@ void FindFileDialog::showFiles(const QStringList &files)
 {
     foundFilesTree->clear();
 
-    for (int i = 0; i < files.count(); ++i) {
-        QTreeWidgetItem *item = new QTreeWidgetItem(foundFilesTree);
-        item->setText(0, files[i]);
-    }
+    for (const QString &file : files)
+        new QTreeWidgetItem(foundFilesTree, {file});
 
     if (files.count() > 0)
         foundFilesTree->setCurrentItem(foundFilesTree->topLevelItem(0));
@@ -131,19 +128,14 @@ void FindFileDialog::createComboBoxes()
     fileNameComboBox = new QComboBox;
 
     fileNameComboBox->setEditable(true);
-    fileNameComboBox->setSizePolicy(QSizePolicy::Expanding,
-                                    QSizePolicy::Preferred);
+    fileNameComboBox->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
 
     directoryComboBox->setMinimumContentsLength(30);
-    directoryComboBox->setSizeAdjustPolicy(
-            QComboBox::AdjustToContents);
-    directoryComboBox->setSizePolicy(QSizePolicy::Expanding,
-                                     QSizePolicy::Preferred);
-
-    connect(fileNameComboBox, &QComboBox::editTextChanged,
-            this, &FindFileDialog::update);
-    connect(directoryComboBox, &QComboBox::currentTextChanged,
-            this, &FindFileDialog::update);
+    directoryComboBox->setSizeAdjustPolicy(QComboBox::AdjustToContents);
+    directoryComboBox->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
+
+    connect(fileNameComboBox, &QComboBox::editTextChanged, this, &FindFileDialog::update);
+    connect(directoryComboBox, &QComboBox::currentTextChanged, this, &FindFileDialog::update);
 }
 
 void FindFileDialog::createFilesTree()
@@ -154,8 +146,7 @@ void FindFileDialog::createFilesTree()
     foundFilesTree->setRootIsDecorated(false);
     foundFilesTree->setSelectionMode(QAbstractItemView::SingleSelection);
 
-    connect(foundFilesTree, &QTreeWidget::itemActivated,
-            this, &FindFileDialog::openFile);
+    connect(foundFilesTree, &QTreeWidget::itemActivated, this, &FindFileDialog::openFile);
 }
 
 void FindFileDialog::createLabels()
diff --git a/examples/assistant/simpletextviewer/findfiledialog.h b/examples/assistant/simpletextviewer/findfiledialog.h
index 6dcd15d9b..7e77938dd 100644
--- a/examples/assistant/simpletextviewer/findfiledialog.h
+++ b/examples/assistant/simpletextviewer/findfiledialog.h
@@ -12,7 +12,6 @@ class QDialogButtonBox;
 class QLabel;
 class QToolButton;
 class QTreeWidget;
-class QTreeWidgetItem;
 QT_END_NAMESPACE
 
 class Assistant;
@@ -42,8 +41,8 @@ private:
     void createLabels();
     void createLayout();
 
-    Assistant *currentAssistant;
     TextEdit *currentEditor;
+    Assistant *currentAssistant;
     QTreeWidget *foundFilesTree;
 
     QComboBox *directoryComboBox;
diff --git a/examples/assistant/simpletextviewer/mainwindow.cpp b/examples/assistant/simpletextviewer/mainwindow.cpp
index 321e46ddd..3709ae7df 100644
--- a/examples/assistant/simpletextviewer/mainwindow.cpp
+++ b/examples/assistant/simpletextviewer/mainwindow.cpp
@@ -15,10 +15,10 @@
 
 // ![0]
 MainWindow::MainWindow()
+    : textViewer(new TextEdit)
+    , assistant(new Assistant)
 {
-    assistant = new Assistant;
 // ![0]
-    textViewer = new TextEdit;
     textViewer->setContents(QLibraryInfo::path(QLibraryInfo::ExamplesPath)
             + QLatin1String("/assistant/simpletextviewer/documentation/intro.html"));
     setCentralWidget(textViewer);
@@ -103,7 +103,6 @@ void MainWindow::createMenus()
     helpMenu->addAction(aboutAct);
     helpMenu->addAction(aboutQtAct);
 
-
     menuBar()->addMenu(fileMenu);
     menuBar()->addMenu(helpMenu);
 }
diff --git a/examples/assistant/simpletextviewer/mainwindow.h b/examples/assistant/simpletextviewer/mainwindow.h
index 81a5dd10e..59b5472f0 100644
--- a/examples/assistant/simpletextviewer/mainwindow.h
+++ b/examples/assistant/simpletextviewer/mainwindow.h
@@ -33,8 +33,8 @@ private:
     void createActions();
     void createMenus();
 
-    Assistant *assistant;
     TextEdit *textViewer;
+    Assistant *assistant;
 
     QMenu *fileMenu;
     QMenu *helpMenu;
diff --git a/examples/assistant/simpletextviewer/textedit.cpp b/examples/assistant/simpletextviewer/textedit.cpp
index 4a1f7159f..2f52f73a1 100644
--- a/examples/assistant/simpletextviewer/textedit.cpp
+++ b/examples/assistant/simpletextviewer/textedit.cpp
@@ -14,11 +14,11 @@ TextEdit::TextEdit(QWidget *parent)
 
 void TextEdit::setContents(const QString &fileName)
 {
-    QFileInfo fi(fileName);
+    const QFileInfo fi(fileName);
     srcUrl = QUrl::fromLocalFile(fi.absoluteFilePath());
     QFile file(fileName);
     if (file.open(QIODevice::ReadOnly)) {
-        QString data(file.readAll());
+        const QString data(QString::fromUtf8(file.readAll()));
         if (fileName.endsWith(".html"))
             setHtml(data);
         else