Polish the codecs example

- Port to Qt 5 connection syntax.
- Remove unneeded member variables.
- Adapt to screen size.
- Add a tab widget with a hex dump view to the preview dialog.
- Handle conversion errors in preview dialog,
  add status label displaying errors and warnings about failures
  and invalid characters encountered.
- Fix translated messages.

Change-Id: I916100c903e73d0d2326523753ed7398b1c34df0
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>

examples/widgets/tools/codecs/mainwindow.cpp

@@ -45,8 +45,8 @@
 
 MainWindow::MainWindow()
 {
-    textEdit = new QTextEdit;
+    textEdit = new QPlainTextEdit;
-    textEdit->setLineWrapMode(QTextEdit::NoWrap);
+    textEdit->setLineWrapMode(QPlainTextEdit::NoWrap);
     setCentralWidget(textEdit);
 
     findCodecs();
@@ -54,55 +54,58 @@ MainWindow::MainWindow()
     previewForm = new PreviewForm(this);
     previewForm->setCodecList(codecs);
 
-    createActions();
     createMenus();
 
     setWindowTitle(tr("Codecs"));
-    resize(500, 400);
+
+    const QRect screenGeometry = QApplication::desktop()->screenGeometry(this);
+    resize(screenGeometry.width() / 2, screenGeometry.height() * 2 / 3);
 }
 
 void MainWindow::open()
 {
-    QString fileName = QFileDialog::getOpenFileName(this);
+    const QString fileName = QFileDialog::getOpenFileName(this);
-    if (!fileName.isEmpty()) {
+    if (fileName.isEmpty())
+        return;
     QFile file(fileName);
     if (!file.open(QFile::ReadOnly)) {
         QMessageBox::warning(this, tr("Codecs"),
                              tr("Cannot read file %1:\n%2")
-                                 .arg(fileName)
+                             .arg(QDir::toNativeSeparators(fileName),
-                                 .arg(file.errorString()));
+                                  file.errorString()));
         return;
     }
 
-        QByteArray data = file.readAll();
+    const QByteArray data = file.readAll();
 
+    previewForm->setWindowTitle(tr("Choose Encoding for %1").arg(QFileInfo(fileName).fileName()));
     previewForm->setEncodedData(data);
     if (previewForm->exec())
         textEdit->setPlainText(previewForm->decodedString());
 }
-}
 
 void MainWindow::save()
 {
-    QString fileName = QFileDialog::getSaveFileName(this);
+    const QAction *action = qobject_cast<const QAction *>(sender());
-    if (!fileName.isEmpty()) {
+    const QByteArray codecName = action->data().toByteArray();
+    const QString title = tr("Save As (%1)").arg(QLatin1String(codecName));
+
+    QString fileName = QFileDialog::getSaveFileName(this, title);
+    if (fileName.isEmpty())
+        return;
     QFile file(fileName);
     if (!file.open(QFile::WriteOnly | QFile::Text)) {
         QMessageBox::warning(this, tr("Codecs"),
                              tr("Cannot write file %1:\n%2")
-                                 .arg(fileName)
+                             .arg(QDir::toNativeSeparators(fileName),
-                                 .arg(file.errorString()));
+                                  file.errorString()));
         return;
     }
 
-        QAction *action = qobject_cast<QAction *>(sender());
-        QByteArray codecName = action->data().toByteArray();
-
     QTextStream out(&file);
     out.setCodec(codecName.constData());
     out << textEdit->toPlainText();
 }
-}
 
 void MainWindow::about()
 {
@@ -133,9 +136,9 @@ void MainWindow::findCodecs()
         QString sortKey = codec->name().toUpper();
         int rank;
 
-        if (sortKey.startsWith("UTF-8")) {
+        if (sortKey.startsWith(QLatin1String("UTF-8"))) {
             rank = 1;
-        } else if (sortKey.startsWith("UTF-16")) {
+        } else if (sortKey.startsWith(QLatin1String("UTF-16"))) {
             rank = 2;
         } else if (iso8859RegExp.exactMatch(sortKey)) {
             if (iso8859RegExp.cap(1).size() == 1)
@@ -145,58 +148,38 @@ void MainWindow::findCodecs()
         } else {
             rank = 5;
         }
-        sortKey.prepend(QChar('0' + rank));
+        sortKey.prepend(QLatin1Char('0' + rank));
 
         codecMap.insert(sortKey, codec);
     }
     codecs = codecMap.values();
 }
 
-void MainWindow::createActions()
+void MainWindow::createMenus()
 {
-    openAct = new QAction(tr("&Open..."), this);
+    QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
+    QAction *openAct =
+        fileMenu->addAction(tr("&Open..."), this, &MainWindow::open);
     openAct->setShortcuts(QKeySequence::Open);
-    connect(openAct, SIGNAL(triggered()), this, SLOT(open()));
 
-    foreach (QTextCodec *codec, codecs) {
+    QMenu *saveAsMenu = fileMenu->addMenu(tr("&Save As"));
-        QString text = tr("%1...").arg(QString(codec->name()));
+    connect(saveAsMenu, &QMenu::aboutToShow,
-
+            this, &MainWindow::aboutToShowSaveAsMenu);
-        QAction *action = new QAction(text, this);
+    foreach (const QTextCodec *codec, codecs) {
-        action->setData(codec->name());
+        const QByteArray name = codec->name();
-        connect(action, SIGNAL(triggered()), this, SLOT(save()));
+        QAction *action = saveAsMenu->addAction(tr("%1...").arg(QLatin1String(name)));
+        action->setData(QVariant(name));
+        connect(action, &QAction::triggered, this, &MainWindow::save);
         saveAsActs.append(action);
     }
 
-    exitAct = new QAction(tr("E&xit"), this);
-    exitAct->setShortcuts(QKeySequence::Quit);
-    connect(exitAct, SIGNAL(triggered()), this, SLOT(close()));
-
-    aboutAct = new QAction(tr("&About"), this);
-    connect(aboutAct, SIGNAL(triggered()), this, SLOT(about()));
-
-    aboutQtAct = new QAction(tr("About &Qt"), this);
-    connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt()));
-}
-
-void MainWindow::createMenus()
-{
-    saveAsMenu = new QMenu(tr("&Save As"), this);
-    foreach (QAction *action, saveAsActs)
-        saveAsMenu->addAction(action);
-    connect(saveAsMenu, SIGNAL(aboutToShow()),
-            this, SLOT(aboutToShowSaveAsMenu()));
-
-    fileMenu = new QMenu(tr("&File"), this);
-    fileMenu->addAction(openAct);
-    fileMenu->addMenu(saveAsMenu);
     fileMenu->addSeparator();
-    fileMenu->addAction(exitAct);
+    QAction *exitAct = fileMenu->addAction(tr("E&xit"), this, &QWidget::close);
+    exitAct->setShortcuts(QKeySequence::Quit);
 
-    helpMenu = new QMenu(tr("&Help"), this);
-    helpMenu->addAction(aboutAct);
-    helpMenu->addAction(aboutQtAct);
-
-    menuBar()->addMenu(fileMenu);
     menuBar()->addSeparator();
-    menuBar()->addMenu(helpMenu);
+
+    QMenu *helpMenu = menuBar()->addMenu(tr("&Help"));
+    helpMenu->addAction(tr("&About"), this, &MainWindow::about);
+    helpMenu->addAction(tr("About &Qt"), qApp, &QApplication::aboutQt);
 }

examples/widgets/tools/codecs/mainwindow.h

@@ -46,9 +46,8 @@
 
 QT_BEGIN_NAMESPACE
 class QAction;
-class QMenu;
 class QTextCodec;
-class QTextEdit;
+class QPlainTextEdit;
 QT_END_NAMESPACE
 class PreviewForm;
 
@@ -67,21 +66,12 @@ private slots:
 
 private:
     void findCodecs();
-    void createActions();
     void createMenus();
 
-    QTextEdit *textEdit;
+    QList<QAction *> saveAsActs;
+    QPlainTextEdit *textEdit;
     PreviewForm *previewForm;
     QList<QTextCodec *> codecs;
-
-    QMenu *fileMenu;
-    QMenu *helpMenu;
-    QMenu *saveAsMenu;
-    QAction *openAct;
-    QList<QAction *> saveAsActs;
-    QAction *exitAct;
-    QAction *aboutAct;
-    QAction *aboutQtAct;
 };
 
 #endif

examples/widgets/tools/codecs/previewform.cpp

@@ -42,47 +42,159 @@
 
 #include "previewform.h"
 
+// Helpers for creating hex dumps
+static void indent(QTextStream &str, int indent)
+{
+    for (int i = 0; i < indent; ++i)
+        str << ' ';
+}
+
+static void formatHex(QTextStream &str, const QByteArray &data)
+{
+    const int fieldWidth = str.fieldWidth();
+    const QTextStream::FieldAlignment alignment = str.fieldAlignment();
+    const int base = str.integerBase();
+    const QChar padChar = str.padChar();
+    str.setIntegerBase(16);
+    str.setPadChar(QLatin1Char('0'));
+    str.setFieldAlignment(QTextStream::AlignRight);
+
+    const unsigned char *p = reinterpret_cast<const unsigned char *>(data.constBegin());
+    for (const unsigned char *end = p + data.size(); p < end; ++p) {
+        str << ' ';
+        str.setFieldWidth(2);
+        str << unsigned(*p);
+        str.setFieldWidth(fieldWidth);
+    }
+    str.setFieldAlignment(alignment);
+    str.setPadChar(padChar);
+    str.setIntegerBase(base);
+}
+
+static void formatPrintableCharacters(QTextStream &str, const QByteArray &data)
+{
+    for (int i = 0, size = data.size(); i < size; ++i) {
+        const char c = data.at(i);
+        switch (c) {
+        case '\0':
+            str << "\\0";
+            break;
+        case '\t':
+            str << "\\t";
+            break;
+        case '\r':
+            str << "\\r";
+            break;
+        case '\n':
+            str << "\\n";
+            break;
+        default:
+            if (c >= 32 && uchar(c) < 127)
+                str << ' ' << c;
+            else
+                str << "..";
+            break;
+        }
+    }
+}
+
+static QString formatHexDump(const QByteArray &data)
+{
+    enum { lineWidth = 16 };
+    QString result;
+    QTextStream str(&result);
+    str.setIntegerBase(16);
+    str.setPadChar(QLatin1Char('0'));
+    const int fieldWidth = str.fieldWidth();
+    const QTextStream::FieldAlignment alignment = str.fieldAlignment();
+    for (int a = 0, size = data.size(); a < size; a += lineWidth) {
+        str.setFieldAlignment(QTextStream::AlignRight);
+        str.setFieldWidth(8);
+        str << a;
+        str.setFieldWidth(fieldWidth);
+        str.setFieldAlignment(alignment);
+
+        const int end = qMin(a + lineWidth, size);
+        const QByteArray line = data.mid(a, end - a);
+
+        formatHex(str, line);
+        indent(str, 3 * (lineWidth - line.size()));
+
+        str << ' ';
+        formatPrintableCharacters(str, line);
+        indent(str, 2 * (lineWidth - line.size()));
+        str << '\n';
+    }
+    return result;
+}
+
 PreviewForm::PreviewForm(QWidget *parent)
     : QDialog(parent)
 {
+    setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
     encodingComboBox = new QComboBox;
 
-    encodingLabel = new QLabel(tr("&Encoding:"));
+    QLabel *encodingLabel = new QLabel(tr("&Encoding:"));
     encodingLabel->setBuddy(encodingComboBox);
 
-    textEdit = new QTextEdit;
+    textEdit = new QPlainTextEdit;
-    textEdit->setLineWrapMode(QTextEdit::NoWrap);
+    textEdit->setLineWrapMode(QPlainTextEdit::NoWrap);
     textEdit->setReadOnly(true);
+    hexDumpEdit = new QPlainTextEdit;
+    hexDumpEdit->setLineWrapMode(QPlainTextEdit::NoWrap);
+    hexDumpEdit->setReadOnly(true);
+    hexDumpEdit->setFont(QFontDatabase::systemFont(QFontDatabase::FixedFont));
 
-    buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok
+    QDialogButtonBox *buttonBox =
-                                    | QDialogButtonBox::Cancel);
+        new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
+    okButton = buttonBox->button(QDialogButtonBox::Ok);
 
-    connect(encodingComboBox, SIGNAL(activated(int)),
+    typedef void(QComboBox::*ComboBoxIntSignal)(int);
-            this, SLOT(updateTextEdit()));
+    connect(encodingComboBox, static_cast<ComboBoxIntSignal>(&QComboBox::activated),
-    connect(buttonBox, SIGNAL(accepted()), this, SLOT(accept()));
+            this, &PreviewForm::updateTextEdit);
-    connect(buttonBox, SIGNAL(rejected()), this, SLOT(reject()));
+    connect(buttonBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject);
 
-    QGridLayout *mainLayout = new QGridLayout;
+    QGridLayout *mainLayout = new QGridLayout(this);
     mainLayout->addWidget(encodingLabel, 0, 0);
     mainLayout->addWidget(encodingComboBox, 0, 1);
-    mainLayout->addWidget(textEdit, 1, 0, 1, 2);
+    tabWidget = new QTabWidget;
-    mainLayout->addWidget(buttonBox, 2, 0, 1, 2);
+    tabWidget->addTab(textEdit, tr("Preview"));
-    setLayout(mainLayout);
+    tabWidget->addTab(hexDumpEdit, tr("Hex Dump"));
+    mainLayout->addWidget(tabWidget, 1, 0, 1, 2);
+    statusLabel = new QLabel;
+    mainLayout->addWidget(statusLabel, 2, 0, 1, 2);
+    mainLayout->addWidget(buttonBox, 3, 0, 1, 2);
 
-    setWindowTitle(tr("Choose Encoding"));
+    const QRect screenGeometry = QApplication::desktop()->screenGeometry(this);
-    resize(400, 300);
+    resize(screenGeometry.width() * 2 / 5, screenGeometry.height() / 2);
 }
 
 void PreviewForm::setCodecList(const QList<QTextCodec *> &list)
 {
     encodingComboBox->clear();
-    foreach (QTextCodec *codec, list)
+    foreach (const QTextCodec *codec, list) {
-        encodingComboBox->addItem(codec->name(), codec->mibEnum());
+        encodingComboBox->addItem(QLatin1String(codec->name()),
+                                  QVariant(codec->mibEnum()));
+    }
+}
+
+void PreviewForm::reset()
+{
+    decodedStr.clear();
+    textEdit->clear();
+    hexDumpEdit->clear();
+    statusLabel->clear();
+    statusLabel->setStyleSheet(QString());
+    okButton->setEnabled(false);
+    tabWidget->setCurrentIndex(0);
 }
 
 void PreviewForm::setEncodedData(const QByteArray &data)
 {
+    reset();
     encodedData = data;
+    hexDumpEdit->setPlainText(formatHexDump(data));
     updateTextEdit();
 }
 
@@ -90,12 +202,30 @@ void PreviewForm::updateTextEdit()
 {
     int mib = encodingComboBox->itemData(
                       encodingComboBox->currentIndex()).toInt();
-    QTextCodec *codec = QTextCodec::codecForMib(mib);
+    const QTextCodec *codec = QTextCodec::codecForMib(mib);
+    const QString name = QLatin1String(codec->name());
 
-    QTextStream in(&encodedData);
+    QTextCodec::ConverterState state;
-    in.setAutoDetectUnicode(false);
+    decodedStr = codec->toUnicode(encodedData.constData(), encodedData.size(), &state);
-    in.setCodec(codec);
-    decodedStr = in.readAll();
 
-    textEdit->setPlainText(decodedStr);
+    bool success = true;
+    if (state.remainingChars) {
+        success = false;
+        const QString message =
+            tr("%1: conversion error at character %2")
+            .arg(name).arg(encodedData.size() - state.remainingChars + 1);
+        statusLabel->setText(message);
+        statusLabel->setStyleSheet(QStringLiteral("background-color: \"red\";"));
+    } else if (state.invalidChars) {
+        statusLabel->setText(tr("%1: %n invalid characters", 0, state.invalidChars).arg(name));
+        statusLabel->setStyleSheet(QStringLiteral("background-color: \"yellow\";"));
+    } else {
+        statusLabel->setText(tr("%1: %n bytes converted", 0, encodedData.size()).arg(name));
+        statusLabel->setStyleSheet(QString());
+    }
+    if (success)
+        textEdit->setPlainText(decodedStr);
+    else
+        textEdit->clear();
+    okButton->setEnabled(success);
 }

examples/widgets/tools/codecs/previewform.h

@@ -48,8 +48,10 @@ QT_BEGIN_NAMESPACE
 class QComboBox;
 class QDialogButtonBox;
 class QLabel;
+class QPlainTextEdit;
+class QPushButton;
+class QTabWidget;
 class QTextCodec;
-class QTextEdit;
 QT_END_NAMESPACE
 
 class PreviewForm : public QDialog
@@ -57,7 +59,7 @@ class PreviewForm : public QDialog
     Q_OBJECT
 
 public:
-    PreviewForm(QWidget *parent = 0);
+    explicit PreviewForm(QWidget *parent = Q_NULLPTR);
 
     void setCodecList(const QList<QTextCodec *> &list);
     void setEncodedData(const QByteArray &data);
@@ -67,13 +69,17 @@ private slots:
     void updateTextEdit();
 
 private:
+    void reset();
+
     QByteArray encodedData;
     QString decodedStr;
 
+    QPushButton *okButton;
+    QTabWidget *tabWidget;
     QComboBox *encodingComboBox;
-    QLabel *encodingLabel;
+    QPlainTextEdit *textEdit;
-    QTextEdit *textEdit;
+    QPlainTextEdit *hexDumpEdit;
-    QDialogButtonBox *buttonBox;
+    QLabel *statusLabel;
 };
 
 #endif