Polish the XML bookmarks examples

- Use Qt 5 connect syntax.
- Streamline code, remove unused members.
- Add a context menu for copying and opening the URLs.
- Add const to XML code.
- In the XML code, show the use of QStringLiteral in static inline
  functions to create strings versus QLatin1String in comparison
  overloads to avoid allocating strings from const char * literals.

Change-Id: Ib5e62ca188e271ffe01996dff3c9ea8e0b60739a
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

7 files changed, 87 insertions, 78 deletions

diff --git a/examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc b/examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc
index 0720e3eadd..ad093c2098 100644
--- a/examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc
+++ b/examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc
@@ -167,7 +167,7 @@
     add them to the \c fileMenu and \c helpMenu. The connections are as shown
     below:
 
-    \snippet streambookmarks/mainwindow.cpp 4
+    \snippet streambookmarks/mainwindow.cpp 5
 
     The \c createMenus() function creates the \c fileMenu and \c helpMenu
     and adds the QAction objects to them in order to create the menu shown
diff --git a/examples/xml/streambookmarks/mainwindow.cpp b/examples/xml/streambookmarks/mainwindow.cpp
index 7c0fd8720d..c9a18fa3c4 100644
--- a/examples/xml/streambookmarks/mainwindow.cpp
+++ b/examples/xml/streambookmarks/mainwindow.cpp
@@ -63,18 +63,41 @@ MainWindow::MainWindow()
     treeWidget = new QTreeWidget;
     treeWidget->header()->setSectionResizeMode(QHeaderView::Stretch);
     treeWidget->setHeaderLabels(labels);
+#if !defined(QT_NO_CONTEXTMENU) && !defined(QT_NO_CLIPBOARD)
+    treeWidget->setContextMenuPolicy(Qt::CustomContextMenu);
+    connect(treeWidget, &QWidget::customContextMenuRequested,
+            this, &MainWindow::onCustomContextMenuRequested);
+#endif
     setCentralWidget(treeWidget);
 
-    createActions();
     createMenus();
 
     statusBar()->showMessage(tr("Ready"));
 
     setWindowTitle(tr("QXmlStream Bookmarks"));
-    resize(480, 320);
+    const QSize availableSize = QApplication::desktop()->availableGeometry(this).size();
+    resize(availableSize.width() / 2, availableSize.height() / 3);
 }
 //! [0]
 
+#if !defined(QT_NO_CONTEXTMENU) && !defined(QT_NO_CLIPBOARD)
+void MainWindow::onCustomContextMenuRequested(const QPoint &pos)
+{
+    const QTreeWidgetItem *item = treeWidget->itemAt(pos);
+    if (!item)
+        return;
+    const QString url = item->text(1);
+    QMenu contextMenu;
+    QAction *copyAction = contextMenu.addAction(tr("Copy Link to Clipboard"));
+    QAction *openAction = contextMenu.addAction(tr("Open"));
+    QAction *action = contextMenu.exec(treeWidget->viewport()->mapToGlobal(pos));
+    if (action == copyAction)
+        QGuiApplication::clipboard()->setText(url);
+    else if (action == openAction)
+        QDesktopServices::openUrl(QUrl(url));
+}
+#endif // !QT_NO_CONTEXTMENU && !QT_NO_CLIPBOARD
+
 //! [1]
 void MainWindow::open()
 {
@@ -92,8 +115,8 @@ void MainWindow::open()
     if (!file.open(QFile::ReadOnly | QFile::Text)) {
         QMessageBox::warning(this, tr("QXmlStream Bookmarks"),
                              tr("Cannot read file %1:\n%2.")
-                             .arg(fileName)
-                             .arg(file.errorString()));
+                             .arg(QDir::toNativeSeparators(fileName),
+                                  file.errorString()));
         return;
     }
 
@@ -101,8 +124,8 @@ void MainWindow::open()
     if (!reader.read(&file)) {
         QMessageBox::warning(this, tr("QXmlStream Bookmarks"),
                              tr("Parse error in file %1:\n\n%2")
-                             .arg(fileName)
-                             .arg(reader.errorString()));
+                             .arg(QDir::toNativeSeparators(fileName),
+                                  reader.errorString()));
     } else {
         statusBar()->showMessage(tr("File loaded"), 2000);
     }
@@ -124,8 +147,8 @@ void MainWindow::saveAs()
     if (!file.open(QFile::WriteOnly | QFile::Text)) {
         QMessageBox::warning(this, tr("QXmlStream Bookmarks"),
                              tr("Cannot write file %1:\n%2.")
-                             .arg(fileName)
-                             .arg(file.errorString()));
+                             .arg(QDir::toNativeSeparators(fileName),
+                                  file.errorString()));
         return;
     }
 
@@ -144,41 +167,23 @@ void MainWindow::about()
 }
 //! [3]
 
-//! [4]
-void MainWindow::createActions()
+//! [5]
+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()));
 
-    saveAsAct = new QAction(tr("&Save As..."), this);
+    QAction *saveAsAct = fileMenu->addAction(tr("&Save As..."), this, &MainWindow::saveAs);
     saveAsAct->setShortcuts(QKeySequence::SaveAs);
-    connect(saveAsAct, SIGNAL(triggered()), this, SLOT(saveAs()));
 
-    exitAct = new QAction(tr("E&xit"), this);
+    QAction *exitAct = fileMenu->addAction(tr("E&xit"), this, &QWidget::close);
     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()));
-}
-//! [4]
-
-//! [5]
-void MainWindow::createMenus()
-{
-    fileMenu = menuBar()->addMenu(tr("&File"));
-    fileMenu->addAction(openAct);
-    fileMenu->addAction(saveAsAct);
-    fileMenu->addAction(exitAct);
 
     menuBar()->addSeparator();
 
-    helpMenu = menuBar()->addMenu(tr("&Help"));
-    helpMenu->addAction(aboutAct);
-    helpMenu->addAction(aboutQtAct);
+    QMenu *helpMenu = menuBar()->addMenu(tr("&Help"));
+    helpMenu->addAction(tr("&About"), this, &MainWindow::about);
+    helpMenu->addAction(tr("About &Qt"), qApp, &QCoreApplication::quit);
 }
 //! [5]
diff --git a/examples/xml/streambookmarks/mainwindow.h b/examples/xml/streambookmarks/mainwindow.h
index 2b6feeb26f..fbdc1e0c62 100644
--- a/examples/xml/streambookmarks/mainwindow.h
+++ b/examples/xml/streambookmarks/mainwindow.h
@@ -69,20 +69,13 @@ public slots:
     void open();
     void saveAs();
     void about();
-
+#if !defined(QT_NO_CONTEXTMENU) && !defined(QT_NO_CLIPBOARD)
+    void onCustomContextMenuRequested(const QPoint &pos);
+#endif
 private:
-    void createActions();
     void createMenus();
 
     QTreeWidget *treeWidget;
-
-    QMenu *fileMenu;
-    QMenu *helpMenu;
-    QAction *openAct;
-    QAction *saveAsAct;
-    QAction *exitAct;
-    QAction *aboutAct;
-    QAction *aboutQtAct;
 };
 //! [0]
 
diff --git a/examples/xml/streambookmarks/xbelreader.cpp b/examples/xml/streambookmarks/xbelreader.cpp
index 53d6b94ba0..099985d91e 100644
--- a/examples/xml/streambookmarks/xbelreader.cpp
+++ b/examples/xml/streambookmarks/xbelreader.cpp
@@ -72,10 +72,12 @@ bool XbelReader::read(QIODevice *device)
     xml.setDevice(device);
 
     if (xml.readNextStartElement()) {
-        if (xml.name() == "xbel" && xml.attributes().value("version") == "1.0")
+        if (xml.name() == QLatin1String("xbel")
+            && xml.attributes().value(versionAttribute()) == QLatin1String("1.0")) {
             readXBEL();
-        else
+        } else {
             xml.raiseError(QObject::tr("The file is not an XBEL version 1.0 file."));
+        }
     }
 
     return !xml.error();
@@ -95,14 +97,14 @@ QString XbelReader::errorString() const
 //! [3]
 void XbelReader::readXBEL()
 {
-    Q_ASSERT(xml.isStartElement() && xml.name() == "xbel");
+    Q_ASSERT(xml.isStartElement() && xml.name() == QLatin1String("xbel"));
 
     while (xml.readNextStartElement()) {
-        if (xml.name() == "folder")
+        if (xml.name() == QLatin1String("folder"))
             readFolder(0);
-        else if (xml.name() == "bookmark")
+        else if (xml.name() == QLatin1String("bookmark"))
             readBookmark(0);
-        else if (xml.name() == "separator")
+        else if (xml.name() == QLatin1String("separator"))
             readSeparator(0);
         else
             xml.skipCurrentElement();
@@ -113,7 +115,7 @@ void XbelReader::readXBEL()
 //! [4]
 void XbelReader::readTitle(QTreeWidgetItem *item)
 {
-    Q_ASSERT(xml.isStartElement() && xml.name() == "title");
+    Q_ASSERT(xml.isStartElement() && xml.name() == QLatin1String("title"));
 
     QString title = xml.readElementText();
     item->setText(0, title);
@@ -123,7 +125,7 @@ void XbelReader::readTitle(QTreeWidgetItem *item)
 //! [5]
 void XbelReader::readSeparator(QTreeWidgetItem *item)
 {
-    Q_ASSERT(xml.isStartElement() && xml.name() == "separator");
+    Q_ASSERT(xml.isStartElement() && xml.name() == QLatin1String("separator"));
 
     QTreeWidgetItem *separator = createChildItem(item);
     separator->setFlags(item->flags() & ~Qt::ItemIsSelectable);
@@ -134,20 +136,20 @@ void XbelReader::readSeparator(QTreeWidgetItem *item)
 
 void XbelReader::readFolder(QTreeWidgetItem *item)
 {
-    Q_ASSERT(xml.isStartElement() && xml.name() == "folder");
+    Q_ASSERT(xml.isStartElement() && xml.name() == QLatin1String("folder"));
 
     QTreeWidgetItem *folder = createChildItem(item);
-    bool folded = (xml.attributes().value("folded") != "no");
+    bool folded = (xml.attributes().value(foldedAttribute()) != QLatin1String("no"));
     treeWidget->setItemExpanded(folder, !folded);
 
     while (xml.readNextStartElement()) {
-        if (xml.name() == "title")
+        if (xml.name() == QLatin1String("title"))
             readTitle(folder);
-        else if (xml.name() == "folder")
+        else if (xml.name() == QLatin1String("folder"))
             readFolder(folder);
-        else if (xml.name() == "bookmark")
+        else if (xml.name() == QLatin1String("bookmark"))
             readBookmark(folder);
-        else if (xml.name() == "separator")
+        else if (xml.name() == QLatin1String("separator"))
             readSeparator(folder);
         else
             xml.skipCurrentElement();
@@ -156,16 +158,16 @@ void XbelReader::readFolder(QTreeWidgetItem *item)
 
 void XbelReader::readBookmark(QTreeWidgetItem *item)
 {
-    Q_ASSERT(xml.isStartElement() && xml.name() == "bookmark");
+    Q_ASSERT(xml.isStartElement() && xml.name() == QLatin1String("bookmark"));
 
     QTreeWidgetItem *bookmark = createChildItem(item);
     bookmark->setFlags(bookmark->flags() | Qt::ItemIsEditable);
     bookmark->setIcon(0, bookmarkIcon);
     bookmark->setText(0, QObject::tr("Unknown title"));
-    bookmark->setText(1, xml.attributes().value("href").toString());
+    bookmark->setText(1, xml.attributes().value(hrefAttribute()).toString());
 
     while (xml.readNextStartElement()) {
-        if (xml.name() == "title")
+        if (xml.name() == QLatin1String("title"))
             readTitle(bookmark);
         else
             xml.skipCurrentElement();
diff --git a/examples/xml/streambookmarks/xbelreader.h b/examples/xml/streambookmarks/xbelreader.h
index 3175441ddd..fd486a430f 100644
--- a/examples/xml/streambookmarks/xbelreader.h
+++ b/examples/xml/streambookmarks/xbelreader.h
@@ -71,6 +71,10 @@ public:
 
     QString errorString() const;
 
+    static inline QString versionAttribute() { return QStringLiteral("version"); }
+    static inline QString hrefAttribute() { return QStringLiteral("href"); }
+    static inline QString foldedAttribute() { return QStringLiteral("folded"); }
+
 private:
 //! [2]
     void readXBEL();
diff --git a/examples/xml/streambookmarks/xbelwriter.cpp b/examples/xml/streambookmarks/xbelwriter.cpp
index fdf2e1095e..2959680678 100644
--- a/examples/xml/streambookmarks/xbelwriter.cpp
+++ b/examples/xml/streambookmarks/xbelwriter.cpp
@@ -51,9 +51,14 @@
 #include <QtWidgets>
 
 #include "xbelwriter.h"
+#include "xbelreader.h"
+
+static inline QString yesValue() { return QStringLiteral("yes"); }
+static inline QString noValue() { return QStringLiteral("no"); }
+static inline QString titleElement() { return QStringLiteral("title"); }
 
 //! [0]
-XbelWriter::XbelWriter(QTreeWidget *treeWidget)
+XbelWriter::XbelWriter(const QTreeWidget *treeWidget)
     : treeWidget(treeWidget)
 {
     xml.setAutoFormatting(true);
@@ -66,9 +71,9 @@ bool XbelWriter::writeFile(QIODevice *device)
     xml.setDevice(device);
 
     xml.writeStartDocument();
-    xml.writeDTD("<!DOCTYPE xbel>");
-    xml.writeStartElement("xbel");
-    xml.writeAttribute("version", "1.0");
+    xml.writeDTD(QStringLiteral("<!DOCTYPE xbel>"));
+    xml.writeStartElement(QStringLiteral("xbel"));
+    xml.writeAttribute(XbelReader::versionAttribute(), QStringLiteral("1.0"));
     for (int i = 0; i < treeWidget->topLevelItemCount(); ++i)
         writeItem(treeWidget->topLevelItem(i));
 
@@ -78,24 +83,24 @@ bool XbelWriter::writeFile(QIODevice *device)
 //! [1]
 
 //! [2]
-void XbelWriter::writeItem(QTreeWidgetItem *item)
+void XbelWriter::writeItem(const QTreeWidgetItem *item)
 {
     QString tagName = item->data(0, Qt::UserRole).toString();
-    if (tagName == "folder") {
+    if (tagName == QLatin1String("folder")) {
         bool folded = !treeWidget->isItemExpanded(item);
         xml.writeStartElement(tagName);
-        xml.writeAttribute("folded", folded ? "yes" : "no");
-        xml.writeTextElement("title", item->text(0));
+        xml.writeAttribute(XbelReader::foldedAttribute(), folded ? yesValue() : noValue());
+        xml.writeTextElement(titleElement(), item->text(0));
         for (int i = 0; i < item->childCount(); ++i)
             writeItem(item->child(i));
         xml.writeEndElement();
-    } else if (tagName == "bookmark") {
+    } else if (tagName == QLatin1String("bookmark")) {
         xml.writeStartElement(tagName);
         if (!item->text(1).isEmpty())
-            xml.writeAttribute("href", item->text(1));
-        xml.writeTextElement("title", item->text(0));
+            xml.writeAttribute(XbelReader::hrefAttribute(), item->text(1));
+        xml.writeTextElement(titleElement(), item->text(0));
         xml.writeEndElement();
-    } else if (tagName == "separator") {
+    } else if (tagName == QLatin1String("separator")) {
         xml.writeEmptyElement(tagName);
     }
 }
diff --git a/examples/xml/streambookmarks/xbelwriter.h b/examples/xml/streambookmarks/xbelwriter.h
index b15bf60e31..465d8f0dc4 100644
--- a/examples/xml/streambookmarks/xbelwriter.h
+++ b/examples/xml/streambookmarks/xbelwriter.h
@@ -62,13 +62,13 @@ QT_END_NAMESPACE
 class XbelWriter
 {
 public:
-    XbelWriter(QTreeWidget *treeWidget);
+    explicit XbelWriter(const QTreeWidget *treeWidget);
     bool writeFile(QIODevice *device);
 
 private:
-    void writeItem(QTreeWidgetItem *item);
+    void writeItem(const QTreeWidgetItem *item);
     QXmlStreamWriter xml;
-    QTreeWidget *treeWidget;
+    const QTreeWidget *treeWidget;
 };
 //! [0]