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>

4 files changed, 72 insertions, 66 deletions

diff --git a/examples/xml/dombookmarks/mainwindow.cpp b/examples/xml/dombookmarks/mainwindow.cpp
index e0f208d336..fade2dfc96 100644
--- a/examples/xml/dombookmarks/mainwindow.cpp
+++ b/examples/xml/dombookmarks/mainwindow.cpp
@@ -58,13 +58,13 @@ MainWindow::MainWindow()
     xbelTree = new XbelTree;
     setCentralWidget(xbelTree);
 
-    createActions();
     createMenus();
 
     statusBar()->showMessage(tr("Ready"));
 
     setWindowTitle(tr("DOM Bookmarks"));
-    resize(480, 320);
+    const QSize availableSize = QApplication::desktop()->availableGeometry(this).size();
+    resize(availableSize.width() / 2, availableSize.height() / 3);
 }
 
 void MainWindow::open()
@@ -80,8 +80,8 @@ void MainWindow::open()
     if (!file.open(QFile::ReadOnly | QFile::Text)) {
         QMessageBox::warning(this, tr("SAX Bookmarks"),
                              tr("Cannot read file %1:\n%2.")
-                             .arg(fileName)
-                             .arg(file.errorString()));
+                             .arg(QDir::toNativeSeparators(fileName),
+                                  file.errorString()));
         return;
     }
 
@@ -102,8 +102,8 @@ void MainWindow::saveAs()
     if (!file.open(QFile::WriteOnly | QFile::Text)) {
         QMessageBox::warning(this, tr("SAX Bookmarks"),
                              tr("Cannot write file %1:\n%2.")
-                             .arg(fileName)
-                             .arg(file.errorString()));
+                             .arg(QDir::toNativeSeparators(fileName),
+                                  file.errorString()));
         return;
     }
 
@@ -119,37 +119,21 @@ void MainWindow::about()
                          "documents."));
 }
 
-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()));
 
-    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()));
-}
-
-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);
 }
diff --git a/examples/xml/dombookmarks/mainwindow.h b/examples/xml/dombookmarks/mainwindow.h
index 6d490caf64..0a8c7bdd82 100644
--- a/examples/xml/dombookmarks/mainwindow.h
+++ b/examples/xml/dombookmarks/mainwindow.h
@@ -68,18 +68,9 @@ public slots:
     void about();
 
 private:
-    void createActions();
     void createMenus();
 
     XbelTree *xbelTree;
-
-    QMenu *fileMenu;
-    QMenu *helpMenu;
-    QAction *openAct;
-    QAction *saveAsAct;
-    QAction *exitAct;
-    QAction *aboutAct;
-    QAction *aboutQtAct;
 };
 
 #endif
diff --git a/examples/xml/dombookmarks/xbeltree.cpp b/examples/xml/dombookmarks/xbeltree.cpp
index 82afc48bd9..f7ff1de638 100644
--- a/examples/xml/dombookmarks/xbeltree.cpp
+++ b/examples/xml/dombookmarks/xbeltree.cpp
@@ -52,6 +52,18 @@
 
 #include "xbeltree.h"
 
+enum { DomElementRole = Qt::UserRole + 1 };
+
+Q_DECLARE_METATYPE(QDomElement)
+
+static inline QString titleElement() { return QStringLiteral("title"); }
+static inline QString folderElement() { return QStringLiteral("folder"); }
+static inline QString bookmarkElement() { return QStringLiteral("bookmark"); }
+
+static inline QString versionAttribute() { return QStringLiteral("version"); }
+static inline QString hrefAttribute() { return QStringLiteral("href"); }
+static inline QString foldedAttribute() { return QStringLiteral("folded"); }
+
 XbelTree::XbelTree(QWidget *parent)
     : QTreeWidget(parent)
 {
@@ -68,6 +80,24 @@ XbelTree::XbelTree(QWidget *parent)
     bookmarkIcon.addPixmap(style()->standardPixmap(QStyle::SP_FileIcon));
 }
 
+#if !defined(QT_NO_CONTEXTMENU) && !defined(QT_NO_CLIPBOARD)
+void XbelTree::contextMenuEvent(QContextMenuEvent *event)
+{
+    const QTreeWidgetItem *item = itemAt(event->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(event->globalPos());
+    if (action == copyAction)
+        QGuiApplication::clipboard()->setText(url);
+    else if (action == openAction)
+        QDesktopServices::openUrl(QUrl(url));
+}
+#endif // !QT_NO_CONTEXTMENU && !QT_NO_CLIPBOARD
+
 bool XbelTree::read(QIODevice *device)
 {
     QString errorStr;
@@ -89,8 +119,8 @@ bool XbelTree::read(QIODevice *device)
         QMessageBox::information(window(), tr("DOM Bookmarks"),
                                  tr("The file is not an XBEL file."));
         return false;
-    } else if (root.hasAttribute("version")
-               && root.attribute("version") != "1.0") {
+    } else if (root.hasAttribute(versionAttribute())
+               && root.attribute(versionAttribute()) != QLatin1String("1.0")) {
         QMessageBox::information(window(), tr("DOM Bookmarks"),
                                  tr("The file is not an XBEL version 1.0 "
                                     "file."));
@@ -99,22 +129,20 @@ bool XbelTree::read(QIODevice *device)
 
     clear();
 
-    disconnect(this, SIGNAL(itemChanged(QTreeWidgetItem*,int)),
-               this, SLOT(updateDomElement(QTreeWidgetItem*,int)));
+    disconnect(this, &QTreeWidget::itemChanged, this, &XbelTree::updateDomElement);
 
-    QDomElement child = root.firstChildElement("folder");
+    QDomElement child = root.firstChildElement(folderElement());
     while (!child.isNull()) {
         parseFolderElement(child);
-        child = child.nextSiblingElement("folder");
+        child = child.nextSiblingElement(folderElement());
     }
 
-    connect(this, SIGNAL(itemChanged(QTreeWidgetItem*,int)),
-            this, SLOT(updateDomElement(QTreeWidgetItem*,int)));
+    connect(this, &QTreeWidget::itemChanged, this, &XbelTree::updateDomElement);
 
     return true;
 }
 
-bool XbelTree::write(QIODevice *device)
+bool XbelTree::write(QIODevice *device) const
 {
     const int IndentSize = 4;
 
@@ -123,21 +151,21 @@ bool XbelTree::write(QIODevice *device)
     return true;
 }
 
-void XbelTree::updateDomElement(QTreeWidgetItem *item, int column)
+void XbelTree::updateDomElement(const QTreeWidgetItem *item, int column)
 {
-    QDomElement element = domElementForItem.value(item);
+    QDomElement element = item->data(0, DomElementRole).value<QDomElement>();
     if (!element.isNull()) {
         if (column == 0) {
-            QDomElement oldTitleElement = element.firstChildElement("title");
-            QDomElement newTitleElement = domDocument.createElement("title");
+            QDomElement oldTitleElement = element.firstChildElement(titleElement());
+            QDomElement newTitleElement = domDocument.createElement(titleElement());
 
             QDomText newTitleText = domDocument.createTextNode(item->text(0));
             newTitleElement.appendChild(newTitleText);
 
             element.replaceChild(newTitleElement, oldTitleElement);
         } else {
-            if (element.tagName() == "bookmark")
-                element.setAttribute("href", item->text(1));
+            if (element.tagName() == bookmarkElement())
+                element.setAttribute(hrefAttribute(), item->text(1));
         }
     }
 }
@@ -147,7 +175,7 @@ void XbelTree::parseFolderElement(const QDomElement &element,
 {
     QTreeWidgetItem *item = createItem(element, parentItem);
 
-    QString title = element.firstChildElement("title").text();
+    QString title = element.firstChildElement(titleElement()).text();
     if (title.isEmpty())
         title = QObject::tr("Folder");
 
@@ -155,25 +183,25 @@ void XbelTree::parseFolderElement(const QDomElement &element,
     item->setIcon(0, folderIcon);
     item->setText(0, title);
 
-    bool folded = (element.attribute("folded") != "no");
+    bool folded = (element.attribute(foldedAttribute()) != QLatin1String("no"));
     setItemExpanded(item, !folded);
 
     QDomElement child = element.firstChildElement();
     while (!child.isNull()) {
-        if (child.tagName() == "folder") {
+        if (child.tagName() == folderElement()) {
             parseFolderElement(child, item);
-        } else if (child.tagName() == "bookmark") {
+        } else if (child.tagName() == bookmarkElement()) {
             QTreeWidgetItem *childItem = createItem(child, item);
 
-            QString title = child.firstChildElement("title").text();
+            QString title = child.firstChildElement(titleElement()).text();
             if (title.isEmpty())
                 title = QObject::tr("Folder");
 
             childItem->setFlags(item->flags() | Qt::ItemIsEditable);
             childItem->setIcon(0, bookmarkIcon);
             childItem->setText(0, title);
-            childItem->setText(1, child.attribute("href"));
-        } else if (child.tagName() == "separator") {
+            childItem->setText(1, child.attribute(hrefAttribute()));
+        } else if (child.tagName() == QLatin1String("separator")) {
             QTreeWidgetItem *childItem = createItem(child, item);
             childItem->setFlags(item->flags() & ~(Qt::ItemIsSelectable | Qt::ItemIsEditable));
             childItem->setText(0, QString(30, 0xB7));
@@ -191,6 +219,6 @@ QTreeWidgetItem *XbelTree::createItem(const QDomElement &element,
     } else {
         item = new QTreeWidgetItem(this);
     }
-    domElementForItem.insert(item, element);
+    item->setData(0, DomElementRole, QVariant::fromValue(element));
     return item;
 }
diff --git a/examples/xml/dombookmarks/xbeltree.h b/examples/xml/dombookmarks/xbeltree.h
index bf4b55ea74..f6c7ef8bfe 100644
--- a/examples/xml/dombookmarks/xbeltree.h
+++ b/examples/xml/dombookmarks/xbeltree.h
@@ -52,7 +52,6 @@
 #define XBELTREE_H
 
 #include <QDomDocument>
-#include <QHash>
 #include <QIcon>
 #include <QTreeWidget>
 
@@ -64,10 +63,15 @@ public:
     XbelTree(QWidget *parent = 0);
 
     bool read(QIODevice *device);
-    bool write(QIODevice *device);
+    bool write(QIODevice *device) const;
+
+protected:
+#if !defined(QT_NO_CONTEXTMENU) && !defined(QT_NO_CLIPBOARD)
+    void contextMenuEvent(QContextMenuEvent *event) Q_DECL_OVERRIDE;
+#endif
 
 private slots:
-    void updateDomElement(QTreeWidgetItem *item, int column);
+    void updateDomElement(const QTreeWidgetItem *item, int column);
 
 private:
     void parseFolderElement(const QDomElement &element,
@@ -76,7 +80,6 @@ private:
                                 QTreeWidgetItem *parentItem = 0);
 
     QDomDocument domDocument;
-    QHash<QTreeWidgetItem *, QDomElement> domElementForItem;
     QIcon folderIcon;
     QIcon bookmarkIcon;
 };