Polish DnD Examples.

- Remove class DragLabel in draggabletext and add a static creation
  function instead since it only has a constructor setting some
  properties.
- Use QRegularExpression instead of QRegExp
- Use new connection syntax.
- Ensure compilation with
  DEFINES += QT_NO_CAST_TO_ASCII QT_NO_CAST_FROM_ASCII
  demonstrating use of QLatin1String vs QStringLiteral.
- Streamline code.

Change-Id: I2e2ddeb40837dba379990836c77fb72ad7263e2d
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>

7 files changed, 41 insertions, 50 deletions

diff --git a/examples/widgets/draganddrop/puzzle/main.cpp b/examples/widgets/draganddrop/puzzle/main.cpp
index 706ebe4d70..e8ecbe37db 100644
--- a/examples/widgets/draganddrop/puzzle/main.cpp
+++ b/examples/widgets/draganddrop/puzzle/main.cpp
@@ -48,7 +48,7 @@ int main(int argc, char *argv[])
 
     QApplication app(argc, argv);
     MainWindow window;
-    window.openImage(":/images/example.jpg");
+    window.loadImage(QStringLiteral(":/images/example.jpg"));
     window.show();
     return app.exec();
 }
diff --git a/examples/widgets/draganddrop/puzzle/mainwindow.cpp b/examples/widgets/draganddrop/puzzle/mainwindow.cpp
index 0fbdfc3f8d..48e79946e7 100644
--- a/examples/widgets/draganddrop/puzzle/mainwindow.cpp
+++ b/examples/widgets/draganddrop/puzzle/mainwindow.cpp
@@ -55,26 +55,27 @@ MainWindow::MainWindow(QWidget *parent)
     setWindowTitle(tr("Puzzle"));
 }
 
-void MainWindow::openImage(const QString &path)
+void MainWindow::openImage()
 {
-    QString fileName = path;
+    const QString fileName =
+        QFileDialog::getOpenFileName(this, tr("Open Image"), QString(),
+                                     tr("Image Files (*.png *.jpg *.bmp)"));
 
-    if (fileName.isNull()) {
-        fileName = QFileDialog::getOpenFileName(this,
-            tr("Open Image"), "", "Image Files (*.png *.jpg *.bmp)");
-    }
+    if (!fileName.isEmpty())
+        loadImage(fileName);
+}
 
-    if (!fileName.isEmpty()) {
-        QPixmap newImage;
-        if (!newImage.load(fileName)) {
-            QMessageBox::warning(this, tr("Open Image"),
-                                  tr("The image file could not be loaded."),
-                                  QMessageBox::Cancel);
-            return;
-        }
-        puzzleImage = newImage;
-        setupPuzzle();
+void MainWindow::loadImage(const QString &fileName)
+{
+    QPixmap newImage;
+    if (!newImage.load(fileName)) {
+        QMessageBox::warning(this, tr("Open Image"),
+                             tr("The image file could not be loaded."),
+                             QMessageBox::Close);
+        return;
     }
+    puzzleImage = newImage;
+    setupPuzzle();
 }
 
 void MainWindow::setCompleted()
@@ -120,19 +121,15 @@ void MainWindow::setupMenus()
 {
     QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
 
-    QAction *openAction = fileMenu->addAction(tr("&Open..."));
+    QAction *openAction = fileMenu->addAction(tr("&Open..."), this, &MainWindow::openImage);
     openAction->setShortcuts(QKeySequence::Open);
 
-    QAction *exitAction = fileMenu->addAction(tr("E&xit"));
+    QAction *exitAction = fileMenu->addAction(tr("E&xit"), qApp, &QCoreApplication::quit);
     exitAction->setShortcuts(QKeySequence::Quit);
 
     QMenu *gameMenu = menuBar()->addMenu(tr("&Game"));
 
-    QAction *restartAction = gameMenu->addAction(tr("&Restart"));
-
-    connect(openAction, SIGNAL(triggered()), this, SLOT(openImage()));
-    connect(exitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
-    connect(restartAction, SIGNAL(triggered()), this, SLOT(setupPuzzle()));
+    gameMenu->addAction(tr("&Restart"), this, &MainWindow::setupPuzzle);
 }
 
 void MainWindow::setupWidgets()
@@ -144,8 +141,8 @@ void MainWindow::setupWidgets()
     piecesList = new PiecesList(puzzleWidget->pieceSize(), this);
 
 
-    connect(puzzleWidget, SIGNAL(puzzleCompleted()),
-            this, SLOT(setCompleted()), Qt::QueuedConnection);
+    connect(puzzleWidget, &PuzzleWidget::puzzleCompleted,
+            this, &MainWindow::setCompleted, Qt::QueuedConnection);
 
     frameLayout->addWidget(piecesList);
     frameLayout->addWidget(puzzleWidget);
diff --git a/examples/widgets/draganddrop/puzzle/mainwindow.h b/examples/widgets/draganddrop/puzzle/mainwindow.h
index 093a14472e..b5b7d0d903 100644
--- a/examples/widgets/draganddrop/puzzle/mainwindow.h
+++ b/examples/widgets/draganddrop/puzzle/mainwindow.h
@@ -56,9 +56,10 @@ class MainWindow : public QMainWindow
 
 public:
     MainWindow(QWidget *parent = 0);
+    void loadImage(const QString &path);
 
 public slots:
-    void openImage(const QString &path = QString());
+    void openImage();
     void setupPuzzle();
 
 private slots:
diff --git a/examples/widgets/draganddrop/puzzle/pieceslist.cpp b/examples/widgets/draganddrop/puzzle/pieceslist.cpp
index e60fd0a9ff..fb27aa2304 100644
--- a/examples/widgets/draganddrop/puzzle/pieceslist.cpp
+++ b/examples/widgets/draganddrop/puzzle/pieceslist.cpp
@@ -57,7 +57,7 @@ PiecesList::PiecesList(int pieceSize, QWidget *parent)
 
 void PiecesList::dragEnterEvent(QDragEnterEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece"))
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType()))
         event->accept();
     else
         event->ignore();
@@ -65,7 +65,7 @@ void PiecesList::dragEnterEvent(QDragEnterEvent *event)
 
 void PiecesList::dragMoveEvent(QDragMoveEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) {
         event->setDropAction(Qt::MoveAction);
         event->accept();
     } else {
@@ -75,8 +75,8 @@ void PiecesList::dragMoveEvent(QDragMoveEvent *event)
 
 void PiecesList::dropEvent(QDropEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
-        QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece");
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) {
+        QByteArray pieceData = event->mimeData()->data(PiecesList::puzzleMimeType());
         QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
         QPixmap pixmap;
         QPoint location;
@@ -112,7 +112,7 @@ void PiecesList::startDrag(Qt::DropActions /*supportedActions*/)
     dataStream << pixmap << location;
 
     QMimeData *mimeData = new QMimeData;
-    mimeData->setData("image/x-puzzle-piece", itemData);
+    mimeData->setData(PiecesList::puzzleMimeType(), itemData);
 
     QDrag *drag = new QDrag(this);
     drag->setMimeData(mimeData);
diff --git a/examples/widgets/draganddrop/puzzle/pieceslist.h b/examples/widgets/draganddrop/puzzle/pieceslist.h
index 83c1ad8285..07fa504f41 100644
--- a/examples/widgets/draganddrop/puzzle/pieceslist.h
+++ b/examples/widgets/draganddrop/puzzle/pieceslist.h
@@ -51,6 +51,8 @@ public:
     explicit PiecesList(int pieceSize, QWidget *parent = 0);
     void addPiece(QPixmap pixmap, QPoint location);
 
+    static QString puzzleMimeType() { return QStringLiteral("image/x-puzzle-piece"); }
+
 protected:
     void dragEnterEvent(QDragEnterEvent *event) Q_DECL_OVERRIDE;
     void dragMoveEvent(QDragMoveEvent *event) Q_DECL_OVERRIDE;
diff --git a/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp b/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp
index 69c0cbf0cc..29052da4fb 100644
--- a/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp
+++ b/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp
@@ -39,6 +39,7 @@
 ****************************************************************************/
 
 #include "puzzlewidget.h"
+#include "pieceslist.h"
 
 #include <QDrag>
 #include <QDragEnterEvent>
@@ -65,7 +66,7 @@ void PuzzleWidget::clear()
 
 void PuzzleWidget::dragEnterEvent(QDragEnterEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece"))
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType()))
         event->accept();
     else
         event->ignore();
@@ -83,8 +84,8 @@ void PuzzleWidget::dragMoveEvent(QDragMoveEvent *event)
 {
     QRect updateRect = highlightedRect.united(targetSquare(event->pos()));
 
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")
-        && findPiece(targetSquare(event->pos())) == -1) {
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())
+        && pieceRects.indexOf(targetSquare(event->pos())) == -1) {
 
         highlightedRect = targetSquare(event->pos());
         event->setDropAction(Qt::MoveAction);
@@ -99,10 +100,10 @@ void PuzzleWidget::dragMoveEvent(QDragMoveEvent *event)
 
 void PuzzleWidget::dropEvent(QDropEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")
-        && findPiece(targetSquare(event->pos())) == -1) {
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())
+        && pieceRects.indexOf(targetSquare(event->pos())) == -1) {
 
-        QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece");
+        QByteArray pieceData = event->mimeData()->data(PiecesList::puzzleMimeType());
         QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
         QRect square = targetSquare(event->pos());
         QPixmap pixmap;
@@ -130,19 +131,10 @@ void PuzzleWidget::dropEvent(QDropEvent *event)
     }
 }
 
-int PuzzleWidget::findPiece(const QRect &pieceRect) const
-{
-    for (int i = 0; i < pieceRects.size(); ++i) {
-        if (pieceRect == pieceRects[i])
-            return i;
-    }
-    return -1;
-}
-
 void PuzzleWidget::mousePressEvent(QMouseEvent *event)
 {
     QRect square = targetSquare(event->pos());
-    int found = findPiece(square);
+    int found = pieceRects.indexOf(square);
 
     if (found == -1)
         return;
@@ -164,7 +156,7 @@ void PuzzleWidget::mousePressEvent(QMouseEvent *event)
     dataStream << pixmap << location;
 
     QMimeData *mimeData = new QMimeData;
-    mimeData->setData("image/x-puzzle-piece", itemData);
+    mimeData->setData(PiecesList::puzzleMimeType(), itemData);
 
     QDrag *drag = new QDrag(this);
     drag->setMimeData(mimeData);
diff --git a/examples/widgets/draganddrop/puzzle/puzzlewidget.h b/examples/widgets/draganddrop/puzzle/puzzlewidget.h
index 6bf264b5e0..eb8a3a29f9 100644
--- a/examples/widgets/draganddrop/puzzle/puzzlewidget.h
+++ b/examples/widgets/draganddrop/puzzle/puzzlewidget.h
@@ -75,7 +75,6 @@ protected:
     void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
 
 private:
-    int findPiece(const QRect &pieceRect) const;
     const QRect targetSquare(const QPoint &position) const;
 
     QList<QPixmap> piecePixmaps;