qt 6.5.1 original

examples/widgets/draganddrop/CMakeLists.txt

@@ -0,0 +1,8 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+qt_internal_add_example(draggableicons)
+qt_internal_add_example(draggabletext)
+qt_internal_add_example(dropsite)
+qt_internal_add_example(fridgemagnets)
+qt_internal_add_example(puzzle)

examples/widgets/draganddrop/README

@@ -0,0 +1,9 @@
+Qt supports native drag and drop on all platforms via an extensible
+MIME-based system that enables applications to send data to each other in the
+most appropriate formats.
+
+Drag and drop can also be implemented for internal use by applications.
+
+
+Documentation for these examples can be found via the Examples
+link in the main Qt documentation.

examples/widgets/draganddrop/draganddrop.pro

@@ -0,0 +1,6 @@
+TEMPLATE    = subdirs
+SUBDIRS     = draggableicons \
+              draggabletext \
+              dropsite \
+              fridgemagnets \
+              puzzle

examples/widgets/draganddrop/draggableicons/CMakeLists.txt

@@ -0,0 +1,51 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(draggableicons LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/widgets/draganddrop/draggableicons")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(draggableicons
+    dragwidget.cpp dragwidget.h
+    main.cpp
+)
+
+set_target_properties(draggableicons PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(draggableicons PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Widgets
+)
+
+# Resources:
+set(draggableicons_resource_files
+    "images/boat.png"
+    "images/car.png"
+    "images/house.png"
+)
+
+qt_add_resources(draggableicons "draggableicons"
+    PREFIX
+        "/"
+    FILES
+        ${draggableicons_resource_files}
+)
+
+install(TARGETS draggableicons
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/widgets/draganddrop/draggableicons/draggableicons.pro

@@ -0,0 +1,10 @@
+QT += widgets
+
+HEADERS     = dragwidget.h
+RESOURCES   = draggableicons.qrc
+SOURCES     = dragwidget.cpp \
+              main.cpp
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/widgets/draganddrop/draggableicons
+INSTALLS += target

examples/widgets/draganddrop/draggableicons/draggableicons.qrc

@@ -0,0 +1,7 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource prefix="">
+   <file>images/boat.png</file>
+   <file>images/car.png</file>
+   <file>images/house.png</file>
+</qresource>
+</RCC>

examples/widgets/draganddrop/draggableicons/dragwidget.cpp

@@ -0,0 +1,131 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtWidgets>
+
+#include "dragwidget.h"
+
+//! [0]
+DragWidget::DragWidget(QWidget *parent)
+    : QFrame(parent)
+{
+    setMinimumSize(200, 200);
+    setFrameStyle(QFrame::Sunken | QFrame::StyledPanel);
+    setAcceptDrops(true);
+
+    QLabel *boatIcon = new QLabel(this);
+    boatIcon->setPixmap(QPixmap(":/images/boat.png"));
+    boatIcon->move(10, 10);
+    boatIcon->show();
+    boatIcon->setAttribute(Qt::WA_DeleteOnClose);
+
+    QLabel *carIcon = new QLabel(this);
+    carIcon->setPixmap(QPixmap(":/images/car.png"));
+    carIcon->move(100, 10);
+    carIcon->show();
+    carIcon->setAttribute(Qt::WA_DeleteOnClose);
+
+    QLabel *houseIcon = new QLabel(this);
+    houseIcon->setPixmap(QPixmap(":/images/house.png"));
+    houseIcon->move(10, 80);
+    houseIcon->show();
+    houseIcon->setAttribute(Qt::WA_DeleteOnClose);
+}
+//! [0]
+
+void DragWidget::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+}
+
+void DragWidget::dragMoveEvent(QDragMoveEvent *event)
+{
+    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+}
+
+void DragWidget::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
+        QByteArray itemData = event->mimeData()->data("application/x-dnditemdata");
+        QDataStream dataStream(&itemData, QIODevice::ReadOnly);
+
+        QPixmap pixmap;
+        QPoint offset;
+        dataStream >> pixmap >> offset;
+
+        QLabel *newIcon = new QLabel(this);
+        newIcon->setPixmap(pixmap);
+        newIcon->move(event->position().toPoint() - offset);
+        newIcon->show();
+        newIcon->setAttribute(Qt::WA_DeleteOnClose);
+
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+}
+
+//! [1]
+void DragWidget::mousePressEvent(QMouseEvent *event)
+{
+    QLabel *child = static_cast<QLabel*>(childAt(event->position().toPoint()));
+    if (!child)
+        return;
+
+    QPixmap pixmap = child->pixmap();
+
+    QByteArray itemData;
+    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
+    dataStream << pixmap << QPoint(event->position().toPoint() - child->pos());
+//! [1]
+
+//! [2]
+    QMimeData *mimeData = new QMimeData;
+    mimeData->setData("application/x-dnditemdata", itemData);
+//! [2]
+
+//! [3]
+    QDrag *drag = new QDrag(this);
+    drag->setMimeData(mimeData);
+    drag->setPixmap(pixmap);
+    drag->setHotSpot(event->position().toPoint() - child->pos());
+//! [3]
+
+    QPixmap tempPixmap = pixmap;
+    QPainter painter;
+    painter.begin(&tempPixmap);
+    painter.fillRect(pixmap.rect(), QColor(127, 127, 127, 127));
+    painter.end();
+
+    child->setPixmap(tempPixmap);
+
+    if (drag->exec(Qt::CopyAction | Qt::MoveAction, Qt::CopyAction) == Qt::MoveAction) {
+        child->close();
+    } else {
+        child->show();
+        child->setPixmap(pixmap);
+    }
+}

examples/widgets/draganddrop/draggableicons/dragwidget.h

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef DRAGWIDGET_H
+#define DRAGWIDGET_H
+
+#include <QFrame>
+
+QT_BEGIN_NAMESPACE
+class QDragEnterEvent;
+class QDropEvent;
+QT_END_NAMESPACE
+
+//! [0]
+class DragWidget : public QFrame
+{
+public:
+    explicit DragWidget(QWidget *parent = nullptr);
+
+protected:
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+};
+//! [0]
+
+#endif // DRAGWIDGET_H

examples/widgets/draganddrop/draggableicons/main.cpp

@@ -0,0 +1,24 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QApplication>
+#include <QHBoxLayout>
+
+#include "dragwidget.h"
+
+int main(int argc, char *argv[])
+{
+    Q_INIT_RESOURCE(draggableicons);
+
+    QApplication app(argc, argv);
+
+    QWidget mainWidget;
+    QHBoxLayout *horizontalLayout = new QHBoxLayout(&mainWidget);
+    horizontalLayout->addWidget(new DragWidget);
+    horizontalLayout->addWidget(new DragWidget);
+
+    mainWidget.setWindowTitle(QObject::tr("Draggable Icons"));
+    mainWidget.show();
+
+    return app.exec();
+}

examples/widgets/draganddrop/draggabletext/CMakeLists.txt

@@ -0,0 +1,49 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(draggabletext LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/widgets/draganddrop/draggabletext")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(draggabletext
+    dragwidget.cpp dragwidget.h
+    main.cpp
+)
+
+set_target_properties(draggabletext PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(draggabletext PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Widgets
+)
+
+# Resources:
+set(draggabletext_resource_files
+    "words.txt"
+)
+
+qt_add_resources(draggabletext "draggabletext"
+    PREFIX
+        "/dictionary"
+    FILES
+        ${draggabletext_resource_files}
+)
+
+install(TARGETS draggabletext
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/widgets/draganddrop/draggabletext/draggabletext.pro

@@ -0,0 +1,10 @@
+QT += widgets
+
+HEADERS     = dragwidget.h
+RESOURCES   = draggabletext.qrc
+SOURCES     = dragwidget.cpp \
+              main.cpp
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/widgets/draganddrop/draggabletext
+INSTALLS += target

examples/widgets/draganddrop/draggabletext/draggabletext.qrc

@@ -0,0 +1,5 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource prefix="/dictionary">
+   <file>words.txt</file>
+</qresource>
+</RCC>

examples/widgets/draganddrop/draggabletext/dragwidget.cpp

@@ -0,0 +1,130 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtWidgets>
+
+#include "dragwidget.h"
+
+static QLabel *createDragLabel(const QString &text, QWidget *parent)
+{
+    QLabel *label = new QLabel(text, parent);
+    label->setAutoFillBackground(true);
+    label->setFrameShape(QFrame::Panel);
+    label->setFrameShadow(QFrame::Raised);
+    return label;
+}
+
+static QString hotSpotMimeDataKey() { return QStringLiteral("application/x-hotspot"); }
+
+DragWidget::DragWidget(QWidget *parent)
+    : QWidget(parent)
+{
+    QFile dictionaryFile(QStringLiteral(":/dictionary/words.txt"));
+    dictionaryFile.open(QIODevice::ReadOnly);
+    QTextStream inputStream(&dictionaryFile);
+
+    int x = 5;
+    int y = 5;
+
+    while (!inputStream.atEnd()) {
+        QString word;
+        inputStream >> word;
+        if (!word.isEmpty()) {
+            QLabel *wordLabel = createDragLabel(word, this);
+            wordLabel->move(x, y);
+            wordLabel->show();
+            wordLabel->setAttribute(Qt::WA_DeleteOnClose);
+            x += wordLabel->width() + 2;
+            if (x >= 245) {
+                x = 5;
+                y += wordLabel->height() + 2;
+            }
+        }
+    }
+
+    setAcceptDrops(true);
+    setMinimumSize(400, qMax(200, y));
+    setWindowTitle(tr("Draggable Text"));
+}
+
+void DragWidget::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (event->mimeData()->hasText()) {
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+}
+
+void DragWidget::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasText()) {
+        const QMimeData *mime = event->mimeData();
+        QStringList pieces = mime->text().split(QRegularExpression(QStringLiteral("\\s+")),
+                                                Qt::SkipEmptyParts);
+        QPoint position = event->position().toPoint();
+        QPoint hotSpot;
+
+        QByteArrayList hotSpotPos = mime->data(hotSpotMimeDataKey()).split(' ');
+        if (hotSpotPos.size() == 2) {
+            hotSpot.setX(hotSpotPos.first().toInt());
+            hotSpot.setY(hotSpotPos.last().toInt());
+        }
+
+        for (const QString &piece : pieces) {
+            QLabel *newLabel = createDragLabel(piece, this);
+            newLabel->move(position - hotSpot);
+            newLabel->show();
+            newLabel->setAttribute(Qt::WA_DeleteOnClose);
+
+            position += QPoint(newLabel->width(), 0);
+        }
+
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+    for (QWidget *widget : findChildren<QWidget *>()) {
+        if (!widget->isVisible())
+            widget->deleteLater();
+    }
+}
+
+void DragWidget::mousePressEvent(QMouseEvent *event)
+{
+    QLabel *child = qobject_cast<QLabel*>(childAt(event->position().toPoint()));
+    if (!child)
+        return;
+
+    QPoint hotSpot = event->position().toPoint() - child->pos();
+
+    QMimeData *mimeData = new QMimeData;
+    mimeData->setText(child->text());
+    mimeData->setData(hotSpotMimeDataKey(),
+                      QByteArray::number(hotSpot.x()) + ' ' + QByteArray::number(hotSpot.y()));
+
+    qreal dpr = window()->windowHandle()->devicePixelRatio();
+    QPixmap pixmap(child->size() * dpr);
+    pixmap.setDevicePixelRatio(dpr);
+    child->render(&pixmap);
+
+    QDrag *drag = new QDrag(this);
+    drag->setMimeData(mimeData);
+    drag->setPixmap(pixmap);
+    drag->setHotSpot(hotSpot);
+
+    Qt::DropAction dropAction = drag->exec(Qt::CopyAction | Qt::MoveAction, Qt::CopyAction);
+
+    if (dropAction == Qt::MoveAction)
+        child->close();
+}

examples/widgets/draganddrop/draggabletext/dragwidget.h

@@ -0,0 +1,25 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef DRAGWIDGET_H
+#define DRAGWIDGET_H
+
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+class QDragEnterEvent;
+class QDropEvent;
+QT_END_NAMESPACE
+
+class DragWidget : public QWidget
+{
+public:
+    explicit DragWidget(QWidget *parent = nullptr);
+
+protected:
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+};
+
+#endif // DRAGWIDGET_H

examples/widgets/draganddrop/draggabletext/main.cpp

@@ -0,0 +1,16 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QApplication>
+
+#include "dragwidget.h"
+
+int main(int argc, char *argv[])
+{
+    Q_INIT_RESOURCE(draggabletext);
+
+    QApplication app(argc, argv);
+    DragWidget window;
+    window.show();
+    return app.exec();
+}

examples/widgets/draganddrop/draggabletext/words.txt

@@ -0,0 +1,41 @@
+Qt
+Quarterly
+is
+a
+paper
+based
+newsletter
+exclusively
+available
+to
+Qt
+customers
+Every
+quarter
+we
+mail
+out
+an
+issue
+that
+we
+hope
+will
+bring
+added
+insight
+and
+pleasure
+to
+your
+Qt
+programming
+with
+high
+quality
+technical
+articles
+written
+by
+Qt
+experts

examples/widgets/draganddrop/dropsite/CMakeLists.txt

@@ -0,0 +1,38 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(dropsite LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/widgets/draganddrop/dropsite")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(dropsite
+    droparea.cpp droparea.h
+    dropsitewindow.cpp dropsitewindow.h
+    main.cpp
+)
+
+set_target_properties(dropsite PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(dropsite PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Widgets
+)
+
+install(TARGETS dropsite
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/widgets/draganddrop/dropsite/droparea.cpp

@@ -0,0 +1,93 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "droparea.h"
+
+#include <QDragEnterEvent>
+#include <QMimeData>
+
+using namespace Qt::StringLiterals;
+
+//! [DropArea constructor]
+DropArea::DropArea(QWidget *parent)
+    : QLabel(parent)
+{
+    setMinimumSize(200, 200);
+    setFrameStyle(QFrame::Sunken | QFrame::StyledPanel);
+    setAlignment(Qt::AlignCenter);
+    setAcceptDrops(true);
+    setAutoFillBackground(true);
+    clear();
+}
+//! [DropArea constructor]
+
+//! [dragEnterEvent() function]
+void DropArea::dragEnterEvent(QDragEnterEvent *event)
+{
+    setText(tr("<drop content>"));
+    setBackgroundRole(QPalette::Highlight);
+
+    event->acceptProposedAction();
+    emit changed(event->mimeData());
+}
+//! [dragEnterEvent() function]
+
+//! [dragMoveEvent() function]
+void DropArea::dragMoveEvent(QDragMoveEvent *event)
+{
+    event->acceptProposedAction();
+}
+//! [dragMoveEvent() function]
+
+//! [dropEvent() function part1]
+void DropArea::dropEvent(QDropEvent *event)
+{
+    const QMimeData *mimeData = event->mimeData();
+//! [dropEvent() function part1]
+
+//! [dropEvent() function part2]
+    if (mimeData->hasImage()) {
+        setPixmap(qvariant_cast<QPixmap>(mimeData->imageData()));
+    } else if (mimeData->hasFormat(u"text/markdown"_s)) {
+        setText(QString::fromUtf8(mimeData->data(u"text/markdown"_s)));
+        setTextFormat(Qt::MarkdownText);
+    } else if (mimeData->hasHtml()) {
+        setText(mimeData->html());
+        setTextFormat(Qt::RichText);
+    } else if (mimeData->hasText()) {
+        setText(mimeData->text());
+        setTextFormat(Qt::PlainText);
+    } else if (mimeData->hasUrls()) {
+        QList<QUrl> urlList = mimeData->urls();
+        QString text;
+        for (qsizetype i = 0, count = qMin(urlList.size(), qsizetype(32)); i < count; ++i)
+            text += urlList.at(i).path() + u'\n';
+        setText(text);
+    } else {
+        setText(tr("Cannot display data"));
+    }
+//! [dropEvent() function part2]
+
+//! [dropEvent() function part3]
+    setBackgroundRole(QPalette::Dark);
+    event->acceptProposedAction();
+}
+//! [dropEvent() function part3]
+
+//! [dragLeaveEvent() function]
+void DropArea::dragLeaveEvent(QDragLeaveEvent *event)
+{
+    clear();
+    event->accept();
+}
+//! [dragLeaveEvent() function]
+
+//! [clear() function]
+void DropArea::clear()
+{
+    setText(tr("<drop content>"));
+    setBackgroundRole(QPalette::Dark);
+
+    emit changed();
+}
+//! [clear() function]

examples/widgets/draganddrop/dropsite/droparea.h

@@ -0,0 +1,37 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef DROPAREA_H
+#define DROPAREA_H
+
+#include <QLabel>
+
+QT_BEGIN_NAMESPACE
+class QMimeData;
+QT_END_NAMESPACE
+
+//! [DropArea header part1]
+class DropArea : public QLabel
+{
+    Q_OBJECT
+
+public:
+    explicit DropArea(QWidget *parent = nullptr);
+
+public slots:
+    void clear();
+
+signals:
+    void changed(const QMimeData *mimeData = nullptr);
+//! [DropArea header part1]
+
+//! [DropArea header part2]
+protected:
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dragLeaveEvent(QDragLeaveEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+};
+//! [DropArea header part2]
+
+#endif // DROPAREA_H

examples/widgets/draganddrop/dropsite/dropsite.pro

@@ -0,0 +1,12 @@
+QT += widgets
+requires(qtConfig(tablewidget))
+
+HEADERS = droparea.h \
+          dropsitewindow.h
+SOURCES = droparea.cpp \
+          dropsitewindow.cpp \
+          main.cpp
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/widgets/draganddrop/dropsite
+INSTALLS += target

examples/widgets/draganddrop/dropsite/dropsitewindow.cpp

@@ -0,0 +1,135 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QPushButton>
+#include <QDialogButtonBox>
+#include <QHeaderView>
+#include <QTableWidget>
+#include <QTableWidgetItem>
+#include <QVBoxLayout>
+
+#include <QClipboard>
+#include <QGuiApplication>
+
+#include <QMimeData>
+
+#include "droparea.h"
+#include "dropsitewindow.h"
+
+using namespace Qt::StringLiterals;
+
+//! [constructor part1]
+DropSiteWindow::DropSiteWindow()
+{
+    abstractLabel = new QLabel(tr("This example accepts drags from other "
+                                  "applications and displays the MIME types "
+                                  "provided by the drag object."));
+    abstractLabel->setWordWrap(true);
+    abstractLabel->adjustSize();
+//! [constructor part1]
+
+//! [constructor part2]
+    dropArea = new DropArea;
+    connect(dropArea, &DropArea::changed,
+            this, &DropSiteWindow::updateFormatsTable);
+//! [constructor part2]
+
+//! [constructor part3]
+    formatsTable = new QTableWidget;
+    formatsTable->setColumnCount(2);
+    formatsTable->setEditTriggers(QAbstractItemView::NoEditTriggers);
+    formatsTable->setHorizontalHeaderLabels({tr("Format"),  tr("Content")});
+    formatsTable->horizontalHeader()->setStretchLastSection(true);
+//! [constructor part3]
+
+//! [constructor part4]
+    clearButton = new QPushButton(tr("Clear"));
+    copyButton = new QPushButton(tr("Copy"));
+    quitButton = new QPushButton(tr("Quit"));
+
+    buttonBox = new QDialogButtonBox;
+    buttonBox->addButton(clearButton, QDialogButtonBox::ActionRole);
+    buttonBox->addButton(copyButton, QDialogButtonBox::ActionRole);
+#if !QT_CONFIG(clipboard)
+    copyButton->setVisible(false);
+#endif
+
+    buttonBox->addButton(quitButton, QDialogButtonBox::RejectRole);
+
+    connect(quitButton, &QAbstractButton::clicked, this, &QWidget::close);
+    connect(clearButton, &QAbstractButton::clicked, dropArea, &DropArea::clear);
+    connect(copyButton, &QAbstractButton::clicked, this, &DropSiteWindow::copy);
+//! [constructor part4]
+
+//! [constructor part5]
+    QVBoxLayout *mainLayout = new QVBoxLayout(this);
+    mainLayout->addWidget(abstractLabel);
+    mainLayout->addWidget(dropArea);
+    mainLayout->addWidget(formatsTable);
+    mainLayout->addWidget(buttonBox);
+
+    setWindowTitle(tr("Drop Site"));
+    resize(700, 500);
+}
+//! [constructor part5]
+
+//! [updateFormatsTable() part1]
+void DropSiteWindow::updateFormatsTable(const QMimeData *mimeData)
+{
+    formatsTable->setRowCount(0);
+    copyButton->setEnabled(false);
+    if (!mimeData)
+        return;
+//! [updateFormatsTable() part1]
+
+//! [updateFormatsTable() part2]
+    const QStringList formats = mimeData->formats();
+    for (const QString &format : formats) {
+        QTableWidgetItem *formatItem = new QTableWidgetItem(format);
+        formatItem->setFlags(Qt::ItemIsEnabled);
+        formatItem->setTextAlignment(Qt::AlignTop | Qt::AlignLeft);
+//! [updateFormatsTable() part2]
+
+//! [updateFormatsTable() part3]
+        QString text;
+        if (format == u"text/plain") {
+            text = mimeData->text().simplified();
+        } else if (format == u"text/markdown") {
+            text = QString::fromUtf8(mimeData->data(u"text/markdown"_s));
+        } else if (format == u"text/html") {
+            text = mimeData->html().simplified();
+        } else if (format == u"text/uri-list") {
+            QList<QUrl> urlList = mimeData->urls();
+            for (qsizetype i = 0, count = qMin(urlList.size(), qsizetype(32)); i < count; ++i)
+                text.append(urlList.at(i).toString() + u' ');
+        } else {
+            QByteArray data = mimeData->data(format);
+            if (data.size() > 32)
+                data.truncate(32);
+            text = QString::fromLatin1(data.toHex(' ')).toUpper();
+        }
+//! [updateFormatsTable() part3]
+
+//! [updateFormatsTable() part4]
+        int row = formatsTable->rowCount();
+        formatsTable->insertRow(row);
+        formatsTable->setItem(row, 0, new QTableWidgetItem(format));
+        formatsTable->setItem(row, 1, new QTableWidgetItem(text));
+    }
+
+    formatsTable->resizeColumnToContents(0);
+#if QT_CONFIG(clipboard)
+    copyButton->setEnabled(formatsTable->rowCount() > 0);
+#endif
+}
+//! [updateFormatsTable() part4]
+
+void DropSiteWindow::copy()
+{
+#if QT_CONFIG(clipboard)
+    QString text;
+    for (int row = 0, rowCount = formatsTable->rowCount(); row < rowCount; ++row)
+        text += formatsTable->item(row, 0)->text() + ": " + formatsTable->item(row, 1)->text() + '\n';
+    QGuiApplication::clipboard()->setText(text);
+#endif
+}

examples/widgets/draganddrop/dropsite/dropsitewindow.h

@@ -0,0 +1,42 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef DROPSITEWINDOW_H
+#define DROPSITEWINDOW_H
+
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+class QDialogButtonBox;
+class QLabel;
+class QMimeData;
+class QPushButton;
+class QTableWidget;
+QT_END_NAMESPACE
+class DropArea;
+
+//! [DropSiteWindow header]
+class DropSiteWindow : public QWidget
+{
+    Q_OBJECT
+
+public:
+    DropSiteWindow();
+
+public slots:
+    void updateFormatsTable(const QMimeData *mimeData);
+    void copy();
+
+private:
+    DropArea *dropArea;
+    QLabel *abstractLabel;
+    QTableWidget *formatsTable;
+
+    QPushButton *clearButton;
+    QPushButton *copyButton;
+    QPushButton *quitButton;
+    QDialogButtonBox *buttonBox;
+};
+//! [DropSiteWindow header]
+
+#endif // DROPSITEWINDOW_H

examples/widgets/draganddrop/dropsite/main.cpp

@@ -0,0 +1,16 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QApplication>
+
+#include "dropsitewindow.h"
+
+//! [main() function]
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    DropSiteWindow window;
+    window.show();
+    return app.exec();
+}
+//! [main() function]

examples/widgets/draganddrop/fridgemagnets/CMakeLists.txt

@@ -0,0 +1,50 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(fridgemagnets LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/widgets/draganddrop/fridgemagnets")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(fridgemagnets
+    draglabel.cpp draglabel.h
+    dragwidget.cpp dragwidget.h
+    main.cpp
+)
+
+set_target_properties(fridgemagnets PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(fridgemagnets PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Widgets
+)
+
+# Resources:
+set(fridgemagnets_resource_files
+    "words.txt"
+)
+
+qt_add_resources(fridgemagnets "fridgemagnets"
+    PREFIX
+        "/dictionary"
+    FILES
+        ${fridgemagnets_resource_files}
+)
+
+install(TARGETS fridgemagnets
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/widgets/draganddrop/fridgemagnets/draglabel.cpp

@@ -0,0 +1,51 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "draglabel.h"
+
+#include <QtWidgets>
+
+//! [0]
+DragLabel::DragLabel(const QString &text, QWidget *parent)
+    : QLabel(parent)
+{
+    QFontMetrics metric(font());
+    QSize size = metric.size(Qt::TextSingleLine, text);
+
+    QImage image(size.width() + 12, size.height() + 12, QImage::Format_ARGB32_Premultiplied);
+    image.fill(qRgba(0, 0, 0, 0));
+
+    QFont font;
+    font.setStyleStrategy(QFont::ForceOutline);
+//! [0]
+
+//! [1]
+    QLinearGradient gradient(0, 0, 0, image.height()-1);
+    gradient.setColorAt(0.0, Qt::white);
+    gradient.setColorAt(0.2, QColor(200, 200, 255));
+    gradient.setColorAt(0.8, QColor(200, 200, 255));
+    gradient.setColorAt(1.0, QColor(127, 127, 200));
+
+    QPainter painter;
+    painter.begin(&image);
+    painter.setRenderHint(QPainter::Antialiasing);
+    painter.setBrush(gradient);
+    painter.drawRoundedRect(QRectF(0.5, 0.5, image.width()-1, image.height()-1),
+                            25, 25, Qt::RelativeSize);
+
+    painter.setFont(font);
+    painter.setBrush(Qt::black);
+    painter.drawText(QRect(QPoint(6, 6), size), Qt::AlignCenter, text);
+    painter.end();
+//! [1]
+
+//! [2]
+    setPixmap(QPixmap::fromImage(image));
+    m_labelText = text;
+}
+//! [2]
+
+QString DragLabel::labelText() const
+{
+    return m_labelText;
+}

examples/widgets/draganddrop/fridgemagnets/draglabel.h

@@ -0,0 +1,27 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef DRAGLABEL_H
+#define DRAGLABEL_H
+
+#include <QLabel>
+
+QT_BEGIN_NAMESPACE
+class QDragEnterEvent;
+class QDragMoveEvent;
+class QFrame;
+QT_END_NAMESPACE
+
+//! [0]
+class DragLabel : public QLabel
+{
+public:
+    DragLabel(const QString &text, QWidget *parent);
+    QString labelText() const;
+
+private:
+    QString m_labelText;
+};
+//! [0]
+
+#endif // DRAGLABEL_H

examples/widgets/draganddrop/fridgemagnets/dragwidget.cpp

@@ -0,0 +1,176 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "draglabel.h"
+#include "dragwidget.h"
+
+#include <QtWidgets>
+
+static inline QString fridgetMagnetsMimeType() { return QStringLiteral("application/x-fridgemagnet"); }
+
+//! [0]
+DragWidget::DragWidget(QWidget *parent)
+    : QWidget(parent)
+{
+    QFile dictionaryFile(QStringLiteral(":/dictionary/words.txt"));
+    dictionaryFile.open(QFile::ReadOnly);
+    QTextStream inputStream(&dictionaryFile);
+//! [0]
+
+//! [1]
+    int x = 5;
+    int y = 5;
+
+    while (!inputStream.atEnd()) {
+        QString word;
+        inputStream >> word;
+        if (!word.isEmpty()) {
+            DragLabel *wordLabel = new DragLabel(word, this);
+            wordLabel->move(x, y);
+            wordLabel->show();
+            wordLabel->setAttribute(Qt::WA_DeleteOnClose);
+            x += wordLabel->width() + 2;
+            if (x >= 245) {
+                x = 5;
+                y += wordLabel->height() + 2;
+            }
+        }
+    }
+//! [1]
+
+//! [2]
+    QPalette newPalette = palette();
+    newPalette.setColor(QPalette::Window, Qt::white);
+    setPalette(newPalette);
+
+    setMinimumSize(400, qMax(200, y));
+    setWindowTitle(tr("Fridge Magnets"));
+//! [2] //! [3]
+    setAcceptDrops(true);
+}
+//! [3]
+
+//! [4]
+void DragWidget::dragEnterEvent(QDragEnterEvent *event)
+{
+//! [4] //! [5]
+    if (event->mimeData()->hasFormat(fridgetMagnetsMimeType())) {
+        if (children().contains(event->source())) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+//! [5] //! [6]
+        }
+//! [6] //! [7]
+    } else if (event->mimeData()->hasText()) {
+        event->acceptProposedAction();
+    } else {
+        event->ignore();
+    }
+}
+//! [7]
+
+//! [8]
+void DragWidget::dragMoveEvent(QDragMoveEvent *event)
+{
+    if (event->mimeData()->hasFormat(fridgetMagnetsMimeType())) {
+        if (children().contains(event->source())) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else if (event->mimeData()->hasText()) {
+        event->acceptProposedAction();
+    } else {
+        event->ignore();
+    }
+}
+//! [8]
+
+//! [9]
+void DragWidget::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasFormat(fridgetMagnetsMimeType())) {
+        const QMimeData *mime = event->mimeData();
+//! [9] //! [10]
+        QByteArray itemData = mime->data(fridgetMagnetsMimeType());
+        QDataStream dataStream(&itemData, QIODevice::ReadOnly);
+
+        QString text;
+        QPoint offset;
+        dataStream >> text >> offset;
+//! [10]
+//! [11]
+        DragLabel *newLabel = new DragLabel(text, this);
+        newLabel->move(event->position().toPoint() - offset);
+        newLabel->show();
+        newLabel->setAttribute(Qt::WA_DeleteOnClose);
+
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+//! [11] //! [12]
+    } else if (event->mimeData()->hasText()) {
+        QStringList pieces = event->mimeData()->text().split(
+            QRegularExpression(QStringLiteral("\\s+")), Qt::SkipEmptyParts);
+        QPoint position = event->position().toPoint();
+
+        for (const QString &piece : pieces) {
+            DragLabel *newLabel = new DragLabel(piece, this);
+            newLabel->move(position);
+            newLabel->show();
+            newLabel->setAttribute(Qt::WA_DeleteOnClose);
+
+            position += QPoint(newLabel->width(), 0);
+        }
+
+        event->acceptProposedAction();
+    } else {
+        event->ignore();
+    }
+}
+//! [12]
+
+//! [13]
+void DragWidget::mousePressEvent(QMouseEvent *event)
+{
+//! [13]
+//! [14]
+    DragLabel *child = static_cast<DragLabel*>(childAt(event->position().toPoint()));
+    if (!child)
+        return;
+
+    QPoint hotSpot = event->position().toPoint() - child->pos();
+
+    QByteArray itemData;
+    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
+    dataStream << child->labelText() << QPoint(hotSpot);
+//! [14]
+
+//! [15]
+    QMimeData *mimeData = new QMimeData;
+    mimeData->setData(fridgetMagnetsMimeType(), itemData);
+    mimeData->setText(child->labelText());
+//! [15]
+
+//! [16]
+    QDrag *drag = new QDrag(this);
+    drag->setMimeData(mimeData);
+    drag->setPixmap(child->pixmap());
+    drag->setHotSpot(hotSpot);
+
+    child->hide();
+//! [16]
+
+//! [17]
+    if (drag->exec(Qt::MoveAction | Qt::CopyAction, Qt::CopyAction) == Qt::MoveAction)
+        child->close();
+    else
+        child->show();
+}
+//! [17]

examples/widgets/draganddrop/fridgemagnets/dragwidget.h

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef DRAGWIDGET_H
+#define DRAGWIDGET_H
+
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+class QDragEnterEvent;
+class QDropEvent;
+QT_END_NAMESPACE
+
+//! [0]
+class DragWidget : public QWidget
+{
+public:
+    explicit DragWidget(QWidget *parent = nullptr);
+
+protected:
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+};
+//! [0]
+
+#endif // DRAGWIDGET_H

examples/widgets/draganddrop/fridgemagnets/fridgemagnets.pro

@@ -0,0 +1,12 @@
+QT += widgets
+
+HEADERS     = draglabel.h \
+              dragwidget.h
+RESOURCES   = fridgemagnets.qrc
+SOURCES     = draglabel.cpp \
+              dragwidget.cpp \
+              main.cpp
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/widgets/draganddrop/fridgemagnets
+INSTALLS += target

examples/widgets/draganddrop/fridgemagnets/fridgemagnets.qrc

@@ -0,0 +1,5 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource prefix="/dictionary">
+   <file>words.txt</file>
+</qresource>
+</RCC>

examples/widgets/draganddrop/fridgemagnets/main.cpp

@@ -0,0 +1,25 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QApplication>
+
+#include "dragwidget.h"
+
+int main(int argc, char *argv[])
+{
+    Q_INIT_RESOURCE(fridgemagnets);
+
+    QApplication app(argc, argv);
+#ifdef QT_KEYPAD_NAVIGATION
+    QApplication::setNavigationMode(Qt::NavigationModeCursorAuto);
+#endif
+    DragWidget window;
+
+    bool smallScreen = QApplication::arguments().contains(QStringLiteral("-small-screen"));
+    if (smallScreen)
+        window.showFullScreen();
+    else
+        window.show();
+
+    return app.exec();
+}

examples/widgets/draganddrop/fridgemagnets/words.txt

@@ -0,0 +1,48 @@
+Colorless
+green
+ideas
+sleep
+furiously
+A
+colorless
+green
+idea
+is
+a
+new
+untried
+idea
+that
+is
+without
+vividness
+dull
+and
+unexciting
+To
+sleep
+furiously
+may
+seem
+a
+puzzling
+turn
+of
+phrase
+but
+the
+mind
+in
+sleep
+often
+indeed
+moves
+furiously
+with
+ideas
+and
+images
+flickering
+in
+and
+out

examples/widgets/draganddrop/puzzle/CMakeLists.txt

@@ -0,0 +1,51 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(puzzle LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/widgets/draganddrop_puzzle")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(draganddrop_puzzle
+    main.cpp
+    mainwindow.cpp mainwindow.h
+    pieceslist.cpp pieceslist.h
+    puzzlewidget.cpp puzzlewidget.h
+)
+
+set_target_properties(draganddrop_puzzle PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(draganddrop_puzzle PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Widgets
+)
+
+# Resources:
+set(puzzle_resource_files
+    "example.jpg"
+)
+
+qt_add_resources(draganddrop_puzzle "puzzle"
+    PREFIX
+        "/images"
+    FILES
+        ${puzzle_resource_files}
+)
+
+install(TARGETS draganddrop_puzzle
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/widgets/draganddrop/puzzle/main.cpp

@@ -0,0 +1,17 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "mainwindow.h"
+
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    Q_INIT_RESOURCE(puzzle);
+
+    QApplication app(argc, argv);
+    MainWindow window;
+    window.loadImage(QStringLiteral(":/images/example.jpg"));
+    window.show();
+    return app.exec();
+}

examples/widgets/draganddrop/puzzle/mainwindow.cpp

@@ -0,0 +1,118 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "mainwindow.h"
+#include "pieceslist.h"
+#include "puzzlewidget.h"
+
+#include <QtWidgets>
+#include <stdlib.h>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent)
+{
+    setupMenus();
+    setupWidgets();
+
+    setSizePolicy(QSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed));
+    setWindowTitle(tr("Puzzle"));
+}
+
+void MainWindow::openImage()
+{
+    const QString directory =
+        QStandardPaths::standardLocations(QStandardPaths::PicturesLocation).value(0, QDir::homePath());
+    QFileDialog dialog(this, tr("Open Image"), directory);
+    dialog.setAcceptMode(QFileDialog::AcceptOpen);
+    dialog.setFileMode(QFileDialog::ExistingFile);
+    QStringList mimeTypeFilters;
+    for (const QByteArray &mimeTypeName : QImageReader::supportedMimeTypes())
+        mimeTypeFilters.append(mimeTypeName);
+    mimeTypeFilters.sort();
+    dialog.setMimeTypeFilters(mimeTypeFilters);
+    dialog.selectMimeTypeFilter("image/jpeg");
+    if (dialog.exec() == QDialog::Accepted)
+        loadImage(dialog.selectedFiles().constFirst());
+}
+
+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()
+{
+    QMessageBox::information(this, tr("Puzzle Completed"),
+                             tr("Congratulations! You have completed the puzzle!\n"
+                                "Click OK to start again."),
+                             QMessageBox::Ok);
+
+    setupPuzzle();
+}
+
+void MainWindow::setupPuzzle()
+{
+    int size = qMin(puzzleImage.width(), puzzleImage.height());
+    puzzleImage = puzzleImage.copy((puzzleImage.width() - size) / 2,
+        (puzzleImage.height() - size) / 2, size, size).scaled(puzzleWidget->width(),
+            puzzleWidget->height(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
+
+    piecesList->clear();
+
+    for (int y = 0; y < 5; ++y) {
+        for (int x = 0; x < 5; ++x) {
+            int pieceSize = puzzleWidget->pieceSize();
+            QPixmap pieceImage = puzzleImage.copy(x * pieceSize, y * pieceSize, pieceSize, pieceSize);
+            piecesList->addPiece(pieceImage, QPoint(x, y));
+        }
+    }
+
+    for (int i = 0; i < piecesList->count(); ++i) {
+        if (QRandomGenerator::global()->bounded(2) == 1) {
+            QListWidgetItem *item = piecesList->takeItem(i);
+            piecesList->insertItem(0, item);
+        }
+    }
+
+    puzzleWidget->clear();
+}
+
+void MainWindow::setupMenus()
+{
+    QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
+
+    QAction *openAction = fileMenu->addAction(tr("&Open..."), this, &MainWindow::openImage);
+    openAction->setShortcuts(QKeySequence::Open);
+
+    QAction *exitAction = fileMenu->addAction(tr("E&xit"), qApp, &QCoreApplication::quit);
+    exitAction->setShortcuts(QKeySequence::Quit);
+
+    QMenu *gameMenu = menuBar()->addMenu(tr("&Game"));
+
+    gameMenu->addAction(tr("&Restart"), this, &MainWindow::setupPuzzle);
+}
+
+void MainWindow::setupWidgets()
+{
+    QFrame *frame = new QFrame;
+    QHBoxLayout *frameLayout = new QHBoxLayout(frame);
+    puzzleWidget = new PuzzleWidget(400);
+
+    piecesList = new PiecesList(puzzleWidget->pieceSize(), this);
+
+
+    connect(puzzleWidget, &PuzzleWidget::puzzleCompleted,
+            this, &MainWindow::setCompleted, Qt::QueuedConnection);
+
+    frameLayout->addWidget(piecesList);
+    frameLayout->addWidget(puzzleWidget);
+    setCentralWidget(frame);
+}

examples/widgets/draganddrop/puzzle/mainwindow.h

@@ -0,0 +1,40 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QPixmap>
+
+class PiecesList;
+class PuzzleWidget;
+QT_BEGIN_NAMESPACE
+class QListWidgetItem;
+QT_END_NAMESPACE
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    explicit MainWindow(QWidget *parent = nullptr);
+    void loadImage(const QString &path);
+
+public slots:
+    void openImage();
+    void setupPuzzle();
+
+private slots:
+    void setCompleted();
+
+private:
+    void setupMenus();
+    void setupWidgets();
+
+    QPixmap puzzleImage;
+    PiecesList *piecesList;
+    PuzzleWidget *puzzleWidget;
+};
+
+#endif // MAINWINDOW_H

examples/widgets/draganddrop/puzzle/pieceslist.cpp

@@ -0,0 +1,87 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "pieceslist.h"
+
+#include <QDrag>
+#include <QDragEnterEvent>
+#include <QMimeData>
+
+PiecesList::PiecesList(int pieceSize, QWidget *parent)
+    : QListWidget(parent), m_PieceSize(pieceSize)
+{
+    setDragEnabled(true);
+    setViewMode(QListView::IconMode);
+    setIconSize(QSize(m_PieceSize, m_PieceSize));
+    setSpacing(10);
+    setAcceptDrops(true);
+    setDropIndicatorShown(true);
+}
+
+void PiecesList::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType()))
+        event->accept();
+    else
+        event->ignore();
+}
+
+void PiecesList::dragMoveEvent(QDragMoveEvent *event)
+{
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) {
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+    } else {
+        event->ignore();
+    }
+}
+
+void PiecesList::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) {
+        QByteArray pieceData = event->mimeData()->data(PiecesList::puzzleMimeType());
+        QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
+        QPixmap pixmap;
+        QPoint location;
+        dataStream >> pixmap >> location;
+
+        addPiece(pixmap, location);
+
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+    } else {
+        event->ignore();
+    }
+}
+
+void PiecesList::addPiece(const QPixmap &pixmap, const QPoint &location)
+{
+    QListWidgetItem *pieceItem = new QListWidgetItem(this);
+    pieceItem->setIcon(QIcon(pixmap));
+    pieceItem->setData(Qt::UserRole, QVariant(pixmap));
+    pieceItem->setData(Qt::UserRole+1, location);
+    pieceItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDragEnabled);
+}
+
+void PiecesList::startDrag(Qt::DropActions /*supportedActions*/)
+{
+    QListWidgetItem *item = currentItem();
+
+    QByteArray itemData;
+    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
+    QPixmap pixmap = qvariant_cast<QPixmap>(item->data(Qt::UserRole));
+    QPoint location = item->data(Qt::UserRole+1).toPoint();
+
+    dataStream << pixmap << location;
+
+    QMimeData *mimeData = new QMimeData;
+    mimeData->setData(PiecesList::puzzleMimeType(), itemData);
+
+    QDrag *drag = new QDrag(this);
+    drag->setMimeData(mimeData);
+    drag->setHotSpot(QPoint(pixmap.width()/2, pixmap.height()/2));
+    drag->setPixmap(pixmap);
+
+    if (drag->exec(Qt::MoveAction) == Qt::MoveAction)
+        delete takeItem(row(item));
+}

examples/widgets/draganddrop/puzzle/pieceslist.h

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef PIECESLIST_H
+#define PIECESLIST_H
+
+#include <QListWidget>
+
+class PiecesList : public QListWidget
+{
+    Q_OBJECT
+
+public:
+    explicit PiecesList(int pieceSize, QWidget *parent = nullptr);
+    void addPiece(const QPixmap &pixmap, const QPoint &location);
+
+    static QString puzzleMimeType() { return QStringLiteral("image/x-puzzle-piece"); }
+
+protected:
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+    void startDrag(Qt::DropActions supportedActions) override;
+
+    int m_PieceSize;
+};
+
+#endif // PIECESLIST_H

examples/widgets/draganddrop/puzzle/puzzle.pro

@@ -0,0 +1,17 @@
+QT += widgets
+requires(qtConfig(filedialog))
+
+HEADERS     = mainwindow.h \
+              pieceslist.h \
+              puzzlewidget.h
+RESOURCES   = puzzle.qrc
+SOURCES     = main.cpp \
+              mainwindow.cpp \
+              pieceslist.cpp \
+              puzzlewidget.cpp
+
+QMAKE_PROJECT_NAME = dndpuzzle
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/widgets/draganddrop/puzzle
+INSTALLS += target

examples/widgets/draganddrop/puzzle/puzzle.qrc

@@ -0,0 +1,5 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource prefix="/images">
+   <file>example.jpg</file>
+</qresource>
+</RCC>

examples/widgets/draganddrop/puzzle/puzzlewidget.cpp

@@ -0,0 +1,167 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "puzzlewidget.h"
+#include "pieceslist.h"
+
+#include <QDrag>
+#include <QDragEnterEvent>
+#include <QMimeData>
+#include <QPainter>
+
+PuzzleWidget::PuzzleWidget(int imageSize, QWidget *parent)
+    : QWidget(parent), m_ImageSize(imageSize)
+{
+    setAcceptDrops(true);
+    setMinimumSize(m_ImageSize, m_ImageSize);
+    setMaximumSize(m_ImageSize, m_ImageSize);
+}
+
+void PuzzleWidget::clear()
+{
+    pieces.clear();
+    highlightedRect = QRect();
+    inPlace = 0;
+    update();
+}
+
+void PuzzleWidget::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType()))
+        event->accept();
+    else
+        event->ignore();
+}
+
+void PuzzleWidget::dragLeaveEvent(QDragLeaveEvent *event)
+{
+    QRect updateRect = highlightedRect;
+    highlightedRect = QRect();
+    update(updateRect);
+    event->accept();
+}
+
+void PuzzleWidget::dragMoveEvent(QDragMoveEvent *event)
+{
+    QRect updateRect = highlightedRect.united(targetSquare(event->position().toPoint()));
+
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())
+        && findPiece(targetSquare(event->position().toPoint())) == -1) {
+
+        highlightedRect = targetSquare(event->position().toPoint());
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+    } else {
+        highlightedRect = QRect();
+        event->ignore();
+    }
+
+    update(updateRect);
+}
+
+void PuzzleWidget::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())
+        && findPiece(targetSquare(event->position().toPoint())) == -1) {
+
+        QByteArray pieceData = event->mimeData()->data(PiecesList::puzzleMimeType());
+        QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
+        Piece piece;
+        piece.rect = targetSquare(event->position().toPoint());
+        dataStream >> piece.pixmap >> piece.location;
+
+        pieces.append(piece);
+
+        highlightedRect = QRect();
+        update(piece.rect);
+
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+
+        if (piece.location == piece.rect.topLeft() / pieceSize()) {
+            inPlace++;
+            if (inPlace == 25)
+                emit puzzleCompleted();
+        }
+    } else {
+        highlightedRect = QRect();
+        event->ignore();
+    }
+}
+
+int PuzzleWidget::findPiece(const QRect &pieceRect) const
+{
+    for (int i = 0, size = pieces.size(); i < size; ++i) {
+        if (pieces.at(i).rect == pieceRect)
+            return i;
+    }
+    return -1;
+}
+
+void PuzzleWidget::mousePressEvent(QMouseEvent *event)
+{
+    QRect square = targetSquare(event->position().toPoint());
+    const int found = findPiece(square);
+
+    if (found == -1)
+        return;
+
+    Piece piece = pieces.takeAt(found);
+
+    if (piece.location == square.topLeft() / pieceSize())
+        inPlace--;
+
+    update(square);
+
+    QByteArray itemData;
+    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
+
+    dataStream << piece.pixmap << piece.location;
+
+    QMimeData *mimeData = new QMimeData;
+    mimeData->setData(PiecesList::puzzleMimeType(), itemData);
+
+    QDrag *drag = new QDrag(this);
+    drag->setMimeData(mimeData);
+    drag->setHotSpot(event->position().toPoint() - square.topLeft());
+    drag->setPixmap(piece.pixmap);
+
+    if (drag->exec(Qt::MoveAction) != Qt::MoveAction) {
+        pieces.insert(found, piece);
+        update(targetSquare(event->position().toPoint()));
+
+        if (piece.location == square.topLeft() / pieceSize())
+            inPlace++;
+    }
+}
+
+void PuzzleWidget::paintEvent(QPaintEvent *event)
+{
+    QPainter painter(this);
+    painter.fillRect(event->rect(), Qt::white);
+
+    if (highlightedRect.isValid()) {
+        painter.setBrush(QColor("#ffcccc"));
+        painter.setPen(Qt::NoPen);
+        painter.drawRect(highlightedRect.adjusted(0, 0, -1, -1));
+    }
+
+    for (const Piece &piece : pieces)
+        painter.drawPixmap(piece.rect, piece.pixmap);
+}
+
+const QRect PuzzleWidget::targetSquare(const QPoint &position) const
+{
+    QPoint topLeft = QPoint(position.x() / pieceSize(), position.y() / pieceSize()) * pieceSize();
+    return QRect(topLeft, QSize(pieceSize(), pieceSize()));
+}
+
+int PuzzleWidget::pieceSize() const
+{
+    return m_ImageSize / 5;
+}
+
+int PuzzleWidget::imageSize() const
+{
+    return m_ImageSize;
+}

examples/widgets/draganddrop/puzzle/puzzlewidget.h

@@ -0,0 +1,56 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef PUZZLEWIDGET_H
+#define PUZZLEWIDGET_H
+
+#include <QPoint>
+#include <QPixmap>
+#include <QList>
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+class QDragEnterEvent;
+class QDropEvent;
+class QMouseEvent;
+QT_END_NAMESPACE
+
+class PuzzleWidget : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit PuzzleWidget(int imageSize, QWidget *parent = nullptr);
+    void clear();
+
+    int pieceSize() const;
+    int imageSize() const;
+
+signals:
+    void puzzleCompleted();
+
+protected:
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragLeaveEvent(QDragLeaveEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+    void paintEvent(QPaintEvent *event) override;
+
+private:
+    struct Piece {
+        QPixmap pixmap;
+        QRect rect;
+        QPoint location;
+    };
+
+    int findPiece(const QRect &pieceRect) const;
+    const QRect targetSquare(const QPoint &position) const;
+
+    QList<Piece> pieces;
+    QRect highlightedRect;
+    int inPlace;
+    int m_ImageSize;
+};
+
+#endif // PUZZLEWIDGET_H