Implement drag and drop support

Create a QDrag for drag and drop operations that are started in the web
page. React on drag and drop event of QWidget and QQuickItem.

Task-number: QTBUG-43008
Change-Id: If09f09de6e6d5b5f02835985a17cc6bc3262f411
Reviewed-by: Alexandru Croitor <alexandru.croitor@theqtcompany.com>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>

15 files changed, 367 insertions, 11 deletions

diff --git a/src/core/type_conversion.cpp b/src/core/type_conversion.cpp
index d4b988552..99a7da099 100644
--- a/src/core/type_conversion.cpp
+++ b/src/core/type_conversion.cpp
@@ -37,6 +37,7 @@
 #include "type_conversion.h"
 
 #include <ui/events/event_constants.h>
+#include <ui/gfx/image/image_skia.h>
 #include <QtCore/qcoreapplication.h>
 
 namespace QtWebEngineCore {
@@ -116,6 +117,14 @@ QImage toQImage(const SkBitmap &bitmap)
     return image;
 }
 
+QImage toQImage(const gfx::ImageSkiaRep &imageSkiaRep)
+{
+    QImage image = toQImage(imageSkiaRep.sk_bitmap());
+    if (!image.isNull() && imageSkiaRep.scale() != 1.0f)
+        image.setDevicePixelRatio(imageSkiaRep.scale());
+    return image;
+}
+
 int flagsFromModifiers(Qt::KeyboardModifiers modifiers)
 {
     int modifierFlags = ui::EF_NONE;
@@ -140,4 +149,5 @@ int flagsFromModifiers(Qt::KeyboardModifiers modifiers)
     return modifierFlags;
 }
 
+
 } // namespace QtWebEngineCore
diff --git a/src/core/type_conversion.h b/src/core/type_conversion.h
index da0ee3e5c..5cf7267f2 100644
--- a/src/core/type_conversion.h
+++ b/src/core/type_conversion.h
@@ -46,6 +46,7 @@
 #include <QRect>
 #include <QString>
 #include <QUrl>
+#include <base/strings/nullable_string16.h>
 #include "base/files/file_path.h"
 #include "base/time/time.h"
 #include "content/public/common/file_chooser_file_info.h"
@@ -58,6 +59,10 @@
 #include "ui/gfx/geometry/rect_f.h"
 #include "url/gurl.h"
 
+namespace gfx {
+class ImageSkiaRep;
+}
+
 namespace QtWebEngineCore {
 
 inline QString toQt(const base::string16 &string)
@@ -83,6 +88,11 @@ inline base::string16 toString16(const QString &qString)
 #endif
 }
 
+inline base::NullableString16 toNullableString16(const QString &qString)
+{
+    return base::NullableString16(toString16(qString), qString.isNull());
+}
+
 inline QUrl toQt(const GURL &url)
 {
     return QUrl(QString::fromStdString(url.spec()));
@@ -150,6 +160,7 @@ inline QImage toQImage(const SkBitmap &bitmap, QImage::Format format)
 }
 
 QImage toQImage(const SkBitmap &bitmap);
+QImage toQImage(const gfx::ImageSkiaRep &imageSkiaRep);
 
 inline QMatrix4x4 toQt(const SkMatrix44 &m)
 {
diff --git a/src/core/web_contents_adapter.cpp b/src/core/web_contents_adapter.cpp
index 923bb1e2d..ad582d7d3 100644
--- a/src/core/web_contents_adapter.cpp
+++ b/src/core/web_contents_adapter.cpp
@@ -55,6 +55,7 @@
 #include "web_engine_context.h"
 #include "web_engine_settings.h"
 
+#include <base/run_loop.h>
 #include "base/values.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
@@ -65,6 +66,7 @@
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/favicon_status.h"
+#include <content/public/common/drop_data.h>
 #include "content/public/common/page_state.h"
 #include "content/public/common/page_zoom.h"
 #include "content/public/common/renderer_preferences.h"
@@ -77,7 +79,10 @@
 #include <QStringList>
 #include <QStyleHints>
 #include <QVariant>
+#include <QtCore/qmimedata.h>
 #include <QtGui/qaccessible.h>
+#include <QtGui/qdrag.h>
+#include <QtGui/qpixmap.h>
 #include <QtWebChannel/QWebChannel>
 
 namespace QtWebEngineCore {
@@ -312,6 +317,9 @@ WebContentsAdapterPrivate::WebContentsAdapterPrivate()
     , adapterClient(0)
     , nextRequestId(CallbackDirectory::ReservedCallbackIdsEnd)
     , lastFindRequestId(0)
+    , currentDropData(nullptr)
+    , currentDropAction(Qt::IgnoreAction)
+    , inDragUpdateLoop(false)
 {
 }
 
@@ -961,6 +969,154 @@ void WebContentsAdapter::setWebChannel(QWebChannel *channel)
     channel->connectTo(d->webChannelTransport.get());
 }
 
+static QMimeData *mimeDataFromDropData(const content::DropData &dropData)
+{
+    QMimeData *mimeData = new QMimeData();
+    if (!dropData.text.is_null()) {
+        mimeData->setText(toQt(dropData.text.string()));
+        return mimeData;
+    }
+    if (!dropData.html.is_null()) {
+        mimeData->setHtml(toQt(dropData.html.string()));
+        return mimeData;
+    }
+    if (dropData.url.is_valid()) {
+        mimeData->setUrls(QList<QUrl>() << toQt(dropData.url));
+        return mimeData;
+    }
+    return mimeData;
+}
+
+void WebContentsAdapter::startDragging(QObject *dragSource, const content::DropData &dropData,
+                                       Qt::DropActions allowedActions, const QPixmap &pixmap,
+                                       const QPoint &offset)
+{
+    Q_D(WebContentsAdapter);
+
+    if (d->currentDropData)
+        return;
+
+    // Clear certain fields of the drop data to not run into DCHECKs
+    // of DropDataToWebDragData in render_view_impl.cc.
+    content::DropData fixedDropData = dropData;
+    fixedDropData.download_metadata.clear();
+    fixedDropData.file_contents.clear();
+    fixedDropData.file_description_filename.clear();
+
+    d->currentDropAction = Qt::IgnoreAction;
+    d->currentDropData = &fixedDropData;
+    QDrag *drag = new QDrag(dragSource);    // will be deleted by Qt's DnD implementation
+    drag->setMimeData(mimeDataFromDropData(fixedDropData));
+    if (!pixmap.isNull()) {
+        drag->setPixmap(pixmap);
+        drag->setHotSpot(offset);
+    }
+
+    {
+        base::MessageLoop::ScopedNestableTaskAllower allow(base::MessageLoop::current());
+        drag->exec(allowedActions);
+    }
+
+    content::RenderViewHost *rvh = d->webContents->GetRenderViewHost();
+    rvh->DragSourceSystemDragEnded();
+    d->currentDropData = nullptr;
+}
+
+static blink::WebDragOperationsMask toWeb(const Qt::DropActions action)
+{
+    int result = blink::WebDragOperationNone;
+    if (action & Qt::CopyAction)
+        result |= blink::WebDragOperationCopy;
+    if (action & Qt::LinkAction)
+        result |= blink::WebDragOperationLink;
+    if (action & Qt::MoveAction)
+        result |= blink::WebDragOperationMove;
+    return static_cast<blink::WebDragOperationsMask>(result);
+}
+
+static void fillDropDataFromMimeData(content::DropData *dropData, const QMimeData *mimeData)
+{
+    if (mimeData->hasText())
+        dropData->text = toNullableString16(mimeData->text());
+    if (mimeData->hasHtml())
+        dropData->html = toNullableString16(mimeData->html());
+    Q_FOREACH (const QUrl &url, mimeData->urls()) {
+        if (url.isLocalFile()) {
+            ui::FileInfo uifi;
+            uifi.path = toFilePath(url.toLocalFile());
+            dropData->filenames.push_back(uifi);
+        }
+    }
+}
+
+void WebContentsAdapter::enterDrag(QDragEnterEvent *e, const QPoint &screenPos)
+{
+    Q_D(WebContentsAdapter);
+
+    scoped_ptr<content::DropData> ownedDropData;
+    const content::DropData *rvhDropData = d->currentDropData;
+    if (!rvhDropData) {
+        // The drag originated outside the WebEngineView.
+        ownedDropData.reset(new content::DropData);
+        fillDropDataFromMimeData(ownedDropData.get(), e->mimeData());
+        rvhDropData = ownedDropData.get();
+    }
+
+    content::RenderViewHost *rvh = d->webContents->GetRenderViewHost();
+    rvh->DragTargetDragEnter(*rvhDropData, toGfx(e->pos()), toGfx(screenPos),
+                             toWeb(e->possibleActions()),
+                             flagsFromModifiers(e->keyboardModifiers()));
+}
+
+Qt::DropAction WebContentsAdapter::updateDragPosition(QDragMoveEvent *e, const QPoint &screenPos)
+{
+    Q_D(WebContentsAdapter);
+    content::RenderViewHost *rvh = d->webContents->GetRenderViewHost();
+    rvh->DragTargetDragOver(toGfx(e->pos()), toGfx(screenPos), toWeb(e->possibleActions()),
+                            blink::WebInputEvent::LeftButtonDown);
+
+    // Wait until we get notified via RenderViewHostDelegateView::UpdateDragCursor. This calls
+    // WebContentsAdapter::updateDragAction that will eventually quit the nested loop.
+    base::RunLoop loop;
+    d->inDragUpdateLoop = true;
+    d->dragUpdateLoopQuitClosure = loop.QuitClosure();
+    loop.Run();
+
+    return d->currentDropAction;
+}
+
+void WebContentsAdapter::updateDragAction(Qt::DropAction action)
+{
+    Q_D(WebContentsAdapter);
+    d->currentDropAction = action;
+    finishDragUpdate();
+}
+
+void WebContentsAdapter::finishDragUpdate()
+{
+    Q_D(WebContentsAdapter);
+    if (d->inDragUpdateLoop) {
+        d->dragUpdateLoopQuitClosure.Run();
+        d->inDragUpdateLoop = false;
+    }
+}
+
+void WebContentsAdapter::endDragging(const QPoint &clientPos, const QPoint &screenPos)
+{
+    Q_D(WebContentsAdapter);
+    finishDragUpdate();
+    content::RenderViewHost *rvh = d->webContents->GetRenderViewHost();
+    rvh->DragTargetDrop(toGfx(clientPos), toGfx(screenPos), 0);
+}
+
+void WebContentsAdapter::leaveDrag()
+{
+    Q_D(WebContentsAdapter);
+    finishDragUpdate();
+    content::RenderViewHost *rvh = d->webContents->GetRenderViewHost();
+    rvh->DragTargetDragLeave();
+}
+
 WebContentsAdapterClient::RenderProcessTerminationStatus
 WebContentsAdapterClient::renderProcessExitStatus(int terminationStatus) {
     auto status = WebContentsAdapterClient::RenderProcessTerminationStatus(-1);
diff --git a/src/core/web_contents_adapter.h b/src/core/web_contents_adapter.h
index 01da38894..d38979177 100644
--- a/src/core/web_contents_adapter.h
+++ b/src/core/web_contents_adapter.h
@@ -52,6 +52,8 @@ struct WebPreferences;
 
 QT_BEGIN_NAMESPACE
 class QAccessibleInterface;
+class QDragEnterEvent;
+class QDragMoveEvent;
 class QWebChannel;
 QT_END_NAMESPACE
 
@@ -153,6 +155,15 @@ public:
     QPointF lastScrollOffset() const;
     QSizeF lastContentsSize() const;
 
+    void startDragging(QObject *dragSource, const content::DropData &dropData,
+                       Qt::DropActions allowedActions, const QPixmap &pixmap, const QPoint &offset);
+    void enterDrag(QDragEnterEvent *e, const QPoint &screenPos);
+    Qt::DropAction updateDragPosition(QDragMoveEvent *e, const QPoint &screenPos);
+    void updateDragAction(Qt::DropAction action);
+    void finishDragUpdate();
+    void endDragging(const QPoint &clientPos, const QPoint &screenPos);
+    void leaveDrag();
+
     // meant to be used within WebEngineCore only
     content::WebContents *webContents() const;
 
diff --git a/src/core/web_contents_adapter_client.h b/src/core/web_contents_adapter_client.h
index 92d5aa093..b19cc5241 100644
--- a/src/core/web_contents_adapter_client.h
+++ b/src/core/web_contents_adapter_client.h
@@ -50,6 +50,10 @@ QT_FORWARD_DECLARE_CLASS(QKeyEvent)
 QT_FORWARD_DECLARE_CLASS(QVariant)
 QT_FORWARD_DECLARE_CLASS(CertificateErrorController)
 
+namespace content {
+struct DropData;
+}
+
 namespace QtWebEngineCore {
 
 class AuthenticationDialogController;
@@ -243,9 +247,11 @@ public:
     virtual void allowCertificateError(const QSharedPointer<CertificateErrorController> &errorController) = 0;
     virtual void updateScrollPosition(const QPointF &position) = 0;
     virtual void updateContentsSize(const QSizeF &size) = 0;
+    virtual void startDragging(const content::DropData &dropData, Qt::DropActions allowedActions,
+                               const QPixmap &pixmap, const QPoint &offset) = 0;
 
     virtual BrowserContextAdapter* browserContextAdapter() = 0;
-
+    virtual WebContentsAdapter* webContentsAdapter() = 0;
 };
 
 } // namespace QtWebEngineCore
diff --git a/src/core/web_contents_adapter_p.h b/src/core/web_contents_adapter_p.h
index 093b9059d..63f075bce 100644
--- a/src/core/web_contents_adapter_p.h
+++ b/src/core/web_contents_adapter_p.h
@@ -50,6 +50,7 @@
 
 #include "web_contents_adapter.h"
 
+#include <base/callback.h>
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 
@@ -57,6 +58,12 @@
 
 QT_FORWARD_DECLARE_CLASS(QWebChannel)
 
+class WebEngineContext;
+
+namespace content {
+struct DropData;
+}
+
 namespace QtWebEngineCore {
 
 class BrowserContextAdapter;
@@ -81,6 +88,10 @@ public:
     WebContentsAdapterClient *adapterClient;
     quint64 nextRequestId;
     int lastFindRequestId;
+    const content::DropData *currentDropData;
+    Qt::DropAction currentDropAction;
+    bool inDragUpdateLoop;
+    base::Closure dragUpdateLoopQuitClosure;
 };
 
 } // namespace QtWebEngineCore
diff --git a/src/core/web_contents_view_qt.cpp b/src/core/web_contents_view_qt.cpp
index 67addacd5..153966aea 100644
--- a/src/core/web_contents_view_qt.cpp
+++ b/src/core/web_contents_view_qt.cpp
@@ -40,10 +40,14 @@
 #include "content_browser_client_qt.h"
 #include "render_widget_host_view_qt_delegate.h"
 #include "type_conversion.h"
+#include "web_contents_adapter.h"
 #include "web_engine_context.h"
 
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/public/common/context_menu_params.h"
+#include <ui/gfx/image/image_skia.h>
+
+#include <QtGui/qpixmap.h>
 
 namespace QtWebEngineCore {
 
@@ -164,15 +168,51 @@ void WebContentsViewQt::ShowContextMenu(content::RenderFrameHost *, const conten
     m_client->contextMenuRequested(contextMenuData);
 }
 
-void WebContentsViewQt::StartDragging(const content::DropData& drop_data, blink::WebDragOperationsMask allowed_ops, const gfx::ImageSkia& image, const gfx::Vector2d& image_offset, const content::DragEventSourceInfo& event_info)
+Qt::DropActions toQtDropActions(blink::WebDragOperationsMask ops)
+{
+    Qt::DropActions result;
+    if (ops & blink::WebDragOperationCopy)
+        result |= Qt::CopyAction;
+    if (ops & blink::WebDragOperationLink)
+        result |= Qt::LinkAction;
+    if (ops & blink::WebDragOperationMove || ops & blink::WebDragOperationDelete)
+        result |= Qt::MoveAction;
+    return result;
+}
+
+Qt::DropAction toQt(blink::WebDragOperation op)
+{
+    if (op == blink::WebDragOperationCopy)
+        return Qt::CopyAction;
+    if (op == blink::WebDragOperationLink)
+        return Qt::LinkAction;
+    if (op == blink::WebDragOperationMove || op == blink::WebDragOperationDelete)
+        return Qt::MoveAction;
+    return Qt::IgnoreAction;
+}
+
+void WebContentsViewQt::StartDragging(const content::DropData &drop_data,
+                                      blink::WebDragOperationsMask allowed_ops,
+                                      const gfx::ImageSkia &image,
+                                      const gfx::Vector2d &image_offset,
+                                      const content::DragEventSourceInfo &event_info)
+{
+    Q_UNUSED(event_info);
+
+    QPixmap pixmap;
+    QPoint hotspot;
+    pixmap = QPixmap::fromImage(toQImage(image.GetRepresentation(m_client->dpiScale())));
+    if (!pixmap.isNull()) {
+        hotspot.setX(image_offset.x());
+        hotspot.setY(image_offset.y());
+    }
+
+    m_client->startDragging(drop_data, toQtDropActions(allowed_ops), pixmap, hotspot);
+}
+
+void WebContentsViewQt::UpdateDragCursor(blink::WebDragOperation dragOperation)
 {
-    Q_UNUSED(&drop_data);
-    Q_UNUSED(allowed_ops);
-    Q_UNUSED(&image);
-    Q_UNUSED(&image_offset);
-    Q_UNUSED(&event_info);
-    // Tell the renderer to cancel the drag, see StartDragging's declaration in render_view_host_delegate_view.h for info.
-    m_webContents->SystemDragEnded();
+    m_client->webContentsAdapter()->updateDragAction(toQt(dragOperation));
 }
 
 void WebContentsViewQt::TakeFocus(bool reverse)
diff --git a/src/core/web_contents_view_qt.h b/src/core/web_contents_view_qt.h
index cbbca2371..084fa615d 100644
--- a/src/core/web_contents_view_qt.h
+++ b/src/core/web_contents_view_qt.h
@@ -104,7 +104,11 @@ public:
 
     virtual gfx::Rect GetViewBounds() const Q_DECL_OVERRIDE { QT_NOT_YET_IMPLEMENTED return gfx::Rect(); }
 
-    virtual void StartDragging(const content::DropData& drop_data, blink::WebDragOperationsMask allowed_ops, const gfx::ImageSkia& image, const gfx::Vector2d& image_offset, const content::DragEventSourceInfo& event_info) Q_DECL_OVERRIDE;
+    void StartDragging(const content::DropData &drop_data, blink::WebDragOperationsMask allowed_ops,
+                       const gfx::ImageSkia &image,  const gfx::Vector2d &image_offset,
+                       const content::DragEventSourceInfo &event_info) Q_DECL_OVERRIDE;
+
+    void UpdateDragCursor(blink::WebDragOperation dragOperation) Q_DECL_OVERRIDE;
 
     virtual void ShowContextMenu(content::RenderFrameHost *, const content::ContextMenuParams &params) Q_DECL_OVERRIDE;
 
diff --git a/src/webengine/api/qquickwebengineview.cpp b/src/webengine/api/qquickwebengineview.cpp
index 7b0ed0a33..df1f46852 100644
--- a/src/webengine/api/qquickwebengineview.cpp
+++ b/src/webengine/api/qquickwebengineview.cpp
@@ -621,6 +621,11 @@ BrowserContextAdapter *QQuickWebEngineViewPrivate::browserContextAdapter()
     return m_profile->d_ptr->browserContext();
 }
 
+WebContentsAdapter *QQuickWebEngineViewPrivate::webContentsAdapter()
+{
+    return adapter.data();
+}
+
 WebEngineSettings *QQuickWebEngineViewPrivate::webEngineSettings() const
 {
     return m_settings->d_ptr.data();
@@ -749,7 +754,8 @@ QQuickWebEngineView::QQuickWebEngineView(QQuickItem *parent)
     Q_D(QQuickWebEngineView);
     d->e->q_ptr = d->q_ptr = this;
     this->setActiveFocusOnTab(true);
-    this->setFlags(QQuickItem::ItemIsFocusScope | QQuickItem::ItemAcceptsInputMethod);
+    this->setFlags(QQuickItem::ItemIsFocusScope | QQuickItem::ItemAcceptsInputMethod
+                   | QQuickItem::ItemAcceptsDrops);
 
 #ifndef QT_NO_ACCESSIBILITY
     QQuickAccessibleAttached *accessible = QQuickAccessibleAttached::qmlAttachedProperties(this);
@@ -999,6 +1005,13 @@ void QQuickWebEngineViewPrivate::renderProcessTerminated(
                                       renderProcessExitStatus(terminationStatus)), exitCode);
 }
 
+void QQuickWebEngineViewPrivate::startDragging(const content::DropData &dropData,
+                                               Qt::DropActions allowedActions,
+                                               const QPixmap &pixmap, const QPoint &offset)
+{
+    adapter->startDragging(q_ptr->window(), dropData, allowedActions, pixmap, offset);
+}
+
 bool QQuickWebEngineView::isLoading() const
 {
     Q_D(const QQuickWebEngineView);
@@ -1265,6 +1278,39 @@ void QQuickWebEngineView::itemChange(ItemChange change, const ItemChangeData &va
     QQuickItem::itemChange(change, value);
 }
 
+static QPoint mapToScreen(const QQuickItem *item, const QPoint &clientPos)
+{
+    return item->window()->position() + item->mapToScene(clientPos).toPoint();
+}
+
+void QQuickWebEngineView::dragEnterEvent(QDragEnterEvent *e)
+{
+    Q_D(QQuickWebEngineView);
+    e->accept();
+    d->adapter->enterDrag(e, mapToScreen(this, e->pos()));
+}
+
+void QQuickWebEngineView::dragLeaveEvent(QDragLeaveEvent *e)
+{
+    Q_D(QQuickWebEngineView);
+    e->accept();
+    d->adapter->leaveDrag();
+}
+
+void QQuickWebEngineView::dragMoveEvent(QDragMoveEvent *e)
+{
+    Q_D(QQuickWebEngineView);
+    e->accept();
+    d->adapter->updateDragPosition(e, mapToScreen(this, e->pos()));
+}
+
+void QQuickWebEngineView::dropEvent(QDropEvent *e)
+{
+    Q_D(QQuickWebEngineView);
+    e->accept();
+    d->adapter->endDragging(e->pos(), mapToScreen(this, e->pos()));
+}
+
 void QQuickWebEngineView::triggerWebAction(WebAction action)
 {
     Q_D(QQuickWebEngineView);
diff --git a/src/webengine/api/qquickwebengineview_p.h b/src/webengine/api/qquickwebengineview_p.h
index 9f7a45156..c533d0fca 100644
--- a/src/webengine/api/qquickwebengineview_p.h
+++ b/src/webengine/api/qquickwebengineview_p.h
@@ -329,6 +329,10 @@ Q_SIGNALS:
 protected:
     void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry);
     void itemChange(ItemChange, const ItemChangeData &);
+    void dragEnterEvent(QDragEnterEvent *e) Q_DECL_OVERRIDE;
+    void dragLeaveEvent(QDragLeaveEvent *e) Q_DECL_OVERRIDE;
+    void dragMoveEvent(QDragMoveEvent *e) Q_DECL_OVERRIDE;
+    void dropEvent(QDropEvent *e) Q_DECL_OVERRIDE;
 
 private:
     Q_DECLARE_PRIVATE(QQuickWebEngineView)
diff --git a/src/webengine/api/qquickwebengineview_p_p.h b/src/webengine/api/qquickwebengineview_p_p.h
index 69ba60ccd..beb5b49bc 100644
--- a/src/webengine/api/qquickwebengineview_p_p.h
+++ b/src/webengine/api/qquickwebengineview_p_p.h
@@ -174,8 +174,11 @@ public:
                                      int exitCode) Q_DECL_OVERRIDE;
     virtual void updateScrollPosition(const QPointF &position) Q_DECL_OVERRIDE;
     virtual void updateContentsSize(const QSizeF &size) Q_DECL_OVERRIDE;
+    void startDragging(const content::DropData &dropData, Qt::DropActions allowedActions,
+                       const QPixmap &pixmap, const QPoint &offset) Q_DECL_OVERRIDE;
 
     virtual QtWebEngineCore::BrowserContextAdapter *browserContextAdapter() Q_DECL_OVERRIDE;
+    QtWebEngineCore::WebContentsAdapter *webContentsAdapter() Q_DECL_OVERRIDE;
 
     void setDevicePixelRatio(qreal);
     void adoptWebContents(QtWebEngineCore::WebContentsAdapter *webContents);
diff --git a/src/webenginewidgets/api/qwebenginepage.cpp b/src/webenginewidgets/api/qwebenginepage.cpp
index ec98a8346..d69437641 100644
--- a/src/webenginewidgets/api/qwebenginepage.cpp
+++ b/src/webenginewidgets/api/qwebenginepage.cpp
@@ -421,6 +421,11 @@ BrowserContextAdapter *QWebEnginePagePrivate::browserContextAdapter()
     return profile->d_ptr->browserContext();
 }
 
+WebContentsAdapter *QWebEnginePagePrivate::webContentsAdapter()
+{
+    return adapter.data();
+}
+
 QWebEnginePage::QWebEnginePage(QObject* parent)
     : QObject(parent)
     , d_ptr(new QWebEnginePagePrivate())
@@ -1089,6 +1094,13 @@ void QWebEnginePagePrivate::renderProcessTerminated(RenderProcessTerminationStat
                                       terminationStatus), exitCode);
 }
 
+void QWebEnginePagePrivate::startDragging(const content::DropData &dropData,
+                                          Qt::DropActions allowedActions, const QPixmap &pixmap,
+                                          const QPoint &offset)
+{
+    adapter->startDragging(view, dropData, allowedActions, pixmap, offset);
+}
+
 QMenu *QWebEnginePage::createStandardContextMenu()
 {
     Q_D(QWebEnginePage);
diff --git a/src/webenginewidgets/api/qwebenginepage_p.h b/src/webenginewidgets/api/qwebenginepage_p.h
index 2ec5f6288..e7f4cac4e 100644
--- a/src/webenginewidgets/api/qwebenginepage_p.h
+++ b/src/webenginewidgets/api/qwebenginepage_p.h
@@ -126,8 +126,11 @@ public:
                                      int exitCode) Q_DECL_OVERRIDE;
     virtual void updateScrollPosition(const QPointF &position) Q_DECL_OVERRIDE;
     virtual void updateContentsSize(const QSizeF &size) Q_DECL_OVERRIDE;
+    void startDragging(const content::DropData &dropData, Qt::DropActions allowedActions,
+                       const QPixmap &pixmap, const QPoint &offset) Q_DECL_OVERRIDE;
 
     virtual QtWebEngineCore::BrowserContextAdapter *browserContextAdapter() Q_DECL_OVERRIDE;
+    QtWebEngineCore::WebContentsAdapter *webContentsAdapter() Q_DECL_OVERRIDE;
 
     void updateAction(QWebEnginePage::WebAction) const;
     void updateNavigationActions();
diff --git a/src/webenginewidgets/api/qwebengineview.cpp b/src/webenginewidgets/api/qwebengineview.cpp
index 362849732..e066f2d0e 100644
--- a/src/webenginewidgets/api/qwebengineview.cpp
+++ b/src/webenginewidgets/api/qwebengineview.cpp
@@ -122,6 +122,7 @@ QWebEngineView::QWebEngineView(QWidget *parent)
 {
     Q_D(QWebEngineView);
     d->q_ptr = this;
+    setAcceptDrops(true);
 
     // This causes the child RenderWidgetHostViewQtDelegateWidgets to fill this widget.
     setLayout(new QStackedLayout);
@@ -312,6 +313,40 @@ void QWebEngineView::hideEvent(QHideEvent *event)
     page()->d_ptr->wasHidden();
 }
 
+void QWebEngineView::dragEnterEvent(QDragEnterEvent *e)
+{
+    Q_D(QWebEngineView);
+    e->accept();
+    d->page->d_ptr->adapter->enterDrag(e, mapToGlobal(e->pos()));
+}
+
+void QWebEngineView::dragLeaveEvent(QDragLeaveEvent *e)
+{
+    Q_D(QWebEngineView);
+    e->accept();
+    d->page->d_ptr->adapter->leaveDrag();
+}
+
+void QWebEngineView::dragMoveEvent(QDragMoveEvent *e)
+{
+    Q_D(QWebEngineView);
+    QtWebEngineCore::WebContentsAdapter *adapter = d->page->d_ptr->adapter.data();
+    Qt::DropAction dropAction = adapter->updateDragPosition(e, mapToGlobal(e->pos()));
+    if (Qt::IgnoreAction == dropAction) {
+        e->ignore();
+    } else {
+        e->setDropAction(dropAction);
+        e->accept();
+    }
+}
+
+void QWebEngineView::dropEvent(QDropEvent *e)
+{
+    Q_D(QWebEngineView);
+    e->accept();
+    d->page->d_ptr->adapter->endDragging(e->pos(), mapToGlobal(e->pos()));
+}
+
 #ifndef QT_NO_ACCESSIBILITY
 int QWebEngineViewAccessible::childCount() const
 {
diff --git a/src/webenginewidgets/api/qwebengineview.h b/src/webenginewidgets/api/qwebengineview.h
index e16bbf4af..432813395 100644
--- a/src/webenginewidgets/api/qwebengineview.h
+++ b/src/webenginewidgets/api/qwebengineview.h
@@ -122,6 +122,10 @@ protected:
     virtual bool event(QEvent*) Q_DECL_OVERRIDE;
     virtual void showEvent(QShowEvent *) Q_DECL_OVERRIDE;
     virtual void hideEvent(QHideEvent *) Q_DECL_OVERRIDE;
+    void dragEnterEvent(QDragEnterEvent *e) Q_DECL_OVERRIDE;
+    void dragLeaveEvent(QDragLeaveEvent *e) Q_DECL_OVERRIDE;
+    void dragMoveEvent(QDragMoveEvent *e) Q_DECL_OVERRIDE;
+    void dropEvent(QDropEvent *e) Q_DECL_OVERRIDE;
 
 private:
     Q_DISABLE_COPY(QWebEngineView)