Makes it possible to extract all data from a QML DropArea

There's many types that aren't being covered by DropArea API, such as
images. getDataAsString is not acceptable, since fromUtf8 chokes on
reading non-utf8.
This patch introduces getDataAsArrayBuffer method that won't try to convert
the data into a QString and simply pass a QV4::ArrayBuffer, that internally
keeps a QByteArray.

Change-Id: I65411b3d365ee6c5e13effd9167156771ee08a05
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

4 files changed, 52 insertions, 0 deletions

diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 5e450859ec..ba6f5a3b79 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -1266,6 +1266,8 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
         return ld->d()->locale;
     if (QV4::DateObject *d = value.asDateObject())
         return d->toQDateTime();
+    if (QV4::ArrayBuffer *d = value.as<ArrayBuffer>())
+        return d->asByteArray();
     // NOTE: since we convert QTime to JS Date, round trip will change the variant type (to QDateTime)!
 
     QV4::ScopedObject o(scope, value);
diff --git a/src/quick/items/qquickdroparea.cpp b/src/quick/items/qquickdroparea.cpp
index 217b455d43..e46d546a16 100644
--- a/src/quick/items/qquickdroparea.cpp
+++ b/src/quick/items/qquickdroparea.cpp
@@ -36,6 +36,7 @@
 #include "qquickitem_p.h"
 #include "qquickwindow.h"
 
+#include <private/qv4arraybuffer_p.h>
 #include <private/qqmlengine_p.h>
 
 #ifndef QT_NO_DRAGANDDROP
@@ -496,6 +497,14 @@ void QQuickDropArea::dropEvent(QDropEvent *event)
     Returns the data for the given \a format converted to a string. \a format should be one contained in the \l formats property.
 */
 
+/*!
+    \qmlmethod string QtQuick::DragEvent::getDataAsArrayBuffer(string format)
+    \since 5.5
+
+    Returns the data for the given \a format into an ArrayBuffer, which can
+    easily be translated into a QByteArray. \a format should be one contained in the \l formats property.
+*/
+
 QObject *QQuickDropEvent::source()
 {
     if (const QQuickDragMimeData *dragMime = qobject_cast<const QQuickDragMimeData *>(event->mimeData()))
@@ -566,6 +575,17 @@ void QQuickDropEvent::getDataAsString(QQmlV4Function *args)
     }
 }
 
+void QQuickDropEvent::getDataAsArrayBuffer(QQmlV4Function *args)
+{
+    if (args->length() != 0) {
+        QV4::ExecutionEngine *v4 = args->v4engine();
+        QV4::Scope scope(v4);
+        QV4::ScopedValue v(scope, (*args)[0]);
+        const QString format = v->toQString();
+        args->setReturnValue(v4->newArrayBuffer(event->mimeData()->data(format))->asReturnedValue());
+    }
+}
+
 void QQuickDropEvent::acceptProposedAction(QQmlV4Function *)
 {
     event->acceptProposedAction();
diff --git a/src/quick/items/qquickdroparea_p.h b/src/quick/items/qquickdroparea_p.h
index e35ec40757..3223f4203b 100644
--- a/src/quick/items/qquickdroparea_p.h
+++ b/src/quick/items/qquickdroparea_p.h
@@ -96,6 +96,7 @@ public:
     QStringList formats() const;
 
     Q_INVOKABLE void getDataAsString(QQmlV4Function *);
+    Q_INVOKABLE void getDataAsArrayBuffer(QQmlV4Function *);
     Q_INVOKABLE void acceptProposedAction(QQmlV4Function *);
     Q_INVOKABLE void accept(QQmlV4Function *);
 
diff --git a/tests/auto/quick/qquickdroparea/tst_qquickdroparea.cpp b/tests/auto/quick/qquickdroparea/tst_qquickdroparea.cpp
index ece439d01a..67ee1a3714 100644
--- a/tests/auto/quick/qquickdroparea/tst_qquickdroparea.cpp
+++ b/tests/auto/quick/qquickdroparea/tst_qquickdroparea.cpp
@@ -78,6 +78,7 @@ private slots:
 //    void drop_external();
     void competingDrags();
     void simultaneousDrags();
+    void dropStuff();
 
 private:
     QQmlEngine engine;
@@ -1157,6 +1158,34 @@ void tst_QQuickDropArea::simultaneousDrags()
     QWindowSystemInterface::handleDrop(&alternateWindow, &data, QPoint(50, 50), Qt::CopyAction);
 }
 
+void tst_QQuickDropArea::dropStuff()
+{
+    QQuickWindow window;
+    QQmlComponent component(&engine);
+    component.setData(
+            "import QtQuick 2.3\n"
+            "DropArea {\n"
+                "width: 100; height: 100\n"
+                "property var array\n"
+                "onDropped: { array = drop.getDataAsArrayBuffer('text/x-red'); }\n"
+            "}", QUrl());
+
+    QScopedPointer<QObject> object(component.create());
+    QQuickItem *dropArea = qobject_cast<QQuickItem *>(object.data());
+    QVERIFY(dropArea);
+    dropArea->setParentItem(window.contentItem());
+
+    QMimeData data;
+    data.setData("text/x-red", "red");
+
+    QCOMPARE(evaluate<QVariant>(dropArea, "array"), QVariant());
+
+    QWindowSystemInterface::handleDrag(&window, &data, QPoint(50, 50), Qt::CopyAction);
+    QWindowSystemInterface::handleDrop(&window, &data, QPoint(50, 50), Qt::CopyAction);
+    QCOMPARE(evaluate<int>(dropArea, "array.byteLength"), 3);
+    QCOMPARE(evaluate<QByteArray>(dropArea, "array"), QByteArray("red"));
+}
+
 QTEST_MAIN(tst_QQuickDropArea)
 
 #include "tst_qquickdroparea.moc"