wasm: write file to storage on drop

Change-Id: Ibd1b5d623da07ad611cce577929a23ba991b6738
Pick-to: 6.7
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

src/plugins/platforms/wasm/qwasmclipboard.cpp

@@ -70,16 +70,7 @@ static void qClipboardPasteTo(val event)
 {
     event.call<void>("preventDefault"); // prevent browser from handling drop event
 
-    static std::shared_ptr<qstdweb::CancellationFlag> readDataCancellation = nullptr;
+    QWasmIntegration::get()->getWasmClipboard()->sendClipboardData(event);
-    dom::DataTransfer transfer(event["clipboardData"]);
-    auto data = transfer.toMimeDataWithFile();
-    if (data->formats().isEmpty())
-        return;
-    // Persist clipboard data so that the app can read it when handling the CTRL+V
-    QWasmIntegration::get()->clipboard()->QPlatformClipboard::setMimeData(data,
-                                                                          QClipboard::Clipboard);
-    QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyPress, Qt::Key_V,
-                                            Qt::ControlModifier, "V");
 }
 
 EMSCRIPTEN_BINDINGS(qtClipboardModule) {
@@ -292,4 +283,22 @@ void QWasmClipboard::writeToClipboard()
     document.call<val>("execCommand", val("copy"));
 }
 
+void QWasmClipboard::sendClipboardData(emscripten::val event)
+{
+    dom::DataTransfer transfer(event["clipboardData"]);
+    QMimeData *mData;
+    const auto pointerCallback = std::function([&](QMimeData &data) {
+        mData = &data;
+        // Persist clipboard data so that the app can read it when handling the CTRL+V
+        QWasmIntegration::get()->clipboard()->QPlatformClipboard::setMimeData(mData,
+                                                                              QClipboard::Clipboard);
+        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyPress, Qt::Key_V,
+                                               Qt::ControlModifier, "V");
+        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyRelease, Qt::Key_V,
+                                               Qt::ControlModifier, "V");
+    });
+
+    transfer.toMimeDataWithFile(pointerCallback); // mimedata
+
+}
 QT_END_NAMESPACE

src/plugins/platforms/wasm/qwasmclipboard.h

@@ -38,6 +38,7 @@ public:
     ProcessKeyboardResult processKeyboard(const KeyEvent &event);
     static void installEventHandlers(const emscripten::val &target);
     bool hasClipboardApi();
+    void sendClipboardData(emscripten::val event);
 
 private:
     void initClipboardPermissions();

src/plugins/platforms/wasm/qwasmdom.cpp

@@ -3,7 +3,6 @@
 
 #include "qwasmdom.h"
 
-#include <QMimeData>
 #include <QtCore/qpoint.h>
 #include <QtCore/qrect.h>
 #include <QtGui/qimage.h>
@@ -15,6 +14,9 @@
 
 QT_BEGIN_NAMESPACE
 
+// this needs to live outside the life of DataTransfer
+Q_GLOBAL_STATIC(QMimeData, resultMimeData);
+
 namespace dom {
 namespace {
 std::string dropActionToDropEffect(Qt::DropAction action)
@@ -36,7 +38,9 @@ std::string dropActionToDropEffect(Qt::DropAction action)
 }
 } // namespace
 
-DataTransfer::DataTransfer(emscripten::val webDataTransfer) : webDataTransfer(webDataTransfer) { }
+DataTransfer::DataTransfer(emscripten::val webDataTransfer)
+    : webDataTransfer(webDataTransfer) {
+}
 
 DataTransfer::~DataTransfer() = default;
 
@@ -78,10 +82,9 @@ void DataTransfer::setDataFromMimeData(const QMimeData &mimeData)
     }
 }
 
-QMimeData *DataTransfer::toMimeDataWithFile()
+QMimeData *DataTransfer::toMimeDataWithFile(std::function<void(QMimeData &)> callback)
 {
-    QMimeData *resultMimeData = new QMimeData(); // QScopedPointer?
+    resultMimeData->clear();
-
     enum class ItemKind {
         File,
         String,
@@ -99,8 +102,43 @@ QMimeData *DataTransfer::toMimeDataWithFile()
         case ItemKind::File: {
             m_webFile = item.call<emscripten::val>("getAsFile");
             qstdweb::File webfile(m_webFile);
-            QUrl fileUrl(QStringLiteral("file:///") + QString::fromStdString(webfile.name()));
+            if (webfile.size() == 0
-            uriList.append(fileUrl);
+                || webfile.size() > 1e+9) { // limit file size to 1 GB
+                qWarning() << "Something happened, File size is" << webfile.size();
+                continue;
+            }
+            QByteArray fileContent(webfile.size(), Qt::Uninitialized);
+            QString  mimeFormat = QString::fromStdString(webfile.type());
+            QString fileName = QString::fromStdString(webfile.name());
+
+            // there's a file, now read it
+            webfile.stream(fileContent.data(), [=]() {
+                QList<QUrl> fileUriList;
+                if (!fileContent.isEmpty()) {
+                     if (mimeFormat.contains("image/")) {
+                        QImage image;
+                        image.loadFromData(fileContent, nullptr);
+                        resultMimeData->setImageData(image);
+                    } else {
+                        QUrl fileUrl(QStringLiteral("file:///") +
+                                    QString::fromStdString(webfile.name()));
+                        fileUriList.append(fileUrl);
+                        QFile file(fileName);
+                        if (!file.open(QFile::WriteOnly)) {
+                            qWarning() << "File was not opened";
+                            return;
+                        }
+
+                        if (file.write(fileContent) < 0)
+                            qWarning() << "Write failed";
+
+                        file.close();
+                        resultMimeData->setUrls(fileUriList);
+                    }
+                    callback(*resultMimeData);
+                }
+            });
+
             break;
         }
         case ItemKind::String:
@@ -131,9 +169,15 @@ QMimeData *DataTransfer::toMimeDataWithFile()
             }
             break;
         }
-    }
+    } // end items
-    if (!uriList.isEmpty())
+
+    if (!uriList.isEmpty()) {
         resultMimeData->setUrls(uriList);
+    }
+
+    if (resultMimeData->formats().length() > 0)
+        callback(*resultMimeData);
+
     return resultMimeData;
 }
 

src/plugins/platforms/wasm/qwasmdom.h

@@ -15,13 +15,14 @@
 #include <memory>
 #include <string>
 
+#include <QMimeData>
 QT_BEGIN_NAMESPACE
 
 namespace qstdweb {
     struct CancellationFlag;
 }
 
-class QMimeData;
+
 class QPoint;
 class QRect;
 
@@ -35,7 +36,7 @@ struct DataTransfer
     DataTransfer &operator=(const DataTransfer &other);
     DataTransfer &operator=(DataTransfer &&other);
 
-    QMimeData *toMimeDataWithFile() ;
+    QMimeData *toMimeDataWithFile(std::function<void(QMimeData &)> callback);
     QMimeData *toMimeDataPreview();
     void setDragImage(emscripten::val element, const QPoint &hotspot);
     void setData(std::string format, std::string data);

src/plugins/platforms/wasm/qwasmdrag.cpp

@@ -14,6 +14,7 @@
 #include <QtCore/qeventloop.h>
 #include <QtCore/qmimedata.h>
 #include <QtCore/qtimer.h>
+#include <QFile>
 
 #include <functional>
 #include <string>
@@ -155,19 +156,28 @@ void QWasmDrag::onNativeDrop(DragEvent *event)
                                         ? m_dragState->drag->supportedActions()
                                         : (Qt::DropAction::CopyAction | Qt::DropAction::MoveAction
                                            | Qt::DropAction::LinkAction);
+    Qt::MouseButton mouseButton = event->mouseButton;
+    QFlags<Qt::KeyboardModifier> modifiers = event->modifiers;
 
+    const auto pointerCallback = std::function([&, wasmWindow, pointInTargetWindowCoords,
+    actions, mouseButton, modifiers](QMimeData &data) {
+        if (data.formats().count() == 0)
+            return;
         auto dropResponse = std::make_shared<QPlatformDropQtResponse>(true, Qt::DropAction::CopyAction);
-    QMimeData *data = event->dataTransfer.toMimeDataWithFile();
+
-    *dropResponse = QWindowSystemInterface::handleDrop(event->targetWindow, data,
+        *dropResponse = QWindowSystemInterface::handleDrop(wasmWindow->window(), &data,
                                                            pointInTargetWindowCoords.toPoint(), actions,
-                                                       event->mouseButton, event->modifiers);
+                                                           mouseButton, modifiers);
 
         if (dropResponse->isAccepted()) {
-        event->acceptDrop();
+//            event->acceptDrop(); // boom
-        event->dataTransfer.setDropAction(dropResponse->acceptedAction());
+//            event->dataTransfer.setDropAction(dropResponse->acceptedAction());
 
             m_dragState->dropAction = dropResponse->acceptedAction();
         }
+    });
+
+     event->dataTransfer.toMimeDataWithFile(pointerCallback);
 }
 
 void QWasmDrag::onNativeDragFinished(DragEvent *event)