qohosnativedrageventshandler.cpp

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// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include <QtCore/private/qcore_ohos_p.h>
#include <QtCore/private/qohoscommon_p.h>
#include <QtCore/private/qohoslogger_p.h>
#include <QtCore/qmimedata.h>
#include <QtGui/private/qdnd_p.h>
#include <QtGui/private/qguiapplication_p.h>
#include <QtGui/private/qhighdpiscaling_p.h>
#include <arkui/drag_and_drop.h>
#include <arkui/native_node.h>
#include <arkui/native_type.h>
#include <arkui/ui_input_event.h>
#include <array>
#include <chrono>
#include <condition_variable>
#include <cstdint>
#include <database/udmf/udmf.h>
#include <functional>
#include <future>
#include <info/application_target_sdk_version.h>
#include <memory>
#include <mutex>
#include <optional>
#include <qarkui/qarkuiutils.h>
#include <qarkui/qnativenodeapi.h>
#include <qarkui/qohosdrageventcshim.h>
#include <qohosjsutils.h>
#include <qohosplatformdrag.h>
#include <qohosudmf.h>
#include <qohosudmfconversions.h>
#include <qohosutils.h>
#include <qpa/qplatformdrag.h>
#include <qpa/qplatformintegration.h>
#include <qpa/qwindowsysteminterface.h>
#include <render/qohosbatchingrequestshandler.h>
#include <render/qohosdrageventutils.h>
#include <render/qohosnativedrageventshandler.h>
#include <string>
#include <type_traits>
#include <vector>
 
namespace ch = std::chrono;
 
QT_BEGIN_NAMESPACE
 
namespace {
 
// The following DragResult values are listed in the ArkTS documentation and accepted by
// OH_ArkUI_DragEvent_SetDragResult(), but they have no corresponding ArkUI_DragResult
// enumerators and 4 currently lies outside the C++ value range [0, 3] of ArkUI_DragResult,
// so both are passed as integers to qohosdrageventcshim.c.
enum class DropStatus : std::underlying_type_t<::ArkUI_DragResult>
{
    Enabled = 3,
    Disabled = 4,
};
 
struct DragEventInfo
{
    QPoint localDropPos;
    Qt::DropActions dropActions;
    Qt::KeyboardModifiers keyboardModifiers;
};
 
template<typename T>
QOhosSupplier<T> makeImplicitlySharedSupplier(QOhosSupplier<T> baseSupplier)
{
    auto sharedBaseSupplier = QtOhos::moveToSharedPtr(std::move(baseSupplier));
    return [sharedBaseSupplier]() {
        return (*sharedBaseSupplier)();
    };
}
 
std::int32_t getDragEventDataTypeCount(::ArkUI_DragEvent *dragEvent)
{
    std::int32_t dataTypeCount = 0;
    QArkUi::callArkUiOrFailOnErrorResult(
        Q_OHOS_NAMED_FUNC(::OH_ArkUI_DragEvent_GetDataTypeCount),
        dragEvent, &dataTypeCount);
 
    return dataTypeCount;
}
 
std::vector<std::string> getDragEventDataTypes(::ArkUI_DragEvent *dragEvent)
{
    constexpr auto dataTypeMaxLength = 128;
 
    auto dataTypeCount = getDragEventDataTypeCount(dragEvent);
    if (dataTypeCount == 0)
        return {};
 
    std::vector<std::array<char, dataTypeMaxLength + 1>> dataTypesStringData;
    dataTypesStringData.resize(dataTypeCount);
 
    std::vector<char *> dataTypesStringPointers;
    for (std::int32_t i = 0; i < dataTypeCount; ++i)
        dataTypesStringPointers.push_back(dataTypesStringData[i].data());
 
    QArkUi::callArkUiOrFailOnErrorResult(
        Q_OHOS_NAMED_FUNC(::OH_ArkUI_DragEvent_GetDataTypes),
        dragEvent, dataTypesStringPointers.data(),  dataTypesStringPointers.size(), dataTypeMaxLength);
 
    return {dataTypesStringPointers.begin(), dataTypesStringPointers.end()};
}
 
std::shared_ptr<QOhosUdmfData> tryGetDragEventUdmfDataOrNull(::ArkUI_DragEvent *dragEvent)
{
    QOhosUdmfData udmfData;
    auto getUdmfDataRes = QArkUi::callArkUi(
        Q_OHOS_NAMED_FUNC(::OH_ArkUI_DragEvent_GetUdmfData),
        dragEvent, udmfData.nativePtr());
 
    return getUdmfDataRes == ARKUI_ERROR_CODE_NO_ERROR
        ? QtOhos::moveToSharedPtr(std::move(udmfData))
        : nullptr;
}
 
void setDragEventSuggestedDropOperationIfAvailable(
    ::ArkUI_DragEvent *dragEvent, std::optional<::ArkUI_DropOperation> optDropOperation)
{
    if (optDropOperation.has_value()) {
        QArkUi::callArkUiOrFailOnErrorResult(
            Q_OHOS_NAMED_FUNC(::OH_ArkUI_DragEvent_SetSuggestedDropOperation),
            dragEvent, optDropOperation.value());
    }
}
 
std::uint64_t getDragEventModifierKeyStates(::ArkUI_DragEvent *dragEvent)
{
    std::uint64_t keys;
    QArkUi::callArkUiOrFailOnErrorResult(
        Q_OHOS_NAMED_FUNC(::OH_ArkUI_DragEvent_GetModifierKeyStates),
        dragEvent, &keys);
    return keys;
}
 
Qt::KeyboardModifiers mapArkUiModifierKeyStatesToQt(std::uint64_t modifierKeyStates)
{
    static const std::pair<std::uint64_t, Qt::KeyboardModifier> arkUiToQtModifiersMap[] = {
        {::ARKUI_MODIFIER_KEY_CTRL, Qt::KeyboardModifier::ControlModifier},
        {::ARKUI_MODIFIER_KEY_SHIFT, Qt::KeyboardModifier::ShiftModifier},
        {::ARKUI_MODIFIER_KEY_ALT, Qt::KeyboardModifier::AltModifier},
        {::ARKUI_MODIFIER_KEY_FN, Qt::KeyboardModifier::MetaModifier},
    };
 
    Qt::KeyboardModifiers modifiers;
    for (const auto &mod : arkUiToQtModifiersMap)
        modifiers.setFlag(mod.second, (modifierKeyStates & mod.first) != 0);
 
    return modifiers;
}
 
template<typename Context, typename Result>
std::optional<Result> tryRunInQtThreadAndGetResult(
    QtOhos::QThreadSafeRef<Context> context, std::function<Result(Context &)> qtThreadProcessFunc)
{
    constexpr auto maxResultWaitTime = ch::milliseconds(50);
 
    auto resultPromise = std::make_shared<std::promise<Result>>();
    auto resultFuture = resultPromise->get_future();
 
    context.visitInQtThreadIfAlive(
        [qtThreadProcessFunc = std::move(qtThreadProcessFunc), resultPromise](Context &context) {
            resultPromise->set_value(qtThreadProcessFunc(context));
        });
 
    return
        resultFuture.wait_for(maxResultWaitTime) == std::future_status::ready
            ? std::optional<Result>(resultFuture.get())
            : std::nullopt;
}
 
QOhosPlatformDrag *getQOhosPlatformDrag()
{
    return static_cast<QOhosPlatformDrag *>(QGuiApplicationPrivate::platformIntegration()->drag());
}
 
Qt::DropAction processDropInQWindow(
    QWindow &qWindow, const DragEventInfo &dragEventInfo,
    QOhosSupplier<std::unique_ptr<QMimeData>> dropDataFactory)
{
    QDrag *currentDrag = QDragManager::self()->object();
    if (currentDrag != nullptr)
        getQOhosPlatformDrag()->handlePreDrop();
    QPlatformDropQtResponse qtResponse = QWindowSystemInterface::handleDrop(
        &qWindow,
        currentDrag != nullptr ? currentDrag->mimeData() : dropDataFactory().get(),
        dragEventInfo.localDropPos,
        currentDrag != nullptr ? currentDrag->supportedActions() : dragEventInfo.dropActions,
        Qt::LeftButton, dragEventInfo.keyboardModifiers);
    auto updatedDropAction =
        qtResponse.isAccepted()
            ? qtResponse.acceptedAction()
            : Qt::IgnoreAction;
    if (currentDrag != nullptr)
        getQOhosPlatformDrag()->updateDropAction(updatedDropAction);
    return updatedDropAction;
}
 
void processPendingDropRequestAsynchronously(
    QOhosJsState &jsState, QtOhos::QThreadSafeRef<QWindow> qWindowRef, const DragEventInfo &dragEventInfo,
    QOhosSupplier<std::unique_ptr<QMimeData>> dropDataFactory, std::int32_t pendingDropRequestId)
{
    qOhosPrintfDebug("%s: async processing of drop request with id=%d", Q_FUNC_INFO, pendingDropRequestId);
 
    auto qtDropActionConsumer = QtOhos::moveToSharedPtr(
        QtOhos::makeCallOnceConsumerWrapper<QOhosJsState &, Qt::DropAction>(
            [pendingDropRequestId](QOhosJsState &, Qt::DropAction qtDropAction) {
                qOhosPrintfDebug(
                    "%s: got qtDropAction=%d for drop request with id=%d",
                    Q_FUNC_INFO, static_cast<int>(qtDropAction), pendingDropRequestId);
                QArkUi::callArkUiOrFailOnErrorResult(
                    Q_OHOS_NAMED_FUNC(::OH_ArkUI_NotifyDragResult),
                    pendingDropRequestId,
                    qtDropAction != Qt::IgnoreAction
                        ? ::ARKUI_DRAG_RESULT_SUCCESSFUL
                        : ::ARKUI_DRAG_RESULT_FAILED);
                QArkUi::callArkUiOrFailOnErrorResult(
                    Q_OHOS_NAMED_FUNC(::OH_ArkUI_NotifyDragEndPendingDone),
                    pendingDropRequestId);
            }));
 
    constexpr auto notifyDragEndPendingTimeout = ch::milliseconds(1500);
    QtOhos::setJsTimeout(
        jsState,
        [pendingDropRequestId, qtDropActionConsumer](const QOhosCallbackInfo &cbInfo) {
            if ((*qtDropActionConsumer)(cbInfo.jsState(), Qt::IgnoreAction))
                qOhosPrintfDebug("%s: used timeout action for drop request with id=%d", Q_FUNC_INFO, pendingDropRequestId);
        },
        notifyDragEndPendingTimeout);
 
    qWindowRef.visitInQtThreadIfAlive(
        [dragEventInfo, dropDataFactory = std::move(dropDataFactory), qtDropActionConsumer](QWindow &qWindow) mutable {
            auto dropAction = processDropInQWindow(qWindow, dragEventInfo, std::move(dropDataFactory));
            QOhosJsThreadGateway::runAndWait(
                [&](QOhosJsState &jsState) {
                    (*qtDropActionConsumer)(jsState, dropAction);
                },
                Q_FUNC_INFO);
        });
}
 
bool isAsyncDropHandlingAllowed()
{
    return qEnvironmentVariableIntValue("IO__QT__USE_ASYNC_DROP_END_HANDLING") != 0;
}
 
bool tryStartAsyncProcessingOfDropEvent(
    QOhosJsState &jsState, ::ArkUI_DragEvent *dragEvent, QtOhos::QThreadSafeRef<QWindow> qWindowRef,
    const DragEventInfo &dragEventInfo, QOhosSupplier<std::unique_ptr<QMimeData>> dropDataFactory)
{
    if (!isAsyncDropHandlingAllowed())
        return false;
 
    std::int32_t pendingDropRequestId = 0;
    QArkUi::callArkUiOrFailOnErrorResult(
        Q_OHOS_NAMED_FUNC(::OH_ArkUI_DragEvent_RequestDragEndPending),
        dragEvent, &pendingDropRequestId);
    processPendingDropRequestAsynchronously(
        jsState, qWindowRef, dragEventInfo,
        std::move(dropDataFactory), pendingDropRequestId);
 
    return true;
}
 
QPoint getDragEventTouchDisplayPosition(::ArkUI_DragEvent *dragEvent)
{
    return QPoint(
        ::OH_ArkUI_DragEvent_GetTouchPointXToDisplay(dragEvent),
        ::OH_ArkUI_DragEvent_GetTouchPointYToDisplay(dragEvent));
}
 
class DragMoveResponder
{
public:
    explicit DragMoveResponder(QtOhos::QThreadSafeRef<QWindow> qWindowRef);
 
    std::optional<Qt::DropAction> respondToMove(
        const DragEventInfo &dragEventInfo, QOhosSupplier<std::unique_ptr<QMimeData>> dropDataFactory);
 
    void forgetLastDropAction();
 
private:
    struct DropActionState
    {
        std::mutex mutex;
        std::condition_variable answerCondVar;
        std::uint64_t answeredRequestId = 0;
        std::optional<Qt::DropAction> optDropAction;
    };
 
    std::shared_ptr<DropActionState> m_sharedDropActionState;
    QOhosConsumer<std::function<void(std::function<void(QWindow &)> &)>> m_pendingQueryUpdater;
    std::uint64_t m_lastRequestId = 0;
    std::optional<ch::steady_clock::time_point> m_optLastFailedWaitTime;
};
 
DragMoveResponder::DragMoveResponder(QtOhos::QThreadSafeRef<QWindow> qWindowRef)
    : m_sharedDropActionState(std::make_shared<DropActionState>())
    , m_pendingQueryUpdater(
        makeQtOhosBatchingQtRequestsHandler<std::function<void(QWindow &)>>(
            qWindowRef.toQObjectThreadSafeRef(),
            [qWindowRef](std::function<void(QWindow &)> &&query) {
                query(*qWindowRef.data());
            }))
{
}
 
std::optional<Qt::DropAction> DragMoveResponder::respondToMove(
    const DragEventInfo &dragEventInfo, QOhosSupplier<std::unique_ptr<QMimeData>> dropDataFactory)
{
    // the timeout outlasts a usual round trip but not a frame, the cooldown keeps a miss rare
    constexpr auto answerWaitTimeout = ch::milliseconds(5);
    constexpr auto waitCooldownAfterTimeout = ch::milliseconds(200);
 
    const auto requestId = ++m_lastRequestId;
    auto queryFunc =
        [dragEventInfo, dropDataFactory = std::move(dropDataFactory),
         sharedDropActionState = m_sharedDropActionState, requestId](QWindow &qWindow) {
            QDrag *currentDrag = QDragManager::self()->object();
            QPlatformDragQtResponse qtResponse = QWindowSystemInterface::handleDrag(
                &qWindow,
                currentDrag != nullptr ? currentDrag->mimeData() : dropDataFactory().get(),
                dragEventInfo.localDropPos,
                currentDrag != nullptr ? currentDrag->supportedActions() : dragEventInfo.dropActions,
                Qt::LeftButton, dragEventInfo.keyboardModifiers);
            if (currentDrag != nullptr && qtResponse.isAccepted() && qtResponse.acceptedAction() != Qt::IgnoreAction)
                getQOhosPlatformDrag()->updateDropAction(qtResponse.acceptedAction());
 
            {
                std::lock_guard<std::mutex> stateLock(sharedDropActionState->mutex);
                if (requestId <= sharedDropActionState->answeredRequestId)
                    return;
 
                sharedDropActionState->answeredRequestId = requestId;
                sharedDropActionState->optDropAction = qtResponse.acceptedAction();
            }
            sharedDropActionState->answerCondVar.notify_all();
        };
 
    m_pendingQueryUpdater(
        [&](std::function<void(QWindow &)> &pendingQuery) {
            pendingQuery = std::move(queryFunc);
        });
 
    const auto now = ch::steady_clock::now();
    const bool waitingMakesSense =
        !m_optLastFailedWaitTime || now - m_optLastFailedWaitTime.value() >= waitCooldownAfterTimeout;
 
    {
        std::unique_lock<std::mutex> stateLock(m_sharedDropActionState->mutex);
        if (waitingMakesSense) {
            const bool answered = m_sharedDropActionState->answerCondVar.wait_for(
                stateLock, answerWaitTimeout,
                [&]() {
                    return m_sharedDropActionState->answeredRequestId >= requestId;
                });
            if (answered)
                m_optLastFailedWaitTime.reset();
            else
                m_optLastFailedWaitTime = now;
        }
 
        return m_sharedDropActionState->optDropAction;
    }
}
 
void DragMoveResponder::forgetLastDropAction()
{
    std::lock_guard<std::mutex> stateLock(m_sharedDropActionState->mutex);
    m_sharedDropActionState->answeredRequestId = m_lastRequestId;
    m_sharedDropActionState->optDropAction.reset();
}
 
}
 
QOhosConsumer<::ArkUI_NodeEvent *> makeQOhosNativeDragEventsHandler(
    QtOhos::QThreadSafeRef<QWindow> qWindowRef)
{
    auto eventsHandler = [qWindowRef, dragMoveResponder = DragMoveResponder(qWindowRef)](
        QOhosJsState &jsState, ::ArkUI_NodeEvent *nodeEvent) mutable {
        auto eventType = QArkUi::callArkUi(Q_OHOS_NAMED_FUNC(OH_ArkUI_NodeEvent_GetEventType), nodeEvent);
        auto *dragEvent = QArkUi::callArkUiOrFailOnNullResult(Q_OHOS_NAMED_FUNC(::OH_ArkUI_NodeEvent_GetDragEvent), nodeEvent);
        auto node = QArkUi::callArkUiOrFailOnNullResult(Q_OHOS_NAMED_FUNC(OH_ArkUI_NodeEvent_GetNodeHandle), nodeEvent);
 
        auto touchDisplayPosition = getDragEventTouchDisplayPosition(dragEvent);
        auto nodeDisplayPosition = QArkUi::Node::nodeDisplayPosition(node);
        auto localPosition = touchDisplayPosition - nodeDisplayPosition;
 
        DragEventInfo dragEventInfo = {
            .localDropPos = localPosition,
            .dropActions = mapQOhosArkUiDropOperationToQt(getQOhosDragEventDropOperation(dragEvent)),
            .keyboardModifiers = mapArkUiModifierKeyStatesToQt(getDragEventModifierKeyStates(dragEvent)),
        };
 
        qOhosPrintfDebug("QNativeNode: got drag event: %d, (%d,%d)", eventType, dragEventInfo.localDropPos.x(), dragEventInfo.localDropPos.y());
 
        switch (eventType) {
        case ::NODE_ON_DRAG_ENTER:
            dragMoveResponder.forgetLastDropAction();
            Q_FALLTHROUGH();
        case ::NODE_ON_DRAG_MOVE:
            {
                auto qtDropAction = dragMoveResponder.respondToMove(
                    dragEventInfo,
                    makeDummyQMimeDataFactoryFromUdmfDataTypes(getDragEventDataTypes(dragEvent)));
                QArkUi::callArkUiOrFailOnErrorResult(
                    Q_OHOS_NAMED_FUNC(::qOhosSetArkUiDragEventDragResult),
                    dragEvent,
                    static_cast<std::uint32_t>(
                        qtDropAction.value_or(Qt::IgnoreAction) != Qt::IgnoreAction
                            ? DropStatus::Enabled
                            : DropStatus::Disabled));
                setDragEventSuggestedDropOperationIfAvailable(
                    dragEvent, qAndThen(qtDropAction, &tryMapQOhosArkUiDropOperationFromQt));
            }
            break;
        case ::NODE_ON_DRAG_LEAVE:
            qWindowRef.visitInQtThreadIfAlive(
                [](QWindow &qWindow) {
                    std::ignore = QWindowSystemInterface::handleDrag(
                        &qWindow, nullptr, QPoint(), Qt::IgnoreAction, Qt::MouseButtons(), Qt::KeyboardModifiers());
                });
            break;
        case ::NODE_ON_DROP:
            {
                QOhosSupplier<std::unique_ptr<QMimeData>> dropDataFactory;
                if (getDragEventDataTypeCount(dragEvent) != 0) {
                    auto optDragUdmfData = tryGetDragEventUdmfDataOrNull(dragEvent);
                    dropDataFactory = optDragUdmfData
                        ? createQMimeDataFactoryFromUdmfData(std::move(*optDragUdmfData))
                        : &std::make_unique<QMimeData>;
                } else {
                    dropDataFactory = &std::make_unique<QMimeData>;
                }
                auto copyableDropDataFactory = makeImplicitlySharedSupplier(std::move(dropDataFactory));
 
                bool asyncProcessingStarted = tryStartAsyncProcessingOfDropEvent(
                    jsState, dragEvent, qWindowRef, dragEventInfo, copyableDropDataFactory);
 
                if (!asyncProcessingStarted) {
                    auto qtDropAction = tryRunInQtThreadAndGetResult<QWindow, Qt::DropAction>(
                        qWindowRef,
                        [dragEventInfo, copyableDropDataFactory](QWindow &qWindow) {
                            return processDropInQWindow(qWindow, dragEventInfo, copyableDropDataFactory);
                        });
                    QArkUi::callArkUiOrFailOnErrorResult(
                        Q_OHOS_NAMED_FUNC(::OH_ArkUI_DragEvent_SetDragResult),
                        dragEvent,
                        qtDropAction.value_or(Qt::IgnoreAction) != Qt::IgnoreAction
                            ? ::ARKUI_DRAG_RESULT_SUCCESSFUL
                            : ::ARKUI_DRAG_RESULT_FAILED);
                    setDragEventSuggestedDropOperationIfAvailable(
                        dragEvent, qAndThen(qtDropAction, &tryMapQOhosArkUiDropOperationFromQt));
                }
            }
            break;
        default:
            break;
        }
    };
 
    return [eventsHandler = std::move(eventsHandler)](::ArkUI_NodeEvent *nodeEvent) mutable {
        QOhosJsThreadGateway::runAndWait(
            [&](QOhosJsState &jsState) {
                eventsHandler(jsState, nodeEvent);
            },
            Q_FUNC_INFO);
    };
}
 
QT_END_NAMESPACE