androidjniaccessibility.cpp

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// Copyright (C) 2021 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
// Qt-Security score:significant reason:default
 
#include "androidjniaccessibility.h"
#include "androidjnimain.h"
#include "qandroidplatformintegration.h"
#include "qandroidplatformwindow.h"
#include "qandroidinputcontext.h"
#include "qpa/qplatformaccessibility.h"
#include <QtGui/private/qaccessiblebridgeutils_p.h>
#include "qguiapplication.h"
#include "qwindow.h"
#include "qrect.h"
#include "QtGui/qaccessible.h"
#include <QtCore/qmath.h>
#include <QtCore/private/qjnihelpers_p.h>
#include <QtCore/QJniObject>
#include <QtGui/private/qhighdpiscaling_p.h>
 
#include <QtCore/QObject>
#include <QtCore/qpointer.h>
#include <QtCore/qscopeguard.h>
#include <QtCore/qvarlengtharray.h>
 
static const char m_qtTag[] = "Qt A11Y";
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
namespace QtAndroidAccessibility
{
    static jmethodID m_setClassNameMethodID = 0;
    static jmethodID m_addActionMethodID = 0;
    static jmethodID m_setCheckableMethodID = 0;
    static jmethodID m_setCheckedMethodID = 0;
    static jmethodID m_setClickableMethodID = 0;
    static jmethodID m_setContentDescriptionMethodID = 0;
    static jmethodID m_setEditableMethodID = 0;
    static jmethodID m_setEnabledMethodID = 0;
    static jmethodID m_setFocusableMethodID = 0;
    static jmethodID m_setFocusedMethodID = 0;
    static jmethodID m_setHeadingMethodID = 0;
    static jmethodID m_setScrollableMethodID = 0;
    static jmethodID m_setTextSelectionMethodID = 0;
    static jmethodID m_setRangeInfoMethodID = 0;
    static jmethodID m_setVisibleToUserMethodID = 0;
 
    static int RANGE_TYPE_INT = 0;
    static int RANGE_TYPE_FLOAT = 0;
    static int RANGE_TYPE_PERCENT = 0;
    static int RANGE_TYPE_INDETERMINATE = 0;
 
    static bool m_accessibilityActivated = false;
 
    // This object is needed to schedule the execution of the code that
    // deals with accessibility instances to the Qt main thread.
    // Because of that almost every method here is split into two parts.
    // The _helper part is executed in the context of m_accessibilityContext
    // on the main thread. The other part is executed in Java thread.
    Q_CONSTINIT static QPointer<QObject> m_accessibilityContext = {};
 
    // This method is called from the Qt main thread, and normally a
    // QGuiApplication instance will be used as a parent.
    void createAccessibilityContextObject(QObject *parent)
    {
        if (m_accessibilityContext)
            m_accessibilityContext->deleteLater();
        m_accessibilityContext = new QObject(parent);
    }
 
    template <typename Func, typename Ret>
    void runInObjectContext(QObject *context, Func &&func, Ret *retVal)
    {
        if (QAndroidPlatformWindow::surfacesCount() == 0) {
            __android_log_print(ANDROID_LOG_WARN, m_qtTag,
                "Could not run accessibility call in object context, no valid surface.");
            return;
        }
 
        QtAndroidPrivate::AndroidDeadlockProtector protector(
            u"QtAndroidAccessibility::runInObjectContext()"_s);
        if (!protector.acquire()) {
            __android_log_print(ANDROID_LOG_WARN, m_qtTag,
                                "Could not run accessibility call in object context, accessing "
                                "main thread could lead to deadlock");
            return;
        }
 
        if (!QtAndroid::blockEventLoopsWhenSuspended()
            || QGuiApplication::applicationState() != Qt::ApplicationSuspended) {
            QMetaObject::invokeMethod(context, func, Qt::BlockingQueuedConnection, retVal);
        } else {
            __android_log_print(ANDROID_LOG_WARN, m_qtTag,
                                "Could not run accessibility call in object context, event loop suspended.");
        }
    }
 
    bool isActive()
    {
        return m_accessibilityActivated;
    }
 
    static void setActive(JNIEnv */*env*/, jobject /*thiz*/, jboolean active)
    {
        QMutexLocker lock(QtAndroid::platformInterfaceMutex());
        QAndroidPlatformIntegration *platformIntegration = QtAndroid::androidPlatformIntegration();
        m_accessibilityActivated = active;
        if (platformIntegration) {
            platformIntegration->accessibility()->setActive(active);
        } else {
            __android_log_print(ANDROID_LOG_DEBUG, m_qtTag,
                "Android platform integration is not ready, accessibility activation deferred.");
        }
    }
 
    QAccessibleInterface *interfaceFromId(jint objectId)
    {
        QAccessibleInterface *iface = nullptr;
        if (objectId == -1) {
            QWindow *win = qApp->focusWindow();
            if (win)
                iface = win->accessibleRoot();
        } else {
            iface = QAccessible::accessibleInterface(objectId);
        }
        return iface;
    }
 
    void notifyLocationChange(uint accessibilityObjectId)
    {
        QtAndroid::notifyAccessibilityLocationChange(accessibilityObjectId);
    }
 
    static int parentId_helper(int objectId); // forward declaration
 
    void notifyObjectHide(uint accessibilityObjectId)
    {
        const auto parentObjectId = parentId_helper(accessibilityObjectId);
        QtAndroid::notifyObjectHide(accessibilityObjectId, parentObjectId);
    }
 
    void notifyObjectShow(uint accessibilityObjectId)
    {
        const auto parentObjectId = parentId_helper(accessibilityObjectId);
        QtAndroid::notifyObjectShow(parentObjectId);
    }
 
    void notifyObjectFocus(uint accessibilityObjectId)
    {
        QtAndroid::notifyObjectFocus(accessibilityObjectId);
    }
 
    static jstring jvalueForAccessibleObject(int objectId); // forward declaration
 
    void notifyValueChanged(uint accessibilityObjectId)
    {
        jstring value = jvalueForAccessibleObject(accessibilityObjectId);
        QtAndroid::notifyValueChanged(accessibilityObjectId, value);
    }
 
    // Forward declaration
    static QString descriptionForInterface(QAccessibleInterface *iface);
 
    void notifyDescriptionOrNameChanged(uint accessibilityObjectId)
    {
        QAccessibleInterface *iface = interfaceFromId(accessibilityObjectId);
        if (iface && iface->isValid()) {
            const QString value = descriptionForInterface(iface);
            QtAndroid::notifyDescriptionOrNameChanged(accessibilityObjectId, value);
        }
    }
 
    void notifyScrolledEvent(uint accessiblityObjectId)
    {
        QtAndroid::notifyScrolledEvent(accessiblityObjectId);
    }
 
    void notifyAnnouncementEvent(uint accessibilityObjectId, const QString &message)
    {
        QtAndroid::notifyAnnouncementEvent(accessibilityObjectId, message);
    }
 
    static QVarLengthArray<int, 8> childIdListForAccessibleObject_helper(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (iface && iface->isValid()) {
            const int childCount = iface->childCount();
            QVarLengthArray<jint, 8> ifaceIdArray;
            ifaceIdArray.reserve(childCount);
            for (int i = 0; i < childCount; ++i) {
                QAccessibleInterface *child = iface->child(i);
                if (child && child->isValid())
                    ifaceIdArray.append(QAccessible::uniqueId(child));
            }
            return ifaceIdArray;
        }
        return {};
    }
 
    static jintArray childIdListForAccessibleObject(JNIEnv *env, jobject /*thiz*/, jint objectId)
    {
        if (m_accessibilityContext) {
            QVarLengthArray<jint, 8> ifaceIdArray;
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return childIdListForAccessibleObject_helper(objectId);
            }, &ifaceIdArray);
            jintArray jArray = env->NewIntArray(jsize(ifaceIdArray.count()));
            env->SetIntArrayRegion(jArray, 0, ifaceIdArray.count(), ifaceIdArray.data());
            return jArray;
        }
 
        return env->NewIntArray(jsize(0));
    }
 
    static int parentId_helper(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (iface && iface->isValid()) {
            QAccessibleInterface *parent = iface->parent();
            if (parent && parent->isValid()) {
                if (parent->role() == QAccessible::Application)
                    return -1;
                return QAccessible::uniqueId(parent);
            }
        }
        return -1;
    }
 
    static jint parentId(JNIEnv */*env*/, jobject /*thiz*/, jint objectId)
    {
        jint result = -1;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return parentId_helper(objectId);
            }, &result);
        }
        return result;
    }
 
    static QRect screenRect_helper(int objectId, bool clip = true)
    {
        QRect rect;
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (iface && iface->isValid()) {
            rect = QHighDpi::toNativePixels(iface->rect(), iface->window());
        }
        // If the widget is not fully in-bound in its parent then we have to clip the rectangle to draw
        if (clip && iface && iface->parent() && iface->parent()->isValid()) {
            const auto parentRect = QHighDpi::toNativePixels(iface->parent()->rect(), iface->parent()->window());
            rect = rect.intersected(parentRect);
        }
        return rect;
    }
 
    static jobject screenRect(JNIEnv *env, jobject /*thiz*/, jint objectId)
    {
        QRect rect;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return screenRect_helper(objectId);
            }, &rect);
        }
        jclass rectClass = env->FindClass("android/graphics/Rect");
        jmethodID ctor = env->GetMethodID(rectClass, "<init>", "(IIII)V");
        jobject jrect = env->NewObject(rectClass, ctor, rect.left(), rect.top(), rect.right(), rect.bottom());
        return jrect;
    }
 
    static int hitTest_helper(float x, float y)
    {
        QAccessibleInterface *root = interfaceFromId(-1);
        if (root && root->isValid()) {
            QPoint pos = QHighDpi::fromNativePixels(QPoint(int(x), int(y)), root->window());
 
            QAccessibleInterface *child = root->childAt(pos.x(), pos.y());
            QAccessibleInterface *lastChild = nullptr;
            while (child && (child != lastChild)) {
                lastChild = child;
                child = child->childAt(pos.x(), pos.y());
            }
            if (lastChild)
                return QAccessible::uniqueId(lastChild);
        }
        return -1;
    }
 
    static jint hitTest(JNIEnv */*env*/, jobject /*thiz*/, jfloat x, jfloat y)
    {
        jint result = -1;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [x, y]() {
                return hitTest_helper(x, y);
            }, &result);
        }
        return result;
    }
 
    static void invokeActionOnInterfaceInMainThread(QAccessibleActionInterface* actionInterface,
                                                    const QString& action)
    {
        // Queue the action and return back to Java thread, so that we do not
        // block it for too long
        QMetaObject::invokeMethod(qApp, [actionInterface, action]() {
            actionInterface->doAction(action);
        }, Qt::QueuedConnection);
    }
 
    static bool clickAction_helper(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (!iface || !iface->isValid() || !iface->actionInterface())
            return false;
 
        const auto& actionNames = iface->actionInterface()->actionNames();
 
        if (actionNames.contains(QAccessibleActionInterface::pressAction())) {
            invokeActionOnInterfaceInMainThread(iface->actionInterface(),
                                                QAccessibleActionInterface::pressAction());
        } else if (actionNames.contains(QAccessibleActionInterface::toggleAction())) {
            invokeActionOnInterfaceInMainThread(iface->actionInterface(),
                                                QAccessibleActionInterface::toggleAction());
        } else {
            return false;
        }
        return true;
    }
 
    static bool focusAction_helper(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (!iface || !iface->isValid() || !iface->actionInterface())
            return false;
 
        const auto& actionNames = iface->actionInterface()->actionNames();
 
        if (actionNames.contains(QAccessibleActionInterface::setFocusAction())) {
            QAccessibleActionInterface *actionInterface = iface->actionInterface();
            // Suppress keyboard activation during accessibility focus navigation.
            QMetaObject::invokeMethod(qApp, [actionInterface]() {
                auto *inputContext = QAndroidInputContext::androidInputContext();
                if (inputContext)
                    inputContext->setAccessibilityFocusInProgress(true);
                const auto resetGuard = qScopeGuard([inputContext] {
                    if (inputContext)
                        inputContext->setAccessibilityFocusInProgress(false);
                });
                actionInterface->doAction(QAccessibleActionInterface::setFocusAction());
            }, Qt::QueuedConnection);
            return true;
        }
        return false;
    }
 
    static jboolean clickAction(JNIEnv */*env*/, jobject /*thiz*/, jint objectId)
    {
        bool result = false;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return clickAction_helper(objectId);
            }, &result);
        }
        return result;
    }
 
    static jboolean focusAction(JNIEnv */*env*/, jobject /*thiz*/, jint objectId)
    {
        bool result = false;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return focusAction_helper(objectId);
            }, &result);
        }
        return result;
    }
 
    static bool scroll_helper(int objectId, const QString &actionName)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (iface && iface->isValid())
            return QAccessibleBridgeUtils::performEffectiveAction(iface, actionName);
        return false;
    }
 
    static jboolean scrollForward(JNIEnv */*env*/, jobject /*thiz*/, jint objectId)
    {
        bool result = false;
 
        const auto& ids = childIdListForAccessibleObject_helper(objectId);
        if (ids.isEmpty())
            return false;
 
        const int firstChildId = ids.first();
        const QRect oldPosition = screenRect_helper(firstChildId, false);
 
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return scroll_helper(objectId, QAccessibleActionInterface::increaseAction());
            }, &result);
        }
 
        // Don't check for position change if the call was not successful
        return result && oldPosition != screenRect_helper(firstChildId, false);
    }
 
    static jboolean scrollBackward(JNIEnv */*env*/, jobject /*thiz*/, jint objectId)
    {
        bool result = false;
 
        const auto& ids = childIdListForAccessibleObject_helper(objectId);
        if (ids.isEmpty())
            return false;
 
        const int firstChildId = ids.first();
        const QRect oldPosition = screenRect_helper(firstChildId, false);
 
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return scroll_helper(objectId, QAccessibleActionInterface::decreaseAction());
            }, &result);
        }
 
        // Don't check for position change if the call was not successful
        return result && oldPosition != screenRect_helper(firstChildId, false);
    }
 
    static bool showOnScreen_helper(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (!iface || !iface->isValid() || !iface->actionInterface())
            return false;
 
        const auto actionNames = iface->actionInterface()->actionNames();
 
        if (actionNames.contains(QAccessibleActionInterface::showOnScreenAction())) {
            invokeActionOnInterfaceInMainThread(iface->actionInterface(), QAccessibleActionInterface::showOnScreenAction());
            return true;
        }
        return false;
    }
 
    static jboolean showOnScreen(JNIEnv */*env*/, jobject /*thiz*/, jint objectId)
    {
        bool result = false;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return showOnScreen_helper(objectId);
            }, &result);
        }
        return result;
    }
 
    static QString textFromValue(QAccessibleInterface *iface)
    {
        QString valueStr;
        QAccessibleValueInterface *valueIface = iface->valueInterface();
        if (valueIface) {
            const QVariant valueVar = valueIface->currentValue();
            const auto type = valueVar.typeId();
            if (type == QMetaType::Double || type == QMetaType::Float) {
                // QVariant's toString() formats floating-point values with
                // FloatingPointShortest, which is not an accessible
                // representation; nor, in many cases, is it suitable to the UI
                // element whose value we're looking at. So roll our own
                // A11Y-friendly conversion to string.
                const double val = valueVar.toDouble();
                // Try to use minimumStepSize() to determine precision
                bool stepIsValid = false;
                const double step = qAbs(valueIface->minimumStepSize().toDouble(&stepIsValid));
                if (!stepIsValid || qFuzzyIsNull(step)) {
                    // Ignore step, use default precision
                    valueStr = qFuzzyIsNull(val) ? u"0"_s : QString::number(val, 'f');
                } else {
                    const int precision = [](double s) {
                        int count = 0;
                        while (s < 1. && !qFuzzyCompare(s, 1.)) {
                            ++count;
                            s *= 10;
                        }
                        // If s is now 1.25, we want to show some more digits,
                        // but don't want to get silly with a step like 1./7;
                        // so only include a few extra digits.
                        const int stop = count + 3;
                        const auto fractional = [](double v) {
                            double whole = 0.0;
                            std::modf(v + 0.5, &whole);
                            return qAbs(v - whole);
                        };
                        s = fractional(s);
                        while (count < stop && !qFuzzyIsNull(s)) {
                            ++count;
                            s = fractional(s * 10);
                        }
                        return count;
                    }(step);
                    valueStr = qFuzzyIsNull(val / step) ? u"0"_s
                                                        : QString::number(val, 'f', precision);
                }
            } else {
                valueStr = valueVar.toString();
            }
        }
        return valueStr;
    }
 
    static jstring jvalueForAccessibleObject(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        const QString value = textFromValue(iface);
        QJniEnvironment env;
        jstring jstr = env->NewString((jchar*)value.constData(), (jsize)value.size());
        if (env.checkAndClearExceptions())
            __android_log_print(ANDROID_LOG_WARN, m_qtTag, "Failed to create jstring");
        return jstr;
    }
 
    static QString classNameForRole(QAccessible::Role role, QAccessible::State state) {
        switch (role) {
        case QAccessible::Role::Button:
        case QAccessible::Role::Link:
        {
            if (state.checkable)
                return QStringLiteral("android.widget.ToggleButton");
            return QStringLiteral("android.widget.Button");
        }
        case QAccessible::Role::CheckBox:
            // As of android/accessibility/utils/Role.java::getRole a CheckBox
            // is NOT android.widget.CheckBox
            return QStringLiteral("android.widget.CompoundButton");
        case QAccessible::Role::Switch:
            return QStringLiteral("android.widget.Switch");
        case QAccessible::Role::Clock:
            return QStringLiteral("android.widget.TextClock");
        case QAccessible::Role::ComboBox:
            return QStringLiteral("android.widget.Spinner");
        case QAccessible::Role::Graphic:
            // QQuickImage does not provide this role it inherits Client from QQuickItem
            return QStringLiteral("android.widget.ImageView");
        case QAccessible::Role::Grouping:
            return QStringLiteral("android.view.ViewGroup");
        case QAccessible::Role::List:
            // As of android/accessibility/utils/Role.java::getRole a List
            // is NOT android.widget.ListView
            return QStringLiteral("android.widget.AbsListView");
        case QAccessible::Role::MenuItem:
            return QStringLiteral("android.view.MenuItem");
        case QAccessible::Role::PopupMenu:
            return QStringLiteral("android.widget.PopupMenu");
        case QAccessible::Role::Separator:
            return QStringLiteral("android.widget.Space");
        case QAccessible::Role::ToolBar:
            return QStringLiteral("android.view.Toolbar");
        case QAccessible::Role::Heading: [[fallthrough]];
        case QAccessible::Role::StaticText:
            // Heading vs. regular Text is finally determined by AccessibilityNodeInfo.isHeading()
            return QStringLiteral("android.widget.TextView");
        case QAccessible::Role::EditableText:
            return QStringLiteral("android.widget.EditText");
        case QAccessible::Role::RadioButton:
            return QStringLiteral("android.widget.RadioButton");
        case QAccessible::Role::ProgressBar:
            return QStringLiteral("android.widget.ProgressBar");
        case QAccessible::Role::SpinBox:
            return QStringLiteral("android.widget.NumberPicker");
        case QAccessible::Role::WebDocument:
            return QStringLiteral("android.webkit.WebView");
        case QAccessible::Role::Dialog:
            return QStringLiteral("android.app.AlertDialog");
        case QAccessible::Role::PageTab:
            return QStringLiteral("android.app.ActionBar.Tab");
        case QAccessible::Role::PageTabList:
            return QStringLiteral("android.widget.TabWidget");
        case QAccessible::Role::ScrollBar:
            return QStringLiteral("android.widget.Scroller");
        case QAccessible::Role::Slider:
            return QStringLiteral("com.google.android.material.slider.Slider");
        case QAccessible::Role::Table:
            // #TODO Evaluate the usage of AccessibleNodeInfo.setCollectionItemInfo() to provide
            // infos about colums, rows und items.
            return QStringLiteral("android.widget.GridView");
        case QAccessible::Role::Pane:
            // #TODO QQuickScrollView, QQuickListView (see QTBUG-137806)
            return QStringLiteral("android.view.ViewGroup");
        case QAccessible::Role::AlertMessage:
        case QAccessible::Role::Animation:
        case QAccessible::Role::Application:
        case QAccessible::Role::Assistant:
        case QAccessible::Role::BlockQuote:
        case QAccessible::Role::Border:
        case QAccessible::Role::ButtonDropGrid:
        case QAccessible::Role::ButtonDropDown:
        case QAccessible::Role::ButtonMenu:
        case QAccessible::Role::Canvas:
        case QAccessible::Role::Caret:
        case QAccessible::Role::Cell:
        case QAccessible::Role::Chart:
        case QAccessible::Role::Client:
        case QAccessible::Role::ColorChooser:
        case QAccessible::Role::Column:
        case QAccessible::Role::ColumnHeader:
        case QAccessible::Role::ComplementaryContent:
        case QAccessible::Role::Cursor:
        case QAccessible::Role::Desktop:
        case QAccessible::Role::Dial:
        case QAccessible::Role::Document:
        case QAccessible::Role::Equation:
        case QAccessible::Role::Footer:
        case QAccessible::Role::Form:
        case QAccessible::Role::Grip:
        case QAccessible::Role::HelpBalloon:
        case QAccessible::Role::HotkeyField:
        case QAccessible::Role::Indicator:
        case QAccessible::Role::LayeredPane:
        case QAccessible::Role::ListItem:
        case QAccessible::Role::MenuBar:
        case QAccessible::Role::NoRole:
        case QAccessible::Role::Note:
        case QAccessible::Role::Notification:
        case QAccessible::Role::Paragraph:
        case QAccessible::Role::PropertyPage:
        case QAccessible::Role::Row:
        case QAccessible::Role::RowHeader:
        case QAccessible::Role::Section:
        case QAccessible::Role::Sound:
        case QAccessible::Role::Splitter:
        case QAccessible::Role::StatusBar:
        case QAccessible::Role::Terminal:
        case QAccessible::Role::TitleBar:
        case QAccessible::Role::ToolTip:
        case QAccessible::Role::Tree:
        case QAccessible::Role::TreeItem:
        case QAccessible::Role::UserRole:
        case QAccessible::Role::Whitespace:
        case QAccessible::Role::Window:
            // If unsure, every visible or interactive element in Android
            // inherits android.view.View and by many extends also TextView.
            // Android itself does a similar thing e.g. in its Settings-App.
            return QStringLiteral("android.view.TextView");
        }
    }
 
    static QString descriptionForInterface(QAccessibleInterface *iface)
    {
        QString desc;
        if (iface && iface->isValid()) {
            bool hasValue = false;
            desc = iface->text(QAccessible::Name);
            const QString descStr = iface->text(QAccessible::Description);
            if (!descStr.isEmpty()) {
                if (!desc.isEmpty())
                    desc.append(QStringLiteral(", "));
                desc.append(descStr);
            }
            if (desc.isEmpty()) {
                desc = iface->text(QAccessible::Value);
                hasValue = !desc.isEmpty();
            }
            if (!hasValue && iface->valueInterface()) {
                const QString valueStr = textFromValue(iface);
                if (!valueStr.isEmpty()) {
                    if (!desc.isEmpty())
                        desc.append(QChar(QChar::Space));
                    desc.append(valueStr);
                }
            }
        }
        return desc;
    }
 
    static QString descriptionForAccessibleObject_helper(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        return descriptionForInterface(iface);
    }
 
    static jstring descriptionForAccessibleObject(JNIEnv *env, jobject /*thiz*/, jint objectId)
    {
        QString desc;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return descriptionForAccessibleObject_helper(objectId);
            }, &desc);
        }
        return env->NewString((jchar*) desc.constData(), (jsize) desc.size());
    }
 
    static QString languageTag_helper(int objectId)
    {
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (!iface || !iface->isValid())
            return QString();
 
        QAccessibleAttributesInterface *attributesIface = iface->attributesInterface();
        if (!attributesIface || !attributesIface->attributeKeys().contains(QAccessible::Attribute::Locale))
            return QString();
 
        return attributesIface->attributeValue(QAccessible::Attribute::Locale).toLocale().bcp47Name();
    }
 
    static jstring languageTag(JNIEnv *env, jobject /*thiz*/, jint objectId)
    {
        QString tag;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return languageTag_helper(objectId);
            }, &tag);
        }
        return env->NewString((jchar*)tag.constData(), (jsize)tag.size());
    }
 
    struct NodeInfo
    {
        bool valid = false;
        QAccessible::State state;
        QAccessible::Role role;
        QStringList actions;
        QString description;
        QString identifier;
        bool hasTextSelection = false;
        int selectionStart = 0;
        int selectionEnd = 0;
        bool hasValue = false;
        QVariant minValue = 0;
        QVariant maxValue = 0;
        QVariant currentValue = 0;
        QVariant valueStepSize = 0;
    };
 
    static NodeInfo populateNode_helper(int objectId)
    {
        NodeInfo info;
        QAccessibleInterface *iface = interfaceFromId(objectId);
        if (iface && iface->isValid()) {
            info.valid = true;
            info.state = iface->state();
            info.role = iface->role();
            info.actions = QAccessibleBridgeUtils::effectiveActionNames(iface);
            info.description = descriptionForInterface(iface);
            info.identifier = QAccessibleBridgeUtils::accessibleId(iface);
            QAccessibleTextInterface *textIface = iface->textInterface();
            if (textIface && (textIface->selectionCount() > 0)) {
                info.hasTextSelection = true;
                textIface->selection(0, &info.selectionStart, &info.selectionEnd);
            }
            QAccessibleValueInterface *valueInterface = iface->valueInterface();
            if (valueInterface) {
                info.hasValue = true;
                info.minValue = valueInterface->minimumValue();
                info.maxValue = valueInterface->maximumValue();
                info.currentValue = valueInterface->currentValue();
                info.valueStepSize = valueInterface->minimumStepSize();
            }
        }
        return info;
    }
 
    static jboolean populateNode(JNIEnv *env, jobject /*thiz*/, jint objectId, jobject node)
    {
        NodeInfo info;
        if (m_accessibilityContext) {
            runInObjectContext(m_accessibilityContext, [objectId]() {
                return populateNode_helper(objectId);
            }, &info);
        }
        if (!info.valid) {
            __android_log_print(ANDROID_LOG_WARN, m_qtTag, "Accessibility: populateNode for Invalid ID");
            return false;
        }
 
        const QString role = classNameForRole(info.role, info.state);
        jstring jrole = env->NewString((jchar*)role.constData(), (jsize)role.size());
        env->CallVoidMethod(node, m_setClassNameMethodID, jrole);
 
        const bool hasClickableAction =
                (info.actions.contains(QAccessibleActionInterface::pressAction())
                 || info.actions.contains(QAccessibleActionInterface::toggleAction()))
                && !(info.role == QAccessible::StaticText || info.role == QAccessible::Heading);
        const bool hasIncreaseAction =
                info.actions.contains(QAccessibleActionInterface::increaseAction());
        const bool hasDecreaseAction =
                info.actions.contains(QAccessibleActionInterface::decreaseAction());
 
        if (info.hasTextSelection && m_setTextSelectionMethodID) {
            env->CallVoidMethod(node, m_setTextSelectionMethodID, info.selectionStart,
                                info.selectionEnd);
        }
 
        if (info.hasValue && m_setRangeInfoMethodID) {
            int valueType = info.currentValue.typeId();
            jint rangeType = RANGE_TYPE_INDETERMINATE;
            switch (valueType) {
            case QMetaType::Float:
            case QMetaType::Double:
                rangeType = RANGE_TYPE_FLOAT;
                break;
            case QMetaType::Int:
                rangeType = RANGE_TYPE_INT;
                break;
            }
 
            float min = info.minValue.toFloat();
            float max = info.maxValue.toFloat();
            float current = info.currentValue.toFloat();
            if (info.role == QAccessible::ProgressBar) {
                rangeType = RANGE_TYPE_PERCENT;
                current = 100 * (current - min) / (max - min);
                min = 0.0f;
                max = 100.0f;
            }
 
            QJniObject rangeInfo("android/view/accessibility/AccessibilityNodeInfo$RangeInfo",
                                 "(IFFF)V", rangeType, min, max, current);
 
            if (rangeInfo.isValid()) {
                env->CallVoidMethod(node, m_setRangeInfoMethodID, rangeInfo.object());
            }
        }
 
        env->CallVoidMethod(node, m_setCheckableMethodID, (bool)info.state.checkable);
        env->CallVoidMethod(node, m_setCheckedMethodID, (bool)info.state.checked);
        env->CallVoidMethod(node, m_setEditableMethodID, info.state.editable);
        env->CallVoidMethod(node, m_setEnabledMethodID, !info.state.disabled);
        env->CallVoidMethod(node, m_setFocusableMethodID, (bool)info.state.focusable);
        env->CallVoidMethod(node, m_setFocusedMethodID, (bool)info.state.focused);
        if (m_setHeadingMethodID)
            env->CallVoidMethod(node, m_setHeadingMethodID, info.role == QAccessible::Heading);
        env->CallVoidMethod(node, m_setVisibleToUserMethodID, !info.state.invisible);
        env->CallVoidMethod(node, m_setScrollableMethodID, hasIncreaseAction || hasDecreaseAction);
        env->CallVoidMethod(node, m_setClickableMethodID, hasClickableAction || info.role == QAccessible::Link);
 
        // Add ACTION_CLICK
        if (hasClickableAction)
            env->CallVoidMethod(node, m_addActionMethodID, (int)0x00000010);    // ACTION_CLICK defined in AccessibilityNodeInfo
 
        // Add ACTION_SCROLL_FORWARD
        if (hasIncreaseAction)
            env->CallVoidMethod(node, m_addActionMethodID, (int)0x00001000);    // ACTION_SCROLL_FORWARD defined in AccessibilityNodeInfo
 
        // Add ACTION_SCROLL_BACKWARD
        if (hasDecreaseAction)
            env->CallVoidMethod(node, m_addActionMethodID, (int)0x00002000);    // ACTION_SCROLL_BACKWARD defined in AccessibilityNodeInfo
 
        // try to fill in the text property, this is what the screen reader reads
        jstring jdesc = env->NewString((jchar*)info.description.constData(),
                                       (jsize)info.description.size());
        //CALL_METHOD(node, "setText", "(Ljava/lang/CharSequence;)V", jdesc)
        env->CallVoidMethod(node, m_setContentDescriptionMethodID, jdesc);
 
        QJniObject(node).callMethod<void>("setViewIdResourceName", info.identifier);
 
        return true;
    }
 
    static const JNINativeMethod methods[] = {
        {"setActive","(Z)V",(void*)setActive},
        {"childIdListForAccessibleObject", "(I)[I", (jintArray)childIdListForAccessibleObject},
        {"parentId", "(I)I", (void*)parentId},
        {"descriptionForAccessibleObject", "(I)Ljava/lang/String;", (jstring)descriptionForAccessibleObject},
        {"languageTag", "(I)Ljava/lang/String;", (jstring)languageTag},
        {"screenRect", "(I)Landroid/graphics/Rect;", (jobject)screenRect},
        {"hitTest", "(FF)I", (void*)hitTest},
        {"populateNode", "(ILandroid/view/accessibility/AccessibilityNodeInfo;)Z", (void*)populateNode},
        {"clickAction", "(I)Z", (void*)clickAction},
        {"focusAction", "(I)Z", (void*)focusAction},
        {"scrollForward", "(I)Z", (void*)scrollForward},
        {"scrollBackward", "(I)Z", (void*)scrollBackward},
        {"showOnScreen", "(I)Z", (void *)showOnScreen}
    };
 
#define GET_AND_CHECK_STATIC_METHOD(VAR, CLASS, METHOD_NAME, METHOD_SIGNATURE)
    VAR = env->GetMethodID(CLASS, METHOD_NAME, METHOD_SIGNATURE);
    if (!VAR) {
        __android_log_print(ANDROID_LOG_FATAL, QtAndroid::qtTagText(), QtAndroid::methodErrorMsgFmt(), METHOD_NAME, METHOD_SIGNATURE);
        return false;
    }
 
#define CHECK_AND_INIT_STATIC_FIELD(TYPE, VAR, CLASS, FIELD_NAME)
    if (env.findStaticField<TYPE>(CLASS, FIELD_NAME) == nullptr) {
        __android_log_print(ANDROID_LOG_FATAL, QtAndroid::qtTagText(),
                            QtAndroid::staticFieldErrorMsgFmt(), FIELD_NAME);
        return false;
    }
    VAR = QJniObject::getStaticField<TYPE>(CLASS, FIELD_NAME);
 
    bool registerNatives(QJniEnvironment &env)
    {
        if (!env.registerNativeMethods("org/qtproject/qt/android/QtNativeAccessibility",
                                      methods, sizeof(methods) / sizeof(methods[0]))) {
            __android_log_print(ANDROID_LOG_FATAL,"Qt A11y", "RegisterNatives failed");
            return false;
        }
 
        jclass nodeInfoClass = env->FindClass("android/view/accessibility/AccessibilityNodeInfo");
        GET_AND_CHECK_STATIC_METHOD(m_setClassNameMethodID, nodeInfoClass, "setClassName", "(Ljava/lang/CharSequence;)V");
        GET_AND_CHECK_STATIC_METHOD(m_addActionMethodID, nodeInfoClass, "addAction", "(I)V");
        GET_AND_CHECK_STATIC_METHOD(m_setCheckableMethodID, nodeInfoClass, "setCheckable", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setCheckedMethodID, nodeInfoClass, "setChecked", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setClickableMethodID, nodeInfoClass, "setClickable", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setContentDescriptionMethodID, nodeInfoClass, "setContentDescription", "(Ljava/lang/CharSequence;)V");
        GET_AND_CHECK_STATIC_METHOD(m_setEditableMethodID, nodeInfoClass, "setEditable", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setEnabledMethodID, nodeInfoClass, "setEnabled", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setFocusableMethodID, nodeInfoClass, "setFocusable", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setFocusedMethodID, nodeInfoClass, "setFocused", "(Z)V");
        if (QtAndroidPrivate::androidSdkVersion() >= 28) {
            GET_AND_CHECK_STATIC_METHOD(m_setHeadingMethodID, nodeInfoClass, "setHeading", "(Z)V");
        }
        GET_AND_CHECK_STATIC_METHOD(m_setScrollableMethodID, nodeInfoClass, "setScrollable", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setVisibleToUserMethodID, nodeInfoClass, "setVisibleToUser", "(Z)V");
        GET_AND_CHECK_STATIC_METHOD(m_setTextSelectionMethodID, nodeInfoClass, "setTextSelection", "(II)V");
        GET_AND_CHECK_STATIC_METHOD(
                m_setRangeInfoMethodID, nodeInfoClass, "setRangeInfo",
                "(Landroid/view/accessibility/AccessibilityNodeInfo$RangeInfo;)V");
 
        jclass rangeInfoClass =
                env->FindClass("android/view/accessibility/AccessibilityNodeInfo$RangeInfo");
        CHECK_AND_INIT_STATIC_FIELD(int, RANGE_TYPE_INT, rangeInfoClass, "RANGE_TYPE_INT");
        CHECK_AND_INIT_STATIC_FIELD(int, RANGE_TYPE_FLOAT, rangeInfoClass, "RANGE_TYPE_FLOAT");
        CHECK_AND_INIT_STATIC_FIELD(int, RANGE_TYPE_PERCENT, rangeInfoClass, "RANGE_TYPE_PERCENT");
        if (QtAndroidPrivate::androidSdkVersion() >= 36) {
            CHECK_AND_INIT_STATIC_FIELD(int, RANGE_TYPE_INDETERMINATE, rangeInfoClass,
                                        "RANGE_TYPE_INDETERMINATE");
        } else {
            RANGE_TYPE_INDETERMINATE = RANGE_TYPE_FLOAT;
        }
 
        return true;
    }
}
 
QT_END_NAMESPACE