qcocoaaccessibilityelement.mm

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// Copyright (C) 2016 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 <AppKit/AppKit.h>
 
#include "qcocoaaccessibilityelement.h"
#include "qcocoaaccessibility.h"
#include "qcocoahelpers.h"
#include "qcocoawindow.h"
#include "qcocoascreen.h"
 
#include <QtCore/qlogging.h>
#include <QtGui/private/qaccessiblecache_p.h>
#include <QtGui/private/qaccessiblebridgeutils_p.h>
#include <QtGui/qaccessible.h>
 
QT_USE_NAMESPACE
 
Q_STATIC_LOGGING_CATEGORY(lcAccessibilityTable, "qt.accessibility.table")
 
using namespace Qt::StringLiterals;
 
#if QT_CONFIG(accessibility)
 
/**
 * Converts between absolute character offsets and line numbers of a
 * QAccessibleTextInterface. Works in exactly one of two modes:
 *
 *  - Pass *line == -1 in order to get a line containing character at the given
 *    *offset
 *  - Pass *offset == -1 in order to get the offset of first character of the
 *    given *line
 *
 * You can optionally also pass non-NULL `start` and `end`, which will in both
 * modes be filled with the offset of the first and last characters of the
 * relevant line.
 */
static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *offset, NSUInteger *start = 0, NSUInteger *end = 0)
{
    Q_ASSERT(*line == -1 || *offset == -1);
    Q_ASSERT(*line != -1 || *offset != -1);
    Q_ASSERT(*offset <= text->characterCount());
 
    int curLine = -1;
    int curStart = 0, curEnd = 0;
 
    do {
        curStart = curEnd;
        text->textAtOffset(curStart, QAccessible::LineBoundary, &curStart, &curEnd);
        // If the text is empty then we just return
        if (curStart == -1 || curEnd == -1) {
            if (start)
                *start = 0;
            if (end)
                *end = 0;
            return;
        }
        ++curLine;
        {
            // check for a case where a single word longer than the text edit's width and gets wrapped
            // in the middle of the word; in this case curEnd will be an offset belonging to the next line
            // and therefore nextEnd will not be equal to curEnd
            int nextStart;
            int nextEnd;
            text->textAtOffset(curEnd, QAccessible::LineBoundary, &nextStart, &nextEnd);
            if (nextEnd == curEnd)
                ++curEnd;
        }
    } while ((*line == -1 || curLine < *line) && (*offset == -1 || (curEnd <= *offset)) && curEnd <= text->characterCount());
 
    curEnd = qMin(curEnd, text->characterCount());
 
    if (*line == -1)
        *line = curLine;
    if (*offset == -1)
        *offset = curStart;
 
    Q_ASSERT(curStart >= 0);
    Q_ASSERT(curEnd >= 0);
    if (start)
        *start = curStart;
    if (end)
        *end = curEnd;
}
 
@implementation QMacAccessibilityElement {
    QAccessible::Id axid;
    int m_rowIndex;
    int m_columnIndex;
 
    // used by NSAccessibilityTable
    NSMutableArray<QMacAccessibilityElement *> *rows;       // corresponds to accessibilityRows
    NSMutableArray<QMacAccessibilityElement *> *columns;    // corresponds to accessibilityColumns
 
    // If synthesizedRole is set, this means that this objects does not have a corresponding
    // QAccessibleInterface, but it is synthesized by the cocoa plugin in order to meet the
    // NSAccessibility requirements.
    // The ownership is controlled by the parent object identified with the axid member variable.
    // (Therefore, if this member is set, this objects axid member is the same as the parents axid
    // member)
    NSString *synthesizedRole;
}
 
- (instancetype)initWithId:(QAccessible::Id)anId
{
    return [self initWithId:anId role:nil];
}
 
- (instancetype)initWithId:(QAccessible::Id)anId role:(NSAccessibilityRole)role
{
    Q_ASSERT((int)anId < 0);
    self = [super init];
    if (self) {
        axid = anId;
        m_rowIndex = -1;
        m_columnIndex = -1;
        rows = nil;
        columns = nil;
        synthesizedRole = role;
        // table: if this is not created as an element managed by the table, then
        // it's either the table itself, or an element created for an already existing
        // cell interface (or an element that's not at all related to a table).
        if (!synthesizedRole) {
            if (QAccessibleInterface *iface = QAccessible::accessibleInterface(axid)) {
                if (iface->tableInterface()) {
                    [self updateTableModel];
                } else if (const auto *cell = iface->tableCellInterface()) {
                    // If we create an element for a table cell, initialize it with row/column
                    // and insert it into the corresponding row's columns array.
                    m_rowIndex = cell->rowIndex();
                    m_columnIndex = cell->columnIndex();
                    QAccessibleInterface *table = cell->table();
                    Q_ASSERT(table);
                    QAccessibleTableInterface *tableInterface = table->tableInterface();
                    if (tableInterface) {
                        auto *tableElement = [QMacAccessibilityElement elementWithInterface:table];
                        Q_ASSERT(tableElement);
                        if (!tableElement->rows
                         || int(tableElement->rows.count) <= m_rowIndex
                         || int(tableElement->rows.count) != tableInterface->rowCount()) {
                            qCWarning(lcAccessibilityTable)
                                       << "Cell requested for row" << m_rowIndex << "is out of"
                                       << "bounds for table with" << (tableElement->rows ?
                                            tableElement->rows.count : tableInterface->rowCount())
                                       << "rows! Resizing table model.";
                            [tableElement updateTableModel];
                        }
 
                        Q_ASSERT(tableElement->rows);
                        Q_ASSERT(int(tableElement->rows.count) > m_rowIndex);
 
                        auto *rowElement = tableElement->rows[m_rowIndex];
                        if (!rowElement->columns || int(rowElement->columns.count) != tableInterface->columnCount()) {
                            if (rowElement->columns) {
                                qCWarning(lcAccessibilityTable)
                                        << "Table representation column count is out of sync:"
                                        << rowElement->columns.count << "!=" << tableInterface->columnCount();
                                [rowElement->columns autorelease];
                                rowElement->columns = nil;
                            }
                            rowElement->columns = [rowElement populateTableRow:tableInterface->columnCount()];
                            [rowElement->columns retain];
                        }
 
                        qCDebug(lcAccessibilityTable) << "Creating cell representation for"
                                                      << m_rowIndex << m_columnIndex
                                                      << "in table with"
                                                      << tableElement->rows.count << "rows and"
                                                      << rowElement->columns.count << "columns";
 
                        rowElement->columns[m_columnIndex] = self;
                    }
                }
            }
        }
    }
 
    return self;
}
 
/*!
    \internal
 
    Constructs a new element with the ID \a anId and inserts it into the cache.
 
    Elements representing table rows, columns, and cells are created directly
    via initWithId (in populateTableArray and populateTableRow), as they don't
    get added to the cache until later.
*/
+ (instancetype)elementWithId:(QAccessible::Id)anId
{
    Q_ASSERT(anId);
    if (!anId)
        return nil;
 
    QAccessibleCache *cache = QAccessibleCache::instance();
 
    QMacAccessibilityElement *element = cache->elementForId(anId);
    if (!element) {
        Q_ASSERT(QAccessible::accessibleInterface(anId));
        element = [[self alloc] initWithId:anId];
        if (cache->insertElement(anId, element))
            [element release];
    }
    return element;
}
 
+ (instancetype)elementWithInterface:(QAccessibleInterface *)iface
{
    Q_ASSERT(iface);
    if (!iface)
        return nil;
 
    const QAccessible::Id anId = QAccessible::uniqueId(iface);
    return [self elementWithId:anId];
}
 
+ (void)removeElementsFromCache:(NSArray *)array {
    for (uint i = 0; i < array.count; ++i) {
        QMacAccessibilityElement *cell = [array objectAtIndex:i];
        if (cell->axid) { // it's a proper cell, remove from cache
            QAccessibleCache::instance()->deleteInterface(cell->axid);
        }
    }
}
 
// called by QAccessibleCache::removeAccessibleElement, which also releases
- (void)invalidate {
    axid = 0;
    if (rows) {
        [QMacAccessibilityElement removeElementsFromCache:rows];
        [rows autorelease];
        rows = nil;
    }
    if (columns) {
        [QMacAccessibilityElement removeElementsFromCache:columns];
        [columns autorelease];
        columns = nil;
    }
    synthesizedRole = nil;
 
    NSAccessibilityPostNotification(self, NSAccessibilityUIElementDestroyedNotification);
}
 
/*!
    \internal
 
    If this element represents a table, then the rows and columns array are both
    populated with elements representing the rows and columns. If this elements
    represents a row, then the columns array is populated with elements
    representing the cells. Not all of those synthesized elements might be in
    the cache, but those that are need to be removed so that we don't end up
    with stale representations of children when the higher-level element
    expires.
*/
- (void)dealloc {
    if (rows) {
        [QMacAccessibilityElement removeElementsFromCache:rows];
        [rows release]; // will also release all entries first
    }
    if (columns) {
        [QMacAccessibilityElement removeElementsFromCache:columns];
        [columns release]; // will also release all entries first
    }
    QAccessibleCache::instance()->deleteInterface(axid);
    [super dealloc];
}
 
- (BOOL)isEqual:(id)object {
    if ([object isKindOfClass:[QMacAccessibilityElement class]]) {
        QMacAccessibilityElement *other = object;
        return other->axid == axid && other->synthesizedRole == synthesizedRole;
    } else {
        return NO;
    }
}
 
- (NSUInteger)hash {
    return axid;
}
 
- (BOOL)isManagedByParent {
    return synthesizedRole != nil;
}
 
- (NSMutableArray *)populateTableArray:(NSAccessibilityRole)role count:(int)count
{
    if (self.qtInterface) {
        auto *array = [NSMutableArray<QMacAccessibilityElement *> arrayWithCapacity:count];
        Q_ASSERT(array);
        for (int n = 0; n < count; ++n) {
            // columns will have same axid as table (but not inserted in cache)
            QMacAccessibilityElement *element =
                    [[QMacAccessibilityElement alloc] initWithId:axid role:role];
            if (element) {
                if (role == NSAccessibilityRowRole)
                    element->m_rowIndex = n;
                else if (role == NSAccessibilityColumnRole)
                    element->m_columnIndex = n;
                [array addObject:element];
                [element release];
            } else {
                qWarning("QCocoaAccessibility: invalid child");
            }
        }
        return array;
    }
    return nil;
}
 
- (NSMutableArray *)populateTableRow:(int)count
{
    Q_ASSERT(synthesizedRole == NSAccessibilityRowRole);
    qCDebug(lcAccessibilityTable) << "Populating table row" << m_rowIndex
                                  << "with" << count << "placeholder cells";
    // When macOS asks for the children of a row, then we populate the row's column
    // array with synthetic elements as place holders. This way, we don't have to
    // create QAccessibleInterfaces for every cell before they are really needed.
    // We don't add those synthetic elements into the cache, and we give them the
    // same axid as the table. This way, we can get easily to the table, and from
    // there to the QAccessibleInterface for the cell, when we have to eventually
    // associate such an interface with the element (at which point it is no longer
    // a placeholder).
    auto *array = [NSMutableArray<QMacAccessibilityElement *> arrayWithCapacity:count];
    Q_ASSERT(array);
 
    for (int n = 0; n < count; ++n) {
        // columns will have same axid as table (but not inserted in cache)
        QMacAccessibilityElement *cell =
                [[QMacAccessibilityElement alloc] initWithId:axid role:NSAccessibilityCellRole];
        if (cell) {
            cell->m_rowIndex = m_rowIndex;
            cell->m_columnIndex = n;
            [array addObject:cell];
            [cell release];
        }
    }
    return array;
}
 
- (void)updateTableModel
{
    if (QAccessibleInterface *iface = self.qtInterface) {
        if (QAccessibleTableInterface *table = iface->tableInterface()) {
            Q_ASSERT(!self.isManagedByParent);
            qCDebug(lcAccessibilityTable) << "Updating table representation with"
                                          << table->rowCount() << table->columnCount();
            if (rows) {
                [rows autorelease];
                rows = nil;
            }
            rows = [self populateTableArray:NSAccessibilityRowRole count:table->rowCount()];
            [rows retain];
            if (columns) {
                [columns autorelease];
                columns = nil;
            }
            columns = [self populateTableArray:NSAccessibilityColumnRole count:table->columnCount()];
            [columns retain];
        }
    }
}
 
- (QAccessibleInterface *)qtInterface
{
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface || !iface->isValid())
        return nullptr;
 
    // If this is a placeholder element for a table cell, associate it with the
    // cell interface (which will be created now, if needed). The current axid is
    // for the table to which the cell belongs, so iface is pointing at the table.
    if (synthesizedRole == NSAccessibilityCellRole) {
        // get the cell interface - there must be a valid one
        QAccessibleTableInterface *table = iface->tableInterface();
        Q_ASSERT(table);
        QAccessibleInterface *cell = table->cellAt(m_rowIndex, m_columnIndex);
        if (!cell)
            return nullptr;
        Q_ASSERT(cell->isValid());
        iface = cell;
 
        // no longer a placeholder
        axid = QAccessible::uniqueId(cell);
        synthesizedRole = nil;
 
        QAccessibleCache *cache = QAccessibleCache::instance();
        if (QMacAccessibilityElement *cellElement = cache->elementForId(axid)) {
            // there already is another, non-placeholder element in the cache
            Q_ASSERT(cellElement->synthesizedRole == nil);
            // we have to release it if it's not us
            if (cellElement != self) {
                // for the same cell position
                Q_ASSERT(cellElement->m_rowIndex == m_rowIndex && cellElement->m_columnIndex == m_columnIndex);
            }
        }
 
        cache->insertElement(axid, self);
    }
    return iface;
}
 
//
// accessibility protocol
//
 
- (BOOL)isAccessibilityFocused
{
    // Just check if the app thinks we're focused.
    id focusedElement = NSApp.accessibilityApplicationFocusedUIElement;
    return [focusedElement isEqual:self];
}
 
// attributes
 
+ (id) lineNumberForIndex: (int)index forText:(const QString &)text
{
    auto textBefore = QStringView(text).left(index);
    qsizetype newlines = textBefore.count(u'\n');
    return @(newlines);
}
 
- (BOOL) accessibilityNotifiesWhenDestroyed {
    return YES;
}
 
- (NSString *) accessibilityRole {
    // shortcut for cells, rows, and columns in a table
    if (synthesizedRole)
        return synthesizedRole;
    if (QAccessibleInterface *iface = self.qtInterface)
        return QCocoaAccessible::macRole(iface);
    return NSAccessibilityUnknownRole;
}
 
- (NSString *) accessibilitySubRole {
    if (QAccessibleInterface *iface = self.qtInterface)
        return QCocoaAccessible::macSubrole(iface);
    return NSAccessibilityUnknownRole;
}
 
- (NSString *) accessibilityRoleDescription {
    if (self.qtInterface)
        return NSAccessibilityRoleDescription(self.accessibilityRole, self.accessibilitySubRole);
    return NSAccessibilityUnknownRole;
}
 
- (NSArray *) accessibilityChildren {
    // shortcut for cells
    if (synthesizedRole == NSAccessibilityCellRole)
        return nil;
 
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return nil;
    if (QAccessibleTableInterface *table = iface->tableInterface()) {
        // either a table or table rows/columns
        if (!synthesizedRole) {
            // This is the table element, parent of all rows and columns
            /*
             * Typical 2x2 table hierarchy as can be observed in a table found under
             *   Apple -> System Settings -> General -> Login Items    (macOS 13)
             *
             *  (AXTable)
             *  | Columns: NSArray* (2 items)
             *  | Rows: NSArray* (2 items)
             *  | Visible Columns: NSArray* (2 items)
             *  | Visible Rows: NSArray* (2 items)
             *  | Children: NSArray* (5 items)
        +----<--| Header: (AXGroup)
        |    *  +-- (AXRow)
        |    *  |   +-- (AXText)
        |    *  |   +-- (AXTextField)
        |    *  +-- (AXRow)
        |    *  |   +-- (AXText)
        |    *  |   +-- (AXTextField)
        |    *  +-- (AXColumn)
        |    *  |     Header: "Item" (sort button)
        |    *  |     Index: 0
        |    *  |     Rows: NSArray* (2 items)
        |    *  |     Visible Rows: NSArray* (2 items)
        |    *  +-- (AXColumn)
        |    *  |     Header: "Kind" (sort button)
        |    *  |     Index: 1
        |    *  |     Rows: NSArray* (2 items)
        |    *  |     Visible Rows: NSArray* (2 items)
        +---->  +-- (AXGroup)
             *      +-- (AXButton/AXSortButton) Item [NSAccessibilityTableHeaderCellProxy]
             *      +-- (AXButton/AXSortButton) Kind [NSAccessibilityTableHeaderCellProxy]
             */
            NSArray *rs = [self accessibilityRows];
            NSArray *cs = [self accessibilityColumns];
            const int rCount = int([rs count]);
            const int cCount = int([cs count]);
            int childCount = rCount + cCount;
            NSMutableArray<QMacAccessibilityElement *> *tableChildren =
                    [NSMutableArray<QMacAccessibilityElement *> arrayWithCapacity:childCount];
            for (int i = 0; i < rCount; ++i) {
                [tableChildren addObject:[rs objectAtIndex:i]];
            }
            for (int i = 0; i < cCount; ++i) {
                [tableChildren addObject:[cs objectAtIndex:i]];
            }
            return NSAccessibilityUnignoredChildren(tableChildren);
        } else if (synthesizedRole == NSAccessibilityColumnRole) {
            return nil;
        } else if (synthesizedRole == NSAccessibilityRowRole) {
            // axid matches the parent table axid so that we can easily find the parent table
            // children of row are cell/any items
            Q_ASSERT(m_rowIndex >= 0);
            Q_ASSERT(rows == nil);
            const unsigned int numColumns = table->columnCount();
            if (!columns || columns.count != numColumns) {
                if (columns) {
                    [columns autorelease];
                    columns = nil;
                }
                columns = [self populateTableRow:numColumns];
                [columns retain];
            }
            return NSAccessibilityUnignoredChildren(columns);
        }
    }
    return QCocoaAccessible::unignoredChildren(iface);
}
 
- (NSArray *) accessibilitySelectedChildren {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface || !iface->isValid())
        return nil;
 
    QAccessibleSelectionInterface *selection = iface->selectionInterface();
    if (!selection)
        return nil;
 
    const QList<QAccessibleInterface *> selectedList = selection->selectedItems();
    const qsizetype numSelected = selectedList.size();
    NSMutableArray<QMacAccessibilityElement *> *selectedChildren =
            [NSMutableArray<QMacAccessibilityElement *> arrayWithCapacity:numSelected];
    for (QAccessibleInterface *selectedChild : selectedList) {
        if (selectedChild && selectedChild->isValid()) {
            QAccessible::Id id = QAccessible::uniqueId(selectedChild);
            QMacAccessibilityElement *element = [QMacAccessibilityElement elementWithId:id];
            if (element)
                [selectedChildren addObject:element];
        }
    }
    return NSAccessibilityUnignoredChildren(selectedChildren);
}
 
- (id) accessibilityWindow {
    // Go up until we find a parent that is a window
    NSAccessibilityElement *parent = self.accessibilityParent;
    if (parent && parent.accessibilityRole == NSAccessibilityWindowRole)
        return parent;
    return [parent accessibilityWindow];
}
 
- (id) accessibilityTopLevelUIElementAttribute {
    // We're in the same top level element as our parent.
    return [self.accessibilityParent accessibilityTopLevelUIElementAttribute];
}
 
- (NSString *) accessibilityTitle {
    if (QAccessibleInterface *iface = self.qtInterface) {
        if (iface->role() == QAccessible::StaticText)
            return nil;
        if (self.isManagedByParent)
            return nil;
        return iface->text(QAccessible::Name).toNSString();
    }
    return nil;
}
 
- (id) accessibilityTitleUIElement {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return nil;
 
    const auto labelRelations = iface->relations(QAccessible::Label);
    if (labelRelations.empty())
        return nil;
 
    QAccessibleInterface *label = labelRelations.first().first;
    if (!label)
        return nil;
 
    QMacAccessibilityElement *accessibleElement = [QMacAccessibilityElement elementWithInterface:label];
    if (!accessibleElement)
        return nil;
 
    return NSAccessibilityUnignoredAncestor(accessibleElement);
}
 
- (NSString*) accessibilityIdentifier {
    if (QAccessibleInterface *iface = self.qtInterface)
        return QAccessibleBridgeUtils::accessibleId(iface).toNSString();
    return nil;
}
 
- (BOOL) isAccessibilityEnabled {
    if (QAccessibleInterface *iface = self.qtInterface)
        return !iface->state().disabled;
    return false;
}
 
- (id)accessibilityParent {
    if (synthesizedRole == NSAccessibilityCellRole) {
        // a synthetic cell without interface - shortcut to the row
        QMacAccessibilityElement *tableElement =
                    [QMacAccessibilityElement elementWithId:axid];
        Q_ASSERT(tableElement && tableElement->rows);
        Q_ASSERT(int(tableElement->rows.count) > m_rowIndex);
        QMacAccessibilityElement *rowElement = tableElement->rows[m_rowIndex];
        return rowElement;
    }
 
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return nil;
 
    if (self.isManagedByParent) {
        // axid is the same for the parent element
        return NSAccessibilityUnignoredAncestor([QMacAccessibilityElement elementWithId:axid]);
    }
 
    if (QAccessibleInterface *parent = iface->parent()) {
        if (parent->tableInterface()) {
            QMacAccessibilityElement *tableElement =
                    [QMacAccessibilityElement elementWithInterface:parent];
 
            // parent of cell should be row
            int rowIndex = -1;
            if (m_rowIndex >= 0 && m_columnIndex >= 0)
                rowIndex = m_rowIndex;
            else if (QAccessibleTableCellInterface *cell = iface->tableCellInterface())
                rowIndex = cell->rowIndex();
            Q_ASSERT(tableElement->rows);
            if (rowIndex > int([tableElement->rows count]) || rowIndex == -1)
                return nil;
            QMacAccessibilityElement *rowElement = tableElement->rows[rowIndex];
            return NSAccessibilityUnignoredAncestor(rowElement);
        }
        // macOS expects that the hierarchy is:
        // App -> Window -> Children
        // We don't actually have the window reflected properly in QAccessibility;
        // the native framework does that for us. Check if the parent is the
        // Application or a window, and if so return the native NSView instead.
        if (parent->role() != QAccessible::Application && parent->role() != QAccessible::Window)
            return NSAccessibilityUnignoredAncestor([QMacAccessibilityElement elementWithInterface: parent]);
    }
 
    if (QWindow *window = iface->window()) {
        QPlatformWindow *platformWindow = window->handle();
        if (platformWindow) {
            QCocoaWindow *win = static_cast<QCocoaWindow*>(platformWindow);
            return NSAccessibilityUnignoredAncestor(qnsview_cast(win->view()));
        }
    }
    return nil;
}
 
- (NSRect)accessibilityFrame {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return NSZeroRect;
 
    QRect rect;
    if (self.isManagedByParent) {
        if (QAccessibleTableInterface *table = iface->tableInterface()) {
            // Construct the geometry of the Row/Column by looking at the individual table cells
            // ### Assumes that cells logical coordinates have spatial ordering (e.g finds the
            // rows width by taking the union between the leftmost item and the rightmost item in
            // a row).
            // Otherwise, we have to iterate over *all* cells in a row/columns to
            // find out the Row/Column geometry
            const bool isRow = synthesizedRole == NSAccessibilityRowRole;
            QPoint cellPos;
            int &row = isRow ? cellPos.ry() : cellPos.rx();
            int &col = isRow ? cellPos.rx() : cellPos.ry();
 
            NSUInteger trackIndex = self.accessibilityIndex;
            if (trackIndex != NSNotFound) {
                row = int(trackIndex);
                if (QAccessibleInterface *firstCell = table->cellAt(cellPos.y(), cellPos.x())) {
                    rect = firstCell->rect();
                    col = isRow ? table->columnCount() : table->rowCount();
                    if (col > 1) {
                        --col;
                        if (QAccessibleInterface *lastCell =
                                    table->cellAt(cellPos.y(), cellPos.x()))
                            rect = rect.united(lastCell->rect());
                    }
                }
            }
        }
    } else {
        rect = iface->rect();
    }
 
    return QCocoaScreen::mapToNative(rect);
}
 
- (NSString*)accessibilityLabel {
    if (QAccessibleInterface *iface = self.qtInterface)
        return iface->text(QAccessible::Description).toNSString();
    qWarning() << "Called accessibilityLabel on invalid object: " << axid;
    return nil;
}
 
- (void)setAccessibilityLabel:(NSString*)label{
    if (QAccessibleInterface *iface = self.qtInterface)
        iface->setText(QAccessible::Description, QString::fromNSString(label));
}
 
- (id) accessibilityValue {
    if (QAccessibleInterface *iface = self.qtInterface) {
        // VoiceOver asks for the value attribute for all elements. Return nil
        // if we don't want the element to have a value attribute.
        if (QCocoaAccessible::hasValueAttribute(iface))
            return QCocoaAccessible::getValueAttribute(iface);
    }
    return nil;
}
 
 
- (id) accessibilityMinValue {
    if (QAccessibleInterface *iface = self.qtInterface) {
        if (iface->valueInterface()) {
            return iface->valueInterface()->minimumValue().toString().toNSString();
        }
    }
    return nil;
}
 
 
- (id) accessibilityMaxValue {
    if (QAccessibleInterface *iface = self.qtInterface) {
        if (iface->valueInterface()) {
            return iface->valueInterface()->maximumValue().toString().toNSString();
        }
    }
    return nil;
}
 
- (NSInteger) accessibilityNumberOfCharacters {
    if (QAccessibleInterface *iface = self.qtInterface) {
        if (QAccessibleTextInterface *text = iface->textInterface())
            return text->characterCount();
    }
    return 0;
}
 
- (NSString *) accessibilitySelectedText {
    if (QAccessibleInterface *iface = self.qtInterface) {
        if (QAccessibleTextInterface *text = iface->textInterface()) {
            int start = 0;
            int end = 0;
            text->selection(0, &start, &end);
            return text->text(start, end).toNSString();
        }
    }
    return nil;
}
 
- (NSRange) accessibilitySelectedTextRange {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return NSRange();
    if (QAccessibleTextInterface *text = iface->textInterface()) {
        int start = 0;
        int end = 0;
        if (text->selectionCount() > 0) {
            text->selection(0, &start, &end);
        } else {
            start = text->cursorPosition();
            end = start;
        }
        return NSMakeRange(quint32(start), quint32(end - start));
    }
    return NSMakeRange(0, 0);
}
 
- (NSInteger)accessibilityLineForIndex:(NSInteger)index {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return 0;
    if (QAccessibleTextInterface *text = iface->textInterface()) {
        QString textToPos = text->text(0, index);
        return textToPos.count('\n');
    }
    return 0;
}
 
- (NSRange)accessibilityVisibleCharacterRange {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return NSRange();
    // FIXME This is not correct and may impact performance for big texts
    if (QAccessibleTextInterface *text = iface->textInterface())
        return NSMakeRange(0, static_cast<uint>(text->characterCount()));
    return NSMakeRange(0, static_cast<uint>(iface->text(QAccessible::Name).length()));
}
 
- (NSInteger) accessibilityInsertionPointLineNumber {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return 0;
    if (QAccessibleTextInterface *text = iface->textInterface()) {
        int position = text->cursorPosition();
        return [self accessibilityLineForIndex:position];
    }
    return 0;
}
 
- (NSArray *)accessibilityParameterizedAttributeNames {
 
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface) {
        qWarning() << "Called attribute on invalid object: " << axid;
        return nil;
    }
 
    if (iface->textInterface()) {
        return @[
            NSAccessibilityStringForRangeParameterizedAttribute,
            NSAccessibilityLineForIndexParameterizedAttribute,
            NSAccessibilityRangeForLineParameterizedAttribute,
            NSAccessibilityRangeForPositionParameterizedAttribute,
//          NSAccessibilityRangeForIndexParameterizedAttribute,
            NSAccessibilityBoundsForRangeParameterizedAttribute,
//          NSAccessibilityRTFForRangeParameterizedAttribute,
            NSAccessibilityStyleRangeForIndexParameterizedAttribute,
            NSAccessibilityAttributedStringForRangeParameterizedAttribute
        ];
    }
 
    return nil;
}
 
- (id)accessibilityAttributeValue:(NSString *)attribute forParameter:(id)parameter {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface) {
        qWarning() << "Called attribute on invalid object: " << axid;
        return nil;
    }
 
    if (!iface->textInterface())
        return nil;
 
    if ([attribute isEqualToString: NSAccessibilityStringForRangeParameterizedAttribute]) {
        NSRange range = [parameter rangeValue];
        QString text = iface->textInterface()->text(range.location, range.location + range.length);
        return text.toNSString();
    }
    if ([attribute isEqualToString: NSAccessibilityLineForIndexParameterizedAttribute]) {
        int index = [parameter intValue];
        if (index < 0 || index > iface->textInterface()->characterCount())
            return nil;
        int line = 0; // true for all single line edits
        if (iface->state().multiLine) {
            line = -1;
            convertLineOffset(iface->textInterface(), &line, &index);
        }
        return @(line);
    }
    if ([attribute isEqualToString: NSAccessibilityRangeForLineParameterizedAttribute]) {
        int line = [parameter intValue];
        if (line < 0)
            return nil;
        int lineOffset = -1;
        NSUInteger startOffset = 0;
        NSUInteger endOffset = 0;
        convertLineOffset(iface->textInterface(), &line, &lineOffset, &startOffset, &endOffset);
        return [NSValue valueWithRange:NSMakeRange(startOffset, endOffset - startOffset)];
    }
    if ([attribute isEqualToString: NSAccessibilityBoundsForRangeParameterizedAttribute]) {
        NSRange range = [parameter rangeValue];
        QRect firstRect = iface->textInterface()->characterRect(range.location);
        QRectF rect;
        if (range.length > 0) {
            NSUInteger position = range.location + range.length - 1;
            if (position > range.location && iface->textInterface()->text(position, position + 1) == "\n"_L1)
                --position;
            QRect lastRect = iface->textInterface()->characterRect(position);
            rect = firstRect.united(lastRect);
        } else {
            rect = firstRect;
            rect.setWidth(1);
        }
        return [NSValue valueWithRect:QCocoaScreen::mapToNative(rect)];
    }
    if ([attribute isEqualToString: NSAccessibilityAttributedStringForRangeParameterizedAttribute]) {
        NSRange range = [parameter rangeValue];
        QString text = iface->textInterface()->text(range.location, range.location + range.length);
        return [[NSAttributedString alloc] initWithString:text.toNSString()];
    } else if ([attribute isEqualToString: NSAccessibilityRangeForPositionParameterizedAttribute]) {
        QPoint point = QCocoaScreen::mapFromNative([parameter pointValue]).toPoint();
        int offset = iface->textInterface()->offsetAtPoint(point);
        return [NSValue valueWithRange:NSMakeRange(static_cast<NSUInteger>(offset), 1)];
    } else if ([attribute isEqualToString: NSAccessibilityStyleRangeForIndexParameterizedAttribute]) {
        int start = 0;
        int end = 0;
        iface->textInterface()->attributes([parameter intValue], &start, &end);
        return [NSValue valueWithRange:NSMakeRange(static_cast<NSUInteger>(start), static_cast<NSUInteger>(end - start))];
    }
    return nil;
}
 
- (BOOL)accessibilityIsAttributeSettable:(NSString *)attribute {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return NO;
 
    if ([attribute isEqualToString:NSAccessibilityFocusedAttribute]) {
        return iface->state().focusable ? YES : NO;
    } else if ([attribute isEqualToString:NSAccessibilityValueAttribute]) {
        if (iface->textInterface() && iface->state().editable)
            return YES;
        if (iface->valueInterface())
            return YES;
        return NO;
    } else if ([attribute isEqualToString:NSAccessibilitySelectedTextRangeAttribute]) {
        return iface->textInterface() ? YES : NO;
    }
    return NO;
}
 
- (void)accessibilitySetValue:(id)value forAttribute:(NSString *)attribute {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return;
    if ([attribute isEqualToString:NSAccessibilityFocusedAttribute]) {
        if (QAccessibleActionInterface *action = iface->actionInterface())
            action->doAction(QAccessibleActionInterface::setFocusAction());
    } else if ([attribute isEqualToString:NSAccessibilityValueAttribute]) {
        if (iface->textInterface()) {
            QString text = QString::fromNSString((NSString *)value);
            iface->setText(QAccessible::Value, text);
        } else if (QAccessibleValueInterface *valueIface = iface->valueInterface()) {
            double val = [value doubleValue];
            valueIface->setCurrentValue(val);
        }
    } else if ([attribute isEqualToString:NSAccessibilitySelectedTextRangeAttribute]) {
        if (QAccessibleTextInterface *text = iface->textInterface()) {
            NSRange range = [value rangeValue];
            if (range.length > 0)
                text->setSelection(0, range.location, range.location + range.length);
            else
                text->setCursorPosition(range.location);
        }
    }
}
 
// actions
 
- (NSArray *)accessibilityActionNames {
    NSMutableArray *nsActions = [[NSMutableArray new] autorelease];
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return nsActions;
 
    const QStringList &supportedActionNames = QAccessibleBridgeUtils::effectiveActionNames(iface);
    for (const QString &qtAction : supportedActionNames) {
        NSString *nsAction = QCocoaAccessible::getTranslatedAction(qtAction);
        if (nsAction)
            [nsActions addObject : nsAction];
    }
 
    return nsActions;
}
 
- (NSString *)accessibilityActionDescription:(NSString *)action {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface)
        return nil; // FIXME is that the right return type??
    QString qtAction = QCocoaAccessible::translateAction(action, iface);
    QString description;
    // Return a description from the action interface if this action is not known to the OS.
    if (qtAction.isEmpty()) {
        if (QAccessibleActionInterface *actionInterface = iface->actionInterface()) {
            qtAction = QString::fromNSString((NSString *)action);
            description = actionInterface->localizedActionDescription(qtAction);
        }
    } else {
        description = qAccessibleLocalizedActionDescription(qtAction);
    }
    return description.toNSString();
}
 
- (void)accessibilityPerformAction:(NSString *)action {
    if (QAccessibleInterface *iface = self.qtInterface) {
        const QString qtAction = QCocoaAccessible::translateAction(action, iface);
        QAccessibleBridgeUtils::performEffectiveAction(iface, qtAction);
    }
}
 
// misc
 
- (BOOL)accessibilityIsIgnored {
    // Short-cut for placeholders and synthesized elements. Working around a bug
    // that corrups lists returned by NSAccessibilityUnignoredChildren, otherwise
    // we could ignore rows and columns that are outside the table.
    if (self.isManagedByParent)
        return false;
 
    if (QAccessibleInterface *iface = self.qtInterface)
        return QCocoaAccessible::shouldBeIgnored(iface);
    return true;
}
 
- (id)accessibilityHitTest:(NSPoint)point {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface) {
//        qDebug("Hit test: INVALID");
        return NSAccessibilityUnignoredAncestor(self);
    }
 
    QPointF screenPoint = QCocoaScreen::mapFromNative(point);
    QAccessibleInterface *childInterface = iface->childAt(screenPoint.x(), screenPoint.y());
    // No child found, meaning we hit this element.
    if (!childInterface || !childInterface->isValid())
        return NSAccessibilityUnignoredAncestor(self);
 
    // find the deepest child at the point
    QAccessibleInterface *childOfChildInterface = nullptr;
    do {
        childOfChildInterface = childInterface->childAt(screenPoint.x(), screenPoint.y());
        if (childOfChildInterface && childOfChildInterface->isValid())
            childInterface = childOfChildInterface;
    } while (childOfChildInterface && childOfChildInterface->isValid());
 
    // hit a child, forward to child accessible interface.
    QMacAccessibilityElement *accessibleElement = [QMacAccessibilityElement elementWithInterface:childInterface];
    if (accessibleElement)
        return NSAccessibilityUnignoredAncestor(accessibleElement);
    return NSAccessibilityUnignoredAncestor(self);
}
 
- (id)accessibilityFocusedUIElement {
    QAccessibleInterface *iface = self.qtInterface;
    if (!iface) {
        qWarning("FocusedUIElement for INVALID");
        return nil;
    }
 
    QAccessibleInterface *childInterface = iface->focusChild();
    if (childInterface && childInterface->isValid()) {
        QMacAccessibilityElement *accessibleElement = [QMacAccessibilityElement elementWithInterface:childInterface];
        return NSAccessibilityUnignoredAncestor(accessibleElement);
    }
 
    return NSAccessibilityUnignoredAncestor(self);
}
 
- (NSString *) accessibilityHelp {
    if (QAccessibleInterface *iface = self.qtInterface) {
        const QString helpText = iface->text(QAccessible::Help);
        if (!helpText.isEmpty())
            return helpText.toNSString();
    }
    return nil;
}
 
/*
 * Support for table
 */
- (NSInteger) accessibilityIndex {
    NSInteger index = 0;
    if (synthesizedRole == NSAccessibilityCellRole)
        return m_columnIndex;
    if (QAccessibleInterface *iface = self.qtInterface) {
        if (self.isManagedByParent) {
            // axid matches the parent table axid so that we can easily find the parent table
            // children of row are cell/any items
            if (iface->tableInterface()) {
                if (m_rowIndex >= 0)
                    index = NSInteger(m_rowIndex);
                else if (m_columnIndex >= 0)
                    index = NSInteger(m_columnIndex);
            }
        }
    }
    return index;
}
 
- (NSArray *) accessibilityRows {
    if (!synthesizedRole && rows) {
        QAccessibleInterface *iface = self.qtInterface;
        QAccessibleTableInterface *tableInterface = iface ? iface->tableInterface() : nullptr;
        if (tableInterface) {
            const unsigned int rowCount = tableInterface->rowCount();
            if (rows.count != rowCount) {
                qCDebug(lcAccessibilityTable) << "Updating table rows with" << rowCount << "rows";
                if (rows) {
                    [rows autorelease];
                    rows = nil;
                }
                rows = [self populateTableArray:NSAccessibilityRowRole
                             count:rowCount];
                [rows retain];
            }
            return NSAccessibilityUnignoredChildren(rows);
        }
    }
    return nil;
}
 
- (NSArray *) accessibilityColumns {
    // we only implement this for a table, not for rows
    if (!synthesizedRole && columns) {
        QAccessibleInterface *iface = self.qtInterface;
        if (iface && iface->tableInterface())
            return NSAccessibilityUnignoredChildren(columns);
    }
    return nil;
}
 
// tabs
 
- (NSArray *) accessibilityTabs {
    QAccessibleInterface *iface = self.qtInterface;
    if (iface && iface->role() == QAccessible::PageTabList) {
        return QCocoaAccessible::unignoredChildren(iface, [](QAccessibleInterface *child){
            return QCocoaAccessible::defaultUnignored(child)
                && child->role() == QAccessible::PageTab;
        });
    }
    return nil;
}
 
@end
 
#endif // QT_CONFIG(accessibility)