qaccessible_mac_cocoa.mm

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#include "qaccessible.h"
#include "qaccessible_mac_p.h"
#include "qdebug.h"
#include "qtabwidget.h"

#include <private/qt_mac_p.h>
#include <private/qcocoaview_mac_p.h>
#include <private/qwidget_p.h>


#ifndef QT_NO_ACCESSIBILITY

#ifdef QT_MAC_USE_COCOA

QT_BEGIN_NAMESPACE

//#define MAC_ACCESSIBILTY_DEVELOPER_MODE

#ifndef QT_NO_DEBUG_STREAM
#ifdef MAC_ACCESSIBILTY_DEVELOPER_MODE
#define MAC_ACCESSIBILTY_DEBUG QT_PREPEND_NAMESPACE(qDebug)
#else
#define MAC_ACCESSIBILTY_DEBUG if (0) QT_PREPEND_NAMESPACE(qDebug)
#endif
#else
#define MAC_ACCESSIBILTY_DEBUG if (0) QT_PREPEND_NAMESPACE(QNoDebug)
#endif

typedef QMap<QAccessible::Role, NSString *> QMacAccessibiltyRoleMap;
Q_GLOBAL_STATIC(QMacAccessibiltyRoleMap, qMacAccessibiltyRoleMap);

static QAInterface interfaceForView(QT_MANGLE_NAMESPACE(QCocoaView) *view)
{
    return QAInterface(QAccessible::queryAccessibleInterface([view qt_qwidget]));
}

/*
    Set up mappings from Qt accessibilty roles to Mac accessibilty roles.
*/
static void populateRoleMap()
{
    QMacAccessibiltyRoleMap &roleMap = *qMacAccessibiltyRoleMap();
    roleMap[QAccessible::MenuItem] = NSAccessibilityMenuItemRole;
    roleMap[QAccessible::MenuBar] = NSAccessibilityMenuBarRole;
    roleMap[QAccessible::ScrollBar] = NSAccessibilityScrollBarRole;
    roleMap[QAccessible::Grip] = NSAccessibilityGrowAreaRole;
    roleMap[QAccessible::Window] = NSAccessibilityWindowRole;
    roleMap[QAccessible::Dialog] = NSAccessibilityWindowRole;
    roleMap[QAccessible::AlertMessage] = NSAccessibilityWindowRole;
    roleMap[QAccessible::ToolTip] = NSAccessibilityWindowRole;
    roleMap[QAccessible::HelpBalloon] = NSAccessibilityWindowRole;
    roleMap[QAccessible::PopupMenu] = NSAccessibilityMenuRole;
    roleMap[QAccessible::Application] = NSAccessibilityApplicationRole;
    roleMap[QAccessible::Pane] = NSAccessibilityGroupRole;
    roleMap[QAccessible::Grouping] = NSAccessibilityGroupRole;
    roleMap[QAccessible::Separator] = NSAccessibilitySplitterRole;
    roleMap[QAccessible::ToolBar] = NSAccessibilityToolbarRole;
    roleMap[QAccessible::PageTab] = NSAccessibilityRadioButtonRole;
    roleMap[QAccessible::ButtonMenu] = NSAccessibilityMenuButtonRole;
    roleMap[QAccessible::ButtonDropDown] = NSAccessibilityPopUpButtonRole;
    roleMap[QAccessible::SpinBox] = NSAccessibilityIncrementorRole;
    roleMap[QAccessible::Slider] = NSAccessibilitySliderRole;
    roleMap[QAccessible::ProgressBar] = NSAccessibilityProgressIndicatorRole;
    roleMap[QAccessible::ComboBox] = NSAccessibilityPopUpButtonRole;
    roleMap[QAccessible::RadioButton] = NSAccessibilityRadioButtonRole;
    roleMap[QAccessible::CheckBox] = NSAccessibilityCheckBoxRole;
    roleMap[QAccessible::StaticText] = NSAccessibilityStaticTextRole;
    roleMap[QAccessible::Table] = NSAccessibilityTableRole;
    roleMap[QAccessible::StatusBar] = NSAccessibilityStaticTextRole;
    roleMap[QAccessible::Column] = NSAccessibilityColumnRole;
    roleMap[QAccessible::ColumnHeader] = NSAccessibilityColumnRole;
    roleMap[QAccessible::Row] = NSAccessibilityRowRole;
    roleMap[QAccessible::RowHeader] = NSAccessibilityRowRole;
    roleMap[QAccessible::Cell] = NSAccessibilityTextFieldRole;
    roleMap[QAccessible::PushButton] = NSAccessibilityButtonRole;
    roleMap[QAccessible::EditableText] = NSAccessibilityTextFieldRole;
    roleMap[QAccessible::Link] = NSAccessibilityTextFieldRole;
    roleMap[QAccessible::Indicator] = NSAccessibilityValueIndicatorRole;
    roleMap[QAccessible::Splitter] = NSAccessibilitySplitGroupRole;
    roleMap[QAccessible::List] = NSAccessibilityListRole;
    roleMap[QAccessible::ListItem] = NSAccessibilityStaticTextRole;
    roleMap[QAccessible::Cell] = NSAccessibilityStaticTextRole;
}

/*
    Returns a Mac accessibility role for the given interface, or
    NSAccessibilityUnknownRole if no role mapping is found.
*/
static NSString *macRoleForInterface(QAInterface interface)
{
    const QAccessible::Role qtRole = interface.role();
    QMacAccessibiltyRoleMap &roleMap = *qMacAccessibiltyRoleMap();

    if (roleMap.isEmpty())
        populateRoleMap();

    MAC_ACCESSIBILTY_DEBUG() << "role for" << interface.object() << "interface role" << hex << qtRole;

    if (roleMap.contains(qtRole)) {
        MAC_ACCESSIBILTY_DEBUG() << "return" <<  roleMap[qtRole];
        return roleMap[qtRole];
    }

    MAC_ACCESSIBILTY_DEBUG() << "return NSAccessibilityUnknownRole";
    return NSAccessibilityUnknownRole;
}

/*
    Is the interface a QTabBar embedded in a QTabWidget?
    (as opposed to a stand-alone tab bar)
*/
static bool isEmbeddedTabBar(const QAInterface &interface)
{
    QObject *object = interface.object();
    if (interface.role() == QAccessible::PageTabList && object)
        return (qobject_cast<QTabWidget *>(object->parent()));

    return false;
}

static bool isInterfaceIgnored(QAInterface interface)
{
    // Mac accessibility does not have an attribute that corresponds to the 
    // Invisible/Offscreen state. Use the ignore facility to disable them.
    const QAccessible::State state = interface.state();
    if (state & QAccessible::Invisible ||
        state & QAccessible::Offscreen )
        return false;

    // Hide QTabBars that has a QTabWidget parent (the QTabWidget handles the accessibility)
    if (isEmbeddedTabBar(interface))
        return false;

    if (QObject * const object = interface.object()) {
        const QString className = QLatin1String(object->metaObject()->className());

        // Prevent VoiceOver from focusing on tool tips by ignoring those
        // interfaces. Shifting VoiceOver focus to the tool tip is confusing
        // and the contents of the tool tip is avalible through the description 
        // attribute anyway.
        if (className == QLatin1String("QTipLabel"))
            return false;
    }

    // Hide interfaces with an unknown role. When developing it's often useful to disable
    // this check to see all interfaces in the hierarchy.
#ifndef MAC_ACCESSIBILTY_DEVELOPER_MODE
    return [macRoleForInterface(interface) isEqualToString: NSAccessibilityUnknownRole];
#else
    return NO;
#endif
}

QT_END_NAMESPACE

@implementation QT_MANGLE_NAMESPACE(QCocoaView) (Accessibility)

- (BOOL)accessibilityIsIgnored
{
    QT_PREPEND_NAMESPACE(QAInterface) interface = QT_PREPEND_NAMESPACE(interfaceForView)(self);
    return isInterfaceIgnored(interface);
}

- (NSArray *)accessibilityAttributeNames
{
    QT_PREPEND_NAMESPACE(QAInterface) interface = QT_PREPEND_NAMESPACE(interfaceForView)(self);

    static NSArray *attributes = nil;
    if (attributes == nil) {
        attributes = [super accessibilityAttributeNames];

    }
    return attributes;
}

- (id)accessibilityAttributeValue:(NSString *)attribute
{
    MAC_ACCESSIBILTY_DEBUG() << "accessibilityAttributeValue" << self <<  
            QT_PREPEND_NAMESPACE(QCFString)::toQString(reinterpret_cast<CFStringRef>(attribute));

    QT_PREPEND_NAMESPACE(QAInterface) interface = QT_PREPEND_NAMESPACE(interfaceForView)(self);

    // Switch on the attribute name and call the appropriate handler function.
    // Pass the call on to the NSView class for attributes we don't handle.
    if ([attribute isEqualToString:@"AXRole"]) {
        return macRoleForInterface(interface);
    } else {
        return [super accessibilityAttributeValue:attribute];    
    }
}

@end

#endif // QT_MAC_USE_COCOA

#endif // QT_NO_ACCESSIBILITY