path: root/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm

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#include "qcocoaaccessibilityelement.h"
#include "qcocoaaccessibility.h"
#include "qcocoahelpers.h"
#include "qcocoawindow.h"
#include "private/qaccessiblecache_p.h"

#include <QtGui/qaccessible.h>

#import <AppKit/NSAccessibility.h>

@implementation QCocoaAccessibleElement

- (id)initWithId:(QAccessible::Id)anId
{
    Q_ASSERT((int)anId < 0);
    self = [super init];
    if (self) {
        axid = anId;
        QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
        Q_ASSERT(iface);
        role = QCocoaAccessible::macRole(iface);
    }

    return self;
}

+ (id)elementWithId:(QAccessible::Id)anId
{
    Q_ASSERT(anId);
    if (!anId)
        return nil;

    QAccessibleCache *cache = QAccessibleCache::instance();

    QCocoaAccessibleElement *element = cache->elementForId(anId);
    if (!element) {
        QAccessibleInterface *iface = QAccessible::accessibleInterface(anId);
        Q_ASSERT(iface);
        if (!iface)
            return nil;
        element = [[self alloc] initWithId:anId];
        cache->insertElement(anId, element);
    }
    return element;
}

- (void)invalidate {
    axid = 0;
    NSAccessibilityPostNotification(self, NSAccessibilityUIElementDestroyedNotification);
    [self release];
}

- (void)dealloc {
    [super dealloc];
}

- (BOOL)isEqual:(id)object {
    if ([object isKindOfClass:[QCocoaAccessibleElement class]]) {
        QCocoaAccessibleElement *other = object;
        return other->axid == axid;
    } else {
        return NO;
    }
}

- (NSUInteger)hash {
    return axid;
}

//
// accessibility protocol
//

// attributes

+ (id) lineNumberForIndex: (int)index forText:(const QString &)text
{
    QStringRef textBefore = QStringRef(&text, 0, index);
    int newlines = textBefore.count(QLatin1Char('\n'));
    return [NSNumber numberWithInt: newlines];
}

- (BOOL) accessibilityNotifiesWhenDestroyed {
    return YES;
}

- (NSArray *)accessibilityAttributeNames {
    static NSArray *defaultAttributes = nil;

    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface)
        return defaultAttributes;

    if (defaultAttributes == nil) {
        defaultAttributes = [[NSArray alloc] initWithObjects:
        NSAccessibilityRoleAttribute,
        NSAccessibilityRoleDescriptionAttribute,
        NSAccessibilityChildrenAttribute,
        NSAccessibilityFocusedAttribute,
        NSAccessibilityParentAttribute,
        NSAccessibilityWindowAttribute,
        NSAccessibilityTopLevelUIElementAttribute,
        NSAccessibilityPositionAttribute,
        NSAccessibilitySizeAttribute,
        NSAccessibilityTitleAttribute,
        NSAccessibilityDescriptionAttribute,
        NSAccessibilityEnabledAttribute,
        nil];
    }

    NSMutableArray *attributes = [[NSMutableArray alloc] initWithCapacity : [defaultAttributes count]];
    [attributes addObjectsFromArray : defaultAttributes];

    if (QCocoaAccessible::hasValueAttribute(iface)) {
        [attributes addObject : NSAccessibilityValueAttribute];
    }

    if (iface->textInterface()) {
        [attributes addObjectsFromArray: [[NSArray alloc] initWithObjects:
            NSAccessibilityNumberOfCharactersAttribute,
            NSAccessibilitySelectedTextAttribute,
            NSAccessibilitySelectedTextRangeAttribute,
            NSAccessibilityVisibleCharacterRangeAttribute,
            NSAccessibilityInsertionPointLineNumberAttribute,
            nil
        ]];

// TODO: multi-selection: NSAccessibilitySelectedTextRangesAttribute,
    }

    if (iface->valueInterface()) {
        [attributes addObjectsFromArray: [[NSArray alloc] initWithObjects:
            NSAccessibilityMinValueAttribute,
            NSAccessibilityMaxValueAttribute,
            nil
        ]];
    }

    return [attributes autorelease];
}

- (id)parentElement {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface)
        return nil;

    if (QWindow *window = iface->window()) {
        QCocoaWindow *win = static_cast<QCocoaWindow*>(window->handle());
        return win->qtView();
    }

    QAccessibleInterface *parent = iface->parent();
    if (!parent) {
        qWarning() << "INVALID PARENT FOR INTERFACE: " << iface;
        return nil;
    }

    QAccessible::Id parentId = QAccessible::uniqueId(parent);
    return [QCocoaAccessibleElement elementWithId: parentId];
}


- (id) minValueAttribute:(QAccessibleInterface*)iface {
    if (QAccessibleValueInterface *val = iface->valueInterface())
        return [NSNumber numberWithDouble: val->minimumValue().toDouble()];
    return nil;
}

- (id) maxValueAttribute:(QAccessibleInterface*)iface {
    if (QAccessibleValueInterface *val = iface->valueInterface())
        return [NSNumber numberWithDouble: val->maximumValue().toDouble()];
    return nil;
}

- (id)accessibilityAttributeValue:(NSString *)attribute {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface) {
        qWarning() << "Called attribute on invalid object: " << axid;
        return nil;
    }

    if ([attribute isEqualToString:NSAccessibilityRoleAttribute]) {
        return role;
    } else if ([attribute isEqualToString:NSAccessibilityRoleDescriptionAttribute]) {
        return NSAccessibilityRoleDescription(role, nil);
    } else if ([attribute isEqualToString:NSAccessibilityChildrenAttribute]) {
        return QCocoaAccessible::unignoredChildren(iface);
    } else if ([attribute isEqualToString:NSAccessibilityFocusedAttribute]) {
        // Just check if the app thinks we're focused.
        id focusedElement = [NSApp accessibilityAttributeValue:NSAccessibilityFocusedUIElementAttribute];
        return [NSNumber numberWithBool:[focusedElement isEqual:self]];
    } else if ([attribute isEqualToString:NSAccessibilityParentAttribute]) {
        return NSAccessibilityUnignoredAncestor([self parentElement]);
    } else if ([attribute isEqualToString:NSAccessibilityWindowAttribute]) {
        // We're in the same window as our parent.
        return [[self parentElement] accessibilityAttributeValue:NSAccessibilityWindowAttribute];
    } else if ([attribute isEqualToString:NSAccessibilityTopLevelUIElementAttribute]) {
        // We're in the same top level element as our parent.
        return [[self parentElement] accessibilityAttributeValue:NSAccessibilityTopLevelUIElementAttribute];
    } else if ([attribute isEqualToString:NSAccessibilityPositionAttribute]) {
        QPoint qtPosition = iface->rect().topLeft();
        QSize qtSize = iface->rect().size();
        return [NSValue valueWithPoint: NSMakePoint(qtPosition.x(), qt_mac_flipYCoordinate(qtPosition.y() + qtSize.height()))];
    } else if ([attribute isEqualToString:NSAccessibilitySizeAttribute]) {
        QSize qtSize = iface->rect().size();
        return [NSValue valueWithSize: NSMakeSize(qtSize.width(), qtSize.height())];
    } else if ([attribute isEqualToString:NSAccessibilityTitleAttribute]) {
        return QCFString::toNSString(iface->text(QAccessible::Name));
    } else if ([attribute isEqualToString:NSAccessibilityDescriptionAttribute]) {
        return QCFString::toNSString(iface->text(QAccessible::Description));
    } else if ([attribute isEqualToString:NSAccessibilityEnabledAttribute]) {
        return [NSNumber numberWithBool:!iface->state().disabled];
    } else if ([attribute isEqualToString:NSAccessibilityValueAttribute]) {
        // 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 nil;

        return QCocoaAccessible::getValueAttribute(iface);

    } else if ([attribute isEqualToString:NSAccessibilityNumberOfCharactersAttribute]) {
        if (QAccessibleTextInterface *text = iface->textInterface())
            return [NSNumber numberWithInt: text->characterCount()];
        return nil;
    } else if ([attribute isEqualToString:NSAccessibilitySelectedTextAttribute]) {
        if (QAccessibleTextInterface *text = iface->textInterface()) {
            int start = 0;
            int end = 0;
            text->selection(0, &start, &end);
            return text->text(start, end).toNSString();
        }
        return nil;
    } else if ([attribute isEqualToString:NSAccessibilitySelectedTextRangeAttribute]) {
        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 [NSValue valueWithRange:NSMakeRange(quint32(start), quint32(end - start))];
        }
        return [NSValue valueWithRange: NSMakeRange(0, 0)];
    } else if ([attribute isEqualToString:NSAccessibilityVisibleCharacterRangeAttribute]) {
        // FIXME This is not correct and may impact performance for big texts
        return [NSValue valueWithRange: NSMakeRange(0, iface->textInterface()->characterCount())];

    } else if ([attribute isEqualToString:NSAccessibilityInsertionPointLineNumberAttribute]) {
        if (QAccessibleTextInterface *text = iface->textInterface()) {
            QString textBeforeCursor = text->text(0, text->cursorPosition());
            return [NSNumber numberWithInt: textBeforeCursor.count(QLatin1Char('\n'))];
        }
        return nil;
    } else if ([attribute isEqualToString:NSAccessibilityMinValueAttribute]) {
        return [self minValueAttribute:iface];
    } else if ([attribute isEqualToString:NSAccessibilityMaxValueAttribute]) {
        return [self maxValueAttribute:iface];
    }

    return nil;
}

- (NSArray *)accessibilityParameterizedAttributeNames {

    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface) {
        qWarning() << "Called attribute on invalid object: " << axid;
        return nil;
    }

    if (iface->textInterface()) {
            return [[NSArray alloc] initWithObjects:
                    NSAccessibilityStringForRangeParameterizedAttribute,
                    NSAccessibilityLineForIndexParameterizedAttribute,
                    NSAccessibilityRangeForLineParameterizedAttribute,
                    NSAccessibilityRangeForPositionParameterizedAttribute,
//                    NSAccessibilityRangeForIndexParameterizedAttribute,
                    NSAccessibilityBoundsForRangeParameterizedAttribute,
//                    NSAccessibilityRTFForRangeParameterizedAttribute,
//                    NSAccessibilityStyleRangeForIndexParameterizedAttribute,
                    NSAccessibilityAttributedStringForRangeParameterizedAttribute,
                    nil
                ];
    }

    return nil;
}

- (id)accessibilityAttributeValue:(NSString *)attribute forParameter:(id)parameter {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    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];
        NSNumber *ln = [QCocoaAccessibleElement lineNumberForIndex: index forText: iface->text(QAccessible::Value)];
        return ln;
    }
    if ([attribute isEqualToString: NSAccessibilityRangeForLineParameterizedAttribute]) {
        int lineNumber = [parameter intValue];
        QString text = iface->text(QAccessible::Value);
        int startOffset = 0;
        // skip newlines until we have the one we look for
        for (int i = 0; i < lineNumber; ++i)
            startOffset = text.indexOf(QLatin1Char('\n'), startOffset) + 1;
        if (startOffset < 0) // invalid line number, return the first line
            startOffset = 0;
        int endOffset = text.indexOf(QLatin1Char('\n'), startOffset);
        if (endOffset == -1)
            endOffset = text.length();
        return [NSValue valueWithRange:NSMakeRange(quint32(startOffset), quint32(endOffset - startOffset))];
    }
    if ([attribute isEqualToString: NSAccessibilityBoundsForRangeParameterizedAttribute]) {
        NSRange range = [parameter rangeValue];
        QRect firstRect = iface->textInterface()->characterRect(range.location);
        QRect lastRect = iface->textInterface()->characterRect(range.location + range.length);
        QRect rect = firstRect.united(lastRect); // This is off quite often, but at least a rough approximation
        return [NSValue valueWithRect: NSMakeRect((CGFloat) rect.x(),(CGFloat) qt_mac_flipYCoordinate(rect.y() + rect.height()), rect.width(), rect.height())];
    }
    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()];
    }
    return nil;
}

- (BOOL)accessibilityIsAttributeSettable:(NSString *)attribute {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface)
        return nil;

    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 = QAccessible::accessibleInterface(axid);
    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];
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface)
        return nsActions;

    QAccessibleActionInterface *actionInterface = iface->actionInterface();
    if (actionInterface) {
        QStringList supportedActionNames = actionInterface->actionNames();

        foreach (const QString &qtAction, supportedActionNames) {
            NSString *nsAction = QCocoaAccessible::getTranslatedAction(qtAction);
            if (nsAction)
                [nsActions addObject : nsAction];
        }
    }

    return nsActions;
}

- (NSString *)accessibilityActionDescription:(NSString *)action {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface)
        return nil; // FIXME is that the right return type??
    QAccessibleActionInterface *actionInterface = iface->actionInterface();
    if (actionInterface) {
        QString qtAction = QCocoaAccessible::translateAction(action);

        // Return a description from the action interface if this action is not known to the OS.
        if (qtAction.isEmpty()) {
            QString description = actionInterface->localizedActionDescription(qtAction);
            return QCFString::toNSString(description);
        }
    }

    return NSAccessibilityActionDescription(action);
}

- (void)accessibilityPerformAction:(NSString *)action {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (iface) {
        QAccessibleActionInterface *actionInterface = iface->actionInterface();
        if (actionInterface) {
            actionInterface->doAction(QCocoaAccessible::translateAction(action));
        }
    }
}

// misc

- (BOOL)accessibilityIsIgnored {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface || !iface->isValid())
        return true;
    return QCocoaAccessible::shouldBeIgnored(iface);
}

- (id)accessibilityHitTest:(NSPoint)point {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
    if (!iface || !iface->isValid()) {
//        qDebug() << "Hit test: INVALID";
        return NSAccessibilityUnignoredAncestor(self);
    }

    int y = qt_mac_flipYCoordinate(point.y);
    QAccessibleInterface *childInterface = iface->childAt(point.x, y);
    // No child found, meaning we hit this element.
    if (!childInterface)
        return NSAccessibilityUnignoredAncestor(self);

    // find the deepest child at the point
    QAccessibleInterface *childOfChildInterface = 0;
    do {
        childOfChildInterface = childInterface->childAt(point.x, y);
        if (childOfChildInterface)
            childInterface = childOfChildInterface;
    } while (childOfChildInterface);

    QAccessible::Id childId = QAccessible::uniqueId(childInterface);
    // hit a child, forward to child accessible interface.
    QCocoaAccessibleElement *accessibleElement = [QCocoaAccessibleElement elementWithId:childId];
    if (accessibleElement)
        return NSAccessibilityUnignoredAncestor(accessibleElement);
    return NSAccessibilityUnignoredAncestor(self);
}

- (id)accessibilityFocusedUIElement {
    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);

    if (!iface || !iface->isValid()) {
        qWarning() << "FocusedUIElement for INVALID";
        return nil;
    }

    QAccessibleInterface *childInterface = iface->focusChild();
    if (childInterface) {
        QAccessible::Id childAxid = QAccessible::uniqueId(childInterface);
        QCocoaAccessibleElement *accessibleElement = [QCocoaAccessibleElement elementWithId:childAxid];
        return NSAccessibilityUnignoredAncestor(accessibleElement);
    }

    return NSAccessibilityUnignoredAncestor(self);
}

@end