qaccessiblewidget.cpp

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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
 
#include "qaccessiblewidget.h"
 
#if QT_CONFIG(accessibility)
 
#include "qapplication.h"
#if QT_CONFIG(groupbox)
#include "qgroupbox.h"
#endif
#if QT_CONFIG(label)
#include "qlabel.h"
#endif
#if QT_CONFIG(tooltip)
#include "qtooltip.h"
#endif
#if QT_CONFIG(whatsthis)
#include "qwhatsthis.h"
#endif
#include "qwidget.h"
#include "qdebug.h"
#include <qmath.h>
#if QT_CONFIG(rubberband)
#include <QRubberBand>
#endif
#include <QFocusFrame>
#if QT_CONFIG(menu)
#include <QMenu>
#endif
#include <QtWidgets/private/qwidget_p.h>
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
QWidgetList _q_ac_childWidgets(const QWidget *widget);
 
static QString buddyString(const QWidget *widget)
{
    if (!widget)
        return QString();
    QWidget *parent = widget->parentWidget();
    if (!parent)
        return QString();
#if QT_CONFIG(shortcut) && QT_CONFIG(label)
    for (QObject *o : parent->children()) {
        QLabel *label = qobject_cast<QLabel*>(o);
        if (label && label->buddy() == widget)
            return label->text();
    }
#endif
 
#if QT_CONFIG(groupbox)
    QGroupBox *groupbox = qobject_cast<QGroupBox*>(parent);
    if (groupbox)
        return groupbox->title();
#endif
 
    return QString();
}
 
/* This function will return the offset of the '&' in the text that would be
   preceding the accelerator character.
   If this text does not have an accelerator, -1 will be returned. */
static qsizetype qt_accAmpIndex(const QString &text)
{
#ifndef QT_NO_SHORTCUT
    if (text.isEmpty())
        return -1;
 
    qsizetype fa = 0;
    while ((fa = text.indexOf(u'&', fa)) != -1) {
        ++fa;
        if (fa < text.size()) {
            // ignore "&&"
            if (text.at(fa) == u'&') {
 
                ++fa;
                continue;
            } else {
                return fa - 1;
                break;
            }
        }
    }
 
    return -1;
#else
    Q_UNUSED(text);
    return -1;
#endif
}
 
QString qt_accStripAmp(const QString &text)
{
    QString newText(text);
    qsizetype ampIndex = qt_accAmpIndex(newText);
    if (ampIndex != -1)
        newText.remove(ampIndex, 1);
 
    return newText.replace("&&"_L1, "&"_L1);
}
 
QString qt_accHotKey(const QString &text)
{
#ifndef QT_NO_SHORTCUT
    qsizetype ampIndex = qt_accAmpIndex(text);
    if (ampIndex != -1)
        return QKeySequence(Qt::ALT).toString(QKeySequence::NativeText) + text.at(ampIndex + 1);
#else
    Q_UNUSED(text);
#endif
 
    return QString();
}
 
// ### inherit QAccessibleObjectPrivate
class QAccessibleWidgetPrivate
{
public:
    QAccessibleWidgetPrivate()
        :role(QAccessible::Client)
    {}
 
    QAccessible::Role role;
    QString name;
    QStringList primarySignals;
};
 
QAccessibleWidget::QAccessibleWidget(QWidget *w, QAccessible::Role role, const QString &name)
: QAccessibleObject(w)
{
    Q_ASSERT(widget());
    d = new QAccessibleWidgetPrivate();
    d->role = role;
    d->name = name;
}
 
bool QAccessibleWidget::isValid() const
{
    if (!object() || static_cast<QWidget *>(object())->d_func()->data.in_destructor)
        return false;
    return QAccessibleObject::isValid();
}
 
QWindow *QAccessibleWidget::window() const
{
    const QWidget *w = widget();
    Q_ASSERT(w);
    QWindow *result = w->windowHandle();
    if (!result) {
        if (const QWidget *nativeParent = w->nativeParentWidget())
            result = nativeParent->windowHandle();
    }
    return result;
}
 
QAccessibleWidget::~QAccessibleWidget()
{
    delete d;
}
 
QWidget *QAccessibleWidget::widget() const
{
    return qobject_cast<QWidget*>(object());
}
 
QObject *QAccessibleWidget::parentObject() const
{
    QWidget *w = widget();
    if (!w || w->isWindow() || !w->parentWidget())
        return qApp;
    return w->parent();
}
 
QRect QAccessibleWidget::rect() const
{
    QWidget *w = widget();
    if (!w->isVisible())
        return QRect();
    QPoint wpos = w->mapToGlobal(QPoint(0, 0));
 
    return QRect(wpos.x(), wpos.y(), w->width(), w->height());
}
 
void QAccessibleWidget::addControllingSignal(const QString &signal)
{
    QByteArray s = QMetaObject::normalizedSignature(signal.toLatin1());
    if (Q_UNLIKELY(object()->metaObject()->indexOfSignal(s) < 0))
        qWarning("Signal %s unknown in %s", s.constData(), object()->metaObject()->className());
    d->primarySignals << QLatin1StringView(s);
}
 
static inline bool isAncestor(const QObject *obj, const QObject *child)
{
    while (child) {
        if (child == obj)
            return true;
        child = child->parent();
    }
    return false;
}
 
QList<QPair<QAccessibleInterface *, QAccessible::Relation>>
QAccessibleWidget::relations(QAccessible::Relation match /*= QAccessible::AllRelations*/) const
{
    QList<QPair<QAccessibleInterface *, QAccessible::Relation>> rels;
    if (match & QAccessible::Label) {
        const QAccessible::Relation rel = QAccessible::Label;
        if (QWidget *parent = widget()->parentWidget()) {
#if QT_CONFIG(shortcut) && QT_CONFIG(label)
            // first check for all siblings that are labels to us
            // ideally we would go through all objects and check, but that
            // will be too expensive
            const QList<QWidget*> kids = _q_ac_childWidgets(parent);
            for (QWidget *kid : kids) {
                if (QLabel *labelSibling = qobject_cast<QLabel*>(kid)) {
                    if (labelSibling->buddy() == widget()) {
                        QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(labelSibling);
                        rels.append(qMakePair(iface, rel));
                    }
                }
            }
#endif
#if QT_CONFIG(groupbox)
            QGroupBox *groupbox = qobject_cast<QGroupBox*>(parent);
            if (groupbox && !groupbox->title().isEmpty()) {
                QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(groupbox);
                rels.append(qMakePair(iface, rel));
            }
#endif
        }
    }
 
    if (match & QAccessible::Controlled) {
        QObjectList allReceivers;
        QObject *connectionObject = object();
        for (int sig = 0; sig < d->primarySignals.size(); ++sig) {
            const QObjectList receivers = connectionObject->d_func()->receiverList(d->primarySignals.at(sig).toLatin1());
            allReceivers += receivers;
        }
 
        allReceivers.removeAll(object());  //### The object might connect to itself internally
 
        for (int i = 0; i < allReceivers.size(); ++i) {
            const QAccessible::Relation rel = QAccessible::Controlled;
            QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(allReceivers.at(i));
            if (iface)
                rels.append(qMakePair(iface, rel));
        }
    }
 
    return rels;
}
 
QAccessibleInterface *QAccessibleWidget::parent() const
{
    return QAccessible::queryAccessibleInterface(parentObject());
}
 
QAccessibleInterface *QAccessibleWidget::child(int index) const
{
    Q_ASSERT(widget());
    QWidgetList childList = _q_ac_childWidgets(widget());
    if (index >= 0 && index < childList.size())
        return QAccessible::queryAccessibleInterface(childList.at(index));
    return nullptr;
}
 
QAccessibleInterface *QAccessibleWidget::focusChild() const
{
    if (widget()->hasFocus())
        return QAccessible::queryAccessibleInterface(object());
 
    QWidget *fw = widget()->focusWidget();
    if (!fw)
        return nullptr;
 
    if (isAncestor(widget(), fw)) {
        QAccessibleInterface *iface = QAccessible::queryAccessibleInterface(fw);
        if (!iface || iface == this || !iface->focusChild())
            return iface;
        return iface->focusChild();
    }
    return nullptr;
}
 
int QAccessibleWidget::childCount() const
{
    QWidgetList cl = _q_ac_childWidgets(widget());
    return cl.size();
}
 
int QAccessibleWidget::indexOfChild(const QAccessibleInterface *child) const
{
    if (!child)
        return -1;
    QWidgetList cl = _q_ac_childWidgets(widget());
    return cl.indexOf(qobject_cast<QWidget *>(child->object()));
}
 
// from qwidget.cpp
extern QString qt_setWindowTitle_helperHelper(const QString &, const QWidget*);
 
QString QAccessibleWidget::text(QAccessible::Text t) const
{
    QString str;
 
    switch (t) {
    case QAccessible::Name:
        if (!d->name.isEmpty()) {
            str = d->name;
        } else if (!widget()->accessibleName().isEmpty()) {
            str = widget()->accessibleName();
        } else if (widget()->isWindow()) {
            if (widget()->isMinimized())
                str = qt_setWindowTitle_helperHelper(widget()->windowIconText(), widget());
            else
                str = qt_setWindowTitle_helperHelper(widget()->windowTitle(), widget());
        } else {
            str = qt_accStripAmp(buddyString(widget()));
        }
        break;
    case QAccessible::Description:
        str = widget()->accessibleDescription();
#if QT_CONFIG(tooltip)
        if (str.isEmpty())
            str = widget()->toolTip();
#endif
        break;
    case QAccessible::Help:
#if QT_CONFIG(whatsthis)
        str = widget()->whatsThis();
#endif
        break;
    case QAccessible::Accelerator:
        str = qt_accHotKey(buddyString(widget()));
        break;
    case QAccessible::Value:
        break;
    default:
        break;
    }
    return str;
}
 
QStringList QAccessibleWidget::actionNames() const
{
    QStringList names;
    if (widget()->isEnabled()) {
        if (widget()->focusPolicy() != Qt::NoFocus)
            names << setFocusAction();
    }
    return names;
}
 
void QAccessibleWidget::doAction(const QString &actionName)
{
    if (!widget()->isEnabled())
        return;
 
    if (actionName == setFocusAction()) {
        if (widget()->isWindow())
            widget()->activateWindow();
        widget()->setFocus();
    }
}
 
QStringList QAccessibleWidget::keyBindingsForAction(const QString & /* actionName */) const
{
    return QStringList();
}
 
QAccessible::Role QAccessibleWidget::role() const
{
    return d->role;
}
 
QAccessible::State QAccessibleWidget::state() const
{
    QAccessible::State state;
 
    QWidget *w = widget();
    if (w->testAttribute(Qt::WA_WState_Visible) == false)
        state.invisible = true;
    if (w->focusPolicy() != Qt::NoFocus)
        state.focusable = true;
    if (w->hasFocus())
        state.focused = true;
    if (!w->isEnabled())
        state.disabled = true;
    if (w->isWindow()) {
        if (w->windowFlags() & Qt::WindowSystemMenuHint)
            state.movable = true;
        if (w->minimumSize() != w->maximumSize())
            state.sizeable = true;
        if (w->isActiveWindow())
            state.active = true;
    }
 
    return state;
}
 
QColor QAccessibleWidget::foregroundColor() const
{
    return widget()->palette().color(widget()->foregroundRole());
}
 
QColor QAccessibleWidget::backgroundColor() const
{
    return widget()->palette().color(widget()->backgroundRole());
}
 
void *QAccessibleWidget::interface_cast(QAccessible::InterfaceType t)
{
    if (t == QAccessible::ActionInterface)
       return static_cast<QAccessibleActionInterface*>(this);
    return nullptr;
}
 
QT_END_NAMESPACE
 
#endif // QT_CONFIG(accessibility)