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#include "qfocusframe.h"

#include "qstyle.h"

#include "qbitmap.h"

#include "qstylepainter.h"

#include "qstyleoption.h"

#include "qdebug.h"

#include <private/qwidget_p.h>

QT_BEGIN_NAMESPACE

class QFocusFramePrivate : public QWidgetPrivate

{

    Q_DECLARE_PUBLIC(QFocusFrame)

    QWidget *widget;

    QWidget *frameParent;

    bool showFrameAboveWidget;

public:

    QFocusFramePrivate() {

        widget = 0;

        frameParent = 0;

        sendChildEvents = false;

        showFrameAboveWidget = false;

    }

    void updateSize();

    void update();

};

void QFocusFramePrivate::update()

{

    Q_Q(QFocusFrame);

    q->setParent(frameParent);

    updateSize();

    if (q->parentWidget()->rect().intersects(q->geometry())) {

        if (showFrameAboveWidget)

            q->raise();

        else

            q->stackUnder(widget);

        q->show();

    } else {

        q->hide();

    }

}

void QFocusFramePrivate::updateSize()

{

    Q_Q(QFocusFrame);

    int vmargin = q->style()->pixelMetric(QStyle::PM_FocusFrameVMargin),

        hmargin = q->style()->pixelMetric(QStyle::PM_FocusFrameHMargin);

    QPoint pos(widget->x(), widget->y());

    if (q->parentWidget() != widget->parentWidget())

        pos = widget->parentWidget()->mapTo(q->parentWidget(), pos);

    QRect geom(pos.x()-hmargin, pos.y()-vmargin,

               widget->width()+(hmargin*2), widget->height()+(vmargin*2));

    if(q->geometry() == geom)

        return;

    q->setGeometry(geom);

    QStyleHintReturnMask mask;

    QStyleOption opt;

    q->initStyleOption(&opt);

    if (q->style()->styleHint(QStyle::SH_FocusFrame_Mask, &opt, q, &mask))

        q->setMask(mask.region);

}

/*!

    Initialize \a option with the values from this QFocusFrame. This method is useful

    for subclasses when they need a QStyleOption, but don't want to fill

    in all the information themselves.

    \sa QStyleOption::initFrom()

*/

void QFocusFrame::initStyleOption(QStyleOption *option) const

{

    if (!option)

        return;

    option->initFrom(this);

}

/*!

    \class QFocusFrame

    \brief The QFocusFrame widget provides a focus frame which can be

    outside of a widget's normal paintable area.

    \ingroup basicwidgets

    Normally an application will not need to create its own

    QFocusFrame as QStyle will handle this detail for

    you. A style writer can optionally use a QFocusFrame to have a

    focus area outside of the widget's paintable geometry. In this way

    space need not be reserved for the widget to have focus but only

    set on a QWidget with QFocusFrame::setWidget. It is, however,

    legal to create your own QFocusFrame on a custom widget and set

    its geometry manually via QWidget::setGeometry however you will

    not get auto-placement when the focused widget changes size or

    placement.

*/

/*!

    Constructs a QFocusFrame.

    The focus frame will not monitor \a parent for updates but rather

    can be placed manually or by using QFocusFrame::setWidget. A

    QFocusFrame sets Qt::WA_NoChildEventsForParent attribute; as a

    result the parent will not receive a QEvent::ChildInserted event,

    this will make it possible to manually set the geometry of the

    QFocusFrame inside of a QSplitter or other child event monitoring

    widget.

    \sa QFocusFrame::setWidget()

*/

QFocusFrame::QFocusFrame(QWidget *parent)

    : QWidget(*new QFocusFramePrivate, parent, 0)

{

    setAttribute(Qt::WA_TransparentForMouseEvents);

    setFocusPolicy(Qt::NoFocus);

    setAttribute(Qt::WA_NoChildEventsForParent, true);

    setAttribute(Qt::WA_AcceptDrops, style()->styleHint(QStyle::SH_FocusFrame_AboveWidget, 0, this));

}

/*!

    Destructor.

*/

QFocusFrame::~QFocusFrame()

{

}

/*!

  QFocusFrame will track changes to \a widget and resize itself automatically.

  If the monitored widget's parent changes, QFocusFrame will follow the widget

  and place itself around the widget automatically. If the monitored widget is deleted,

  QFocusFrame will set it to zero.

  \sa QFocusFrame::widget()

*/

void

QFocusFrame::setWidget(QWidget *widget)

{

    Q_D(QFocusFrame);

    if (style()->styleHint(QStyle::SH_FocusFrame_AboveWidget, 0, this))

        d->showFrameAboveWidget = true;

    else

        d->showFrameAboveWidget = false;

    if (widget == d->widget)

        return;

    if (d->widget) {

        // Remove event filters from the widget hierarchy.

        QWidget *p = d->widget;

        do {

            p->removeEventFilter(this);

            if (!d->showFrameAboveWidget || p == d->frameParent)

                break;

            p = p->parentWidget();

        }while (p);

    }

    if (widget && !widget->isWindow() && widget->parentWidget()->windowType() != Qt::SubWindow) {

        d->widget = widget;

        d->widget->installEventFilter(this);

        QWidget *p = widget->parentWidget();

        QWidget *prev = 0;

        if (d->showFrameAboveWidget) {

            // Find the right parent for the focus frame.

            while (p) {

                // Traverse the hirerarchy of the 'widget' for setting event filter.

                // During this if come across toolbar or a top level, use that

                // as the parent for the focus frame. If we find a scroll area

                // use its viewport as the parent.

                bool isScrollArea = false;

                if (p->isWindow() || p->inherits("QToolBar") || (isScrollArea = p->inherits("QAbstractScrollArea"))) {

                    d->frameParent = p;

                    // The previous one in the hierarchy will be the viewport.

                    if (prev && isScrollArea)

                        d->frameParent = prev;

                    break;

                } else {

                    p->installEventFilter(this);

                    prev = p;

                    p = p->parentWidget();

                }

            }

        } else {

            d->frameParent = p;

        }

        d->update();

    } else {

        d->widget = 0;

        hide();

    }

}

/*!

  Returns the currently monitored widget for automatically resize and

  update.

   \sa QFocusFrame::setWidget()

*/

QWidget *

QFocusFrame::widget() const

{

    Q_D(const QFocusFrame);

    return d->widget;

}

/*! \reimp */

void

QFocusFrame::paintEvent(QPaintEvent *)

{

    Q_D(QFocusFrame);

    QStylePainter p(this);

    QStyleOption option;

    initStyleOption(&option);

    int vmargin = style()->pixelMetric(QStyle::PM_FocusFrameVMargin);

    int hmargin = style()->pixelMetric(QStyle::PM_FocusFrameHMargin);

    QWidgetPrivate *wd = qt_widget_private(d->widget);

    QRect rect = wd->clipRect().adjusted(0, 0, hmargin*2, vmargin*2);

    p.setClipRect(rect);

    p.drawControl(QStyle::CE_FocusFrame, option);

}

/*! \reimp */

bool

QFocusFrame::eventFilter(QObject *o, QEvent *e)

{

    Q_D(QFocusFrame);

    if(o == d->widget) {

        switch(e->type()) {

        case QEvent::Move:

        case QEvent::Resize:

            d->updateSize();

            break;

        case QEvent::Hide:

        case QEvent::StyleChange:

            hide();

            break;

        case QEvent::ParentChange:

            if (d->showFrameAboveWidget) {

                QWidget *w = d->widget;

                setWidget(0);

                setWidget(w);

            } else {

                d->update();

            }

            break;

        case QEvent::Show:

            d->update();

            show();

            break;

        case QEvent::PaletteChange:

            setPalette(d->widget->palette());

            break;

        case QEvent::ZOrderChange:

            if (style()->styleHint(QStyle::SH_FocusFrame_AboveWidget, 0, this))

                raise();

            else

                stackUnder(d->widget);

            break;

        case QEvent::Destroy:

            setWidget(0);

            break;

        default:

            break;

        }

    } else if (d->showFrameAboveWidget) {

        // Handle changes in the parent widgets we are monitoring.

        switch(e->type()) {

        case QEvent::Move:

        case QEvent::Resize:

            d->updateSize();

            break;

        case QEvent::ZOrderChange:

            raise();

            break;

        default:

            break;

        }

    }

    return false;

}

/*! \reimp */

bool QFocusFrame::event(QEvent *e)

{

    return QWidget::event(e);

}

QT_END_NAMESPACE