source: trunk/src/qt3support/widgets/q3whatsthis.cpp@ 846

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#include "q3whatsthis.h"
#ifndef QT_NO_WHATSTHIS
#include "qapplication.h"
#include "qwidget.h"
#include "qevent.h"

QT_BEGIN_NAMESPACE

/*! \class Q3WhatsThis
    \compat
*/

/*!
    Constructs a new "What's This?" object for \a widget.
*/
Q3WhatsThis::Q3WhatsThis(QWidget *widget)
    : QObject(widget)
{
    if (widget)
        widget->installEventFilter(this);
}

/*!
    Destroys the "What's This?" object.
*/
Q3WhatsThis::~Q3WhatsThis()
{
}

/*!
    \internal

    Handles "What's This?" events.
*/
bool Q3WhatsThis::eventFilter(QObject *o, QEvent *e)
{
    if (o != parent() || !o->isWidgetType())
        return false;

    if (e->type() == QEvent::WhatsThis) {
        QString s = text(static_cast<QHelpEvent*>(e)->pos());
        if (!s.isEmpty())
            QWhatsThis::showText(static_cast<QHelpEvent*>(e)->globalPos(), s, static_cast<QWidget*>(o));
    } else if (e->type() == QEvent::QueryWhatsThis) {
        QString s = text(static_cast<QHelpEvent*>(e)->pos());
        if (s.isEmpty())
            return false;
    } else if (e->type() == QEvent::WhatsThisClicked) {
        QString href = static_cast<QWhatsThisClickedEvent*>(e)->href();
        if (clicked(href))
            QWhatsThis::hideText();
    } else {
        return false;
    }
    return true;
}

/*!
    This virtual function returns the text for position \a pos in the
    widget that this "What's This?" object documents. If there is no
    "What's This?" text for the position, an empty string is returned.

    The default implementation returns an empty string.
*/
QString Q3WhatsThis::text(const QPoint & /* pos */)
{
    if (parent() && parent()->isWidgetType())
        return static_cast<QWidget*>(parent())->whatsThis();
    return QString();
}

/*!
    This virtual function is called when the user clicks inside the
    "What's this?" window. \a href is the link the user clicked on, or
    an empty string if there was no link.

    If the function returns true (the default), the "What's this?"
    window is closed, otherwise it remains visible.

    The default implementation ignores \a href and returns true.
*/
bool Q3WhatsThis::clicked(const QString & /* href */)
{
    return true;
}

/*!
    \fn void Q3WhatsThis::enterWhatsThisMode()

    Enters "What's This?" mode and returns immediately.

    Qt will install a special cursor and take over mouse input until
    the user clicks somewhere. It then shows any help available and
    ends "What's This?" mode. Finally, Qt removes the special cursor
    and help window and then restores ordinary event processing, at
    which point the left mouse button is no longer pressed.

    The user can also use the Esc key to leave "What's This?" mode.

    \sa inWhatsThisMode(), leaveWhatsThisMode()
*/

/*!
    \fn bool Q3WhatsThis::inWhatsThisMode()

    Returns true if the application is in "What's This?" mode;
    otherwise returns false.

    \sa enterWhatsThisMode(), leaveWhatsThisMode()
*/

/*!
    \fn void Q3WhatsThis::add(QWidget *widget, const QString &text)

    Adds \a text as "What's This?" help for \a widget. If the text is
    rich text formatted (i.e. it contains markup) it will be rendered
    with the default stylesheet QStyleSheet::defaultSheet().

    The text is destroyed if the widget is later destroyed, so it need
    not be explicitly removed.