\brief The HbToolTip class provides a set of static functions that augment the

    standard features provided by the tooltip framework. 

    A tooltip is a short piece of text that opens in a balloon, usually in response to

    the user tapping and holding on a widget or action button. The text provides a brief 

    explanation of the purpose of the item. 

    The easiest way to set a tooltip on a widget or action is to call the \c setToolTip() 

    function provided by QGraphicsItem and QAction, respectively. Both QGraphicsItem and 

    QAction also provide a \c toolTip() getter function. After setting the tooltip, you 

    can generally simply let the tooltip framework handle showing the tooltip when the 

    user taps and holds on the item and hiding the tooltip afterwards. The framework 

    shows the tooltip with the \c Qt::AlignTop alignment flag, which means that the tooltip

    appears above the top edge of the widget. 

    When the tooltip framework detects a tap and hold event, it sends a 

    QGraphicsSceneHelpEvent to the QGraphicsItem that is topmost in the scene under the 

    press point and has a non-empty tooltip text. If the QGraphicsItem accepts 

    the event, the framework does not show the tooltip. This means that when necessary 

    classes that are derived from QGraphicsItem can implement their own logic to show 

    the tooltip; for example, if you want the tooltip to appear to the right of the widget 

    rather than in the default position above it. To do this, the implementation calls

    one of the HbToolTip::showText() static function overloads to display the 

    tooltip.

    The %HbToolTip class has other static functions that provide additional features.

    For example, you can call HbToolTip::isVisible() to find out whether a tooltip is 

    currently displayed and HbToolTip::text() to get the text that is currently visible.

    \section _usecases_hbtooltip Using the HbToolTip class

    This example shows how a custom widget class that is derived fromQGraphicsItem can 

    handle the QGraphicsSceneHelpEvent event to provide custom logic for showing a tooltip. 

    \sa QGraphicsItem, QAction

    This is analogous to calling 

    HbToolTip::showText(const QString&,QGraphicsItem*,const QRectF&,Qt::Alignment)

    with the \a rect argument set to the widget's bounding rectangle

    (QGraphicsItem::boundingRect()).

    \overload

    Shows a given text as a tooltip for a widget using a prefererred alignment. There

    is an additional option to specify a region within the widget that accepts the 

    events that trigger the appearance of the tooltip. If this argument is specified,

    the tooltip disappears when the user's finger moves out of the defined region.

    Specify the preferred alignment of the tooltip relative to the side of the widget 

    using one of the following flags or flag combinations:

    - \c Qt::AlignTop

    - \c Qt::AlignRight

    - \c Qt::AlignLeft

    - \c Qt::AlignTop | \c Qt::AlignRight

    - \c Qt::AlignTop | \c Qt::AlignLeft

    For example, \c Qt::AlignTop aligns the lower edge of the tool tip with the top edge

    of the widget; \c Qt::AlignTop | \c Qt::AlignLeft aligns the lower-right corner of the 

    tooltip with the top-left corner of the widget; and \c Qt::AlignTop | \c Qt::AlignRight

    aligns the lower-left corner of the tooltip with the top-right corner of the widget.

    If the layout is right-to-left, the horizontal alignments are effectively reversed 

    (for example, \c Qt::AlignRight becomes \c Qt::AlignLeft), using the rules described 

    in \c QStyle::visualAlignment().

    If the tooltip cannot be aligned properly using the specified alignment without the

    tooltip intersecting the widget's bounding rectangle, this function uses another of the 

    supported alignment options.

    You can use this function to hide a tooltip by setting \a text to empty or the \a item

    parameter to 0.

    \overload

    \param text The text to be displayed. If this is empty, the function hides the 

                tooltip.

    \param item The widget the tooltip applies to. If this is 0, the function 

                hides the tooltip.

    \param rect The region within the widget that the user can tap to display the tooltip.

                This is expressed in the coordinates of \a item.

    \param preferredAlignment The alignment of the tooltip relative to the side of \a item. 

                This must be one of the supported alignment flags or flag combinations 

                specified above. Any other alignment flags are ignored.

    if ( scene ) {

        HbToolTipLabel *toolTip = scene->d_ptr->toolTip();

        if ( text.isEmpty() ) { // empty text means hide current tip

            toolTip->hide();

        } else {

            toolTip->setText(text);

            toolTip->setRect( item->mapRectToScene(rect) );

            toolTip->showText( item, preferredAlignment );

        }

    Hides the visible tooltip in \a scene. This is equivalent to calling showText() 

    with an empty string or with the \a item parameter set to 0.

    if ( scene ) {

        HbToolTipLabel *toolTip = scene->d_ptr->toolTip();

        if (toolTip->isVisible()) {

            toolTip->hide();

            toolTip->hideTextImmediately();

    Returns true if this tooltip is currently visible.

    \sa showText()

    if ( scene ) {

        return scene->d_ptr->toolTip()->isVisible();

   If the tooltip is visible, this returns the tooltip text; otherwise this function

   returns an empty string.

    if ( scene ) {

        return scene->d_ptr->toolTip()->text();