have the tooltip inform the widget that it's about to tip so last second updates can be made, particularly nice for expensive tooltips

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=786834

widgets/tooltip.cpp

@@ -135,6 +135,7 @@ void ToolTip::showToolTip()
         return;
     }
 
+    d->currentWidget->updateToolTip();
     setData(*d->currentWidget->toolTip());
 
     if( d->windowToPreview != 0 ) {

widgets/widget.cpp

@@ -398,6 +398,10 @@ void Widget::setToolTip(const ToolTipData &tip)
     }
 }
 
+void Widget::updateToolTip()
+{
+}
+
 void Widget::paintWidget(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
 {
     Q_UNUSED(painter);

widgets/widget.h

@@ -279,6 +279,13 @@ public:
     */
     void setToolTip(const ToolTipData &dt);
 
+    /**
+     * Called when the tooltip data should be updated, e.g. right before
+     * a tooltip is shown. This allows tips that are more expensive to
+     * create ahead of time to be set at the last possible moment.
+     */
+    virtual void updateToolTip();
+
     /**
     * Recomended position for a popup window like a menu or a tooltip
     * given its size