/**
* is called after a reparent has taken place to fix up the focus chain(s)
*/
void QGraphicsWidgetPrivate::fixFocusChainBeforeReparenting(QGraphicsWidget *newParent, QGraphicsScene *newScene)
{
Q_Q(QGraphicsWidget);
Q_ASSERT(focusNext && focusPrev);
QGraphicsWidget *n = q; //last one in 'new' list
QGraphicsWidget *o = 0; //last one in 'old' list
QGraphicsWidget *w = focusNext;
QGraphicsWidget *firstOld = 0;
bool wasPreviousNew = true;
if (focusChild) {
// Ensure that the current focus child doesn't leave pointers around
// before reparenting.
focusChild->clearFocus();
}
while (w != q) {
bool isCurrentNew = q->isAncestorOf(w);
if (isCurrentNew) {
if (!wasPreviousNew) {
n->d_func()->focusNext = w;
w->d_func()->focusPrev = n;
}
n = w;
} else { /*if (!isCurrentNew)*/
if (wasPreviousNew) {
if (o) {
o->d_func()->focusNext = w;
w->d_func()->focusPrev = o;
} else {
firstOld = w;
}
}
o = w;
}
w = w->d_func()->focusNext;
wasPreviousNew = isCurrentNew;
}
// repair the 'old' chain
if (firstOld) {
o->d_func()->focusNext = firstOld;
firstOld->d_func()->focusPrev = o;
}
// update tabFocusFirst for oldScene if the item is going to be removed from oldScene
if (newParent)
newScene = newParent->scene();
QGraphicsScene *oldScene = q->scene();
if (oldScene && newScene != oldScene)
oldScene->d_func()->tabFocusFirst = firstOld;
QGraphicsItem *topLevelItem = newParent ? newParent->topLevelItem() : 0;
QGraphicsWidget *topLevel = 0;
if (topLevelItem && topLevelItem->isWidget())
topLevel = static_cast<QGraphicsWidget *>(topLevelItem);
if (topLevel && newParent) {
QGraphicsWidget *last = topLevel->d_func()->focusPrev;
// link last with new chain
last->d_func()->focusNext = q;
focusPrev = last;
// link last in chain with
topLevel->d_func()->focusPrev = n;
n->d_func()->focusNext = topLevel;
} else {
// q is the start of the focus chain
n->d_func()->focusNext = q;
focusPrev = n;
}
}
