internal static Dictionary <object, _HeroState> _allHeroesFor(
BuildContext context,
bool isUserGestureTransition,
NavigatorState navigator)
{
D.assert(context != null);
D.assert(navigator != null);
Dictionary <object, _HeroState> result = new Dictionary <object, _HeroState> {
};
void inviteHero(StatefulElement hero, object tag)
{
D.assert(() => {
if (result.ContainsKey(tag))
{
throw new UIWidgetsError(
new List <DiagnosticsNode>()
{
new ErrorSummary("There are multiple heroes that share the same tag within a subtree."),
new ErrorDescription(
"Within each subtree for which heroes are to be animated (i.e. a PageRoute subtree), " +
"each Hero must have a unique non-null tag.\n" +
$"In this case, multiple heroes had the following tag: {tag}\n"
),
new DiagnosticsProperty <StatefulElement>("Here is the subtree for one of the offending heroes", hero, linePrefix: "# ", style: DiagnosticsTreeStyle.dense),
});
}
return(true);
});
Hero heroWidget = hero.widget as Hero;
_HeroState heroState = hero.state as _HeroState;
if (!isUserGestureTransition || heroWidget.transitionOnUserGestures)
{
result[tag] = heroState;
}
else
{
heroState.ensurePlaceholderIsHidden();
}
}
void visitor(Element element)
{
Widget widget = element.widget;
if (widget is Hero)
{
StatefulElement hero = element as StatefulElement;
object tag = ((Hero)widget).tag;
D.assert(tag != null);
if (Navigator.of(hero) == navigator)
{
inviteHero(hero, tag);
}
else
{
ModalRoute heroRoute = ModalRoute.of(hero);
if (heroRoute != null && heroRoute is PageRoute && heroRoute.isCurrent)
{
inviteHero(hero, tag);
}
}
}
element.visitChildren(visitor);
}
context.visitChildElements(visitor);
return(result);
}
void _startHeroTransition(
PageRoute from,
PageRoute to,
Animation <float> animation,
HeroFlightDirection flightType,
bool isUserGestureTransition
)
{
if (navigator == null || from.subtreeContext == null || to.subtreeContext == null)
{
to.offstage = false; // in case we set this in _maybeStartHeroTransition
return;
}
Rect navigatorRect = HeroUtils._boundingBoxFor(navigator.context);//_globalBoundingBoxFor(navigator.context);
Dictionary <object, _HeroState> fromHeroes =
Hero._allHeroesFor(from.subtreeContext, isUserGestureTransition, navigator);
Dictionary <object, _HeroState> toHeroes =
Hero._allHeroesFor(to.subtreeContext, isUserGestureTransition, navigator);
to.offstage = false;
foreach (object tag in fromHeroes.Keys)
{
if (toHeroes.ContainsKey(tag))
{
HeroFlightShuttleBuilder fromShuttleBuilder = fromHeroes[tag].widget.flightShuttleBuilder;
HeroFlightShuttleBuilder toShuttleBuilder = toHeroes[tag].widget.flightShuttleBuilder;
bool isDiverted = _flights.ContainsKey(tag);
_HeroFlightManifest manifest = new _HeroFlightManifest(
type: flightType,
overlay: navigator.overlay,
navigatorRect: navigatorRect,
fromRoute: from,
toRoute: to,
fromHero: fromHeroes[tag],
toHero: toHeroes[tag],
createRectTween: createRectTween,
shuttleBuilder:
toShuttleBuilder ?? fromShuttleBuilder ?? _defaultHeroFlightShuttleBuilder,
isUserGestureTransition: isUserGestureTransition,
isDiverted: isDiverted
);
//if (_flights.TryGetValue(tag, out var result)) {
if (isDiverted)
{
_flights[tag].divert(manifest);
}
else
{
_flights[tag] = new _HeroFlight(_handleFlightEnded);
_flights[tag].start(manifest);
}
}
else if (_flights.TryGetValue(tag, out var result))
{
result.abort();
}
}
foreach (object tag in toHeroes.Keys)
{
_HeroState heroState = null;
if (!fromHeroes.TryGetValue(tag, out heroState))
{
toHeroes[tag].ensurePlaceholderIsHidden();
}
}
}