public override Widget build(BuildContext context)
{
return(new _CupertinoSliverRefresh(
refreshIndicatorLayoutExtent: widget.refreshIndicatorExtent,
hasLayoutExtent: hasSliverLayoutExtent,
child: new LayoutBuilder(
builder: (BuildContext context1, BoxConstraints constraints) => {
latestIndicatorBoxExtent = constraints.maxHeight;
refreshState = transitionNextState();
if (widget.builder != null && latestIndicatorBoxExtent > 0)
{
return widget.builder(
context1,
refreshState,
latestIndicatorBoxExtent,
widget.refreshTriggerPullDistance,
widget.refreshIndicatorExtent
);
}
return new Container();
}
)
));
}
public static Widget buildSimpleRefreshIndicator(
BuildContext context,
RefreshIndicatorMode refreshState,
float pulledExtent,
float refreshTriggerPullDistance,
float refreshIndicatorExtent
)
{
Curve opacityCurve = new Interval(0.4f, 0.8f, curve: Curves.easeInOut);
return(new Align(
alignment: Alignment.bottomCenter,
child: new Padding(
padding: EdgeInsets.only(bottom: 16.0f),
child: refreshState == RefreshIndicatorMode.drag
? new Opacity(
opacity: opacityCurve.transform(Mathf.Min(pulledExtent / refreshTriggerPullDistance, 1.0f)
),
child: new Icon(
CupertinoIcons.down_arrow,
color: CupertinoDynamicColor.resolve(CupertinoColors.inactiveGray, context),
size: 36.0f
)
)
: new Opacity(
opacity: opacityCurve.transform(
Mathf.Min(pulledExtent / refreshIndicatorExtent, 1.0f)
),
child: new CupertinoActivityIndicator(radius: 14.0f)
)
)
));
}
RefreshIndicatorMode transitionNextState()
{
RefreshIndicatorMode nextState = RefreshIndicatorMode.refresh;
void goToDone()
{
nextState = RefreshIndicatorMode.done;
if (SchedulerBinding.instance.schedulerPhase == SchedulerPhase.idle)
{
setState(() => hasSliverLayoutExtent = false);
}
else
{
SchedulerBinding.instance.addPostFrameCallback((timestamp) => {
setState(() => hasSliverLayoutExtent = false);
});
}
}
switch (refreshState)
{
case RefreshIndicatorMode.inactive:
if (latestIndicatorBoxExtent <= 0)
{
return(RefreshIndicatorMode.inactive);
}
else
{
nextState = RefreshIndicatorMode.drag;
}
goto case RefreshIndicatorMode.drag;
case RefreshIndicatorMode.drag:
if (latestIndicatorBoxExtent == 0)
{
return(RefreshIndicatorMode.inactive);
}
else if (latestIndicatorBoxExtent < widget.refreshTriggerPullDistance)
{
return(RefreshIndicatorMode.drag);
}
else
{
if (widget.onRefresh != null) //HapticFeedback.mediumImpact();
{
SchedulerBinding.instance.addPostFrameCallback((timestamp) => {
refreshTask = widget.onRefresh().whenComplete(() => {
if (mounted)
{
setState(() => refreshTask = null);
refreshState = transitionNextState();
}
});
setState(() => hasSliverLayoutExtent = true);
});
}
return(RefreshIndicatorMode.armed);
}
break;
case RefreshIndicatorMode.armed:
if (refreshState == RefreshIndicatorMode.armed && refreshTask == null)
{
goToDone();
goto case RefreshIndicatorMode.done;
}
if (latestIndicatorBoxExtent > widget.refreshIndicatorExtent)
{
return(RefreshIndicatorMode.armed);
}
else
{
nextState = RefreshIndicatorMode.refresh;
}
goto case RefreshIndicatorMode.refresh;
case RefreshIndicatorMode.refresh:
if (refreshTask != null)
{
return(RefreshIndicatorMode.refresh);
}
else
{
goToDone();
}
goto case RefreshIndicatorMode.done;
case RefreshIndicatorMode.done:
if (latestIndicatorBoxExtent >
widget.refreshTriggerPullDistance * _inactiveResetOverscrollFraction)
{
return(RefreshIndicatorMode.done);
}
else
{
nextState = RefreshIndicatorMode.inactive;
}
break;
}
return(nextState);
}
public override void initState()
{
base.initState();
refreshState = RefreshIndicatorMode.inactive;
}