public override bool updateShouldNotify(InheritedWidget oldWidget)
{
FlexibleSpaceBarSettings _oldWidget = (FlexibleSpaceBarSettings)oldWidget;
return(toolbarOpacity != _oldWidget.toolbarOpacity ||
minExtent != _oldWidget.minExtent ||
maxExtent != _oldWidget.maxExtent ||
currentExtent != _oldWidget.currentExtent);
}
float?_getCollapsePadding(float t, FlexibleSpaceBarSettings settings)
{
switch (widget.collapseMode)
{
case CollapseMode.pin:
return(-(settings.maxExtent.Value - settings.currentExtent.Value));
case CollapseMode.none:
return(0.0f);
case CollapseMode.parallax:
float deltaExtent = settings.maxExtent.Value - settings.minExtent.Value;
return(-new FloatTween(begin: 0.0f, end: deltaExtent / 4.0f).lerp(t));
}
return(null);
}
public override Widget build(BuildContext context)
{
return(new LayoutBuilder(
builder: (BuildContext _context, BoxConstraints constraints) => {
FlexibleSpaceBarSettings settings =
_context.dependOnInheritedWidgetOfExactType <FlexibleSpaceBarSettings>();
D.assert(settings != null,
() =>
"A FlexibleSpaceBar must be wrapped in the widget returned by FlexibleSpaceBar.createSettings().");
List <Widget> children = new List <Widget>();
float deltaExtent = settings.maxExtent.Value - settings.minExtent.Value;
float t = (1.0f - (settings.currentExtent.Value - settings.minExtent.Value) / deltaExtent)
.clamp(0.0f, 1.0f);
if (widget.background != null)
{
float fadeStart = Mathf.Max(0.0f, 1.0f - material_.kToolbarHeight / deltaExtent);
float fadeEnd = 1.0f;
D.assert(fadeStart <= fadeEnd);
float opacity = 1.0f - new Interval(fadeStart, fadeEnd).transform(t);
if (opacity > 0.0f)
{
float height = settings.maxExtent ?? 0;
if (widget.stretchModes.Contains(StretchMode.zoomBackground) &&
constraints.maxHeight > height)
{
height = constraints.maxHeight;
}
children.Add(new Positioned(
top: _getCollapsePadding(t, settings),
left: 0.0f,
right: 0.0f,
height: height,
child: new Opacity(
opacity: opacity,
child: widget.background)
)
);
if (widget.stretchModes.Contains(StretchMode.blurBackground) &&
constraints.maxHeight > settings.maxExtent)
{
float blurAmount = (constraints.maxHeight - settings.maxExtent) / 10 ?? 0;
children.Add(Positioned.fill(
child: new BackdropFilter(
child: new Container(
color: Colors.transparent
),
filter: ui.ImageFilter.blur(
sigmaX: blurAmount,
sigmaY: blurAmount
)
)
));
}
}
}
Widget title = null;
if (widget.title != null)
{
switch (Application.platform)
{
case RuntimePlatform.IPhonePlayer:
title = widget.title;
break;
default:
title = widget.title;
break;
}
}
if (widget.stretchModes.Contains(StretchMode.fadeTitle) &&
constraints.maxHeight > settings.maxExtent)
{
float stretchOpacity =
1 - (((constraints.maxHeight - settings.maxExtent) / 100)?.clamp(0.0f, 1.0f) ?? 0);
title = new Opacity(
opacity: stretchOpacity,
child: title
);
}
ThemeData theme = Theme.of(_context);
float toolbarOpacity = settings.toolbarOpacity.Value;
if (toolbarOpacity > 0.0f)
{
TextStyle titleStyle = theme.primaryTextTheme.title;
titleStyle = titleStyle.copyWith(
color: titleStyle.color.withOpacity(toolbarOpacity));
bool effectiveCenterTitle = _getEffectiveCenterTitle(theme).Value;
EdgeInsetsGeometry padding = widget.titlePadding ??
EdgeInsets.only(
left: effectiveCenterTitle ? 0.0f : 72.0f,
bottom: 16.0f
);
float scaleValue = new FloatTween(begin: 1.5f, end: 1.0f).lerp(t);
Matrix4 scaleTransform = Matrix4.diagonal3Values(scaleValue, scaleValue, 1);
Alignment titleAlignment = _getTitleAlignment(effectiveCenterTitle);
children.Add(new Container(
padding: padding,
child: new Transform(
alignment: titleAlignment,
transform: scaleTransform,
child: new Align(
alignment: titleAlignment,
child: new DefaultTextStyle(
style: titleStyle,
child: new LayoutBuilder(
builder: (BuildContext __context, BoxConstraints _constraints) => {
return new Container(
width: _constraints.maxWidth / scaleValue,
alignment: titleAlignment,
child: title
);
}
)
)
)
)
)
);
}
return new ClipRect(
child: new Stack(
children: children)
);
}
));
}
public override Widget build(BuildContext context)
{
FlexibleSpaceBarSettings settings =
(FlexibleSpaceBarSettings)context.inheritFromWidgetOfExactType(typeof(FlexibleSpaceBarSettings));
D.assert(settings != null,
() => "A FlexibleSpaceBar must be wrapped in the widget returned by FlexibleSpaceBar.createSettings().");
List <Widget> children = new List <Widget>();
float deltaExtent = settings.maxExtent.Value - settings.minExtent.Value;
float t = (1.0f - (settings.currentExtent.Value - settings.minExtent.Value) / deltaExtent)
.clamp(0.0f, 1.0f);
if (this.widget.background != null)
{
float fadeStart = Mathf.Max(0.0f, 1.0f - Constants.kToolbarHeight / deltaExtent);
float fadeEnd = 1.0f;
D.assert(fadeStart <= fadeEnd);
float opacity = 1.0f - new Interval(fadeStart, fadeEnd).transform(t);
if (opacity > 0.0f)
{
children.Add(new Positioned(
top: this._getCollapsePadding(t, settings),
left: 0.0f,
right: 0.0f,
height: settings.maxExtent,
child: new Opacity(
opacity: opacity,
child: this.widget.background)
)
);
}
}
Widget title = null;
if (this.widget.title != null)
{
switch (Application.platform)
{
case RuntimePlatform.IPhonePlayer:
title = this.widget.title;
break;
default:
title = this.widget.title;
break;
}
}
ThemeData theme = Theme.of(context);
float toolbarOpacity = settings.toolbarOpacity.Value;
if (toolbarOpacity > 0.0f)
{
TextStyle titleStyle = theme.primaryTextTheme.title;
titleStyle = titleStyle.copyWith(
color: titleStyle.color.withOpacity(toolbarOpacity));
bool effectiveCenterTitle = this._getEffectiveCenterTitle(theme).Value;
EdgeInsets padding = this.widget.titlePadding ??
EdgeInsets.only(
left: effectiveCenterTitle ? 0.0f : 72.0f,
bottom: 16.0f
);
float scaleValue = new FloatTween(begin: 1.5f, end: 1.0f).lerp(t);
Matrix4 scaleTransform = new Matrix4().diagonal3Values(scaleValue, scaleValue, 1);
Alignment titleAlignment = this._getTitleAlignment(effectiveCenterTitle);
children.Add(new Container(
padding: padding,
child: new Transform(
alignment: titleAlignment,
transform: scaleTransform,
child: new Align(
alignment: titleAlignment,
child: new DefaultTextStyle(
style: titleStyle,
child: title)
)
)
)
);
}
return(new ClipRect(
child: new Stack(
children: children)
));
}