void _updateTabController() { TabController newController = this.widget.controller ?? DefaultTabController.of(this.context); D.assert(() => { if (newController == null) { throw new UIWidgetsError( "No TabController for " + this.widget.GetType() + "\n" + "When creating a " + this.widget.GetType() + ", you must either provide an explicit " + "TabController using the \"controller\" property, or you must ensure that there " + "is a DefaultTabController above the " + this.widget.GetType() + ".\n" + "In this case, there was neither an explicit controller nor a default controller." ); } return(true); }); if (newController == this._controller) { return; } if (this._controller != null) { this._controller.animation.removeListener(this._handleTabControllerAnimationTick); } this._controller = newController; if (this._controller != null) { this._controller.animation.addListener(this._handleTabControllerAnimationTick); } }
public override Widget build(BuildContext context) { Color fixColor = this.color ?? Colors.transparent; Color fixSelectedColor = this.selectedColor ?? Theme.of(context).accentColor; ColorTween selectedColorTween = new ColorTween(begin: fixColor, end: fixSelectedColor); ColorTween previousColorTween = new ColorTween(begin: fixSelectedColor, end: fixColor); TabController tabController = this.controller ?? DefaultTabController.of(context); D.assert(() => { if (tabController == null) { throw new UIWidgetsError( "No TabController for " + this.GetType() + ".\n" + "When creating a " + this.GetType() + ", you must either provide an explicit TabController " + "using the \"controller\" property, or you must ensure that there is a " + "DefaultTabController above the " + this.GetType() + ".\n" + "In this case, there was neither an explicit controller nor a default controller." ); } return(true); }); Animation <float> animation = new CurvedAnimation( parent: tabController.animation, curve: Curves.fastOutSlowIn ); return(new AnimatedBuilder( animation: animation, builder: (BuildContext subContext, Widget child) => { List <Widget> children = new List <Widget>(); for (int tabIndex = 0; tabIndex < tabController.length; tabIndex++) { children.Add(this._buildTabIndicator( tabIndex, tabController, selectedColorTween, previousColorTween) ); } return new Row( mainAxisSize: MainAxisSize.min, children: children ); } )); }