using Unity.UIWidgets.foundation; namespace Unity.UIWidgets.widgets { public class Visibility : StatelessWidget { public Visibility( Key key = null, Widget child = null, Widget replacement = null, bool visible = true, bool maintainState = false, bool maintainAnimation = false, bool maintainSize = false, bool maintainInteractivity = false ) : base(key: key) { D.assert(child != null); D.assert(maintainState == true || maintainAnimation == false, () => "Cannot maintain animations if the state is not also maintained."); D.assert(maintainAnimation == true || maintainSize == false, () => "Cannot maintain size if animations are not maintained."); D.assert(maintainSize == true || maintainInteractivity == false, () => "Cannot maintain interactivity if size is not maintained."); this.replacement = replacement ?? SizedBox.shrink(); this.child = child; this.visible = visible; this.maintainState = maintainState; this.maintainAnimation = maintainAnimation; this.maintainSize = maintainSize; this.maintainInteractivity = maintainInteractivity; } public readonly Widget child; public readonly Widget replacement; public readonly bool visible; public readonly bool maintainState; public readonly bool maintainAnimation; public readonly bool maintainSize; public readonly bool maintainInteractivity; public override Widget build(BuildContext context) { if (this.maintainSize) { Widget result = this.child; if (!this.maintainInteractivity) { result = new IgnorePointer( child: this.child, ignoring: !this.visible ); } return new Opacity( opacity: this.visible ? 1.0f : 0.0f, child: result ); } D.assert(!this.maintainInteractivity); D.assert(!this.maintainSize); if (this.maintainState) { Widget result = this.child; if (!this.maintainAnimation) { result = new TickerMode(child: this.child, enabled: this.visible); } return new Offstage( child: result, offstage: !this.visible ); } D.assert(!this.maintainAnimation); D.assert(!this.maintainState); return this.visible ? this.child : this.replacement; } public override void debugFillProperties(DiagnosticPropertiesBuilder properties) { base.debugFillProperties(properties); properties.add(new FlagProperty("visible", value: this.visible, ifFalse: "hidden", ifTrue: "visible")); properties.add(new FlagProperty("maintainState", value: this.maintainState, ifFalse: "maintainState")); properties.add(new FlagProperty("maintainAnimation", value: this.maintainAnimation, ifFalse: "maintainAnimation")); properties.add(new FlagProperty("maintainSize", value: this.maintainSize, ifFalse: "maintainSize")); properties.add(new FlagProperty("maintainInteractivity", value: this.maintainInteractivity, ifFalse: "maintainInteractivity")); } } }