buildSliverAppBar method

@protected Widget buildSliverAppBar(BuildParameters params)

Implementation

@protected
Widget buildSliverAppBar(BuildParameters params) {
  var leading = builder.tryBuildWidget(params.context,
      params.widgets["leading"], params.state, params.parentContext);
  leading ??= params.buildProp("leadingIcon");

  var title = builder.tryBuildWidget(params.context,
      params.widgets["titleWidget"], params.state, params.parentContext);
  if (title == null && params.props["title"] != null) {
    title = Text(properties.getText(params.props["title"], "appBar"));
  }

  var bottom = builder.tryBuildWidget(params.context,
      params.widgets["bottom"], params.state, params.parentContext);
  if (bottom is! PreferredSizeWidget) {
    bottom = null;
  }

  final actions = <Widget>[];
  if (params.widgets["actions"] != null) {
    for (Map actionSpec in params.widgets["actions"] as List<Map>) {
      actions.add(builder.buildWidget(
          params.context, actionSpec, params.state, params.parentContext));
    }
  }

  final flexible = FlexibleSpaceBar(
    title: title,
    centerTitle: tryParseBool(params.props["centerTitle"]),
    titlePadding: params.buildProp("titlePadding"),
    expandedTitleScale:
        parseDouble(params.props["expandedTitleScale"], defaultValue: 1.5),
    collapseMode: params.buildProp("collapseMode") ?? CollapseMode.parallax,
    stretchModes: [
      params.buildProp("stretchMode") ?? StretchMode.zoomBackground
    ],
    background: builder.tryBuildWidget(params.context,
        params.widgets["background"], params.state, params.parentContext),
  );

  final systemUiOverlayStyleProp = params.props["systemUiOverlayStyle"];
  final systemUiOverlayStyle = systemUiOverlayStyleProp == null
      ? null
      : systemUiOverlayStyleProp == "dark"
          ? SystemUiOverlayStyle.dark
          : SystemUiOverlayStyle.light;

  return SliverAppBar(
    key: properties.getKey(params.id),
    backgroundColor: tryParseColor(params.props["backgroundColor"]),
    foregroundColor: tryParseColor(params.props["foregroundColor"]),
    systemOverlayStyle: systemUiOverlayStyle,
    //title: title,
    //centerTitle: tryParseBool(params.props["centerTitle"]),
    elevation: tryParseDouble(params.props["elevation"]),
    scrolledUnderElevation:
        tryParseDouble(params.props["scrolledUnderElevation"]),
    leading: leading,
    bottom: bottom != null ? bottom as PreferredSizeWidget : null,
    //toolbarHeight: tryParseDouble(params.props["toolbarHeight"]),
    actions: actions,
    expandedHeight: tryParseDouble(params.props["expandedHeight"]),
    collapsedHeight: tryParseDouble(params.props["collapsedHeight"]),
    //onStretchTrigger: params.actions["onStretchTrigger"] != null ? widgetEvents.getFunction(params.context, params.actions["onStretchTrigger"], params.state) : null,
    floating: parseBool(params.props["floating"]),
    pinned: parseBool(params.props["pinned"]),
    snap: parseBool(params.props["snap"]) &&
        parseBool(params.props["floating"]),
    stretch: parseBool(params.props["stretch"]),
    flexibleSpace: flexible,
  );
}