<itemvalue="A single-line [ListTile] with an expansion arrow icon that expands or collapses the tile to reveal or hide the [children]. This widget is typically used with [ListView] to create an "expand collapse" list entry. When used with scrolling widgets like [ListView], a unique [PageStorageKey] must be specified to enable the [ExpansionTile] to save and restore its expanded state when it is scrolled in and out of view. This class overrides the [ListTileThemeData.iconColor] and [ListTileThemeData.textColor] theme properties for its [ListTile]. These colors animate between values when the tile is expanded and collapsed: between [iconColor], [collapsedIconColor] and between [textColor] and [collapsedTextColor]. The expansion arrow icon is shown on the right by default in left-to-right languages (i.e. the trailing edge). This can be changed using [controlAffinity]. This maps to the [leading] and [trailing] properties of [ExpansionTile]. {@tool dartpad} This example demonstrates different configurations of ExpansionTile. See code in examplesapilibmaterialexpansion_tileexpansion_tile.0.dart {@end-tool} See also: [ListTile], useful for creating expansion tile [children] when the expansion tile represents a sublist. The "Expand and collapse" section of <https:material.iocomponentsliststypes>"/>
