Add new YaruExpandable widget (#140)

Co-authored-by: Feichtmeier <Feichtmeier@users.noreply.github.com>

example/lib/example_page_items.dart

@@ -15,6 +15,9 @@ import 'package:yaru_widgets_example/pages/toggle_buttons_row_page.dart';
 import 'package:yaru_widgets_example/widgets/option_button_list.dart';
 import 'package:yaru_widgets_example/widgets/row_list.dart';
 
+const _lorem =
+    'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.';
+
 final examplePageItems = <YaruPageItem>[
   YaruPageItem(
     titleBuilder: (context) => Text('YaruRow'),
@@ -140,5 +143,34 @@ final examplePageItems = <YaruPageItem>[
     titleBuilder: (context) => Text('YaruColorDisk'),
     builder: (context) => ColorDiskPage(),
     iconData: YaruIcons.color_select,
-  )
+  ),
+  YaruPageItem(
+    titleBuilder: (context) => Text('YaruExpandableText'),
+    iconData: YaruIcons.pan_down,
+    builder: (_) => YaruPage(
+      children: [
+        YaruExpandable(
+          child: Text(_lorem),
+          header: Text(
+            'Lorem ipsum dolor sit amet',
+            style: TextStyle(fontWeight: FontWeight.bold),
+          ),
+          expandIcon: Icon(YaruIcons.pan_end),
+        ),
+        YaruExpandable(
+          collapsedChild: Text(
+            _lorem,
+            maxLines: 5,
+            overflow: TextOverflow.fade,
+          ),
+          child: Text(_lorem),
+          header: Text(
+            'Lorem ipsum dolor sit amet',
+            style: TextStyle(fontWeight: FontWeight.bold),
+          ),
+          expandIcon: Icon(YaruIcons.pan_end),
+        )
+      ],
+    ),
+  ),
 ];

lib/src/yaru_expandable.dart

@@ -0,0 +1,67 @@
+import 'package:flutter/material.dart';
+
+const _kAnimationDuration = Duration(milliseconds: 250);
+const _kAnimationCurve = Curves.easeInOutCubic;
+
+class YaruExpandable extends StatefulWidget {
+  const YaruExpandable({
+    Key? key,
+    required this.header,
+    this.expandIcon,
+    required this.child,
+    this.collapsedChild,
+  }) : super(key: key);
+
+  /// Widget placed in the header, against the expand button
+  final Widget header;
+
+  /// Icon used in the expand button
+  /// Prefer use a "right arrow" icon
+  /// A 25° rotation is used when expanded
+  final Widget? expandIcon;
+
+  /// Widget show when expanded
+  final Widget child;
+
+  /// Widget show when collapsed
+  final Widget? collapsedChild;
+
+  @override
+  State<YaruExpandable> createState() => _YaruExpandableState();
+}
+
+class _YaruExpandableState extends State<YaruExpandable> {
+  bool isExpanded = false;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: [
+        Row(
+          mainAxisAlignment: MainAxisAlignment.spaceBetween,
+          children: [
+            GestureDetector(
+                onTap: () => setState(() => isExpanded = !isExpanded),
+                child: widget.header),
+            IconButton(
+                splashRadius: 20,
+                onPressed: () => setState(() => isExpanded = !isExpanded),
+                icon: AnimatedRotation(
+                    turns: isExpanded ? .25 : 0,
+                    duration: _kAnimationDuration,
+                    curve: _kAnimationCurve,
+                    child: widget.expandIcon ?? const Icon(Icons.arrow_right))),
+          ],
+        ),
+        AnimatedCrossFade(
+            firstChild: widget.child,
+            secondChild: widget.collapsedChild ?? Container(),
+            crossFadeState: isExpanded
+                ? CrossFadeState.showFirst
+                : CrossFadeState.showSecond,
+            sizeCurve: _kAnimationCurve,
+            duration: _kAnimationDuration)
+      ],
+    );
+  }
+}

lib/yaru_widgets.dart

@@ -8,6 +8,7 @@ export 'src/yaru_color_disk.dart';
 export 'src/yaru_color_picker_button.dart';
 export 'src/yaru_compact_layout.dart';
 export 'src/yaru_dialog_title.dart';
+export 'src/yaru_expandable.dart';
 export 'src/yaru_expansion_panel_list.dart';
 export 'src/yaru_extra_option_row.dart';
 export 'src/yaru_progress_indicator.dart';