Inspectable is a widget which inspect entire descendant widgets.

• Inspect widgets belonging to its subtree.
• Colorize widgets you want to check.

The goal of Inspectable is to clarify the exact widgets which consturuct current displaying UI for Flutter app developers without IDE.

"Without IDE" may be useful if you want to inspect widget tree built with "release" mode or without connecting real devices with PC.

1. place Inspectable below MaterialApp.

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Inspectable(
        child: MyHomePage(),
        colors: <Type, Color> {
          Text: Colors.blue,
          Material: Colors.red,
          GestureDetector: Colors.teal,
        }
        verbose: true,
      ),
    );
  }
}

Optionally, you can colorize and emphasize the name of widgets with colors property.

verbose is a flag to switch whether to show private widgets which name starts with _.

2. call Inspectable.of(context).inspect() to display Widget tree.

TextButton(
  onPressed: () {
    Inspectable.of(context).inspect();
  },
  child: Text(
    'INSPECT',
  ),
)

3. If you want to inspect only below the specific widget, you can just place another Inspectable there.

Inspectable(
  child: AnyWidgetForInspect();
)

note that in this case, you must use context below AnyWidgetForInspect as context would look up closest ancestor Inspectable of it.

4. If you want to inspect State of StatefulWidget, overriding debugFillProperties() is required. Example below tries to display its private fields, _someIntState and _someBoolState.

@override
void debugFillProperties(properties) {
  super.debugFillProperties(properties);
  properties.add(IntProperty('someIntState', _someIntState, defaultValue: null));
  properties.add(FlagProperty(
    'someBoolState',
    value: _someBoolState,
    defaultValue: null,
    ifTrue: 'flag is true',
    ifFalse: 'flag is false',
  ));
}

As debugFillProperties is often used in Flutter framework, you can refer codes of widgets such as Text to understand more usages in detail.

If you have anything you want to inform me (@chooyan-eng), such as suggestions to enhance this package or functionalities you want etc, feel free to make issues on GitHub or send messages on Twitter en: @tsuyoshi_chujo ja: @chooyan_i18n.