Cant trigger listener in my own code

[Rockvole]

Hi,
Thanks for the plugin.

I can see that your example works. When I try to copy / paste the example code into my own code and include your library it doesn't seem to ever call the listener.
In the listener, I just put a print statement to show the $visible value but it never seems to be called.
Is there anything else I need to do to enable it ?

[Rockvole]

I made a new project just to try your keyboard :

import 'package:flutter/material.dart';
import 'package:keyboard_visibility/keyboard_visibility.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
	return MaterialApp(
	  title: 'Flutter Demo',
	  theme: ThemeData(

		primarySwatch: Colors.blue,
	  ),
	  home: MyHomePage(title: 'Flutter Demo Home Page'),
	);
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);


  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  KeyboardVisibilityNotification _keyboardVisibility = new KeyboardVisibilityNotification();
  int _keyboardVisibilitySubscriberId;
  bool _keyboardState;

  @protected
  void initState() {
	super.initState();

	_keyboardState = _keyboardVisibility.isKeyboardVisible;

	_keyboardVisibilitySubscriberId = _keyboardVisibility.addNewListener(
	  onChange: (bool visible) {
		print("Keyboard visible=$visible");
		setState(() {
		  _keyboardState = visible;
		});
	  },
	);
  }

  @override
  void dispose() {
	_keyboardVisibility.removeListener(_keyboardVisibilitySubscriberId);
  }

  @override
  Widget build(BuildContext context) {
	return Scaffold(
	  appBar: AppBar(
		title: Text(widget.title),
	  ),
	  body: Center(
		child: Column(
		  mainAxisAlignment: MainAxisAlignment.center,
		  children: <Widget>[
			Text(
			  'You have pushed the button this many times:',
			),
			TextField(
			  keyboardType: TextInputType.text,
			  decoration: InputDecoration(
				labelText: 'Input box for keyboard test',
			  ),
			),
		  ],
		),
	  ),
	);
  }
}

[Rockvole]

In my pubspec.yaml I have :

dev_dependencies:
  flutter_test:
    sdk: flutter
  keyboard_visibility:
      path: ../flutter_keyboard_visibility

It still doesnt work even with that basic example. Is there an android setting in the Manifest or something which is also needed ?
Thanks.

[CosmicPangolin]

@Rockvole @adee42 Did you ever make any progress on this? I'm having a similar problem - the listener seems to work in all of my app pages except one...and I have noooo idea why that could be.

[adee42]

Hi man, sorry for the late reply,

@Rockvole: no, there are no further settings needed. I'll check your example

@CosmicPangolin: do you have any further information on what happens on this specific page? Can you provide any example? How are you testing? Android or iOS?

[adee42]

@Rockvole: I checked your example on Android emulator, it works. Can you provide more information on your set up?

[CosmicPangolin]

import 'package:flutter/material.dart';
import 'package:keyboard_visibility/keyboard_visibility.dart';

void main() => runApp(KeyboardApp());

class KeyboardApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Keyboard failz example',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: KeyboardFailzExample(),
    );
  }
}

class KeyboardFailzExample extends StatefulWidget {
  KeyboardFailzExampleState createState() => KeyboardFailzExampleState();
}

class KeyboardFailzExampleState extends State<KeyboardFailzExample> {

  KeyboardVisibilityNotification _keyboardVisibility =
  KeyboardVisibilityNotification();
  int _keyboardVisibilitySubscriberId;
  bool _keyboardState;

  @override
  void initState() {
    super.initState();
    print('Scaffold init');


    _keyboardState = _keyboardVisibility.isKeyboardVisible;
    print(_keyboardVisibility.isKeyboardVisible);

    _keyboardVisibilitySubscriberId = _keyboardVisibility.addNewListener(
      onChange: (bool visible) {
        setState(() {
          _keyboardState = visible;
          print('SCAFFOLD');
          print(_keyboardState);
        });
      },
    );
  }

  @override
  void dispose() {
    super.dispose();
    _keyboardVisibility.removeListener(_keyboardVisibilitySubscriberId);
  }

  Widget build(BuildContext context) {
    return SafeArea(
      child: Scaffold(
        bottomNavigationBar: _keyboardState == false ? TestBar()
            : Transform.translate(
          offset: Offset(
              0.0, -1 * MediaQuery.of(context).viewInsets.bottom),
          child: TestBar(),
        ),
        body: CustomScrollView(
          slivers: <Widget>[
            SliverFillRemaining(),
          ],
        ),
      ),
    );
  }
}

class TestBar extends StatefulWidget {

  TestBarState createState() => TestBarState();
}

class TestBarState extends State<TestBar> {

  KeyboardVisibilityNotification _keyboardVisibility =
  KeyboardVisibilityNotification();
  int _keyboardVisibilitySubscriberId;
  bool _keyboardState;

  @override
  void initState() {
    super.initState();
    print('Bar Init');

    _keyboardState = _keyboardVisibility.isKeyboardVisible;
    print(_keyboardVisibility.isKeyboardVisible);

    _keyboardVisibilitySubscriberId = _keyboardVisibility.addNewListener(
      onChange: (bool visible) {
        setState(() {
          _keyboardState = visible;
          print('BAR');
          print(_keyboardState);
        });
      },
    );
  }

  @override
  void dispose() {
    super.dispose();
    _keyboardVisibility.removeListener(_keyboardVisibilitySubscriberId);
  }


  Widget build(BuildContext context) {
    return BottomAppBar(
      child: TextField(),
    );
  }
}

[adee42]

OK, I will have a look

[CosmicPangolin]

@adee42 Check out that example. 'SCAFFOLD' never gets printed. From my testing so far, both KeyboardVisibilityNotification constructors run just fine, with _keyboardVisibilitySubscription assigned as 'Instance of _BroadcastSubscription'. However, onChange is never called for the Scaffold class.

Interestingly, this issue seems somehow linked to composition...two distinct classes within scaffold (BottomAppBar and some sliver) can have working KeyboardVisibilityNotifications.

[adee42]

If I see correctly, you have two listeners running at the same time. Only one of them (the latter) is triggered

[adee42]

OK, I found the bug and fixed it. The new version 0.5.1 is uploaded and ready to use.

@CosmicPangolin: You have a bug in your code, though. When you update the page, the TextField loses focus which closes the keyboard But given this is only an example, I believe you will get it fixed in the final application

[CosmicPangolin]

Yeaa see the fix, that makes sense. I was over here digging into Broadcast streams being like 'but whyyy wont it take multiple listeners'... :)

No doubt on the bug; the actual codebase is full of components and state management...hence the multiple listeners; I really didn't want to have to dispatch actions and juggle a state object for keyboard stuffs.

Thanks for the quick work, this was blocking me all morning!

[adee42]

@CosmicPangolin: Yes, in Flutter only one EventChannel receives the actual message from Android or iOS. That is why I had to use the internal list of listeners to allow multiple listeners. In my own code I used a 'global' variable, that is why I didn't encounter the same problem as you did.

I am happy I could help. Enjoy!

[adee42]

This issue has been open for some time without any updates, please re-open if you still experience it