Develop Reference

how create a RIVE animation with flutter

I want to create a RIVE animation with flutter. I followed a tutorial in YouTube. I wrote the same thing but when I execute two errors is displayed
(RiveFile.import (data);
file.mainArtboard;)
Here is the code:
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:rive/rive.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
home: MyPage(),
);
}
}
class MyPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Using Rive'),
),
body: RocketContainer());
}
}
class RocketContainer extends StatefulWidget {
#override
_RocketContainerState createState() => _RocketContainerState();
}
class _RocketContainerState extends State<RocketContainer> {
Artboard _artboard;
RiveAnimationController _rocketController;
#override
void initState() {
_loadRiveFile();
super.initState();
}
void _loadRiveFile() async {
final bytes = await rootBundle.load('assets/rocket.riv');
final file = RiveFile.import(bytes);
setState(() {
_artboard = file.mainArtboard;
});
}
void _launch() async {
_artboard.addController(
_rocketController = SimpleAnimation('launch'),
);
setState(() => _rocketController.isActive = true);
}
void _fall() async {
_artboard.addController(
_rocketController = SimpleAnimation('fall'),
);
setState(() => _rocketController.isActive = true);
}
#override
Widget build(BuildContext context) {
return Column(
children: [
Container(
width: MediaQuery.of(context).size.width,
height: MediaQuery.of(context).size.height - 250,
child: _artboard != null
? Rive(
artboard: _artboard,
fit: BoxFit.cover,
)
: Container()),
TextButton(onPressed: () => _launch(), child: Text('launch')),
TextButton(onPressed: () => _fall(), child: Text('fall'))
],
);
}
}
errors:
The current Dart SDK version is 2.10.5.
Because animation depends on cupertino_icons >=1.0.1 which requires SDK version >=2.12.0-0 <3.0.0, version solving failed.
pub get failed (1; Because animation depends on cupertino_icons >=1.0.1 which requires SDK version >=2.12.0-0 <3.0.0, version solving failed.)
*error: Instance member 'import' can't be accessed using static access. (static_access_to_instance_member at [animation] lib\main.dart:47)
*error: The getter 'mainArtboard' isn't defined for the type 'bool'. (undefined_getter at [animation] lib\main.dart:50)

You could have a look at the example provided with the updated and latest documentation of Rive in their official Github repository.
Control playing and pausing a looping animation:
import 'package:flutter/material.dart';
import 'package:rive/rive.dart';
class PlayPauseAnimation extends StatefulWidget {
const PlayPauseAnimation({Key? key}) : super(key: key);
#override
_PlayPauseAnimationState createState() => _PlayPauseAnimationState();
}
class _PlayPauseAnimationState extends State<PlayPauseAnimation> {
// Controller for playback
late RiveAnimationController _controller;
// Toggles between play and pause animation states
void _togglePlay() =>
setState(() => _controller.isActive = !_controller.isActive);
/// Tracks if the animation is playing by whether controller is running
bool get isPlaying => _controller.isActive;
#override
void initState() {
super.initState();
_controller = SimpleAnimation('idle');
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: RiveAnimation.network(
'https://cdn.rive.app/animations/vehicles.riv',
controllers: [_controller],
// Update the play state when the widget's initialized
onInit: () => setState(() {}),
),
),
floatingActionButton: FloatingActionButton(
onPressed: _togglePlay,
tooltip: isPlaying ? 'Pause' : 'Play',
child: Icon(
isPlaying ? Icons.pause : Icons.play_arrow,
),
),
);
}
}
To play an animation from an asset bundle, use:
RiveAnimation.asset('assets/vehicles.riv'
in place of
RiveAnimation.network('https://cdn.rive.app/animations/vehicles.riv',
This line:
_controller = SimpleAnimation('idle');
attempts to play an animation called 'idle'. If your animation is named differently, try replacing the name here.

Methods are not getting executed in the written order inside onPressed

Im trying to create a flutter app with a simple raised button that does the following:
sends an sms in the background using the sms package opens a webpage
2. in the app(only for 5 seconds) using url_launcher opens the phones
3. native app for making a voice call with the onPressed property.
And I wanted it to be in this order so that I can make the phone call at the end. However, the inside the onPressed opens the native phone call app first, which doesnt let my web page open unless I exit out of the phone call app.
Im having a hard time understanding why the phone call native app is opened first, even though I make the call the _makePhoneCall() method only after I make the _launchInApp(toLaunch) call. sendSMS() is being called correctly
How can I set this in a way that the phone call native app is called only after the webpage is opened in the app and follows the order? Any help would be great
Below is the piece of code:
import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:sms/sms.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Packages testing',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Packages testing'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
String _phone = '';
_launchInApp(String url) async {
if (await canLaunch(url)) {
await launch(
url,
forceSafariVC: true,
forceWebView: true,
headers: <String, String>{'my_header_key': 'my_header_value'},
);
} else {
throw 'Could not launch $url';
}
}
_makePhoneCall(String url) async {
if (await canLaunch(url)) {
await launch(url);
} else {
throw 'Could not launch $url';
}
}
void sendSMS() {
SmsSender sender = new SmsSender();
sender.sendSms(new SmsMessage(_phone, 'Testing Handset'));
}
#override
Widget build(BuildContext context) {
const String toLaunch = 'https://flutter.dev/';
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: ListView(
children: <Widget>[
Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(16.0),
child: TextField(
onChanged: (String text) => _phone = text,
decoration:
const InputDecoration(hintText: 'Phone Number')),
),
FlatButton(
onPressed: () => setState(() {
sendSMS();
_launchInApp(toLaunch);
_makePhoneCall('tel:$_phone');
}),
child: const Text('Run All'),
),
const Padding(padding: EdgeInsets.all(16.0)),
],
),
],
),
);
}
}

You will have to use the await keyword before the _launchInApp function to make it work properly. Try the following code.
FlatButton(
onPressed: () aync {
sendSMS();
await _launchInApp(toLaunch);
_makePhoneCall('tel:$_phone');
}),
child: const Text('Run All'),
),

You created async functions but when you called them you did not specify that you want to wait for them to complete. Add the await keyword in OnPressed

How to open PPTs, PDFs, docs, etc. using default applicaitions by tapping on a button in a Flutter app?

I am trying to make an app which opens up a PPT, PDF or Docx file using the default application on the device by tapping on a button in my application. If there is no default app, it should open the "Open With" menu.
I tried to use open_file. But it didn't work. I also tried a few other methods I saw on StackOverflow, but none of them worked for me.

To open file on Internet you can use package https://pub.dev/packages/url_launcher
code snippet for url_launcher
import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';
void main() {
runApp(Scaffold(
body: Center(
child: RaisedButton(
onPressed: _launchURL,
child: Text('Open File'),
),
),
));
}
_launchURL() async {
const url = 'https://yoursite/sample.pdf';
if (await canLaunch(url)) {
await launch(url);
} else {
throw 'Could not launch $url';
}
}
To open file in local path
You can see working demo and full code below
code snippet
final filePath = '/sdcard/Download/sample.pdf';
print('${filePath}');
final message = await OpenFile.open(filePath);
full code
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:open_file/open_file.dart';
void main() => runApp(new MyApp());
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => new _MyAppState();
}
class _MyAppState extends State<MyApp> {
String _openResult = 'Unknown';
Future<void> openFile() async {
final filePath = '/sdcard/Download/sample.pdf';
print('${filePath}');
final message = await OpenFile.open(filePath);
setState(() {
_openResult = message;
});
}
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new Scaffold(
appBar: new AppBar(
title: const Text('Plugin example app'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('open result: $_openResult\n'),
FlatButton(
child: Text('Tap to open file'),
onPressed: openFile,
),
],
),
),
),
);
}
}
Emulator SDCard Download directory has a pdf file
working demo

How to use barcode_scan widget as a child to some other widget?

I am using barcode_scan widget in my flutter app when I call Scan method this widget takes up the whole screen where it show the camera, I want to show that camera view inside another widget.

You can use package https://pub.dev/packages/last_qr_scanner or https://pub.dev/packages/qr_code_scanner
They both use platform view within Flutter
full example code of last_qr_scanner
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:last_qr_scanner/last_qr_scanner.dart';
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
const MyApp({
Key key,
}) : super(key: key);
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');
var qrText = "";
var controller;
#override
void initState() {
super.initState();
}
void _onQRViewCreated(QRViewController controller) {
this.controller = controller;
final channel = controller.channel;
controller.init(qrKey);
channel.setMethodCallHandler((MethodCall call) async {
switch (call.method) {
case "onRecognizeQR":
dynamic arguments = call.arguments;
setState(() {
qrText = arguments.toString();
});
}
});
}
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new Scaffold(
appBar: new AppBar(
title: new Text('Barcode Scanner Example'),
),
body: Column(
children: <Widget>[
Expanded(
child: LastQrScannerPreview(
key: qrKey,
onQRViewCreated: _onQRViewCreated,
),
flex: 4,
),
Expanded(
child: Text("This is the result of scan: $qrText"),
flex: 1,
),
Expanded(
child: RaisedButton(
onPressed: () {
this.controller.toggleTorch();
},
child: Text("Toggle Torch"),
),
flex: 1,
)
],
),
),
);
}
}

Your camera view must be a flutter widget to be embedded in another widget.
You can use this package which outputs the camera preview on a flutter texture and use the Mobile Vision API to detect QR codes and barcodes : https://github.com/rmtmckenzie/flutter_qr_mobile_vision

Does Flutter recycle images in a ListView?

I would like to make an endlessFeed in Fluter but the app terminates without giving me any information why. Basically it happens after I scrolled down about 60 images then it starts to lag a bit and it crashes.
I tested another API but the same there. It uses images with lower resolution so it takes longer to scroll down until it stops working.
So I don't know what happens here. My guess is that there are to many images in the ListView so that the phone can't handle it and crashes.
I've put the whole code below because I don't even know wehere the problem could be. Is there maybe another way to achieve an endlessImageFeed?
import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:cached_network_image/cached_network_image.dart';
// my base url
String imageUrl = "http://192.168.2.107:8000";
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'EndlessFeed',
theme: ThemeData(
primaryColor: Colors.white,
),
home: PhotoList(),
);
}
}
class PhotoList extends StatefulWidget {
#override
PhotoListState createState() => PhotoListState();
}
class PhotoListState extends State<PhotoList> {
StreamController<Photo> streamController;
List<Photo> list = [];
#override
void initState() {
super.initState();
streamController = StreamController.broadcast();
streamController.stream.listen((p) => setState(() => list.add(p)));
load(streamController);
}
load(StreamController<Photo> sc) async {
// URL for API
String url = "http://192.168.2.107:8000/api/";
/* ______________________________________________
I also tried another API but it chrashes also (but it takes longer until crash):
String url = "https://jsonplaceholder.typicode.com/photos/";
______________________________________________ */
var client = new http.Client();
var req = new http.Request('get', Uri.parse(url));
var streamedRes = await client.send(req);
streamedRes.stream
.transform(UTF8.decoder)
.transform(json.decoder)
.expand((e) => e)
.map((map) => Photo.fromJsonMap(map))
.pipe(sc);
}
#override
void dispose() {
super.dispose();
streamController?.close();
streamController = null;
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("EndlessFeed"),
),
body: Center(
child: ListView.builder(
itemBuilder: (BuildContext context, int index) => _makeElement(index),
),
),
);
}
Widget _makeElement(int index) {
if (index >= list.length) {
return null;
}
return Container(
child: Padding(
padding: EdgeInsets.only(top: 20.0),
child: Column(
children: <Widget>[
child: new Container(
// my base URL + one image
child: new Image(image: new CachedNetworkImageProvider(imageUrl + list[index].mImage))
),
),
],
),
));
}
}
class Photo {
final String mImage;
Photo.fromJsonMap(Map map)
: mImage= map['mImage'];
}