Related
I am quite new to app development and I had a few questions about Flutter I was hoping someone could help me with!
First, I am trying to code an intro-slide part in my code. I have found this code online (https://flutterawesome.com/simple-and-configurable-app-introduction-slider-for-flutter/) and when I tried executing it, using my own images, only the background color seems to print. When I remove the background colors, it is just a white screen. Is my pageImage part correct? I saved an assert folder everywhere, so I'm unsure if that is the problem. I have included my code at the end.
Thank you for your time!
class _MyHomePageState extends State<MyHomePage> {
List<Slide> slides = new List();
#override
void initState() {
super.initState();
slides.add(
new Slide(
title: "ERASER",
description: "Allow miles wound place the leave had. To sitting subject no improve studied limited",
pathImage: "assets/images/1.png",
backgroundColor: Colors.pink[200],
),
);
slides.add(
new Slide(
title: "PENCIL",
description: "Ye indulgence unreserved connection alteration appearance",
pathImage: "assets/images/1.png",
backgroundColor: Colors.blue[200],
),
);
slides.add(
new Slide(
title: "RULER",
description:
"Much evil soon high in hope do view. Out may few northward believing attempted. Yet timed being songs marry one defer men our. Although finished blessing do of",
pathImage: "assets/images/3.jpg",
),
);
}
void onDonePress() {
// TODO: go to next screen
}
void onSkipPress() {
// TODO: go to next screen
}
#override
Widget build(BuildContext context) {
return new IntroSlider(
slides: this.slides,
onDonePress: this.onDonePress,
onSkipPress: this.onSkipPress,
);
}
}
**Solution: edit assets in pubspec page
Edit:
On the left (the orange part) is how I want the blue image to appear: No scrolling and fills the whole page. However, I tried to make my image (on the right) fill the page by editing the width and height and I started having to scroll where there is the pink background below and above the image (I assume it is because it keeps having to center the image).
Is there any way to make my image my background so it is like the picture on the left? I understand the orange color background is the background color, but hopefully, by comparing the two it makes sense. Thank you!
I create new intro widget. Here is the code.
import 'package:flutter/material.dart';
class MyIntroView extends StatefulWidget {
final List<Widget> pages;
final VoidCallback onIntroCompleted;
const MyIntroView({
Key key,
#required this.pages,
#required this.onIntroCompleted,
}) : assert(pages != null),
assert(onIntroCompleted != null),
super(key: key);
#override
_MyIntroViewState createState() => _MyIntroViewState();
}
class _MyIntroViewState extends State<MyIntroView> {
PageController _pageController;
int _currentPage = 0;
#override
void initState() {
_pageController = PageController(
initialPage: _currentPage,
);
super.initState();
}
#override
void dispose() {
_pageController.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Stack(
children: <Widget>[
NotificationListener<ScrollEndNotification>(
onNotification: (x) {
setState(() {
_currentPage = _pageController.page.round();
});
return false;
},
child: PageView(
children: widget.pages,
controller: _pageController,
),
),
Align(
alignment: Alignment.bottomCenter,
child: _buildBottomButtons(),
),
],
);
}
bool get _isFinalPage => _currentPage == widget.pages.length - 1;
Widget _buildBottomButtons() {
return Padding(
padding: const EdgeInsets.all(8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Opacity(
opacity: _isFinalPage ? 0.0 : 1.0,
child: _buildButton("SKIP", _gotoLastPage),
),
_buildNavIndicator(),
_isFinalPage
? _buildButton("DONE", widget.onIntroCompleted)
: _buildButton("NEXT", _gotoNextPage),
],
),
);
}
Widget _buildButton(String title, VoidCallback callback) {
return FlatButton(
child: Text(
title,
style: TextStyle(color: Colors.white),
),
onPressed: callback,
);
}
void _gotoLastPage() {
_pageController.animateToPage(
widget.pages.length - 1,
duration: const Duration(milliseconds: 600),
curve: Curves.ease,
);
}
void _gotoNextPage() {
_pageController.nextPage(
duration: const Duration(milliseconds: 600),
curve: Curves.easeInOut,
);
}
Widget _buildNavIndicator() {
final indicatorList = <Widget>[];
for (int i = 0; i < widget.pages.length; i++)
indicatorList.add(_buildIndicator(i == _currentPage));
return Row(children: indicatorList);
}
Widget _buildIndicator(bool isActive) {
return Padding(
padding: const EdgeInsets.all(5.0),
child: DecoratedBox(
decoration: BoxDecoration(
shape: BoxShape.circle,
color: isActive ? Colors.white : Colors.white30,
),
child: SizedBox(width: 8, height: 8),
),
);
}
}
Usage:
import 'package:flutter/material.dart';
import 'package:flutter_app_test3/my_intro_view.dart';
Future<void> main() async {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MyIntroView(
pages: <Widget>[
Image.asset("assets/images/1.png", fit: BoxFit.cover),
Image.asset("assets/images/2.png", fit: BoxFit.cover),
Image.asset("assets/images/3.jpg", fit: BoxFit.cover),
],
onIntroCompleted: () {
print("Into is Completed");
//To the navigation stuff here
},
);
}
}
Ask me if you have any doubts in the comment
just try wrapping your Widget into Scaffold Widget and return
#override
Widget build(BuildContext context) {
return Scaffold(body:IntroSlider(
slides: this.slides,
onDonePress: this.onDonePress,
onSkipPress: this.onSkipPress,
));
}
I was facing the same issue and I fixed it by setting fit:Boxfit.fill for the image.
I have a screen which I pass data back to like so:
final myUpdatedObject = await Navigator.of(context).push(...);
setState({
object = myUpdatedObject;
});
Having checked with a simple print at all places in my widget body that my object is used, the new data is present after it is passed back by the Navigator and setState is called.
However, when the widget is rebuilt, even though the new data is apparently there, it is not reflected in the UI changes, it shows old data.
Is this some sort of caching in debug mode? Whats causing this issue?
The example below starts with a Map named textMessageMap with a message key that populates a Text Widget with 'Home'. Tap the FloatingActionButton and you'll navigate to SecondScreen. If you tap the 'Go back!' button in SecondScreen, the message key in textMessageMap will be updated to read 'Second Screen'. If you tap the back button on the Scaffold of SecondScreen, textMessageMap will be nulled out. Calling setState updates the UI appropriately. See if your implementation is different.
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
Map<String, String> textMessageMap = {'message': 'Home'};
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Text(
'${textMessageMap != null ? textMessageMap['message'] : 'map is null'}',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: new FloatingActionButton(
onPressed: () {
_launchSecondScreen();
},
child: new Icon(Icons.add),
),
);
}
_launchSecondScreen() async {
final value = await Navigator.push(
context,
MaterialPageRoute<Map<String, String>>(
builder: (BuildContext _) => SecondScreen()));
setState(() {
textMessageMap = value;
});
}
}
class SecondScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Second Screen"),
),
body: Center(
child: RaisedButton(
onPressed: () {
// Navigate back to the first screen by popping the current route
// off the stack. The text 'Second Screen' will replace 'Home'.
// If you hit the scaffold's back button, the return value will be
// null instead.
final map = {'message': 'Second Screen'};
Navigator.pop(context, map);
},
child: Text('Go back!'),
),
),
);
}
}
Is there any way to change the default animation when navigating to/from a page in Flutter?
You can use PageRouteBuilder.
The following example shows FadeTransition when you navigate to second screen.
Navigator.push(
context,
PageRouteBuilder(
pageBuilder: (_, __, ___) => Page2(),
transitionDuration: Duration(seconds: 2),
transitionsBuilder: (_, a, __, c) => FadeTransition(opacity: a, child: c),
),
);
If you're using go_router:
GoRoute(
path: '/page2',
pageBuilder: (_, state) {
return CustomTransitionPage(
key: state.pageKey,
child: Page2(),
transitionDuration: Duration(seconds: 2),
transitionsBuilder: (_, a, __, c) => FadeTransition(opacity: a, child: c),
);
},
)
and then:
context.go('/page2');
You can subclass MaterialPageRouteand override buildTransitions.
Eg:
class MyCustomRoute<T> extends MaterialPageRoute<T> {
MyCustomRoute({ WidgetBuilder builder, RouteSettings settings })
: super(builder: builder, settings: settings);
#override
Widget buildTransitions(BuildContext context,
Animation<double> animation,
Animation<double> secondaryAnimation,
Widget child) {
if (settings.isInitialRoute)
return child;
// Fades between routes. (If you don't want any animation,
// just return child.)
return new FadeTransition(opacity: animation, child: child);
}
}
to use :
new RaisedButton(
child: new Text('Goto'),
onPressed: (){
Navigator.push(
context,
new MyCustomRoute(builder: (context) => new SecondPage()),
);
}),
Replace fade transition with your animation
You can achieve this by using CupertinoPageRoute.
Please check the below code.
import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Transition Animation Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new FirstPage(),
);
}
}
class FirstPage extends StatefulWidget {
#override
_FirstPageState createState() => new _FirstPageState();
}
class _FirstPageState extends State<FirstPage> {
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('First Page'),
),
body: new Center(
child: new RaisedButton(
child: new Text('Goto Second Page'),
onPressed: () {
Navigator.of(context).push(new SecondPageRoute());
},
),
),
);
}
}
class SecondPageRoute extends CupertinoPageRoute {
SecondPageRoute()
: super(builder: (BuildContext context) => new SecondPage());
// OPTIONAL IF YOU WISH TO HAVE SOME EXTRA ANIMATION WHILE ROUTING
#override
Widget buildPage(BuildContext context, Animation<double> animation,
Animation<double> secondaryAnimation) {
return new FadeTransition(opacity: animation, child: new SecondPage());
}
}
class SecondPage extends StatefulWidget {
#override
_SecondPageState createState() => new _SecondPageState();
}
class _SecondPageState extends State<SecondPage> {
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Second Page'),
),
body: new Center(
child: new Text('This is the second page'),
),
);
}
}
Some play-around with animation
// OPTIONAL IF YOU WISH TO HAVE SOME EXTRA ANIMATION WHILE ROUTING
#override
Widget buildPage(BuildContext context, Animation<double> animation,
Animation<double> secondaryAnimation) {
return new RotationTransition(
turns: animation,
child: new ScaleTransition(
scale: animation,
child: new FadeTransition(
opacity: animation,
child: new SecondPage(),
),
));
}
I have done this by providing my own builders with custom map in pageTransitionsTheme for the app level theme.
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Startup Name Generator Tile',
home: RandomWords(),
theme: new ThemeData(
primaryColor: Colors.white,
// Add the line below to get horizontal sliding transitions for routes.
pageTransitionsTheme: PageTransitionsTheme(builders: {TargetPlatform.android: CupertinoPageTransitionsBuilder(),}),
),
);
}
}
Of course, I didn't add a map entry for ios as I use only android for TargetPlatform.
You can also check out page_transition package from https://pub.dev/packages/page_transition. This package contains the following different transitions.
fade,
rightToLeft,
leftToRight,
upToDown,
downToUp,
scale (with alignment),
rotate (with alignment),
size (with alignment),
rightToLeftWithFade,
leftToRightWithFade
the simplest way I figured, is to use MaterialPageRoute normally just add: fullscreenDialog: true, inside MaterialPageRoute()
I would like to have my list items perform this animation (mp4) when tapped. I tried using AnimatedCrossFade but it requires its two children to be at the same level, e.g. the detail view cross-fades with the ListView not the tapped item. In fact it seems a Hero animation is the only one that can animate across widgets.
I'm having trouble using Hero. Should it wrap the list item? Does it matter if the Widget subtree is significantly different in the Hero source/destination? Also, can Hero animations be used with LocalHistoryRoutes or staggered animations?
Edit
It's now looking like what I need to do is use an Overlay, the hard part there is that I need to add the selected item to the overlay at the same position on screen where it was tapped, then the animation part would be easy. Possibly of use here is a target/follower pattern e.g. CompositedTransformTarget
You can just use Hero widget to make that kind of animation. Here's my example:
and the source code:
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new FirstPage(title: 'Color Palette'),
);
}
}
class FirstPage extends StatefulWidget {
FirstPage({Key key, this.title}) : super(key: key);
final String title;
#override
_FirstPageState createState() => new _FirstPageState();
}
class _FirstPageState extends State<FirstPage> {
final palette = [
{'#E53935': 0xFFE53935},
{'#D81B60': 0xFFD81B60},
{'#8E24AA': 0xFF8E24AA},
{'#5E35B1': 0xFF5E35B1},
{'#3949AB': 0xFF3949AB},
{'#1E88E5': 0xFF1E88E5},
{'#039BE5': 0xFF039BE5},
{'#00ACC1': 0xFF00ACC1},
{'#00897B': 0xFF00897B},
{'#43A047': 0xFF43A047},
{'#7CB342': 0xFF7CB342},
{'#C0CA33': 0xFFC0CA33},
];
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new Container(
child: new ListView.builder(
itemCount: palette.length,
itemBuilder: (context, index) => new Hero(
tag: palette[index].keys.first,
child: new GestureDetector(
onTap: () {
Navigator
.of(context)
.push(new ColorPageRoute(palette[index]));
},
child: new Container(
height: 64.0,
width: double.infinity,
color: new Color(palette[index].values.first),
child: new Center(
child: new Hero(
tag: 'text-${palette[index].keys.first}',
child: new Text(
palette[index].keys.first,
style: Theme.of(context).textTheme.title.copyWith(
color: Colors.white,
),
),
),
),
),
),
)),
),
);
}
}
class SecondPage extends StatelessWidget {
final Map<String, int> color;
SecondPage({this.color});
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Color'),
),
body: new Hero(
tag: color.keys.first,
child: new Container(
color: new Color(color.values.first),
child: new Center(
child: new Hero(
tag: 'text-${color.keys.first}',
child: new Text(
color.keys.first,
style:
Theme.of(context).textTheme.title.copyWith(color: Colors.white),
),
),
),
),
),
);
}
}
class ColorPageRoute extends MaterialPageRoute {
ColorPageRoute(Map<String, int> color)
: super(
builder: (context) => new SecondPage(
color: color,
));
#override
Widget buildTransitions(BuildContext context, Animation<double> animation,
Animation<double> secondaryAnimation, Widget child) {
return FadeTransition(opacity: animation, child: child);
}
}
Someone wrote an amazing dart-package for just this purpose: https://pub.dev/packages/morpheus#-readme-tab-
All you then need to do is use the MorpheusPageRoute and the package handles the rest.
...
Navigator.push(
context,
MorpheusPageRoute(
builder: (context) => MyWidget(title: title),
),
);
...
I'd just cheat and wrap the whole thing in a Stack - bottom layer would be a page with the AppBar, and the top layer would be transparent until painted on.
onTap, duplicate ListTile onto the top surface, and then a Hero animation would fill the full screen. It's not very elegant, but the framework doesn't (yet) provide for covering the AppBar easily, so having a canvas ready to be painted on for other tricky animations might be resourceful.
I'm unable to comment or edit Lucas' post (new account) but you also need to provide the parentKey of the widget where the animation is to begin:
final widgetKey = GlobalKey();
...
ListTile(
key: widgetKey,
title: Text('My ListItem'),
onTap: () => Navigator.push(
context,
MorpheusPageRoute(
builder: (context) => MyNewPage(),
parentKey: widgetKey,
),
),
),
https://pub.dev/packages/morpheus
When long tab on Text widget, a tooltip show up with 'copy'. When click on the 'copy' the text content should copy to system clipboard.
The following will copy the text on long tap, but does not show up 'copy', so user will not know, the content is copied to the clipboard.
class CopyableText extends StatelessWidget {
final String data;
final TextStyle style;
final TextAlign textAlign;
final TextDirection textDirection;
final bool softWrap;
final TextOverflow overflow;
final double textScaleFactor;
final int maxLines;
CopyableText(
this.data, {
this.style,
this.textAlign,
this.textDirection,
this.softWrap,
this.overflow,
this.textScaleFactor,
this.maxLines,
});
#override
Widget build(BuildContext context) {
return new GestureDetector(
child: new Text(data,
style: style,
textAlign: textAlign,
textDirection: textDirection,
softWrap: softWrap,
overflow: overflow,
textScaleFactor: textScaleFactor,
maxLines: maxLines),
onLongPress: () {
Clipboard.setData(new ClipboardData(text: data));
},
);
}
}
Since Flutter 1.9 you can use
SelectableText("Lorem ipsum...")
When text is selected the "Copy" context button will appear.
You can use a SnackBar to notify the user about the copy.
Here is a relevant code:
String _copy = "Copy Me";
#override
Widget build(BuildContext context) {
final key = new GlobalKey<ScaffoldState>();
return new Scaffold(
key: key,
appBar: new AppBar(
title: new Text("Copy"),
centerTitle: true,
),
body:
new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new GestureDetector(
child: new Text(_copy),
onLongPress: () {
Clipboard.setData(new ClipboardData(text: _copy));
key.currentState.showSnackBar(
new SnackBar(content: new Text("Copied to Clipboard"),));
},
),
new TextField(
decoration: new InputDecoration(hintText: "Paste Here")),
]),
);
}
EDIT
I was working on something and I did the followin, so I thought of revisiting this answer:
import "package:flutter/material.dart";
import 'package:flutter/services.dart';
void main() {
runApp(new MaterialApp(home: new MyApp(),
));
}
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => new _MyAppState();
}
class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
String _copy = "Copy Me";
#override
Widget build(BuildContext context) {
final key = new GlobalKey<ScaffoldState>();
return new Scaffold(
key: key,
appBar: new AppBar(
title: new Text("Copy"),
centerTitle: true,
),
body:
new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new GestureDetector(
child: new CustomToolTip(text: "My Copyable Text"),
onTap: () {
},
),
new TextField(
decoration: new InputDecoration(hintText: "Paste Here")),
]),
);
}
}
class CustomToolTip extends StatelessWidget {
String text;
CustomToolTip({this.text});
#override
Widget build(BuildContext context) {
return new GestureDetector(
child: new Tooltip(preferBelow: false,
message: "Copy", child: new Text(text)),
onTap: () {
Clipboard.setData(new ClipboardData(text: text));
},
);
}
}
There is also list of properties it in SelectableText to enable option copy, paste, selectAll, cut
child: Center(
child: SelectableText('Hello Flutter Developer',
cursorColor: Colors.red,
showCursor: true,
toolbarOptions: ToolbarOptions(
copy: true,
selectAll: true,
cut: false,
paste: false
),
style: Theme.of(context).textTheme.body2)
),
SelectableText widget
const SelectableText(
this.data, {
Key key,
this.focusNode,
this.style,
this.strutStyle,
this.textAlign,
this.textDirection,
this.showCursor = false,
this.autofocus = false,
ToolbarOptions toolbarOptions,
this.maxLines,
this.cursorWidth = 2.0,
this.cursorRadius,
this.cursorColor,
this.dragStartBehavior = DragStartBehavior.start,
this.enableInteractiveSelection = true,
this.onTap,
this.scrollPhysics,
this.textWidthBasis,
})
SelectableText(
"Copy me",
onTap: () {
// you can show toast to the user, like "Copied"
},
)
If you want to have different styling for text, use
SelectableText.rich(
TextSpan(
children: [
TextSpan(text: "Copy me", style: TextStyle(color: Colors.red)),
TextSpan(text: " and leave me"),
],
),
)
I use Clipboard.setData inside function.
...
child: RaisedButton(
onPressed: (){
Clipboard.setData(ClipboardData(text: "$textcopy"));
},
disabledColor: Colors.blue[400],
child: Text("Copy", style: TextStyle(color: Colors.white),),
),
I created a helper class CopiableText to accomplish my job. Just copy the class from below and put it in your code.
Helper class
copiable_text_widget.dart
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
class CopiableText extends StatelessWidget {
final String text;
final String copyMessage;
final Widget child;
CopiableText(this.text, {this.copyMessage, this.child});
#override
Widget build(BuildContext context) {
return Container(
width: double.infinity,
child: InkWell(
onTap: () {
Scaffold.of(context).showSnackBar(SnackBar(
content: Text(this.copyMessage ?? 'Copied to clipboard'),
));
Clipboard.setData(new ClipboardData(text: this.text));
},
child: Align(
alignment: Alignment.centerLeft,
child: Padding(
padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 2),
child: this.child ??
Text(
this.text,
style: TextStyle(color: Color(0xFF1E272E), fontSize: 14),
),
),
),
),
);
}
}
Use it in different ways
import 'package:chaincargo_courier/ui/widgets/copiable_text_widget.dart';
import 'package:flutter/material.dart';
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Container(
child: Column(
children: [
// Just straightforward, click to copy
CopiableText('You are awesome'),
// Give a custom confirmation message
CopiableText(
'Asia, Nepal, Biratnagar',
copyMessage: 'Address copied to clipboard',
),
// Set custom child
CopiableText(
'Stunning view of mount everest',
copyMessage: 'Caption copied to clipboard',
child: Column(
children: [
Image.network(
'https://cdn.pixabay.com/photo/2010/11/29/mount-everest-413_960_720.jpg',
errorBuilder: (BuildContext context, Object exception,
StackTrace stackTrace) {
return Text('Cannot load picture');
},
),
Text('Stunning view of mount everest')
],
),
),
],
),
);
}
}
Just use SelectableText
SelectableText(
iosInfo.identifierForVendor.toString(),
),
Support Links and Copy&Paste
If you want to support both Links and Copy&Paste, use the SelectableLinkify widget.
This widget is part of the flutter_linkify package.
SelectableLinkify(
text: "Made by https://cretezy.com\n\nMail: example#gmail.com",
);