Is there any way to include a Floating Action Button in a screen consisting of a CustomScrollView with a SliverAppBar and a SliverList?
I want to be able to have the default behaviour of a sliver list with a FAB fixed on the screen.
Is it possible?
You can still use the Scaffold when you're using the SliverAppBar such as:
new Scaffold(
body: new CustomScrollView(
slivers: <Widget>[
new SliverAppBar(...),
...
],
),
floatingActionButton: new FloatingActionButton(...),
);
Otherwise, you can generally use a Stack above the CustomScrollView and the FloatingActionButton (in a Positioned) as well.
Related
I'm not sure how I should structure my pages when using a BottomNavBar.
Right now, I use a MainScreen which contains a Scaffold and BottomNavBar
The MainScreen widget contains a list with the different pages. Is this the recommended way to use the bottomNavBar? I know I could also use the Navigator to navigate between the screens, but then it launches a different window for each page, which isn't what you expect when using a bottomNavBar. The way I implemented it now works fine, but how could I use a FloatingActionButton in the one of the screens? Do you always need a Scaffold for that?
List<Widget> screens = [
Screen1(),
Screen2(),
Screen3()
];
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(Constants.APP_NAME),
),
body: screens[_currentIndex],
bottomNavigationBar: CustomBottomNav(onBottomNavPressed: onBottomNavPressed,),
);
}
According to the official BottomNavigationBar class documentation, providing widgets as a <Widget>[ ]is the recommended way to provide widgets. And for the second part of your question, yes. a FloatingActionButton can only be included inside a Scaffold, so you should add one in the widget where you need to use the FloatingActionButton.
I made a Chat app, I made two Text widgets inside a Column widget, now I want to make the Chat message (the 2nd text Widget) Text Widget to go Vertically after filling the spaces horizontally, so what can I do, this is the image of the Chat screen
and What happens is this(image), the images are embedded because I'm a new user
The Code of it is this:-
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
/// USER NAME
Text(userName, style: Theme.of(context).textTheme.subtitle),
/// CHAT MESSAGE
Container(
margin: const EdgeInsets.only(top: 5.0),
child: Text(
theText,
maxLines: null,
style: Theme.of(context).textTheme.body2,
),
),
],
),
I expected the Code to work like the traditional Chat app's messages, the First text widget (USERNAME) worked but the 2nd one (the actual CHAT MESSAGE) didn't work as it Overflows by pixels, So how can I fix this and Make it like the traditional Chat Messages??
I resolved the problem! And here it is:
I just wrapped my whole Column widget with a Flexible widget and it resolved my problem and now I can add Multiline Messages!
I'm keeping the post as to any Newbie facing the same problem 'may' find this useful...
I've started developing in Flutter with webview, charts, tables, but I met some problems with tables.
I use DataTable to represent data in a table.
There is a first problem. By default, it isn't scrollable if data is out of a screen. So I embedded in some Widgets (i.e. SingleChildScrollView, ListView), but it was scrollable only in one direction (vertical or horizontal). I searched something about it and I found a plugin for both directions (bidirectional_scroll_view 0.0.6). After compilation I received an error
Because app depends on bidirectional_scroll_view >=0.0.2 which
requires SDK version <2.1.0, version solving failed.
I'm using Dart SDK version: >=2.1.0 <3.0.0 in configuration.
Next, I found PaginatedDataTable which allows scrollable in both directions, but it is paginated table.
So anybody know is it possible to somehow scroll DataTable in both directions (vertical and horizontal)?
The second question (more important): is it possible to set background colour in header (first) row and first column in a table? Or even in any cell in a table?
For DataColumn/DataCell I tried embed Text in Container and then set Container colour, but the background colour was only set for text, the rest of a cell was with default colour.
i.e.
DataColumn(label: Container(child: Text('2011'), color: Colors.grey,)),
And is it possible to fixed/freeze header (first) row and first column. I mean the table is scrolled and first row/column is always visible on a screen. I couldn't find any solution ..
Expanded(
child: ListView(
children: <Widget>[
SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: DataTable()
)
]
),
)
child: Center(
child: ListView(
children: [
DataTable()
],
scrollDirection: Axis.vertical,
)
)
I am using following in my build() method of 1st screen to change status bar color and it works fine.
// 1st screen's build() method
SystemChrome.setSystemUIOverlayStyle(
SystemUiOverlayStyle(statusBarColor: Colors.green),
);
However when I navigate to 2nd screen the 1st screen status bar color appears on the 2nd screen too. And in 2nd screen's build() method, I am using the same code with different color
// 2nd screen's build() method
SystemChrome.setSystemUIOverlayStyle(
SystemUiOverlayStyle(statusBarColor: Colors.red),
);
I had a similar problem and found the solution. The best way is to use AnnotatedRegion under Scaffold without AppBar (appBar is null) instead of the function SystemChrome.setSystemUIOverlayStyle() to set the system ui color.
Something like:
Scaffold(
body: AnnotatedRegion(
value: SystemUiOverlayStyle(statusBarColor: Colors.red)
child: MyBodyWidget(),
),
);
Btw, the value can be SystemUiOverlayStyle.dark or SystemUiOverlayStyle.light if you only want dark or light overlay instead of a color. Note that statusBarColor only works in Android so far.
Also note that appBar has to be null (absent) for AnnotatedRegion to work. You can write your own MyAppBar widget easily inside MyBodyWidget.
Try setting the 2nd status bar color before doing the Navigator.push to the second screen. Like this
SystemChrome.setSystemUIOverlayStyle(
SystemUiOverlayStyle(statusBarColor: Colors.red),
);
await Navigator.of(context).push(MaterialPageRoute(
builder: (context) => SecondScreen();
));
From Flutter Docs
Call this API in code whose lifecycle matches that of the desired system UI styles. For instance, to change the system UI style on a new page, consider calling when pushing/popping a new PageRoute.
It has a simple solution.
It is one way of several method.(AnnotatedRegion)
First, top parent page buildcontext in Saffold
SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle(
statusBarColor: Colors.transparent, <---- transparent.
and 2nd page of 3rd page ...
if Appbar : Appbar( backgroundcolor: Colors.red <---- want color.
if no Appbar : Scaffold( backgroundcolor: Colors.red <---- want color.
This way, if you do a navigation pop, Page status color return the background color of Appbar or the background color of the scaffold.
It's my shortcut and I hope it helps.
Is it possible to have a ripple rendered over the whole surface of a Card?
InkWell with a child Card renders the ripple behind the Card; Card itself doesn't have an onTap handler...
So, how to get that ripple?
Put the InkWell inside the Card.
Put this simple code
Card(
child: InkWell(
onTap: () {},
),