Flutter: Container + ListView scrollable - flutter

I have a page with container + listView. Now the listView is scrollable, but I would like the whole page to be scrollable. (so if the user scrolls, the container goes 'away')
Column(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
children: posts,
),
],
),
Is this possible, and how can it be achieved?
Thanks!

You can wrap the whole page with a SingleChildScrollView
here is an example:
SingleChildScrollView( // <- added
child: Column(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
shrinkWrap: true, // <- added
primary: false, // <- added
children: posts,
),
],
),
);
for more info about see this question

What if you don't use Column and use ListView.builder and
according to indexes you show the widget.
For example on 0 index you show the Container.
This way you don't have to use any different widget for scrolling
and as per your requirement the container will scroll with the list.
This way there is no chance that you will get any overflow error
like you were getting while using Column.
Plus point of ListView.builder is that your posts will be created lazily and that is efficient way of creating ListView in Flutter. No matter how many posts you have your UI will not lag.
This at first may look like a hack but according to your requirement that the container must also be able to get scrolled, this solution makes sense to me because Container can be considered as a first element of the list.
Let me know if it works for you or not.
Following is the working code for your reference:
#override
Widget build(BuildContext context) {
return ListView.builder(
itemCount: posts.length + 1, // +1 because you are showing one extra widget.
itemBuilder: (BuildContext context, int index) {
if (index == 0) {
return Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text(""));
}
int numberOfExtraWidget = 1; // here we have 1 ExtraWidget i.e Container.
index = index - numberOfExtraWidget; // index of actual post.
return posts[index];
},
);
}
I hope this works for you, in case of any doubt please comment.

There are multiple ways you can achieve what you want. The only problem is that if you have large number of posts, listview with children posts, as shrinkWrap is set to true, will take time to calculate its required height, for that it will have to populate all of its children.
First
ListView(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
physics: NeverScrollableScrollPhysics(),
primary: false,
shrinkWrap: true,
children: posts,
),
),
],
),
Second
SingleChildScrollView(
child: Column(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
physics: NeverScrollableScrollPhysics(),
shrinkWrap: true,
primary: false,
children: posts,
),
],
),
),

use SingleChildScrollView then Container with hard coded container height, then list view builder, that should fix your issue.

I tried the following:
SingleChildScrollView(
child: Container(
height: 1000,
width: 400,
child: ListView(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
children: posts,
),
],
),
),
),
This works, but I would like that the container has a dynamic height and width? Is that possible? Thanks!

Related

Flutter, Nesting scrollable (or list) views

Can anyone clarify for me what I have shown in the 'image' attached is achievable in flutter? if yes, how? explaining the image is a bit hard.
I am new to flutter and trying to nest some scrollable views inside each other.
at first I tried to achieve this by nesting simple scrollable row and columns inside each other but faced some errors and exceptions (unbound height and width).
I searched and found out it is better to use 'CustomScrollView' for nesting lists in each other. tried it but haven't achieved what I want yet.
Any help/hint on how to achieve this would be much appreciated.
Nested Scroll Views
This is definitely possible, and you could use an approach like below, which is inspired by another question on stack overflow. I recommend reading that for better clarification -- here.
Edit: Wrapping the Row widget in a SingleChildScrollView would make the entire page scrollable.
body: Row(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Expanded(
child: ListView.builder(
scrollDirection: Axis.vertical,
itemCount: X,
itemBuilder: (BuildContext context, int index) => ...
),
),
Expanded(
child: ListView.builder(
scrollDirection: Axis.vertical,
itemCount: Y,
itemBuilder: (BuildContext context, int index) => ...
),
),
],
);
If this doesn't help, I'd suggest finding flutter repositories of e.g. Netflix clones or other existing apps known to have scroll views inside a list view.
#bragi, thanks for the answer,
I followed what you suggested and after some trial and error, I finally got it working.
But in terms of efficiency and how the application will respond/render I am not sure if this was the best way to do it:
SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: Row(
// mainAxisSize: MainAxisSize.min,
children: [
makeColumn(),
makeColumn(),
makeColumn(),
makeColumn(),
makeColumn(),
],
),
),
Widget makeColumn() {
return Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
children: [
Container(
width: 150,
height: 150,
color: Colors.green,
),
SizedBox(
width: 150,
height: 500,
child: SingleChildScrollView(
scrollDirection: Axis.vertical,
child: Column(
children: [
Container(), ....
For some reason, the Expanded widget did not work so I had to wrap my second column with SizedBox!

How can i have multiple gridview inside singlechildscrollview?

I want to achieve UI like Windows File Explorer
windows file explorer
Build one list as start and inside it a list of items and the item contains a title and a list of items
The image you attached looks like it could be replicated with a ListView.builder returning an ExpansionTile containing a GridView.
SizedBox(
height: 40,
width: 300,
child: ListView.builder(
itemBuilder: (context, index) {
return ExpansionTile(
title: const Text('title'),
children: [
SizedBox(
height: 100,
width: 200,
child: GridView.count(
crossAxisCount: 3,
children: List.generate(
3,
(index) {
return SizedBox(
height: MediaQuery.of(context).size.height / 1.8,
child: const Icon(Icons.folder),
);
},
),
),
),
],
);
},
),
);
This builds several expansion tiles each containing 3 folder icons. You may consider adding a little bit more to your question as it is a little vague, but I hope this helps!

how to align listview items top left?

i am trying to align list view items at the top left, but it aligns them in the center. I tried this with another widget, it works fine, but with the listview, it doesn't.
here is my code
Container(
height: height * 30,
// color: Colors.grey[400],
alignment: Alignment.topLeft,
child: ListView.builder(
itemBuilder: (context, i) => ReviewItem(
review: book.reviews[i]['review'],
date: book.reviews[i]['date'],
),
itemCount: book.reviews.length,
),
),
this is the review item
Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
timeago.format(DateTime.parse(date)),
style: Theme.of(context).textTheme.headline4.copyWith(
fontSize: width * kFont12Ratio, color: Colors.grey[500]),
),
SizedBox(height: height * 0.5),
Text(review),
Divider(),
],
);
Thanks in advance
By default, ListView will automatically pad the list's scrollable extremities to avoid partial obstructions indicated by MediaQuery's padding. In other words, if you put a widget before the ListView, you should wrap the ListView with a MediaQuery.removePadding widget (with removeTop: true). Like so:
MediaQuery.removePadding(
context: context,
removeTop: true,
child: ListView.builder(...),
);
I achieved that by adding padding inside the listview builder
padding: EdgeInsets.only(top: 0),
You can use padding instead
Or use Stack with Position (top:0,left:0)
Or use Align( )

Flutter ListView - center items if not expanding beyond screen

I have a horizontal ListView and depending on the app state, there might be 1-2 items in the list or many.
Now, I want to have the items centered as long as there are only a few available and scrolling is not needed. So far my items always stick to the left side as you can see in the ListView with the lime background color. That one I wanted centered, even if 2 or 3 items are visible, but with more, it shall scroll and then start at the left side with listing the items.
return Container(
color: Colors.lime,
child: ListView(
shrinkWrap: true,
scrollDirection: Axis.horizontal,
children: listItems));
the items itself are this:
Widget getPersonCircleWidget(BuildContext context, Person p) {
return Container(
color: Colors.transparent, //yellow,
child: Padding(
padding: const EdgeInsets.fromLTRB(10, 0, 10, 0),
child: CircularProfileAvatar('',
child: Image(
fit: BoxFit.cover,
image:
UserPhotoManager.singleton.getUserProfilePhoto(p.userId)),
borderColor: colorCirclePhotoBorder,
borderWidth: 2,
elevation: 10,
radius: 40,
onTap: () {
....
}),
),
);
}
Any idea how to solve this?
Just wrap your ListView with Center widget.
Center(
child: ListView(
shrinkWrap: true,
scrollDirection: Axis.horizontal,
children: listItems.map<Widget>((a) => CircleAvatar(
child: Text(a))).toList(),
),
),
When ListView exceed available room on the screen it will automatically left aligned.
Try it on dartpad.

Flutter Fexible Widget doesn't resize when keyboard shows

So I am working on app which has a chat screen, So I finished with most of the functionality but I noticed that listView isn't resizing when the keyboard shows but the message input does move up.
As you can see Input does move up but not the ListView so I tried to move the ListViewto bottom when the keyboard shows up by moving it to bottom using ScrollController but it also didn't work
Here's my current implementation:
chat_view.dart
Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
child: Column(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
MessageListView(),
ChatInputToolbar(),
]
)
);
message_list_view.dart
Flexible(
child: ListView.builder(
controller: scrollController,
shrinkWrap: true,
reverse: false,
itemCount: messages.length,
itemBuilder: (context, i) {}
)
);
I think that you should wrap your container into SingleChildScrollView, maybe that will help you. I would write something like this:
return SingleChildScrollView(
child: Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
child: Column(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
MessageListView(),
ChatInputToolbar(),
]
),)
);
Use Scaffold widget at the start of your widget tree, it solved my problem
In your Scaffold, set resizeToAvoidBottomPadding property to false then try:
resizeToAvoidBottomInset : false,