Half transparent screen on top of another full screen - flutter

I am trying to create a screen like below which will allow user to show few buttons on top of another screen . So basically it will be on top of another screen which can be seen from the half transparent screen of the top level screen. Not sure how to create it and which widget to use. Can someone please guide here. I am trying to do this using flutter to create android as well as ios app.


You are looking for the stack widget here, develop your first screen and another one which you want to put on top. Put both in stack widget so one can come on top of another one.
On the screen which should be on top, make the first half of it transparent (which can be attained in different ways, one of it would be to use a Card with elevation of 0).


The most accurate answer would be do use an an showModalBottomSheet which we expand from the button into the screen and will also color the screen darker. Example code could be following:
await showModalBottomSheet<void>(
isScrollControlled: true,
context: context,
backgroundColor: Colors.white,
builder: (BuildContext context) {
return Container(width: MediaQuery.of(context).size.width, height: 200);
},
)
With the current answer you would have to write the entire funtionality for it by yourself, which could be quite unnecessary when there is already a widget out there for exactly this case

Related

Flutter - Floating Button inside a popup widget overlaying the scroll

Im working on my first flutter app so i am still learning possible widgets and how they react in certain structures.
So far I was doing well but cant figure out one thing I want to do.
I want to get a floating button inside of my cupertinopopusurface widget like this.
My structure is similar, on the home screen I have a listview builder that builds my cards and when you press on each one it opens a cupertinopopupsurface.
Inside I also built a Single child scroll view structure for all my contant and its scrollable but I would to get a button that overlays it all and is in a fixed placed.
My structure currently is
CupertinoPopupSurface/
Container/
SingleChildScrollView/
Column/
Children/
Row/ (all rows now with content)
I cant get the button fixed somewhere in the structure but then it follows the scrolling its now fixed overlaying the contant.

You can use stack widget inside cupertinopopupsurface like this:
CupertinoPopupSurface(
child: Stack(
children:[
your SingleChildScrollView,
Positioned(left: 16, right: 16, bottom: 16,child: yourbutton),
]
)
)

Programmatically make modalBottomSheet dismissable in Flutter

I use showModalBottomSheet to render a bottom sheet with buttons (StatefulWidgetWithButtons). Once a button is pressed the state of the sheet changes and it gets re-rendered with different content.
I would like that depending on a certain state the sheet becomes not dismissable. I can achieve this using
showModalBottomSheet(
isDismissable: false
builder: (context) => StatefulWidgetWithButtons()
)
however what I want to achieve is that depending on a certain button pressed within StatefulWidgetWithButtons the isDismissable property changes to true (or false).
I don't know how to achieve this since I know I can change the StatefulWidgetWithButtons but that won't rebuild the bottom sheet.
I also don't want to close and show again the bottom sheet but change its dismissable behaviour while it is rendered

I was able to get this behaviour by wrapping the non-dismissible layout variant of the bottom sheet in a GestureDetector with vertical drag handler like so:
GestureDetector(
onVerticalDragUpdate: (_) {},
child: ...
This prevents the default modal bottom sheet drag handlers from taking action
If you want to learn more about this solution and how it works you can read about it here: https://stackoverflow.com/a/71622120/11676468
It definitely seems more like a workaround/hack but it looks like the only alternative is to implement a completely custom showModalBottomSheet from scratch

How to create a custom back press button?

I am new to flutter and curious if we can create a custom back press button, not the one in appbar.
Just like a normal button that takes back to previous screen.

Here's how you so that:
Create a raw material button
Add the on press method to decide which screen it goes to.
In you main.dart, under the routes method, import the screen you want to push the current screen back to and then call it something.
Inside your onPress() method, you can call Navigator.pushNamed(context, routeName).
Now you can customise this raw material button as much as you want. Here are some of the main properties you can set:
textStyle
fillColor
elevation
padding
constraints
shape
child
Now give a name to this custom button you have created by extracting it into a widget.
Call the widget inside your code! If you want it to be aligned at the top left, which is usually where you find it:
Align(
alignment: Alignment.topLeft,
child: CustomButton()
),
Enjoy! PS: If you need any help, feel free to ask me and I will assist you to my best abilities!

How to produce screenshot animation in flutter?

Somebody please suggest me the best package or any way to provide a screenshot taken effect in flutter. Please don't downvote.If I did anything wrong

One way to achieve the effect you are looking for is having your page in a Stack. One entry of the Stack will be your Scaffold page, and the other one will be a white Container that fills the screen space. Something like this in your page's build method:
#override
Widget build(BuildContext context) => Stack(
children: [
Container(color: Colors.white),
Scaffold(
// The rest of your page
),
],
);
Then, you can wrap your white Container in an AnimatedOpacity widget (check out this Flutter.dev article on how to animate fading widgets), and define an animation such that the white Container fades in and then fades out very quickly, achieving a flash-like effect. In the article I mentioned they also explain how to trigger such an animation programatically.

Mimic iOS 13 fullscreen dialog

I noticed that in iOS 13 full screen dialog has changed, introducing a new slide from bottom animation.
Here is an example
Is it possible to mimic this behaviour with flutter? iOS animation it's not a simple slide from bottom but involves also the background page.
Looking throught flutter documentation I found this class but, without any example I can't understand how to use it or if it's what I'm searching.
Thanks

Update: Based on another answer by #VadimKo, I now understand that the stacking effect might also be desired. The answer linked to a package modal_bottom_sheet based on which I have updated my example
If I'm understanding your question right, you want to show a full screen dialog that slides up from the bottom and has UI similar to the one showed in your picture.
CupertinoFullscreenDialogTransition is really just two SlideTransitions stacked up so it's nothing special.
You could achieve something close to the posted images by using showGeneralDialog
In that, you could show anything using the combination of pageBuilder and transitionBuilder. It's very flexible and can even be used to show full routes on top of current route.
If you use CupertinoFullscreenDialogTransition as the pageBuilder it should achieve your goal. It's not required to provide a transitionBuilder since it's being performed by the pageBuilder implicitly.
The following example tries to mimic requested UI by using CupertinoApp, CustomScrollView and CupertinoSliverNavigationBar for the content of the dialog
Update: A transitionBuilder similar to the one provided by modal_bottom_sheet can be used to add the stacking effect.
Important code from the DartPad example:
showGeneralDialog(
barrierDismissible: true,
barrierLabel: 'Settings',
barrierColor: Colors.black,
context: context,
/// This would be slow but good to understand how transitions are working
transitionDuration: const Duration(seconds: 1),
/// Optionally provide the [transitionBuilder] to get the stacking effect
/// as of iOS 13
transitionBuilder: (context, animation, secondaryAnimation, child) {
/// The following transition widget was inspired from `modal_bottom_sheet` package
/// Some modifications have been made to remove certain limitations,
/// See the full DartPad example or take a look at `modal_bottom_sheet`
return _CupertinoModalTransition(
animation: animation,
child: child,
/// This renders the current widget behind the modal
/// Notice the use of [this], it is to make sure correct context is used
behindChild: this.build(this.context),
);
},
pageBuilder: (context, animation, secondaryAnimation) {
/// This is the simplest use case for [CupertinoFullscreenDialogTransition]
/// This provides the slide up and slide down transition effects
return CupertinoFullscreenDialogTransition(
primaryRouteAnimation: animation,
secondaryRouteAnimation: secondaryAnimation,
/// Content of your dialog
child: Container(),
linearTransition: true,
);
},
);
DartPad Full example : https://dartpad.dev/57de88ce8d64dff9d3e6fe0627a8b654
Update: The DartPad example works just like modal_bottom_sheet but without any need to make changes to existing code such as the requirement to use MaterialWithModalsPageRoute or to wrap current/preview routes in CupertinoScaffold both of which are provided by the same package.
Preview:
See the GIF preview: https://i.imgur.com/mZ77M62.gifv
Note: There is already showCupertinoDialog provided by the flutter team but it doesn't provide as much flexibility. It can however be used for normal small dialog popups that don't usually take full screen space.

You can always build your own widgets, however in this case you can use an existing package: Modal bottom sheet
you can also check some more existing flutter issues here: enter link description here

You can use this package cupertino_fullscreen_modal
CupertinoFullscreenModal.of(context).showModal(Widget child, onClose (popValue) {});

You can also try another already existing package Cupertino Stackview
CupertinoStackView(
true, //_isPrimary
"Page I", //_navigation
Scaffold(...), //_child
Colors.black, //_backgroundColor
{Key key,
isDismissible : true,
radius : Radius.circular(10.0)})