Hello readers, Welcome back to another article on flutter.
In this we will see how to hide or show the Floating action button in flutter app when the user scrolls the screen.
Sometimes it is required to hide the FAB button when user scrolls because it blocks the behind view of the screen.
So this is what we want to do today.
Creating Scroll View
First create a screen with any scrolling view like list view or grid view in it and a Floating action button.
Now to hide the fab on scroll we need to listen to the scrolling events of scroll view.
To listen to the scrolling events we need to give the scroll view a custom scroll controller.
Now we can listen to the scroll events of this list view by add callback to the scroll controller .
Creating Custom FAB
Now create a custom Floating action button which will hide/show automatically based on the scroll event. To do this first create a stateful widget and return FAB in the build method.
Now wrap this FAB inside visibility widget to hide or show the Fab.
Create a Boolean variable isVisible to control the visibility of the visibility widget.
Now in the constructor of this CustomFab widget add a parameter of Scroll Controller. So that we can listen scroll events in this widget.
In the initState method of this widget add a callback to this scroll controller.
Now add a condition that if user scroll down make isVisible to false and if user scrolls up name isVisible to true.
To do this we can use the controller.position.userScrollDirection property of controller. This will give the direction in which the user is scrolling(forward or reverse).
Using this we can add a if condition in callback to show / hide our FAB and update the UI by calling setState.
set the visible parameter of Visibility widget to isVisible.
Another Example
Using similar method we can also achieve something like this with extended Floating action button.
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