I'm looking for a way to redirect gestures(touches) from one widget to another. The use case for this is that I need to show a transparent screen(bottom sheet) above another screen(map) using Navigator and redirect gestures from that transparent screen to the one below.
Unfortunately Navigator route absorbs all gestures at the root level, thus they cannot pass-through. I'm also unable to use IgnorePointer because there are interactive elements in the transparent screen.
Is there a way to do this?
p.s. I'm aware that OverlayEntry solves this, but I'm looking for a way to achieve this using Navigator
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I am building my own bottom sheet and want to synchronize closing the sheet with transitioning to the underlying page.
Animation of the page before popping is not an option for my use case.
I am using Navigator with a PageRouteBuilder to animate between pages.
Could someone provide me with a resource on how to achieve this?
Looking at the Flutter Hero Transition, it appears to move the tagged Widgets to an Overlay class that exists in all Navigator Widgets but sits above the main content in the stack.
If this is correct, it allows the Hero to widgets to still respond to the Route scope and its animators but exist above the actual route content. How is this actually done efficiently? Surely this involves taking an entire Widget and storing it in a state for the duration of the animation. That Widget still has to respond to intrinsic responses from its original position such as slivers responding to active scroll actions.
Recreating this could be done with state management but I wondered how the standard hero actually does this. It seems like Widgets are effectively duplicated and then conditionally rendered on the screen defaulting to the overlay during the route animation and swapping out the original widget with an Offstage or similar. Is this how it is done?
The reason for trying to understand it is the need to replicate this behaviour in situations where Navigator is not an effective use case for a transition taking place internally on a page. I built an accordion style navigator but still want a hero transition to take place on the AppBar / NavigationBar. I know that this could be done with Navigator but it doesn't suit the use case. I could also predefine the AppBar content for each internal navigator state of the accordion but that is a lot of additional code.
I've looked through many tutorials for the side nav drawer. I can create one that works fine to lead to different pages. However, when I travel to a page that's different from home, it only gives me the arrow icon to go back to home at the top left instead of keeping the button to bring me back to the side navbar. How can I prevent this?
I can't use the home page to navigate everywhere because it's just supposed to be a blank splash screen.
You can define your drawer in a separate widget file, that you can import everywhere you have a scafold.
I created a package for it because I was missing similar functionality. If you want a Flutter approach for this navigation check out: https://api.flutter.dev/flutter/material/NavigationRail-class.html
Or if you want to have a look at my package: https://pub.dev/packages/side_navigation
It's because you're moving to a new page/Scaffold (probably using Navigator.push()). So, the default button in the AppBar will be the back button.
You can either have the same Drawer in every Scaffold you navigate to, which is not recommended since you'll just keep pushing routes to the navigation stack.
Or, you can change pages within the Scaffold. Check the interactive examples in BottomNavigationBar and NavigationRail to get an idea of how to do it. Basically instead of calling Navigator.push() when a tile in Drawer is tapped, just update the selected index and call setState().
I'm trying to find a way to check the visibility of a Flutter widget when it's either off screen or when it's obscured by another, for example Drawer, Dialog or BottomSheet.
visibility_detector helps with checking whether it's on the screen or not but does not work with the second use case (known limitation).
Is there a lower lever api that I can use to check whether a widget is actually visible to the user?
My use case: I'm adding a widget to the Overlay when something external happens (similar to Tooltip but not on long press). If the user opens for example the Drawer, the widget will appear on top. I want to detect that the child is not visible and delay or cancel the action.
Do I understand your problem?
You have a widget you want to always be on top?
You want the user to interact with that widget first before doing other things?
Use design patterns to make coding easier, your users will thank you.
You can show a Dialog on-top of other widgets with the showGeneralDialog or showDialog functions. Because Dialogs are a design-pattern used in many apps, users will already know how to use them.
Define app behavior with explicit state.
It is too hard to derive app behavior from rendered UI, not all devices are the same size and shape. This means you should try to write a variable that describes your situation and then write the code you need to make that variable's value correct. It sounds like you want a variable like bool overlayIsShowing.
Motivation:
In case of internet connectivity loss I want to show a widget which informs the user on connectivity issues.
I want this widget to show when connectivity status changes, no matter which route is present right now.
The issue is that I can't find a way to overlay this "connectivity loss" widget on top of the main navigator (which comes with the materialApp) class.
What's the best way to implement it?
A similar question was asked here but the solution doesn't seems to be optimal...