Does flutter calls child screen if we navigate back(using back button in app bar) from a child screen to parent screen?

Question

The application has the following screens,

1. Tab Screen (Main/Home Screen)
2. CategoriesScreen( 1st tab Screen)
3. Favorite Screen (2nd Tab screen)
4. CategoryMealsScreen(child Screen of CategoriesScreen)

I have added print statement for each screen Build method to check on the navigation,

When I navigate back from "CategoryMealsScreen" to "CategoriesScreen", I can see that "CategoryMealsScreen" is once again being called why is that so?

Logs :

I/flutter (30320): TabsScreen  ( parent screen )

I/flutter (30320): CategoriesScreen

I/flutter (30320): CategoryMealsScreen ( child screen, pressed back in this screen)

I/flutter (30320): CategoryMealsScreen ( child screen, once again it's being called after landing in CategoriesScreen)

I/flutter (30320): TabsScreen  ( parent screen )

I/flutter (30320): CategoriesScreen

I/flutter (30320): CategoryMealsScreen ( child screen)

I/flutter (30320): CategoryMealsScreen ( child screen, once again it's being called after landing in CategoriesScreen)

I/flutter (30320): TabsScreen ( parent screen )

I/flutter (30320): CategoriesScreen

I/flutter (30320): TabsScreen

I/flutter (30320): FavoritesScreen

I/flutter (30320): TabsScreen ( parent screen )

I/flutter (30320): CategoriesScreen 

I/flutter (30320): CategoryMealsScreen  ( child screen)

I/flutter (30320): CategoryMealsScreen ( i pressed back button in-app bar and navigated back to parent  screen but once again child screen was printed in logs )

Below is the code that pushes the CategoryMealsScreen from CategoriesScreen,

Navigator.of(ctx).pushNamed(
      CategoryMealsScreen.routeName,
      arguments: {
        'id': id,
        'title': title,
      },
    );

My expectation was "CategoryMealsScreen" would not be called again when I navigate back to "TabsScreen"

Thanks in Advance.

Answer 1

"Navigating back" in Flutter is done using navigation.pop(). This goes back one step in the navigation history. If you want to go back several steps, you can use this:

Navigator.of(context).popUntil((route) => route.isFirst);

This navigates back to the root of your widget tree (from your description I assume that this is what you want).

Widgets being rebuilt seems to be the intended behavior in flutter, see: https://github.com/flutter/flutter/issues/11655

Here are some thoughts about handling unwanted rebuilds: https://stackoverflow.com/a/52249579/2102328