Collapsible NavigationBar on scrolling inside a TabBar

Continuing from https://github.com/grahammendick/navigation/issues/339#issuecomment-570185443.

Relevant questions:

For a bare-basic support, from what i understood, two new container views will need to be introduced. The overall CoordinatorLayout view that wraps everything and the new CollapsingToolbarLayout view that will have the existing Toolbar as a direct last-child descendent.

So will that mean that the NavigationBar class will now have to extend CoordinatorLayout and not AppBarLayout? And then use the addView method to add the required hierarchy?

public class NavigationBarView extends CoordinatorLayout {
    private IconResolver iconResolver;
    Toolbar toolbar;
    AppBarLayout appBarLayout;
    CollapsingToolbarLayout collapsingToolbarLayout;

.....

public NavigationBarView(Context context) {
        super(context);

        toolbar = new Toolbar(context);
        appBarLayout = new AppBarLayout(context);
        collapsingToolbarLayout = new CollapsingToolbarLayout(context);
        addView(appBarLayout, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        addView(collapsingToolbarLayout, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        addView(toolbar, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
 ......

Please let me know if my thinking is correct

[grahammendick]

I hope you don’t give up on this because it would be a great addition to the Navigation router. But it does need a lot more research so I’m happy to close this while you concentrate your efforts elsewhere. Thanks again for all your hard work

[grahammendick]

Ok, you do some more research and I’ll give it a go too. Don’t worry, we’ll get there!