CoordinatorLayout inside another CoordinatorLayout

Question

CorodinatorLayout inside another CoordinatorLayout such that scrolling the child-view should also scroll the Parent CoordinatorLayout.

I have a coordinatorLayout with ViewPager that contains different Fragment such that on Scroll will hide the tabLayout

I have another coordinatorLayout that has a viewPager. This fragment is inflated in ViewPager of parent fragment(parent Coordinator layout).

The problem is onScrolling the child fragment in childViewpager only reflects in coordinator layout of child fragment and not in the Parent coordinator layout that I need to do to hide the tablayout.

the structure is:

CoordinatorLayout(p) ->(tablayout(p) & ViewPager(p) -> CoordinatorLayout(c)  ->(tablayout(c) & ViewPAger(c) ->recyclerView(cc)))

p -> parent;

c -> child; cc -> child to child

How to make on scrolling recycler view will affect both coordinator layout so that the toolbar tablayout(p) will be get hides.

Answer 1

I know it's an old question. But I searched a long time to include an CoordinatorLayout in a fragment, which is in another CoordinatorLayout.

I modified the answer of dev.bmax a little bit to call both coordinator layouts and call the attached behaviors of both layouts.

So here is my solution.

@SuppressWarnings("unused")
public class NestedCoordinatorLayout extends CoordinatorLayout implements NestedScrollingChild {

    private NestedScrollingChildHelper mChildHelper;

    public NestedCoordinatorLayout(Context context) {
        super(context);
        mChildHelper = new NestedScrollingChildHelper(this);
        setNestedScrollingEnabled(true);
    }

    public NestedCoordinatorLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        mChildHelper = new NestedScrollingChildHelper(this);
        setNestedScrollingEnabled(true);
    }

    public NestedCoordinatorLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mChildHelper = new NestedScrollingChildHelper(this);
        setNestedScrollingEnabled(true);
    }

    @Override
    public boolean onStartNestedScroll(View child, View target, int     nestedScrollAxes) {
        /* Enable the scrolling behavior of our own children */
        boolean tHandled = super.onStartNestedScroll(child, target, nestedScrollAxes);
        /* Enable the scrolling behavior of the parent's other children  */
        return startNestedScroll(nestedScrollAxes) || tHandled;
    }

    @Override
    public void onStopNestedScroll(View target) {
        /* Disable the scrolling behavior of our own children */
        super.onStopNestedScroll(target);
        /* Disable the scrolling behavior of the parent's other children  */
        stopNestedScroll();
    }

    @Override
    public void onNestedPreScroll(View target, int dx, int dy, int[] consumed) {
        int[][] tConsumed = new int[2][2];
        super.onNestedPreScroll(target, dx, dy, tConsumed[0]);
        dispatchNestedPreScroll(dx, dy, tConsumed[1], null);
        consumed[0] = tConsumed[0][0] + tConsumed[1][0];
        consumed[1] = tConsumed[0][1] + tConsumed[1][1];
    }

    @Override
    public void onNestedScroll(View target, int dxConsumed, int dyConsumed,
                           int dxUnconsumed, int dyUnconsumed) {
        super.onNestedScroll(target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
        dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, null);
    }

    @Override
    public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
        boolean tHandled = super.onNestedPreFling(target, velocityX, velocityY);
        return dispatchNestedPreFling(velocityX, velocityY) || tHandled;
    }

    @Override
    public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
        boolean tHandled = super.onNestedFling(target, velocityX, velocityY, consumed);
        return dispatchNestedFling(velocityX, velocityY, consumed) || tHandled;
    }

    @Override
    public void setNestedScrollingEnabled(boolean enabled) {
        mChildHelper.setNestedScrollingEnabled(enabled);
    }

    @Override
    public boolean isNestedScrollingEnabled() {
        return mChildHelper.isNestedScrollingEnabled();
    }

    @Override
    public boolean startNestedScroll(int axes) {
        return mChildHelper.startNestedScroll(axes);
    }

    @Override
    public void stopNestedScroll() {
        mChildHelper.stopNestedScroll();
    }

    @Override
    public boolean hasNestedScrollingParent() {
        return mChildHelper.hasNestedScrollingParent();
    }

    @Override
    public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed,
                                    int dyUnconsumed, int[] offsetInWindow) {
        return mChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed,
                dyUnconsumed, offsetInWindow);
    }

    @Override
    public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {
        return mChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
    }

    @Override
    public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {
        return mChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
    }

    @Override
    public boolean dispatchNestedPreFling(float velocityX, float velocityY) {
        return mChildHelper.dispatchNestedPreFling(velocityX, velocityY);
    }
}