android - collapsing toolbar and fragment layout not working together

Question

In my app I have two fragments and a MainActivity. The activity_main.xml contains a collapsing toolbar which works perfectly for me when the fragments are empty. In my first fra

Answer 1

<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/background_light"
    android:fitsSystemWindows="true">

    <androidx.core.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="#fcfcfc"
            android:gravity="center"
            android:orientation="vertical"
            android:padding="10dp">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Yogesh" />
        </LinearLayout>

    </androidx.core.widget.NestedScrollView>

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/main.appbar"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <com.google.android.material.appbar.CollapsingToolbarLayout
            android:id="@+id/main.collapsing"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleMarginEnd="64dp"
            app:expandedTitleMarginStart="48dp"
            app:layout_scrollFlags="scroll|exitUntilCollapsed">

            <ImageView
                android:id="@+id/main.backdrop"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:fitsSystemWindows="true"
                android:scaleType="centerCrop"
                android:src="@drawable/bg1"
                app:layout_collapseMode="parallax" />

            <androidx.appcompat.widget.Toolbar
                android:id="@+id/main.toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:visibility="gone"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:title="Test"

                />
        </com.google.android.material.appbar.CollapsingToolbarLayout>

    </com.google.android.material.appbar.AppBarLayout>

</androidx.coordinatorlayout.widget.CoordinatorLayout>

Use this code. And also you need to change color of tollbar which swutching fragment.

toolbar.setBackgroundColor(ContextCompat.getColor(getApplicationContext(), android.R.color.transparent));
                    mFragmentToSet = new HomeDashboardFragment();

Answer 2

You haven't mentioned where the fragments are attached - I assume within the NestedScrollView? If not, that's where they should go.

The problem is most likely the ListView within the fragment - unlike a RecyclerView, it does not implement NestedScrollingChild2 and ScrollingView, which are required for the collapsing toolbar functionality.

Replace the ListView with a RecyclerView and make sure the fragments are within the NestedScrollView that has app:layout_behavior="@string/appbar_scrolling_view_behavior" and it should work.