FloatingActionButton Icon disappear after using hide() function

Question

So i have tab layout with 4 fragment inside it, i want my FAB change icon according to selected tab. But the problem is after using fab.hide()function the icon is disappear. this is what i get

here is my code:

private void fabSettings() {
    mTabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            int position = tab.getPosition();
            switch (position) {
                case 0:
                    mFab.hide();
                    break;
                case 1:
                    mFab.show();
                    mFab.setImageResource(R.drawable.ic_comment_white_24dp);
                    break;
                case 2:
                    mFab.show();
                    mFab.setImageResource(R.drawable.ic_camera_alt_white_24dp);
                    break;
                default:
                    mFab.show();
                    mFab.setImageResource(R.drawable.ic_phone_black_white_24dp);

            }

        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

I want when tab at index 0 selected the FAB is hidden.

Answer 1

Add three FloatingActionButton in your main activity like below:

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="@dimen/appbar_padding_top"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/AppTheme.PopupOverlay">

        </android.support.v7.widget.Toolbar>

        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

<android.support.design.widget.FloatingActionButton
        android:id="@+id/fabM"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|bottom"
        android:layout_margin="@dimen/fab_margin"
        android:src="@drawable/ic_fab_M" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fabChat"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|bottom"
        android:layout_margin="@dimen/fab_margin"
        android:src="@drawable/ic_fab_chat" />


    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fabPerson"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|bottom"
        android:layout_margin="@dimen/fab_margin"
        android:src="@drawable/ic_fab_person"
        android:visibility="gone" />

Now in your MainActivity.java use Fab's default functions to hide and show on each tab selection like below :

private void animateFab(int position) {
    switch (position) {
        case 0:
            fabChat.show();
            fabPerson.hide();
            break;
        case 1:
            fabPerson.show();
            fabChat.hide();
            break;
        case 2:
           fabM.show();
           fabPerson.hide();

        default:
            fabChat.show();
            fabPerson.hide();
            break;
    }
}

Call animateFab function as below:

TabLayout.OnTabSelectedListener onTabSelectedListener = new TabLayout.OnTabSelectedListener() {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        animateFab(tab.getPosition());
    }

    @Override
    public void onTabUnselected(TabLayout.Tab tab) {

    }

    @Override
    public void onTabReselected(TabLayout.Tab tab) {

    }
};

ViewPager.OnPageChangeListener onPageChangeListener = new ViewPager.OnPageChangeListener() {
    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {
        animateFab(position);
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
};