Develop Reference

floating action button in linearlayout not showing

Hello I am trying to align a floating action button to the bottom right of the screen but its showing on the right top corner of the screen what can i do to make it to the bottom right?
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:theme="#style/AppTheme"
android:orientation="vertical"
tools:context=".MainActivity">
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/createRoomButton"
style="#style/Widget.MaterialComponents.FloatingActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|right"
android:layout_margin="16dp"
app:srcCompat="#drawable/ic_add_black_24dp"/>
<SearchView
android:id="#+id/searchInput"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:iconifiedByDefault="false"
android:queryHint="Search Rooms">
<requestFocus />
</SearchView>
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:id="#+id/pullToRefresh"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ListView
android:id="#+id/roomList"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</LinearLayout>

Have made the necessary changes for your UI and now it works perfectly:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:theme="#style/AppTheme"
android:orientation="vertical"
tools:context=".MainActivity">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/createRoomButton"
style="#style/Widget.MaterialComponents.FloatingActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="22dp"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
app:srcCompat="#drawable/ic_add_black_24dp"/>
<SearchView
android:id="#+id/searchInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:iconifiedByDefault="false"
android:layout_marginTop="50dp"
android:queryHint="Search Rooms">
<requestFocus />
</SearchView>
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:id="#+id/pullToRefresh"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ListView
android:id="#+id/roomList"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</RelativeLayout>
</LinearLayout>

Recyclerview cannot be scrolled?

I have this screen.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"/>
</RelativeLayout>
<Button
android:id="#+id/btn_sync"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:onClick="DoUpload"
android:text="Sync with server"
/>
</LinearLayout>
It looks like this (which is OK):
So I add more datas, now it looks like this:
The RecyclerView cannot be scrolled, and the button is hidden. How to fix this?

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
android:layout_weight="1"/>
<Button
android:id="#+id/btn_sync"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_gravity="center_horizontal"
android:onClick="DoUpload"
android:text="Sync with server"/>
</LinearLayout >
</LinearLayout>
just copy this code and use it will be working fine

I have edited the code for you this will solve the problem and button will be at the end of RecyclerView
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="5dp">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical" />
<Button
android:id="#+id/btn_sync"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/my_recycler_view"
android:layout_gravity="center_horizontal"
android:onClick="DoUpload"
android:text="Sync with server" />
</RelativeLayout>
</LinearLayout>

Try this,
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp">
<RelativeLayout
android:layout_above="#id/btn_sync"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"/>
</RelativeLayout>
<Button
android:id="#+id/btn_sync"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:onClick="DoUpload"
android:text="Sync with server"
android:layout_alignParentBottom="true"
/>
</RelativeLayout>

Try using constraint layout like below
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:padding="5dp">
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#id/btn_sync"
android:scrollbars="vertical" />
<Button
android:id="#+id/btn_sync"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:onClick="DoUpload"
android:text="Sync with server" />
</android.support.constraint.ConstraintLayout>
This layout should keep the button from hiding and recyclerview will scroll when more data items are added.

used nestedScrollView
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v4.widget.NestedScrollView
android:id="#+id/nestedScrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</LinearLayout>

Edittext and a button followed by recycler view

I have an empty Activity with RelativeLayout and RecyclerView
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:="match_parent"
android:layout_height="match_parent"
app:layout_behavilayout_widthor="#string/appbar_scrolling_view_behavior"
tools:showIn="#layout/activity_main"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
I need an EditText and a button to be added before RecyclerView.
I guess RecyclerView's padding height should be changed but not sure! Please help me

Try this out. Make your parent layout as Linear layout, your views will get stacked.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<EditText
android:id="#+id/editText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="textPersonName"
android:text="Name"
android:layout_toStartOf="#+id/button" />
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:layout_alignParentEnd="true"/>
</RelativeLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>

Change the LinearLayout to "Vertical" orientation
Use android:layout_weight Property.
Indicates how much of the extra space in the LinearLayout is allocated
to the view associated with these LayoutParams.
Example
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<EditText
android:id="#+id/et_ONE"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="1" />
<Button
android:id="#+id/button_ONE"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:text="Button"
android:layout_weight="1"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="3"/>
</LinearLayout>
You can try with
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavilayout_widthor="#string/appbar_scrolling_view_behavior"
tools:showIn="#layout/activity_main"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<EditText
android:id="#+id/et_ONE"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="1" />
<Button
android:id="#+id/button_ONE"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:text="Button"
android:layout_weight="1"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="3"/>
</LinearLayout>
</RelativeLayout>

is this you want?
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<EditText
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent" />

Try this
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="EditText"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>

Use a LinearLayout before RecyclerView and and provide them an ID(e.g. temp) and use RelativeLayout property layout_below with the RecyclerView, like this android:layout_below="#id/temp"(it will make sure that your RecyclerView will always below then LinearLayout), Now Add your Button and EditText into that LinearLayout (Make sure that LinearLayout should be wrap_content into height)
Use this code, Edit according to your requirement
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:="match_parent"
app:layout_behavilayout_widthor="#string/appbar_scrolling_view_behavior"
tools:showIn="#layout/activity_main"
tools:context=".MainActivity">
<LinearLayout
android:id="#+id/temp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal">
<EditText
android:id="#+id/editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:inputType="textPersonName"
android:text="Name" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/temp" />
</RelativeLayout>
Hope it help!!

ImageView inside Toolbar is not well positioned on tablets

Image
I have a Toolbar with an ImageView inside. My problem is that this image is not positioned at the center of my Toolbar on tablets(it works fine on mobile devices). What can I do? Gravity doesn't work and I can't use a relative layout. There is an image on top showing my problem.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:design="http://schemas.android.com/apk/res-auto"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="mfceo.project.matiasnagore.powerlist.MainActivity">
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="45dp"
android:id="#+id/mainToolbar"
android:background="#fafafa"
android:titleTextColor="#ffffff"
android:layout_gravity="top">
<ImageView
android:id="#+id/imagePowerlist"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/powerlist"
android:scaleType="centerInside"
android:paddingRight="8dp"
android:paddingTop="8dp"
android:paddingBottom="8dp"
android:paddingLeft="55dp" />
</android.support.v7.widget.Toolbar>
<View
android:layout_width="match_parent"
android:layout_height="2dp"
android:background="#drawable/shadow_top"/>
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#ffffff">
</FrameLayout>
<View
android:layout_width="match_parent"
android:layout_height="2dp"
android:background="#drawable/shadow"/>
<android.support.design.widget.BottomNavigationView
android:id="#+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="bottom"
design:menu="#menu/bottom_nav_items"
design:itemIconTint="#drawable/selector"
design:itemTextColor="#drawable/selector"
android:background="#FFFAFAFA" />
</LinearLayout>

You need to add android:layout_gravity="top|center_horizontal" into your ImageView and remove paddings:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:design="http://schemas.android.com/apk/res-auto"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="mfceo.project.matiasnagore.powerlist.MainActivity"><android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="45dp"
android:id="#+id/mainToolbar"
android:background="#fafafa"
android:titleTextColor="#ffffff"
android:layout_gravity="top">
<ImageView
android:id="#+id/imagePowerlist"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/powerlist"
android:scaleType="centerInside"
android:layout_gravity="top|center_horizontal"/>
</android.support.v7.widget.Toolbar>
<View
android:layout_width="match_parent"
android:layout_height="2dp"
android:background="#drawable/shadow_top"/>
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#ffffff">
</FrameLayout>
<View
android:layout_width="match_parent"
android:layout_height="2dp"
android:background="#drawable/shadow"/>
<android.support.design.widget.BottomNavigationView
android:id="#+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="bottom"
design:menu="#menu/bottom_nav_items"
design:itemIconTint="#drawable/selector"
design:itemTextColor="#drawable/selector"
android:background="#FFFAFAFA" /></LinearLayout>

Linear Layout does not fill the whole screen

Why the linear layout does not fill the whole screen?
As you can see I am using match parent in the linear layout.
If I delete the Scrollbar nothing changes. The button is not at the bottom of the screen.
main_activity.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/black"
tools:context="com.sarahp.demo.MainActivity">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout ----------> HERE
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="#+id/textview_demo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginBottom="32dp"
android:layout_marginTop="32dp"
android:text="#string/demo"
android:textSize="42dp"/>
<RelativeLayout
android:id="#+id/fragment_container_a"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<RelativeLayout
android:id="#+id/fragment_container_b"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_alignParentBottom="true"
android:background="#color/transparent"/>
</LinearLayout>
</ScrollView>
</RelativeLayout>
F A is the fragment part.

Give android:fillViewport="true" to your ScrollView.
Your xml will looks like below. Main_Activity.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="40dp"
android:text="Test Demo"
android:textStyle="bold"
android:gravity="center"/>
<RelativeLayout
android:id="#+id/fragment1"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.5"
android:background="#drawable/border_image">
<TextView
android:layout_width="match_parent"
android:layout_height="100dp"
android:gravity="center"
android:text="Test text Fragement1" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/fragment2"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.5"
>
<TextView
android:layout_width="match_parent"
android:layout_height="100dp"
android:gravity="center"
android:text="Test text Fragement2" />
</RelativeLayout>
</LinearLayout>
</ScrollView>
</RelativeLayout>

Remove the relative layout
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="#+id/textview_demo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginBottom="32dp"
android:layout_marginTop="32dp"
android:text="#string/demo"
android:textSize="42dp"/>
<RelativeLayout
android:id="#+id/fragment_container_a"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<RelativeLayout
android:id="#+id/fragment_container_b"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_alignParentBottom="true"
android:background="#color/transparent"/>
</LinearLayout>
</ScrollView>