Android - The difference between layout_gravity and gravity

In short: layout_gravity moves the whole View, gravity moves the content inside the view.

The best way I can think to explain this concept is to show two different ways to center some content on the screen.

The first way uses the layout_gravity attribute:

<?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:orientation="vertical"

tools:context="com.example.android.courtcounter.MainActivity">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Team A"

android:layout_gravity="center"

android:layout_margin="10dp" />

</LinearLayout>

Android App screen showing a small TextView reading "Team A" in the middle of the screen.

The main things to note about this example is that the TextView has a line android:layout_width =“wrap_content”. This means that the box surrounding the text view (seen in blue on the screenshot) is tight to the content inside it. The line: android:layout_gravity=“center” is therefore moving the whole TextView into the center of the parent, LinearLayout.

The second way uses the gravity attribute:

<?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:orientation="vertical" tools:context="com.example.android.courtcounter.MainActivity">

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="Team A" android:gravity="center"

android:layout_margin="10dp" />

</LinearLayout>

A TextView filling the width of the screen with the words "Team A" centered in the middle of the TextView.

There have only been two changes to the code from the earlier example. Firstly, the TextView now has a line android:layout_width =“match_parent”. This means that the box surrounding the text view (seen in blue on the screenshot) is stretched across the whole screen. The line: android:gravity=“center” is therefore moving content of the TextView (i.e. “Team A”) into the center of its expanded view.