Difference between gravity and layout_gravity on A

Question

I know we can set the following values to the android:gravity and android:layout_gravity properties:

1. center
2. center_vertical
3. center_horizontal, etc.

But I am confused regarding both of these.

What is the difference between the usage of android:gravity and android:layout_gravity?

Answer 1

Inside - Outside

• gravity arranges the content inside the view.
• layout_gravity arranges the view's position outside of itself.

Sometimes it helps to see a picture, too. The green and blue are TextViews and the other two background colors are LinearLayouts.

Notes

• The layout_gravity does not work for views in a RelativeLayout. Use it for views in a LinearLayout or FrameLayout. See my supplemental answer for more details.
• The view's width (or height) has to be greater than its content. Otherwise gravity won't have any effect. Thus, wrap_content and gravity are meaningless together.
• The view's width (or height) has to be less than the parent. Otherwise layout_gravity won't have any effect. Thus, match_parent and layout_gravity are meaningless together.
• The layout_gravity=center looks the same as layout_gravity=center_horizontal here because they are in a vertical linear layout. You can't center vertically in this case, so layout_gravity=center only centers horizontally.
• This answer only dealt with setting gravity and layout_gravity on the views within a layout. To see what happens when you set the gravity of the of the parent layout itself, check out the supplemental answer that I referred to above. (Summary: gravity doesn't work well on a RelativeLayout but can be useful with a LinearLayout.)

So remember, layout_gravity arranges a view in its layout. Gravity arranges the content inside the view.

xml

Here is the xml for the above image for your reference:

<?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="0dp"
        android:layout_weight="1"
        android:background="#e3e2ad"
        android:orientation="vertical" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:textSize="24sp"
            android:text="gravity=" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:background="#bcf5b1"
            android:gravity="left"
            android:text="left" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:background="#aacaff"
            android:gravity="center_horizontal"
            android:text="center_horizontal" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:background="#bcf5b1"
            android:gravity="right"
            android:text="right" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:background="#aacaff"
            android:gravity="center"
            android:text="center" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="#d6c6cd"
        android:orientation="vertical" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:textSize="24sp"
            android:text="layout_gravity=" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:layout_gravity="left"
            android:background="#bcf5b1"
            android:text="left" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:layout_gravity="center_horizontal"
            android:background="#aacaff"
            android:text="center_horizontal" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:layout_gravity="right"
            android:background="#bcf5b1"
            android:text="right" />

        <TextView
            android:layout_width="200dp"
            android:layout_height="40dp"
            android:layout_gravity="center"
            android:background="#aacaff"
            android:text="center" />

    </LinearLayout>

</LinearLayout>

Related

• Difference between a View's Padding and Margin
• Match_parent vs wrap_content
• How to set both gravity and layout gravity of a LinearLayout programatically

Answer 2

The basic difference between the two is that-

android:gravity is used for child elements of the view.

android:layout_gravity is used for this element with respect to parent view.

Answer 3

android:gravity

is used to adjust for content of the view relative to its specify position (allocated area). android:gravity="left" would not do anything if layout_width is equal to the "wrap_content"

android:layout_gravity 

is used for view itself relative to the parent or layout file.

Answer 4

Their names should help you:

• android:gravity sets the gravity of the contents (i.e. it's subviews) of the View it's used on.
• android:layout_gravity sets the gravity of the View or Layout relative to its parent.

And an example is here.

Answer 5

Just thought I'd add my own explanation here - coming from a background on iOS, this is how I've internalized the two in iOS terms: "Layout Gravity" affects your position in the superview. "Gravity" affects the position of your subviews within you. Said another way, Layout Gravity positions you yourself while gravity positions your children.

Answer 6

gravity--Applies to its own view.

layout-gravity---Applies to view related to its parent.