CODEWITHSUNDEEP
androidandroid-layoutandroid-linearlayout
horta
horta

Reputation: 2352

How to center the content inside a linear layout?

I'm trying to center an ImageView inside a LinearLayout horizontally and vertically, but I just can't do it. The main reason why I'm not using a RelativeLayout for that is because I need the layout_weight (my Activity consists of four columns that should be equally divided, and also responsive to different screen widths, each column having an ImageView centered and unstretched).

Here is my xml so far:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000"
    android:baselineAligned="false"
    android:gravity="center"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Main" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_speak"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_speak" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_readtext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_readtext" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_edit"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_edit" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_config"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_config" />
    </LinearLayout>
</LinearLayout>

Upvotes: 212

Views: 300082

Answers (6)

Naetmul
Naetmul

Reputation: 15552

android:gravity handles the alignment of its children,

android:layout_gravity handles the alignment of itself within its parent.

So use one of these.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000"
    android:baselineAligned="false"
    android:gravity="center"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Main" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center" >

        <ImageView
            android:id="@+id/imageButton_speak"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_speak" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center" >

        <ImageView
            android:id="@+id/imageButton_readtext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_readtext" />
    </LinearLayout>

    ...
</LinearLayout>

(Every node except leaf nodes should have android:gravity="center".)

or

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000"
    android:baselineAligned="false"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Main" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_speak"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_speak" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_readtext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_readtext" />
    </LinearLayout>

    ...
</LinearLayout>

(Every node except the root node should have android:layout_gravity="center".)

Upvotes: 497

rahulrvp
rahulrvp

Reputation: 2126

If you are looking for an answer in java code,

LinearLayout linearLayout = new LinearLayout(context);
linearLayout.setGravity(Gravity.CENTER);
// add children

Upvotes: 5

ViTUu
ViTUu

Reputation: 1204

I tried solutions mentioned here but It didn't help me. I mind the solution is layout_width have to use wrap_content as value.

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:layout_weight="1" >

Upvotes: 13

Gibolt
Gibolt

Reputation: 47089

android:gravity can be used on a Layout to align its children.

android:layout_gravity can be used on any view to align itself in its parent.

NOTE: If self or children is not centering as expected, check if width/height is match_parent and change to something else

Upvotes: 3

Tarsem Singh
Tarsem Singh

Reputation: 14199

android:layout_gravity is used for the layout itself

Use android:gravity="center" for children of your LinearLayout

So your code should be:

<LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_weight="1" >

Upvotes: 50

pcodex
pcodex

Reputation: 1940

Here's some sample code. This worked for me.

<LinearLayout
    android:gravity="center"
    >
    <TextView
        android:layout_gravity="center"
        />
    <Button
        android:layout_gravity="center"
        />
</LinearLayout>

So you're designing the Linear Layout to place all its contents (TextView and Button) in its center, and then the TextView and Button are placed relative to the center of the Linear Layout.

Upvotes: 7

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