CODEWITHSUNDEEP
androidandroid-layouttextview
Amrmsmb
Amrmsmb

Reputation: 1

how to center a view inside its parent using layout_gravity attribute

would you please let me know why using 

android:layout_gravity="center_horizontal|center_vertical"

does not center the textView in the middle of the LinearLayout?

i know that i can center the TextView inside its parent if i chnaged the TextView parameters to be as follows:

<TextView
        android:id="@+id/tv1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_horizontal|center_vertical"
        android:text="text_1"></TextView>

but what i am trying to do is, to center the TextView inside its parent using "android:layout_gravity"

code:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
android:weightSum="3"
tools:context="com.example.bestandlayout_00.ActMain">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1">

    <TextView
        android:id="@+id/tv1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal|center_vertical"
        android:text="text_1"></TextView>
</LinearLayout>

</LinearLayout>

Upvotes: 2

Views: 519

Answers (3)

Charuka Silva
Charuka Silva

Reputation: 13153

Understand that using this example

android:layout_gravity

  • android:layout_gravity is used to set the position of an element in its parent (e.g. a child View inside a Layout).
  • Supported by LinearLayout and FrameLayout

android:gravity

  • android:gravity is used to set the position of content inside an element (e.g. a text inside a TextView).
<?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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="vertical"
        android:layout_gravity="left"
        android:gravity="center_vertical">

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/first"
            android:background="@color/colorPrimary"
            android:gravity="left"/>

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/second"
            android:background="@color/colorPrimary"
            android:gravity="center"/>

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/third"
            android:background="@color/colorPrimary"
            android:gravity="right"/>

    </LinearLayout>

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

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/first"
            android:background="@color/colorAccent"
            android:gravity="left"/>

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/second"
            android:background="@color/colorAccent"
            android:gravity="center"/>

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/third"
            android:background="@color/colorAccent"
            android:gravity="right"/>

    </LinearLayout>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="vertical"
        android:layout_gravity="right"
        android:gravity="center_vertical">

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/first"
            android:background="@color/colorPrimaryDark"
            android:gravity="left"/>

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/second"
            android:background="@color/colorPrimaryDark"
            android:gravity="center"/>

        <TextView
            android:layout_width="@dimen/fixed"
            android:layout_height="wrap_content"
            android:text="@string/third"
            android:background="@color/colorPrimaryDark"
            android:gravity="right"/>

    </LinearLayout>

</LinearLayout>

Which gets rendered as following:

example_illustration

Now you see 3 colors here thats because of the textView background,

lets take android:layout_gravity,here its used in LinearLayouts, they are positioned inside their parent , left in the parent , middle in the parent , right in the parent (see LinearLayout has/can have children)

lets take android:gravity check those textViews each color has 3 of them and see how they(their content) are possition inside their element (does a text view has children? or only a content?)

I feel this like

gravity - arrange content inside the view , view does not want to move but the content move

layout_gravity - Its not about the content it's the layout which move here and there

Go through the original question as well its cool

Upvotes: 5

Manish
Manish

Reputation: 1091

Try this

<LinearLayout 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:orientation="vertical"
                        android:weightSum="3">

                        <RelativeLayout

                            android:layout_width="match_parent"
                            android:layout_height="0dp"
                            android:layout_weight="1">

                            <TextView
                                android:id="@+id/tv1"
                                android:layout_width="wrap_content"
                                android:layout_height="wrap_content"
                                android:layout_centerInParent="true"
                                android:text="text_1"/>
                        </RelativeLayout>

Upvotes: 1

Jiyeh
Jiyeh

Reputation: 5297

Try this:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
android:weightSum="3">

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

    <TextView
        android:id="@+id/tv1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="text_1"/>
</LinearLayout>

Upvotes: 4

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