[android] Defining a percentage width for a LinearLayout?

I want to define a percentage width (70%) for a LinearLayout that contains some buttons, so that I can center it and so that the child buttons can fill_parent. Here's a picture showing what I mean:

My current layout looks like this:

<?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:id="@+id/layoutContainer" android:orientation="vertical">
    <LinearLayout android:layout_width="fill_parent"
        android:id="@+id/barContainer" android:orientation="horizontal"
        android:layout_height="40dp" android:background="@drawable/titlebackground">
        <ImageView android:id="@+id/barLogo" android:src="@drawable/titlelogo"
            android:layout_gravity="center_vertical" android:adjustViewBounds="true"
            android:layout_height="25dp" android:layout_width="wrap_content"
            android:scaleType="fitXY" android:paddingLeft="5dp"></ImageView>
    </LinearLayout>
    <TextView android:layout_height="wrap_content"
        android:layout_width="fill_parent" android:gravity="center_horizontal"
        android:id="@+id/searchTip" android:text="@string/searchTip"
        android:paddingTop="10dp" android:paddingBottom="10dp"></TextView>
    <LinearLayout android:layout_height="wrap_content"
        android:id="@+id/linearLayout1" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="Button" android:id="@+id/button1"
            android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:layout_width="wrap_content" android:id="@+id/button2" android:layout_height="wrap_content" android:text="Button"></Button>
        <Button android:layout_width="wrap_content" android:id="@+id/button3" android:layout_height="wrap_content" android:text="Button"></Button>
    </LinearLayout>
</LinearLayout>

The LinearLayout im referring to has the id: linearLayout1. How do I do this?

I solved a similar issue applying some padding to the LinearLayout like this:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/app_background"
    android:padding="35dip">

<RelativeLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/black">

</RelativeLayout>
</LinearLayout>

This probably won't give you an exact percentage but can be easily graduated and avoid extra unnecessary layout elements.

i know another solution, that work with weight:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="horizontal"
              android:layout_width="match_parent"
              android:layout_height="match_parent" 
              android:weightSum="10" 
              android:gravity="center_horizontal">

    <LinearLayout
            android:orientation="vertical"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" 
            android:layout_weight="7">
    </LinearLayout>
</LinearLayout>

As a latest update to android in 2015, Google has included percent support library

com.android.support:percent:23.1.0

You can refer to this site for example of using it

https://github.com/JulienGenoud/android-percent-support-lib-sample

Gradle:

dependencies {
    compile 'com.android.support:percent:22.2.0'
}

In the layout:

<android.support.percent.PercentRelativeLayout
    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">

    <View
        android:id="@+id/top_left"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_alignParentTop="true"
        android:background="#ff44aacc"
        app:layout_heightPercent="20%"
        app:layout_widthPercent="70%" />

    <View
        android:id="@+id/top_right"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_alignParentTop="true"
        android:layout_toRightOf="@+id/top_left"
        android:background="#ffe40000"
        app:layout_heightPercent="20%"
        app:layout_widthPercent="30%" />


    <View
        android:id="@+id/bottom"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_below="@+id/top_left"
        android:background="#ff00ff22"
        app:layout_heightPercent="80%" />
</android.support.percent.PercentRelativeLayout>

Google introduced new API called PercentRelativeLayout

Add compile dependency like

compile 'com.android.support:percent:22.2.0'

in that PercentRelativeLayout is what we can do percentagewise layout

*You can use layout_weight properties. If you want to take 70% of parent width you must set child layout_width property value 0dp, like android:layout_width="0dp"*

Use new percentage support library

compile 'com.android.support:percent:24.0.0'

See below example

<android.support.percent.PercentRelativeLayout
     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">
     <ImageView
         app:layout_widthPercent="50%"
         app:layout_heightPercent="50%"
         app:layout_marginTopPercent="25%"
         app:layout_marginLeftPercent="25%"/>
 </android.support.percent.PercentRelativeLayout>

For More Info Tutorial1 Tutorial2 Tutorial3

Hope this can help

<LinearLayout android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:orientation="horizontal">

    <LinearLayout android:layout_width="0dip"
        android:layout_height="wrap_content" android:orientation="horizontal"
        android:id="@+id/linearLayout_dummy1" android:layout_weight=".15">
    </LinearLayout>


    <LinearLayout android:layout_height="wrap_content"
        android:id="@+id/linearLayout1" android:orientation="vertical"
        android:layout_width="0dip" android:layout_weight=".7">
        <Button android:text="Button" android:id="@+id/button1"
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:layout_gravity="center">
        </Button>
        <Button android:layout_width="wrap_content" android:id="@+id/button2"
            android:layout_height="wrap_content" android:text="Button"
            android:layout_gravity="center"></Button>
        <Button android:layout_width="wrap_content" android:id="@+id/button3"
            android:layout_height="wrap_content" android:text="Button"
            android:layout_gravity="center"></Button>
    </LinearLayout>

    <LinearLayout android:layout_width="0dip"
        android:layout_height="wrap_content" android:orientation="horizontal"
        android:id="@+id/linearLayout_dummy2" android:layout_weight=".15">
    </LinearLayout>

</LinearLayout>

(1) Set layout_width to "0dip" (2) Set the layout_height to .xx (% you want)

I think Emiam's approach is right. But also agree with Simon Veloper (one of commentators of Emiam's answer) : When we need the buttons in 70% of width, we should use horizontal orientation for Linearlayout and set width of each Relativelayout to 0dip and their weight as specified So I suggest this version :

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent" android:layout_height="fill_parent"
        android:id="@+id/layoutContainer" android:orientation="horizontal">
    <RelativeLayout
            android:layout_width="0dip"
            android:layout_height="fill_parent"
            android:layout_weight="3">
    </RelativeLayout>
    <RelativeLayout
            android:layout_width="0dip"
            android:layout_height="fill_parent"
            android:layout_weight="14">

            //This is where you add buttons. You can make them "fill_parent".
    </RelativeLayout>
    <RelativeLayout
            android:layout_width="0dip"
            android:layout_height="fill_parent"
            android:layout_weight="3">
    </RelativeLayout>
</LinearLayout>

You can't define width/height/margins/... using percents in your XML. But what you would want to use is the "weight" attribute, which is, IMO, the most similar thing.

Another method would be to set the sizes programmatically after you inflate the layout in your code, by getting the size of your screen and calculating needed margins.