Develop Reference

Android - Two buttons in same line filling the whole width

I have a little problem defining a Relative Layout. I have a List View with scroll and two buttons always visible at the bottom of the list view. I just would like my two button have 50% of the width, filling the line. This is my code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="#+id/testbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="Save" />
<Button
android:id="#+id/cancelButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#+id/testbutton"
android:text="Cancel"/>
<ListView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/LstPeriodOptions"
android:layout_alignParentTop="true"
android:layout_above="#id/testbutton" />
</RelativeLayout>
I tried to introduce the buttons in a Linear Layout and give the gravity=1 with width=0dp but in that case the ListView dissapears. Could you help me please?
Sorry for my english. This is the result I would like to have:
Thanks a lot, best regards.
EDIT: This is what I tried with Linear Layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/container" >
<Button
android:id="#+id/testbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="Guardar" />
<Button
android:id="#+id/cancelButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#+id/testbutton"
android:text="Cancelar"/>
</LinearLayout>
<ListView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/LstPeriodOptions"
android:layout_alignParentTop="true"
android:layout_above="#id/container" />
</RelativeLayout>

Did you try with your LinearLayout in this way because this should work. Note all of the property changes. Since I don't know how yours was, I can't point out all of the differences.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<LinearLayout
android:id="#+id/btnLL"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true">
<Button
android:id="#+id/testbutton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Save" />
<Button
android:id="#+id/cancelButton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Cancel"/>
</LinearLayout>
<ListView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/LstPeriodOptions"
android:layout_above="#id/btnLL" />
</RelativeLayout>

Try out as below to set your button in LinearLayout and set it below your ListView:
<LinearLayout
android:id="#+id/laytbtns"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_below="#+id/LstPeriodOptions" >
<Button
android:id="#+id/testbutton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginRight="5dp"
android:layout_weight="1"
android:text="Save"/>
<Button
android:id="#+id/cancelButton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_weight="1"
android:text="Cancel" />
</LinearLayout>

Try 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:orientation="vertical" >
<ListView
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:id="#+id/LstPeriodOptions"
android:layout_above="#id/testbutton" />
<LinearLayout
android:id="#+id/laytbtns"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_below="#+id/LstPeriodOptions" >
<Button
android:id="#+id/testbutton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginRight="5dp"
android:layout_weight="1"
android:text="Save"/>
<Button
android:id="#+id/cancelButton"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_weight="1"
android:text="Cancel" />
</LinearLayout>
</LinearLayout>

XML Layout overlap

I am trying to create a certain layout, that consists of 2 parts a scrollview and a "footer" at the bottom, but always on top of the scrollview. Everything inside the scrollview must be visible (by scrolling).
This is my current code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/banner" />
<TextView
android:layout_width="fill_parent"
android:paddingTop="1dp"
android:layout_height="3px"
android:background="#DADADA" />
<RelativeLayout
android:id="#+id/InnerRelativeLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true" >
<Button
android:id="#+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:text="Start Connecting" />
<Button
android:id="#+id/button01"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="#+id/button1"
android:layout_alignParentLeft="true"
android:text="First use" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:text="Welcome to ADB Wireless!"
android:textSize="25sp" />
</RelativeLayout>
</LinearLayout>
But it gives an overlap on small screens & landscape mode. I would only like to have the 2 buttons to be inside the 'footer'. Thank you!

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:id="#+id/button_layout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="vertical" >
<Button
android:id="#+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Next" />
<Button
android:id="#+id/button01"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Previous" />
</LinearLayout>
<ScrollView
android:id="#+id/scrollView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="#+id/button_layout" >
</ScrollView>
</RelativeLayout>

How to make a button stay at the bottom of the screen

Hello all im getting really frustrated with my button, how do i make it so it stays at the bottom of the screen,
<?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:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
<TextView
android:id="#+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
<Button
android:id="#+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
?

You can do that by replacing the LinearLayout with RelativeLayout like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/* this puts the textview at the top of the relative layout */
android:layout_alignParentTop="true"
android:text="TextView" />
<TextView
android:id="#+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/* this puts the textview1 at the bottom of the first textview */
android:layout_below="#id/textView1"
android:text="TextView" />
<Button
android:id="#+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/* this puts the button at the bottom of the RelativeLayout */
android:layout_alignParentBottom="true"
android:text="Button" />
</RelativeLayout>
Remove the comment lines if you copy and paste the code because are not working in xml...

Add the empty View with weight 1 between your text views and the button. This view will expand over unused space, keeping the button at the bottom.
<?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:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1" />
<TextView
android:id="#+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
<Button
android:id="#+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>

Please copy this code and use, it will work...
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
<TextView
android:id="#+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
</LinearLayout>
<Button
android:id="#+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>

Align two-button layout left and right in Android

I want to align two buttons with a linear layout, one on the left, and one on the right, like the next and previous buttons on an image gallery. I tried to align them but it doesn't work.
XML layout code:
<?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:orientation="vertical"
android:background="#android:color/white"
android:gravity="bottom" >
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="prev"
android:layout_alignParentRight="true" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="next" />
</LinearLayout>
</LinearLayout>
Actual output:
Expected output:
How can I fix it?

Use a RelativeLayout. There you can set android:layout_alignParentLeft and android:layout_alignParentRight.
This should work for you:
<?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:orientation="vertical"
android:background="#android:color/white"
android:gravity="bottom" >
<RelativeLayout
android:id="#+id/relativeLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="prev"
android:layout_alignParentLeft="true" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="next"
android:layout_alignParentRight="true"/>
</RelativeLayout>
</LinearLayout>

With Linear Layout
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Prev"/>
</LinearLayout>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Next"/>
</LinearLayout>
With Relative Layout
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Prev"
android:layout_alignParentLeft="true"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Next"
android:layout_alignParentRight="true"/>
</RelativeLayout>

Use Relative layout in your LinearLayout;
Also add android:layout_alignParentLeft="true" to "prev" Button
and android:layout_alignParentRight="true" to "next" Button
<?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:background="#android:color/white"
android:gravity="bottom"
android:orientation="vertical" >
<RelativeLayout
android:id="#+id/relativeLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true" <---- ADD this prop
android:text="prev" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true" <----- ADD this prop
android:text="next" />
</RelativeLayout>
</LinearLayout>

I guess, the simplest solution is to use View in your inner LinearLayout.
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="prev"/>
<View
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="1"/>
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="next"/>
</LinearLayout>

Something like this:
<?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" >
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="right" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="Button" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_toLeftOf="#+id/button1"
android:orientation="vertical" >
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
</RelativeLayout>
</LinearLayout>
The idea is, to create a RelativeLayout as container and put first Button and then stick it to the right of parent view. After that, add Another button inside LinearLayout and set this LinearLayout into the left of first Button.
Here's the result.

ur layout xml should be as shown below
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="bottom"
android:background="#fff">
<RelativeLayout
android:id="#+id/relativeLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#000"
android:layout_gravity="bottom" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:text="Pre" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="Next" />
</RelativeLayout>
</RelativeLayout>

Use a RelativeLayout instead of a LinearLayout you can add the tags android:layout_alignParentRight="true" and android:layout_alignParentLeft="true" on each button.

You can use RelativeLayout 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:background="#android:color/white"
android:orientation="vertical" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#android:color/black"
android:gravity="bottom"
android:orientation="horizontal" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:text="prev" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="next" />
</RelativeLayout>
</LinearLayout>
(I used grey instead of white for the screenshot)

Use a FrameLayout and add the layout_gravity attribute in each of the buttons

Do something like this it will surely help you out
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/Linear"
android:textSize="35dp"
android:layout_margin="90dp"
/>
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#android:color/black">
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Relative"
/>
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="200dp"
android:text="Constraint" />
</LinearLayout>
</LinearLayout>

Use margin_Start and End to seprate the buttons in the layout
<?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:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="-:Linear Layout:-"
android:textSize="35sp"
android:layout_gravity="center"
android:layout_marginTop="250dp"
tools:ignore="HardcodedText"/>
<LinearLayout
android:id="#+id/linear2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="90dp">
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Relative"
tools:ignore="ButtonStyle,HardcodedText"/>
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="200dp"
android:text="Constraint"
tools:ignore="ButtonStyle"
/>
</LinearLayout>
</LinearLayout>
[enter image description here][1]
[1]: https://i.stack.imgur.com/NMYj2.png

For Better Performance:
Best to put two views left and right and one view between in linear layout rather than relative layout. Use the below code it will also remove the nesting of views .... It will be good in performance perpective :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical">
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="prev" />
<TextView android:text="Hi its working"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="next" />
</LinearLayout>

Android linear layout align center and right

This is what I have:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:background="#FFFFFF">
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:background="#E30000"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center_horizontal|center_vertical">
<TextView
android:id="#+id/TextView00"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#FFFFFF"
android:textSize="20px"
android:textStyle="bold"
android:text="Something"
android:gravity="right|center_vertical"
/>
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:gravity="right|center_vertical"
android:layout_gravity="center_vertical"
android:background="#E30000">
<Button
android:id="#+id/btnCalls"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/icon"
android:gravity="right|center_vertical"
/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
And I want this:
So horizontal center align the text and vertical center align the button.
What am I missing? I haven't tried RelativeLayout and I would prefer LinearLayout to work this out.

android:gravity="right|center_vertical"
aligns your TextView to the right. How about center_horizontal?
And your LinearLayouts have the same ID, if there is not more code, then I would delete one of them.

try this one
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:background="#FFFFFF">
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:background="#E30000"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center_vertical">
<TextView
android:id="#+id/TextView00"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#FFFFFF"
android:textSize="20px"
android:textStyle="bold"
android:text="Something"
android:layout_weight="1"
android:gravity="center"/>
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:gravity="right|center_vertical"
android:layout_gravity="center_vertical"
android:background="#E30000"
android:layout_width="wrap_content">
<Button
android:id="#+id/btnCalls"
android:layout_width="wrap_content"
android:drawableLeft="#drawable/icon"
android:gravity="right|center_vertical"
android:layout_height="wrap_content"
android:layout_margin="5dip"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>

I found none of the answers work exactly as the OP intended, but the RelativeLayout solution was the closest one. Except that the TextView wasn't centered. But, with layout_centerInParent=true, works like a charm:
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/TextView00"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#FFFFFF"
android:textSize="20px"
android:textStyle="bold"
android:text="Something"
android:layout_centerInParent="true" />
<Button
android:id="#+id/btnCalls"
android:drawableLeft="#drawable/icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"/>
</RelativeLayout>

you have used android:gravity="right|center_vertical" in your textview. Use android:gravity="center".

Try to add empty View inside horizontal LinearLayout between element that you want see left and element that you want to see right, e.g.:
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<View
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="1"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>

define layout weight for TextView and LinearLayout
set android:layout_weight="1" to TextView
set android:layout_weight="0" to LinearLayout
and also change the layout_width="wrap_content" to LinearLayout
and set layout_gravity="center" to TextView

I think,gravity means the position of things inside the component(for textview,it means the text you have given)in component where layout_gravity means position of component itself in the whole layout.So...
Try Using:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:background="#FFFFFF"
>
<LinearLayout android:id="#+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:background="#E30000"
android:layout_gravity="right"
android:gravity="center_vertical|right"
>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|center_vertical"
android:gravity="center_vertical|center"
android:layout_weight="0.9"
>
<TextView
android:id="#+id/TextView00"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#FFFFFF"
android:textSize="20px"
android:textStyle="bold"
android:text="Something"
android:gravity="center_horizontal"
android:layout_gravity="center_horizontal|center_vertical"
/>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|center_vertical"
android:gravity="center_vertical|right"
android:paddingTop="5dip"
android:layout_weight="0.1"
>
<Button
android:id="#+id/btnCalls"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/icon"
android:layout_gravity="center_vertical"
android:gravity="center"
/>
</LinearLayout>
</LinearLayout>
</LinearLayout>

Just use RelativeLayout, and wallaaa!!!
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/TextView00"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#FFFFFF"
android:textSize="20px"
android:textStyle="bold"
android:text="Something"
android:gravity="center" />
<Button
android:id="#+id/btnCalls"
android:drawableLeft="#drawable/icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"/>
</RelativeLayout>

The solution for this is-
android:gravity="center_vertical"
Normally you'll also have to take care of its parent's position too to make sure it works.