title: Problems understanding Android XML layout_weight
body: <p>I really tried to, but I can't understand how Android interprets <code>layout_weight</code> setting...</p>
  
  <p>What I'm trying to achieve is </p>
  
  <ul>
  <li>a header on top with a fixed height</li>
  <li>an input area at the bottom containing an EditText and a Button</li>
  <li>a content part in the middle that's taking all what's left of space  </li>
  </ul>
  
  <p>When typing I'd like to grow the EditText to a specific height and to start scrolling if the text entered exceeds the available height. Doing this I need the surrounding <code>LinearLayout</code> to grow together with the EditText.</p>
  
  <p>If I define a specific height for the inner <code>LinearLayout</code> it won't grow. If I don't, the inner layout takes ALL the space instead of the ScrollView, no matter what I try using <code>layout_weight</code>. :(</p>
  
  <p>My current XML looks like that:</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent" &gt;
      &lt;TextView
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:text="I'm a header" /&gt;
      &lt;ScrollView
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:layout_weight="1"
          android:gravity="bottom"&gt;
          &lt;LinearLayout
              android:id="@+id/itemContainer"
              android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content" /&gt;
      &lt;/ScrollView&gt;
      &lt;LinearLayout
          android:layout_width="fill_parent"
          android:layout_height="50dp"
          android:padding="2dp"
          android:gravity="bottom"
          android:isScrollContainer="true"
          android:background="@drawable/steel" &gt;
          &lt;EditText
              android:id="@+id/edittext01"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:layout_weight="0.2"
              android:scrollbars="vertical"
              android:fadingEdge="vertical"
              android:fadingEdgeLength="60dp"
              android:maxHeight="40dp"
              android:textSize="15sp" /&gt;
          &lt;Button
              android:id="@+id/button"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:layout_weight="0.8"
              android:layout_gravity="right"
              android:text="Send"
              android:textStyle="bold"
              android:textSize="15sp" /&gt;
      &lt;/LinearLayout&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>Any tips are greatly appreciated!</p>