Android positioning problems
<p>So my problem is simple- I want to use XML layouts to precisely control the positioning of widgets on multiple devices. To do this, I thoroughly read the google <a href="http://developer.android.com/guide/practices/screens_support.html" rel="nofollow">docs</a> on supporting multiple devices. According to <a href="http://developer.android.com/guide/practices/screens_support.html#testing" rel="nofollow">this</a> part, the WVGA854 and HVGA are both considered "Normal screen" size. So theoretically, positioning a widget on WVGA854 should look the same as with HVGA. However, the resultant screenshot shows otherwise.<img src="http://i.stack.imgur.com/aFbtY.png" alt="enter image description here"></p>

<p><strong>The widget appears relatively higher placed on the WVGA854 skin</strong>. The XML code is shown below, and was placed under the layout-normal/ folder:</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" &gt;

    &lt;ImageButton
        android:id="@+id/button1"
        android:src="@drawable/icon_unlock"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="300dp"
        android:text="Button" /&gt;

&lt;/RelativeLayout&gt;
</code></pre>

<p>The drawables I constructed are in the proper ratios (3:4:6:8 as <a href="http://developer.android.com/guide/practices/screens_support.html#DesigningResources" rel="nofollow">recommended</a>). So why does this positioning mismatch happen? I beginning to think that using XML to position things is quite fruitless. My app requires very accurate positioning of widgets so even this slight mismatch is a problem. Any help how I can remedy this?</p>

<p><strong>EDIT:</strong>
What I want is for the widget to be placed in a manner such that the ratio of margin from top to the margin from bottom is exactly the same across devices. From the screenshot, you can see that this ratio is not the same for WQVGA854 and HVGA.</p>
