Question

I would like to create a background that contains an image repeating itself horizontally and vertically. Above the entire background I would like to apply a gradient that goes from white to transparent, covering the half of the background.
Now, I would like to know if I can do this with style. It is because I get this warning:

"Possible overdraw: Root element paints background @drawable/background with a 
theme that also paints a background (inferred theme is @android:style/Theme)"

It looks like the background is applied twice, once by the default theme (Theme) and then by my layout, drawable element, or whatever.

So, my questions is: how can I do it by creating a new theme or creating a drawable and disable the default Theme background that would be overdrawn by the new one?

Thanks to everyone!

Answer 1

Assuming you want to set the background for all your windows, the style is defined like this:

<style name="MyTheme" parent="@android:style/Theme.Holo">
    <item name="android:windowBackground">@drawable/activity_background</item>
</style>

If you want to do it for a specific view, usually there is an “android:background” attribute that must be set to your drawable.

To have a bitmap with a gradient on top of it, your drawable must be defined using a layer list like this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

<item>
    <bitmap
        android:dither="true"
        android:src="@drawable/dialog_background_img"
        android:tileMode="repeat" >
    </bitmap>
</item>
<item>
   <shape>
      <gradient
        android:angle="90"
        android:endColor="#66ff0000"
        android:startColor="#5500ff00" />
   </shape>
</item>

</layer-list>