Question

I’m having a problem with layer-list on Android. I want to do a simple pile of images. I can achieve that with the following code:

<layer-list
xmlns:android="http://schemas.android.com/apk/res/android">

<item>
    <rotate 
        android:pivotX="50%" android:pivotY="50%"
        android:fromDegrees="0" android:toDegrees="0">
        <bitmap
            android:src="@drawable/teste1"
            android:gravity="center" />
    </rotate>
</item>

<item>
    <rotate 
        android:pivotX="50%" android:pivotY="50%"
        android:fromDegrees="-9" android:toDegrees="-9">
        <bitmap
            android:src="@drawable/teste3"
            android:gravity="center" />
    </rotate>
</item>

<item>
    <rotate 
        android:pivotX="50%" android:pivotY="50%"
        android:fromDegrees="9" android:toDegrees="9">
        <bitmap
            android:src="@drawable/teste2"
            android:gravity="center" />
    </rotate>
</item>

</layer-list>

But when I run it, the result is cropped on the top and on the bottom, as seen on the following image:

I have another doubt: if I put an ID on the <item> how do I retrieve it on my View so I can change the bitmap in code? The documentation* says I have to use an View.findViewByID, but I want to get the BitmapDrawable, and I can’t cast a View to a Drawable!

I also tried coding the same thing on a CustomView, with Canvas.drawBitmap, but it’s looking very ugly, if someone can point out a good solution using that I would appreciate too.

Thanks in advance

Answer 1

What are you putting that layer list in? What’s the XML that uses it as a drawable? Have you tried adding some top and bottom padding to the view that contains your layer drawable?

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As for accessing the bitmap from code, you need to get the LayerDrawable first, then use its getDrawable or findDrawableByLayerId methods.

For example, if you’re using a layer of bitmap items as the background of a view whose id is ‘container’ you could do this:

// get the layer list being used as the background of 'container'
View view = findViewById(R.id.container);
LayerDrawable layer = (LayerDrawable)view.getBackground();

// get the first layer's BitmapDrawable by index
BitmapDrawable bg = (BitmapDrawable)layer.getDrawable(0);

// get the BitmapDrawable of the layer whose id is 'teste2'
BitmapDrawable bgTeste2 = (BitmapDrawable)layer.findDrawableByLayerId(R.id.teste2);

// do whatever you want with the drawable
bg.setAlpha(60);