How to get a Bitmap from a drawable defined in a xml?

Question

How can I get the bitmap from a xml shape drawable. What am I doing wrong?

shadow.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android"     android:shape="rectangle" >      <gradient         android:angle="270.0"         android:endColor="@android:color/transparent"         android:startColor="#33000000"         android:type="linear" />      <size android:height="7.0dip" />  </shape> 

My method to retrieve the bitmap from drawable:

private Bitmap getBitmap(int id) {     return BitmapFactory.decodeResource(getContext().getResources(), id); } 

getBitmap() is returning null when the id passed in is the shadow.xml drawable id.

Answer 1

This is a fully working solution:

private Bitmap getBitmap(int drawableRes) {     Drawable drawable = getResources().getDrawable(drawableRes);     Canvas canvas = new Canvas();     Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);     canvas.setBitmap(bitmap);     drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());     drawable.draw(canvas);      return bitmap; } 

And here is an example:

Bitmap drawableBitmap = getBitmap(R.drawable.circle_shape); 

circle_shape.xml

<?xml version="1.0" encoding="utf-8"?> <shape     xmlns:android="http://schemas.android.com/apk/res/android"     android:shape="oval">     <size         android:width="15dp"         android:height="15dp" />     <solid         android:color="#94f5b6" />     <stroke         android:width="2dp"         android:color="#487b5a"/> </shape> 

Answer 2

a ShapeDrawable doesn't have a bitmap associated with it - its sole purpose is to be drawn on a canvas. Until its draw method is called, it has no image. If you can get a canvas element at the place where you need to draw the shadow, you can draw it as a shapeDrawable, otherwise you might need a separate, empty view in your layout with the shadow as a background.