android - Getting Bitmap from vector drawable

Question

In my application, I have to set a large icon for a notification. LargeIcon must be a Bitmap, and my drawables are vector images (the new feature in Android, see this link) The problem is when I try to decode a resource that is a vector image, I get a null returned.

Here is the sample of code :

if (BitmapFactory.decodeResource(arg0.getResources(), R.drawable.vector_menu_objectifs) == null)
        Log.d("ISNULL", "NULL");
    else
        Log.d("ISNULL", "NOT NULL");

In this sample, when I replace R.drawable.vector_menu_objectifs with a "normal" image, a png for exemple, the result is not null (I get the correct bitmap) Is there something I'm missing?

Answer 1

Checked on API: 17, 21, 23

public static Bitmap getBitmapFromVectorDrawable(Context context, int drawableId) {
    Drawable drawable = ContextCompat.getDrawable(context, drawableId);
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
        drawable = (DrawableCompat.wrap(drawable)).mutate();
    }

    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),
            drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

UPDATE:

Project gradle:

dependencies {
        classpath 'com.android.tools.build:gradle:2.2.0-alpha5'
    }

Module gradle:

android {
    compileSdkVersion 23
    buildToolsVersion '23.0.3'
    defaultConfig {
        minSdkVersion 16
        targetSdkVersion 23
        vectorDrawables.useSupportLibrary = true
    }
    ...
}
...