A custom non-drawable component

I am trying to learn how to create custom views and components and have already hit the roadblock. I can't seem to get the ability to draw to the canvas using the drawable.draw (canvas) method. But it works if I get a bitmap and draw it using the canvas.drawBitmap () method.

There is nothing interesting in the code:

@Override
protected void onDraw(Canvas canvas) {

    // drawing bitmap directly works
    /*
    Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
    canvas.drawBitmap(bitmap, 10, 10, paint);
    */

    // this doesn't work but mThumb is not null in log
    if(mThumb != null) {
        canvas.save();
        mThumb.draw(canvas);
        Log.d("Custom component - ", "mThumb : " + mThumb);
        canvas.restore();
    }
}

      

        
        
        
      

    

The log displays the mThumb variable containing the drawable. I get it in the standard way:

if(attrs != null) {
    final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CustomView);
    color = a.getColor(R.styleable.CustomView_cv_color, color);
    thumb = a.getDrawable(R.styleable.CustomView_cv_thumb);
    setThumb(thumb);
    a.recycle();
}

setColor(color);

      

        
        
        
      

    

xml for custom view:

<me.mycustomview.MyCustomView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:cv_color="@android:color/holo_red_light"
    app:cv_thumb="@drawable/ic_launcher" />

      

        
        
        
      

    

And in attrs.xml:

<declare-styleable name="CustomView">
    <attr name="cv_color" format="color" />
    <attr name="cv_thumb" format="reference" />
</declare-styleable>

      

        
        
        
      

    

I would really appreciate it if someone could point me in the right direction. Thank!