Android: Drawing tiled bitmaps with bottom or some other alignments similar to css background-position

Question

I want to set a background of a View with a tiled bitmap, but the tiling needs to be anchored to the bottom-left, instead of the top-left corner (the default). For example, if t

Answer 1

Another way would be to extend BitmapDrawable and override the paint() method:

In this method we avoid creating a new bitmap having the size of the view.

class MyBitmapDrawable extends BitmapDrawable {
    private Paint mPaint = new Paint(Paint.FILTER_BITMAP_FLAG | Paint.DITHER_FLAG);
    private boolean mRebuildShader = true;
    private Matrix mMatrix = new Matrix();

    @Override
    public void draw(Canvas canvas) {
        Bitmap bitmap = getBitmap();
        if (bitmap == null) {
            return;
        }

        if (mRebuildShader) {
            mPaint.setShader(new BitmapShader(bitmap, TileMode.REPEAT, TileMode.REPEAT));
            mRebuildShader = false;
        }

        // Translate down by the remainder
        mMatrix.setTranslate(0, getBounds().bottom % getIntrinsicHeight());
        canvas.save();
        canvas.setMatrix(mMatrix);
        canvas.drawRect(getBounds(), mPaint);
        canvas.restore();
    }
}

It can be set to the view like this:

view.setBackgroundDrawable(new MyBitmapDrawable(getResources().getDrawable(R.drawable.smiley).getBitmap()));