code: private void drawNextHalf(Canvas canvas) {
  		canvas.save();
  		canvas.clipRect(isFlippingVertically() ? mBottomRect : mRightRect);
  		
  		final float degreesFlipped = getDegreesFlipped();
  		final Page p = degreesFlipped > 90 ? mCurrentPage : mNextPage;
  
  		// if the view does not exist, skip drawing it
  		if (p.valid) {
  			setDrawWithLayer(p.v, true);
  			drawChild(canvas, p.v, 0);
  		}
  
  		drawNextShadow(canvas);
  		canvas.restore();
  	}
docs: draw bottom/right half
  
  @param canvas