code: protected void drawCircle(Canvas canvas) {
  		resetPaint();
  		if (hasShadow()) {
  			if (isShadowResponsiveEffectEnabled()) {
  				shadowResponsiveDrawer.draw(canvas);
  			} else {
  				drawShadow();
  			}
  		}
  		getPaint().setStyle(Paint.Style.FILL);
  		boolean rippleInProgress = isRippleEffectEnabled()
  				&& ((RippleEffectDrawer) rippleEffectDrawer).isDrawingInProgress();
  		getPaint().setColor(getState() == State.PRESSED || rippleInProgress ?
  				getButtonColorPressed() : getButtonColor());
  		canvas.drawCircle(calculateCenterX(), calculateCenterY(), calculateCircleRadius(), getPaint());
  		LOGGER.trace("Drawn the Action Button circle");
  	}
docs: Draws the main circle of the <b>Action Button</b> and calls
  {@link #drawShadow()} to draw the shadow if present
  
  @param canvas canvas, on which circle is to be drawn