@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

		final int height = getDefaultSize(getSuggestedMinimumHeight(),
				heightMeasureSpec);
		final int width = getDefaultSize(getSuggestedMinimumWidth(),
				widthMeasureSpec);
		final int min = Math.min(width, height);
		float top = 0;
		float left = 0;
		int arcDiameter = 0;

		mTranslateX = (int) (width * 0.5f);
		mTranslateY = (int) (height * 0.5f);
		
		arcDiameter = min - getPaddingLeft();
		mArcRadius = arcDiameter / 2;
		top = height / 2 - (arcDiameter / 2);
		left = width / 2 - (arcDiameter / 2);
		mArcRect.set(left, top, left + arcDiameter, top + arcDiameter);
	
		int arcStart = (int)mProgressSweep + mStartAngle  + mRotation + 90;
		mThumbXPos = (int) (mArcRadius * Math.cos(Math.toRadians(arcStart)));
		mThumbYPos = (int) (mArcRadius * Math.sin(Math.toRadians(arcStart)));
		
		setTouchInSide(mTouchInside);
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	}
Notification that the user has finished a touch gesture. Clients may
want to use this to re-enable advancing the seekarc.

@param seekArc
           The SeekArc in which the touch gesture began
SeekArc_library/src/com/triggertrap/seekarc/SeekArc.java