public void setTouchInSide(boolean isEnabled) {
		int thumbHalfheight = (int) mThumb.getIntrinsicHeight() / 2;
		int thumbHalfWidth = (int) mThumb.getIntrinsicWidth() / 2;
		mTouchInside = isEnabled;
		if (mTouchInside) {
			mTouchIgnoreRadius = (float) mArcRadius / 4;
		} else {
			// Don't use the exact radius makes interaction too tricky
			mTouchIgnoreRadius = mArcRadius
					- Math.min(thumbHalfWidth, thumbHalfheight);
		}
	}
Sets a listener to receive notifications of changes to the SeekArc's
progress level. Also provides notifications of when the user starts and
stops a touch gesture within the SeekArc.

@param l
           The seek bar notification listener

@see SeekArc.OnSeekBarChangeListener
SeekArc_library/src/com/triggertrap/seekarc/SeekArc.java