* @return The column index, or <code>-1</code> if none is found.
	 */
	public int overColumnIndex(int x) {
		int pos = getInsets().left;
		int count = mModel.getColumnCount();
		for (int i = 0; i < count; i++) {
			Column col = mModel.getColumnAtIndex(i);
			if (col.isVisible()) {
				pos += col.getWidth() + (mDrawColumnDividers ? 1 : 0);
				if (x < pos) {
					return i;
				}
			}
		}
		return -1;
	}