code: boolean hasClickedOnce(int click)
      {
          if (click < clicks.length && clicks[click] && !clicked[click])
          {
              clicked[click] = true;
              return true;
          }
          return false;
      }
docs: Check if click is clicked once.
  
  @param click The click to check.
  @return <code>true</code> if clicked once, <code>false</code> else.