Also, at this point, you no longer need the mousedown handler, because you have already clicked.

而且，在此时，不再需要mousedown处理程序，因为已经进行单击。

youdao

Then it's time to ask for listening for various mouse events (mousedown, mouseup, and click) on the shadow tree's rectangle — you'll see how to react to these later.

接下来要求对影像树的矩形监听各种不同的鼠标事件(mousedown、mouseup和click)，后面将看到如何响应这些事件。

youdao

So when the shadow tree's rectangle receives a mousedown event, I change the CSS fill property to something a little flashier -- say pink.

因此，当影像树的矩形接收到 mousedown 事件时，我把 CSS 的 fill 属性改成稍微亮一点的颜色——比如粉红色。

youdao