While reading JavaScript: The Definitive Guide, 5th Edition, I came across Example 17-4 on page 422 that defines a function for dragging absolutely positioned elements. In the example, the function drag() is called in the onmousedown attribute of a document element. The function repositions the element based on the change in location of the mouse which is queried by handlers added to the root document element for captured mousemove and mouseup events. They capture these events on the document for the following reason:
It is important to note that the mousemove and mouseup handlers are registered as capturing event handlers because the user may move the mouse faster than the document element can follow it, and some of these events occur outside the original target element.
This suggests an advantage in quicker response when capturing events.
