Find a line above or below in Javascript

Question

I am working on an internal HTML editor, focusing only on Firefox. I have an element inserted where the cursor should be, as well as left and right arrows, but I cannot find a way to find:

• Beginning and end of line for home and end keys
• Next line up or down for up / down arrows.

I see document.elementFromPoint, but that does not give me a Range object. The Range object itself seems useless when it comes to using pixel positions.

Answer 1

, document.elementFromPoint() document.createRange() Range.selectNodeContents();

(100,200)

var elem = document.elementFromPoint(100,200);
var r = document.createRange();
var s = window.getSelection()
r.selectNodeContents(elem);
s.removeAllRanges();
s.addRange(r);

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Answer 2

, " ". , ? ?

IE Firefox element.getClientRects() . . . quirksmode .

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