javascript - Draw an arrow between two divs

Question

I'm searching for a solution of the question that I expected to be solved already. But I saw only big projects with a lot of features but no simple solution.

Actually I need to get something like that:

So to get an arrow drawing over a div containing some squares (divs)

<div id="container">
<div class="white_field"></div>
<div id="1" class="black_field">
<br style="clear:both;">    
<div id="2" class="black_field">
<div class="white_field"></div>
<br style="clear:both;">    
<div id="3" class="black_field">
<div class="white_field"></div>
</div>

I looked in the canvas direction but stumbled on tha canvas was not visible behind my divs ( maybe some z-index should help ) But still strange that I couldn't find some ready-made solution of a problem that seems to me coming up often. ( to explain some thing on the site arrows are almost a must )

question from:https://stackoverflow.com/questions/20037122/draw-an-arrow-between-two-divs

Answer 1

You might consider SVG.

In particular, you can use a line with a marker-end shaped with an arrow-path.

Be sure to set orient=auto so the arrowhead will be rotated to match the slope of the line.

Since SVG is a DOM element, you can control the start/end position of the line in javascript.

Here is code and a Fiddle: http://jsfiddle.net/m1erickson/9aCsJ/

<svg width="300" height="100">

    <defs>
        <marker id="arrow" markerWidth="13" markerHeight="13" refx="2" refy="6" orient="auto">
            <path d="M2,2 L2,11 L10,6 L2,2" style="fill:red;" />
        </marker>
    </defs>

    <path d="M30,150 L100,50"
          style="stroke:red; stroke-width: 1.25px; fill: none;
                 marker-end: url(#arrow);"
    />

</svg>