d3 on click on circle pause and resume transition of marker along line

Question

I would like help to correct my code to click the marker circle element to pause or resume transition of this element along the line. My code moves marker along a line and I can

Answer 1

To check if the circle is moving in the click function use d3.active(), which...

... returns null if there is no such active transition on the specified node.

Like this:

.on('click', function(d, i) {
    if (d3.active(this)) {
        marker.transition();
        setTimeout(function() {
            pauseValues.lastTime = pauseValues.currentTime;
        }, 100);
    } else {
        transition();
    }
});

Here is your code with that change:

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