Second click on canvas makes highlight disappear

[MichiK]

I was fiddling around with click events to lock points that were highlighted via mouseover in place by clicking on them in synchronized graphs. This works fine so far, but I noticed a strange issue that also appears in a single graph without any special stuff:

When a user clicks somewhere on the canvas, either on the curve or on the highlighting dot or somewhere else, nothing happens on the first click. However, on the second click, either on the same spot or somewhere else on the canvas, the dots highlighting the current value at the curve(s) disappear (but the legend stays visible). However, they reappear once the user moves the mouse again. Only reloading the page helps to restore the original behaviour.

In synchronized graphs, only the dots in the graph that is clicked on disappear. Tthe rest stays visible, so I guess that it may have something to do with click event handling.

Normally, this is just a minor issue but when one messes around with the mouse events (e.g. I overwrite Dygraph.prototype.mouseMove_ and Dygraph.prototype.mouseOut_ to only do something if a flag is set that can be toggled by clicking) it becomes apparent.

The issue can be seen in Firefox and Chrome on the example graph on http://dygraphs.com/.

[laczko090]

I just faced with this issue recently, maybe it helps someone in the future. My solution was to override the clearZoomRect_ method which was called during mouse down in the default interaction model.

[mirabilos]

@laczko090 override how exactly? (I can reproduce the issue.)