(Analyse -> Options) Image aspect ratio calculation fails. Need fix with improved numericInput().

[andrejadd]

The problem is that shiny reacts very quickly to changes in one of the width or height numericInput fields. The calculation breaks because of too many events.

There are three alternatives:

1. use a timer such that observeEvent is only triggered late
2. implement an numericInput that triggers only when the input is left or a Return key is pressed.
3. Find another numericInput that does this.

Point 1. is not very reliable and depends on the user. Point 2. has to be implemented, it was done before, see https://groups.google.com/forum/#!topic/shiny-discuss/BFUgjICEQlc . Better would be Point 3., maybe another search will do.

[andrejadd]

Try debounce?

https://gist.github.com/jcheng5/6141ea7066e62cafb31c