Constrain window aspect ratio in NW.JS - resize

Question

Is it possible to constrain the aspect ratio of a window in an NW.JS app?
I have content which is 800 x 600. In the package.json manifest, I can define the window settings as...
"window": {
"toolbar": false
, "width": 800
, "height": 600
, "min_width": 800
, "min_height": 600
}
I use CSS to preserve the aspect ratio of the content and to fill the window as well as possible:
html, body{
margin: 0;
height: 100%;
}
main {
position: relative;
width:100vw;
max-width:133.3333vh; /* max-width / width = aspect ratio */
min-width: 800px;
height:75vw;
max-height:100vh; /* max-height / height = aspect ratio */
min-height: 600px;
margin: 0 auto;
}
However, if you make the window too wide, a blank area appears on either side. If you make it too tall for its width, a blank area appears at the bottom.
Is there a setting that forces a given aspect ratio?
Or is there now a window resize event that I can listen for so that I can apply window.resizeTo(height*1.333,height) as soon as the window's size is changed?

Answer 1

There does appear to be a resize event:
https://github.com/nwjs/nw.js/issues/799
https://github.com/nwjs/nw.js/wiki/window
You could use code like this to set your event listener:
gui = require('nw.gui');
w = gui.Window.get();
w.on('resize', yourFunctionHere);
but be careful about changing the window size in the handler (e.g. using resizeTo()) as that will trigger a resize and could cause all kinds of chaos. It might work to make the resize conditional on the current aspect ratio, but I can imagine you could still run into problems if you hit some limit or other. Offhand I don't know if there are some facilities (akin to event bubbling &c) that would help in this situation.