example keep margins
by ps7566
HTML
<canvas id="c"></canvas>
JavaScript
var canvas = new fabric.Canvas("c",{
width: 600,
height: 500
});
var a = new fabric.Rect({
left: 70,
top: 70,
fill: 'blue',
width: 100,
height: 100,
strokeWidth: 0
});
var b = new fabric.Rect({
top: a.top + a.height/2,
left: a.left + a.width/2,
width: 80,
height: 60,
fill: 'black',
strokeWidth: 0,
originX: 'center',
originY: 'center',
});
var g=new fabric.Group([a,b]);
g.on('scaling',(e)=>{
var outer_obj = e.target.item(0);
var inner_obj = e.target.
});
g.noScaleCache = false;
canvas.add(g);