Resize background image of canvas - Fabricjs

Question

I am using fabricjs to play around with canvas, and loading a image into it via javascript.

I have a function that resizes the canvas to make it responsive and as such would like to resize the background image that was loaded to fit the canvas too but keep the aspect ratio.

I have not found examples currently that meet my criteria and am hoping someone can assist.

Javascript

var canvas = new fabric.Canvas('drawing_layer');
 var img = new Image();
            img.onload = function () {
                canvas.setBackgroundImage(img.src, canvas.renderAll.bind(canvas), {
                    originX: 'left',
                    originY: 'top',
                    left: 0,
                    top: 0
                });

// initially sets width of canvas to fit the image
                canvas.setDimensions({
                    width: img.width,
                    height: img.height
                });
            };
// below is a call to function that resizes the canvas
resizeCanvas();

//sets listener to resize event
            window.addEventListener('resize', resizeCanvas);

Answer 1

My solution in Angular 2+.

@HostListener('window:resize', ['$event'])
      resizeCanvas(event?: any) {
        const width: number = (window.innerWidth > 0) ? window.innerWidth : screen.width;
        const height: number = (window.innerHeight > 0) ? window.innerHeight : screen.height;
        const widthn: number = width * 0.7;
        const heightn: number = height - 100;
        canvas.setDimensions({
          width: widthn,
          height: heightn,
        });
      }