Resize rectangle with four corners corresponde to mouse position using fabric js

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jQuery

HTML5

Canvas

<canvas id="canvas" width="500" height="500"></canvas>
var canvas = document.getElementById('canvas'),
    ctx = canvas.getContext('2d'),
    rect = {
        x: 150,
        y: 100,
        w: 123,
        h: 58
    },
    handlesSize = 4,
    currentHandle = false,
    drag = false;
 
function init() {
    canvas.addEventListener('mousedown', mouseDown, false);
    canvas.addEventListener('mouseup', mouseUp, false);
    canvas.addEventListener('mousemove', mouseMove, false);
}
 
function point(x, y) {
    return {
        x: x,
        y: y
    };
}
 
function dist(p1, p2) {
    return Math.sqrt((p2.x - p1.x) * (p2.x - p1.x) + (p2.y - p1.y) * (p2.y - p1.y));
}
 
function getHandle(mouse) {
    if (dist(mouse, point(rect.x, rect.y)) <= handlesSize) return 'topleft';
    if (dist(mouse, point(rect.x + rect.w, rect.y)) <= handlesSize) return 'topright';
    if (dist(mouse, point(rect.x, rect.y + rect.h)) <= handlesSize) return 'bottomleft';
    if (dist(mouse, point(rect.x + rect.w, rect.y + rect.h)) <= handlesSize) return 'bottomright';
    if (dist(mouse, point(rect.x + rect.w / 2, rect.y)) <= handlesSize) return 'top';
    if (dist(mouse, point(rect.x, rect.y + rect.h / 2)) <= handlesSize) return 'left';
    if (dist(mouse, point(rect.x + rect.w / 2, rect.y + rect.h)) <= handlesSize) return 'bottom';
    if (dist(mouse, point(rect.x + rect.w, rect.y + rect.h / 2)) <= handlesSize) return 'right';
    return false;
}
 
function mouseDown(e) {
    if (currentHandle) drag = true;
    draw();
}
 
function mouseUp() {
    drag = false;
    currentHandle = false;
    draw();
}
 
function mouseMove(e) {
    var previousHandle = currentHandle;
    if (!drag) currentHandle = getHandle(point(e.pageX - this.offsetLeft, e.pageY - this.offsetTop));
    if (currentHandle && drag) {
        var mousePos = point(e.pageX - this.offsetLeft, e.pageY - this.offsetTop);
        switch (currentHandle) {
            case 'topleft':
                rect.w += rect.x - mousePos.x;
                rect.h += rect.y - mousePos.y;
                rect.x = mousePos.x;
                rect.y = mousePos.y;
                break;
            case 'topright':
                rect.w = mousePos.x - rect.x;
                rect.h += rect.y - mousePos.y;
                rect.y = mousePos.y;
                break;
            case 'bottomleft':
                rect.w += rect.x - mousePos.x;
                rect.x = mousePos.x;
                rect.h = mousePos.y - rect.y;
                break;
            case 'bottomright':
                rect.w = mousePos.x - rect.x;
                rect.h = mousePos.y - rect.y;
                break;
 
            case 'top':
                rect.h += rect.y - mousePos.y;
                rect.y = mousePos.y;
                break;
 
            case 'left':
                rect.w += rect.x - mousePos.x;
                rect.x = mousePos.x;
                break;
 
            case 'bottom':
                rect.h = mousePos.y - rect.y;
                break;
 
            case 'right':
                rect.w = mousePos.x - rect.x;
                break;
        }
    }
    if (drag || currentHandle != previousHandle) draw();
}
 
function draw() {
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillStyle = 'black';
    ctx.fillRect(rect.x, rect.y, rect.w, rect.h);
    if (currentHandle) {
        var posHandle = point(0, 0);
        switch (currentHandle) {
            case 'topleft':
                posHandle.x = rect.x;
                posHandle.y = rect.y;
                break;
            case 'topright':
                posHandle.x = rect.x + rect.w;
                posHandle.y = rect.y;
                break;
            case 'bottomleft':
                posHandle.x = rect.x;
                posHandle.y = rect.y + rect.h;
                break;
            case 'bottomright':
                posHandle.x = rect.x + rect.w;
                posHandle.y = rect.y + rect.h;
                break;
            case 'top':
                posHandle.x = rect.x + rect.w / 2;
                posHandle.y = rect.y;
                break;
            case 'left':
                posHandle.x = rect.x;
                posHandle.y = rect.y + rect.h / 2;
                break;
            case 'bottom':
                posHandle.x = rect.x + rect.w / 2;
                posHandle.y = rect.y + rect.h;
                break;
            case 'right':
                posHandle.x = rect.x + rect.w;
                posHandle.y = rect.y + rect.h / 2;
                break;
        }
        ctx.globalCompositeOperation = 'xor';
        ctx.beginPath();
        ctx.arc(posHandle.x, posHandle.y, handlesSize, 0, 2 * Math.PI);
        ctx.fill();
        ctx.globalCompositeOperation = 'source-over';
    }
}
 
init();
draw();

What I have tried:

In the example above what i posted, When you mouse down or click one of the corner of the resize handler and drag to any point inside the canvas ,the corner of the rectangle comes along with the position of mouse pointer without getting away from the mouse pointer. but, in fabric js When you mouse down or click one of the corner of the rectangle and drag to any point inside canvas it resize and not to the position of the mouse pointer anywhere inside canvas.