Вы пытаетесь достичь чего-то подобного?
1002 *
(function() {
var canvas = this.__canvas = new fabric.Canvas('c');
fabric.Object.prototype.originX = fabric.Object.prototype.originY = 'center';
function makeCircle(left, top, line1, line2, line3, line4) {
var c = new fabric.Circle({
left: left,
top: top,
strokeWidth: 5,
radius: 12,
fill: '#fff',
stroke: '#666'
});
c.hasControls = c.hasBorders = false;
c.line1 = line1;
c.line2 = line2;
c.line3 = line3;
c.line4 = line4;
return c;
}
function makeLine(coords) {
return new fabric.Line(coords, {
fill: 'red',
stroke: 'red',
strokeWidth: 5,
selectable: false,
evented: false,
});
}
var line = makeLine([ 250, 125, 250, 175 ]),
line2 = makeLine([ 250, 175, 250, 250 ]),
line3 = makeLine([ 250, 250, 300, 350]),
line4 = makeLine([ 250, 250, 200, 350]),
line5 = makeLine([ 250, 175, 175, 225 ]),
line6 = makeLine([ 250, 175, 325, 225 ]);
canvas.add(line, line2, line3, line4, line5, line6);
canvas.add(
makeCircle(line.get('x1'), line.get('y1'), null, line),
makeCircle(line.get('x2'), line.get('y2'), line, line2, line5, line6),
makeCircle(line2.get('x2'), line2.get('y2'), line2, line3, line4),
makeCircle(line3.get('x2'), line3.get('y2'), line3),
makeCircle(line4.get('x2'), line4.get('y2'), line4),
makeCircle(line5.get('x2'), line5.get('y2'), line5),
makeCircle(line6.get('x2'), line6.get('y2'), line6)
);
canvas.on('object:moving', function(e) {
var p = e.target;
if(p.type == 'activeSelection'){
for(i=0;i<p._objects.length;i++){
p._objects[i].line1 && p._objects[i].line1.set({ 'x2': p.left+p._objects[i].left, 'y2': p.top+p._objects[i].top });
p._objects[i].line2 && p._objects[i].line2.set({ 'x1': p.left+p._objects[i].left, 'y1': p.top +p._objects[i].top});
p._objects[i].line3 && p._objects[i].line3.set({ 'x1': p.left+p._objects[i].left, 'y1': p.top +p._objects[i].top});
p._objects[i].line4 && p._objects[i].line4.set({ 'x1': p.left+p._objects[i].left, 'y1': p.top +p._objects[i].top});
}
}else{
p.line1 && p.line1.set({ 'x2': p.left, 'y2': p.top });
p.line2 && p.line2.set({ 'x1': p.left, 'y1': p.top });
p.line3 && p.line3.set({ 'x1': p.left, 'y1': p.top });
p.line4 && p.line4.set({ 'x1': p.left, 'y1': p.top });
}
canvas.renderAll();
});
})();
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/2.4.6/fabric.js"></script>
<canvas id="c" width="500" height="600"></canvas>