Drawing Rect

by Roman Bruckner

HTML

<html>
<head>
    <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/jointjs/3.2.0/joint.css" />
</head>
<body>
      <!-- content -->
      <div id="paper"></div>

      <!-- dependencies -->
        <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.4.0/backbone.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/jointjs/3.2.0/joint.js"></script>
    
    </body>
</html>

JavaScript

var graph = new joint.dia.Graph({}, {
  cellNamespace: joint.shapes
});

const paper = new joint.dia.Paper({
  el: document.getElementById('paper'),
  width: 800,
  height: 900,
  model: graph,
  cellViewNamespace: joint.shapes
});

paper.on('blank:pointerdown', function(evt, x, y) {
  const rect = V('rect', {
    'stroke': 'red',
    'fill': 'none',
    'x': x,
    'y': y,
    'width': 1,
    'height': 1,
    'stroke-width': 2
  });
  rect.appendTo(this.svg);
  evt.data = {
    rect,
    ox: x,
    oy: y
  };
});


paper.on('blank:pointermove', function(evt, x, y) {
  const {
    ox,
    oy,
    rect
  } = evt.data;
  const bbox = new g.Rect(ox, oy, x - ox, y - oy);
  if (bbox.width === 0) bbox.width = 1;
  if (bbox.height === 0) bbox.height = 1;
  bbox.normalize();
  evt.data.bbox = bbox;
  rect.attr(bbox.toJSON());
});

paper.on('blank:pointerup', function(evt, x, y) {
  const {
    ox,
    oy,
    rect,
    bbox
  } = evt.data;
  rect.remove();
  if (!bbox) return;
  graph.addCell({
    type: 'standard.Rectangle',
    position: {
      x: bbox.x,
      y: bbox.y
    },
    size: {
      width: bbox.width,
      height: bbox.height
    }
  });
});