MatterDropdown 0.1

Applies physics to DOM elements and lets you bounce them around with the mouse. Built with matter.js and ismailman/decompose-dommatrix.

Example: dropdown.robsite.net
Simple Example: dropdown.robsite.net/simple-example

Usage

Don't. This is just for fun and not meant for people to use, yet. It doesn't really work with changing browser widths or touch controls. Try elopezga/matter-dom-plugin for a somewhat similar thing with more features and support.

But:

1. Include matter.js, matter-dropdown.js:

   <script src="matter.js" type="text/javascript"></script>
   <script src="matter-dropdown.js" type="text/javascript"></script>
   

2. Add a #matter-canvas element and hide it. Optionally do this to see it in debug mode:

   <canvas id="matter-canvas"></canvas>
   <style>
       body {
           position: relative;
       }
       #matter-canvas {
           display: none;
           position: absolute;
           top: 0;
           left: 0;
           right: 0;
           bottom: 0;
           width: 100%;
           height: 100%;
           opacity: 0.5;
           z-index: 100000;
           pointer-events: none;
       }
       body.debug #matter-canvas {
           display: block;
       }
       .matter {
           z-index: 90000;
       }
   </style>
   

3. Add class matter to all elements that should be affected by physics.
   1. Add class matter-static to all fixed elements, on which others bounce off.
   2. Add class matter-static-animated to fixed elements whose position changes (like with CSS- or JS-animations)
4. Initialize MatterDropdown with optional options:

   <script>
       window.addEventListener('load', function() {
           var dropdown = MatterDropdown({
               bounceDebounce: 50,               // how often are bounce-mouse interactions done? in ms
               timeToInteraction: 3000,          // how long until we can interact after creating the first interactive object with dropdown.addElement(el)?
               mouseBounceForce: {x: 0, y: -0.5} // for applyForce() when mouse touches non-static object. lower y = bouncier
           });
           dropdown.init();
       });
   </script>
   

   Now all elements with only the class matter fall down and bounce off the static elements.
5. Add other interactive elements later. For example, show a dropdown submenu and apply physics after 1 second:

   var menuItems = document.querySelectorAll('.menu > li > a');
   menuItems.forEach(function(el) {
       el.addEventListener('click', function(ev) {
           ev.preventDefault();
           var submenu = ev.currentTarget.parentElement.querySelector('ul');
           submenu.classList.add('visible');
           setTimeout(function() {
               dropdown.addElement(submenu);
           }, 1000);
       })
   })
   

6. A border-radius gets recognized automatically. Give the element the class has-boxshadow if it has one. Can only be rgba(0,0,0,0.2) 0 10px 20px; (or change it in matter-dropdown.js)
7. An existing element with class matter is added to the physics objects immediately after init(). Give it the attribute data-matter-init-delay="1000" to delay this by 1000ms.