/* enable javascript to view a demo */
// target elements with the "draggable" class
interact('.draggable')
  .draggable({
    // enable inertial throwing
    inertia: true,
    // keep the element within the area of it's parent
    restrict: {
      restriction: "parent",
      endOnly: true,
      elementRect: { top: 0, left: 0, bottom: 1, right: 1 }
    },
    // enable autoScroll
    autoScroll: true,

    // call this function on every dragmove event
    onmove: dragMoveListener,
    // call this function on every dragend event
    onend: function (event) {
      var textEl = event.target.querySelector('p');

      textEl && (textEl.textContent =
        'moved a distance of '
        + (Math.sqrt(event.dx * event.dx +
                     event.dy * event.dy)|0) + 'px');
    }
  });

  function dragMoveListener (event) {
    var target = event.target,
        // keep the dragged position in the data-x/data-y attributes
        x = (parseFloat(target.getAttribute('data-x')) || 0) + event.dx,
        y = (parseFloat(target.getAttribute('data-y')) || 0) + event.dy;

    // translate the element
    target.style.webkitTransform =
    target.style.transform =
      'translate(' + x + 'px, ' + y + 'px)';

    // update the posiion attributes
    target.setAttribute('data-x', x);
    target.setAttribute('data-y', y);
  }

  // this is used later in the resizing and gesture demos
  window.dragMoveListener = dragMoveListener;

/* enable javascript to view a demo */
/* The dragging code for '.draggable' from the demo above
 * applies to this demo as well so it doesn't have to be repeated. */

// enable draggables to be dropped into this
interact('.dropzone').dropzone({
  // only accept elements matching this CSS selector
  accept: '#yes-drop',
  // Require a 75% element overlap for a drop to be possible
  overlap: 0.75,

  // listen for drop related events:

  ondropactivate: function (event) {
    // add active dropzone feedback
    event.target.classList.add('drop-active');
  },
  ondragenter: function (event) {
    var draggableElement = event.relatedTarget,
        dropzoneElement = event.target;

    // feedback the possibility of a drop
    dropzoneElement.classList.add('drop-target');
    draggableElement.classList.add('can-drop');
    draggableElement.textContent = 'Dragged in';
  },
  ondragleave: function (event) {
    // remove the drop feedback style
    event.target.classList.remove('drop-target');
    event.relatedTarget.classList.remove('can-drop');
    event.relatedTarget.textContent = 'Dragged out';
  },
  ondrop: function (event) {
    event.relatedTarget.textContent = 'Dropped';
  },
  ondropdeactivate: function (event) {
    // remove active dropzone feedback
    event.target.classList.remove('drop-active');
    event.target.classList.remove('drop-target');
  }
});

/* enable javascript to view a demo */
var element = document.getElementById('grid-snap'),
    x = 0, y = 0;

interact(element)
  .draggable({
    snap: {
      targets: [
        interact.createSnapGrid({ x: 30, y: 30 })
      ],
      range: Infinity,
      relativePoints: [ { x: 0, y: 0 } ]
    },
    inertia: true,
    restrict: {
      restriction: element.parentNode,
      elementRect: { top: 0, left: 0, bottom: 1, right: 1 },
      endOnly: true
    }
  })
  .on('dragmove', function (event) {
    x += event.dx;
    y += event.dy;

    event.target.style.webkitTransform =
    event.target.style.transform =
        'translate(' + x + 'px, ' + y + 'px)';
  });

/* enable javascript to view a demo */
interact('.resize-drag')
  .draggable({
    onmove: window.dragMoveListener
  })
  .resizable({
    preserveAspectRatio: true,
    edges: { left: true, right: true, bottom: true, top: true }
  })
  .on('resizemove', function (event) {
    var target = event.target,
        x = (parseFloat(target.getAttribute('data-x')) || 0),
        y = (parseFloat(target.getAttribute('data-y')) || 0);

    // update the element's style
    target.style.width  = event.rect.width + 'px';
    target.style.height = event.rect.height + 'px';

    // translate when resizing from top or left edges
    x += event.deltaRect.left;
    y += event.deltaRect.top;

    target.style.webkitTransform = target.style.transform =
        'translate(' + x + 'px,' + y + 'px)';

    target.setAttribute('data-x', x);
    target.setAttribute('data-y', y);
    target.textContent = Math.round(event.rect.width) + '×' + Math.round(event.rect.height);
  });

/* enable javascript to view a demo */
var angle = 0;

interact('#rotate-area').gesturable({
  onmove: function (event) {
    var arrow = document.getElementById('arrow');

    angle += event.da;

    arrow.style.webkitTransform =
    arrow.style.transform =
      'rotate(' + angle + 'deg)';

    document.getElementById('angle-info').textContent =
      angle.toFixed(2) + '°';
  }
});

/* enable javascript to view a demo */
var scale = 1,
    gestureArea = document.getElementById('gesture-area'),
    scaleElement = document.getElementById('scale-element'),
    resetTimeout;

interact(gestureArea)
  .gesturable({
    onstart: function (event) {
      clearTimeout(resetTimeout);
      scaleElement.classList.remove('reset');
    },
    onmove: function (event) {
      scale = scale * (1 + event.ds);

      scaleElement.style.webkitTransform =
      scaleElement.style.transform =
        'scale(' + scale + ')';

      dragMoveListener(event);
    },
    onend: function (event) {
      resetTimeout = setTimeout(reset, 1000);
      scaleElement.classList.add('reset');
    }
  })
  .draggable({ onmove: dragMoveListener });

function reset () {
  scale = 1;
  scaleElement.style.webkitTransform =
  scaleElement.style.transform =
    'scale(1)';
}

/* enable javascript to view a demo */
interact('.tap-target')
  .on('tap', function (event) {
    event.currentTarget.classList.toggle('switch-bg');
    event.preventDefault();
  })
  .on('doubletap', function (event) {
    event.currentTarget.classList.toggle('large');
    event.currentTarget.classList.remove('rotate');
    event.preventDefault();
  })
  .on('hold', function (event) {
    event.currentTarget.classList.toggle('rotate');
    event.currentTarget.classList.remove('large');
  });