我正在使用 interactjs.io 制作可拖动元素

我需要实现与 jQuery UI 快照完全相同的行为。您可以在 official documentation 中查看示例:

行为是:吸附到所有其他可拖动元素

在 interactjs.io 的文档中，您有“Snapping” (l ink documentation )，但我找不到编码方式。

我在这里创建了一个 fiddle :Fiddle Link

这是我的 JS 代码:

interact('.draggable')
  .draggable({
   onmove: dragMoveListener,
   snap: {},
  });


  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 position attributes
    target.setAttribute('data-x', x);
    target.setAttribute('data-y', y);
  }

我需要修改 snap 部分代码，使可拖动项目与其他项目对齐。

snap: {}

谢谢!!

最佳答案

下面的代码可以给你一些想法来获得你想要的结果。它适用于不同大小的可拖动元素。 Function targets用于设置目标点和线。

可以在this jsfiddle中测试.

var AXIS_RANGE = 12;
var CORNER_RANGE = 14;
var CORNER_EXCLUDE_AXIS = 8;
var AXIS_EXTRA_RANGE = -6;

var myItems = [];
var currentElement = null;
var offX1, offY1, offX2, offY2;

function getPosition(element) {
  return {
    x: parseFloat(element.getAttribute('data-x')) || 0,
    y: parseFloat(element.getAttribute('data-y')) || 0
  };
}

function isBetween(value, min, length) {
  return min - AXIS_EXTRA_RANGE < value && value < (min + length) + AXIS_EXTRA_RANGE;
}

function getDistance(value1, value2) {
  return Math.abs(value1 - value2);
}

function getSnapCoords(element, axis) {
  var result = {
    isOK: false
  };
  if (currentElement && currentElement !== element) {
    var pos = getPosition(element);
    var cur = getPosition(currentElement);
    var distX1a = getDistance(pos.x, cur.x);
    var distX1b = getDistance(pos.x, cur.x + currentElement.offsetWidth);
    var distX2a = getDistance(pos.x + element.offsetWidth, cur.x);
    var distX2b = getDistance(pos.x + element.offsetWidth, cur.x + currentElement.offsetWidth);
    var distY1a = getDistance(pos.y, cur.y);
    var distY1b = getDistance(pos.y, cur.y + currentElement.offsetHeight);
    var distY2a = getDistance(pos.y + element.offsetHeight, cur.y);
    var distY2b = getDistance(pos.y + element.offsetHeight, cur.y + currentElement.offsetHeight);
    var distXa = Math.min(distX1a, distX2a);
    var distXb = Math.min(distX1b, distX2b);
    var distYa = Math.min(distY1a, distY2a);
    var distYb = Math.min(distY1b, distY2b);
    if (distXa < distXb) {
      result.offX = offX1;
    } else {
      result.offX = offX2
    }
    if (distYa < distYb) {
      result.offY = offY1;
    } else {
      result.offY = offY2
    }
    var distX1 = Math.min(distX1a, distX1b);
    var distX2 = Math.min(distX2a, distX2b);
    var distY1 = Math.min(distY1a, distY1b);
    var distY2 = Math.min(distY2a, distY2b);
    var distX = Math.min(distX1, distX2);
    var distY = Math.min(distY1, distY2);
    var dist = Math.max(distX, distY);
    var acceptAxis = dist > CORNER_EXCLUDE_AXIS;

    result.x = distX1 < distX2 ? pos.x : pos.x + element.offsetWidth;
    result.y = distY1 < distY2 ? pos.y : pos.y + element.offsetHeight;

    var inRangeX1 = isBetween(pos.x, cur.x, currentElement.offsetWidth);
    var inRangeX2 = isBetween(cur.x, pos.x, element.offsetWidth);
    var inRangeY1 = isBetween(pos.y, cur.y, currentElement.offsetHeight);
    var inRangeY2 = isBetween(cur.y, pos.y, element.offsetHeight);

    switch (axis) {
      case "x":
        result.isOK = acceptAxis && (inRangeY1 || inRangeY2);
        break;
      case "y":
        result.isOK = acceptAxis && (inRangeX1 || inRangeX2);
        break;
      default:
        result.isOK = true;
        break;
    }
  }
  return result;
}

$('.draggable').each(function() {
  var pos = getPosition(this);
  this.style.transform = 'translate(' + pos.x + 'px, ' + pos.y + 'px)';
  myItems.push(getPosition(this));
});

interact('.draggable').draggable({
  onstart: function(event) {
    currentElement = event.target;
    var pos = getPosition(currentElement);
    offX1 = event.clientX - pos.x;
    offY1 = event.clientY - pos.y;
    offX2 = event.clientX - currentElement.offsetWidth - pos.x;
    offY2 = event.clientY - currentElement.offsetHeight - pos.y;
  },
  onmove: dragMoveListener,
  snap: {
    targets:
      (function() {
        var snapPoints = [];
        $('.draggable').each(function() {
          (function(element) {
            // Slide along the X axis
            snapPoints.push(
              function(x, y) {
                var data = getSnapCoords(element, "x");
                if (data.isOK) {
                  return {
                    x: data.x + data.offX,
                    range: AXIS_RANGE
                  };
                }
              });
            // Slide along the Y axis
            snapPoints.push(
              function(x, y) {
                var data = getSnapCoords(element, "y");
                if (data.isOK) {
                  return {
                    y: data.y + data.offY,
                    range: AXIS_RANGE
                  };
                }
              });
            // Snap to corner
            snapPoints.push(
              function(x, y) {
                var data = getSnapCoords(element);
                if (data.isOK) {
                  return {
                    x: data.x + data.offX,
                    y: data.y + data.offY,
                    range: CORNER_RANGE
                  };
                }
              });
          })(this);
        });
        return snapPoints;
      })()
  },
  onend: function(event) {
    $('.draggable').each(function() {
      currentElement = null;
      myItems.push(getPosition(this));
    });
  }
});

function dragMoveListener(event) {
  var target = event.target;
  var oldPos = getPosition(target);
  var x = oldPos.x + event.dx;
  var y = oldPos.y + event.dy;

  // keep the dragged position in the data-x/data-y attributes
  target.setAttribute('data-x', x);
  target.setAttribute('data-y', y);

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

  $('#position').text('x: ' + x + ' - y: ' + y);

  var result = $.grep(myItems, function(e) {
    if (e.x == parseInt(target.getAttribute('data-x')) || e.y == parseInt(target.getAttribute('data-y')))
      return 1;
  });

  if (result.length >= 1)
    target.style.backgroundColor = '#CCC';
  else
    target.style.backgroundColor = '#FFF';
}

关于javascript - 如何使用 interact.js 将元素对齐到其他可拖动元素，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34811478/