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[Vanilla JS] Drag&Drop 드래그앤드롭 본문

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[Vanilla JS] Drag&Drop 드래그앤드롭

hanbikan 2020. 12. 7. 18:16

 

 

 

 

좀 무섭네요

그냥 원을 움직이는 건 너무 심심해서 이미지 하나 넣어본 것 뿐이에요 별 다른 기능은 없습니다.

 

 

 

HTML/CSS

<html>
  <head>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script src="js-dragdrop.js"></script>
  </head>
  <body>
    <style>
    .target{
      display: flex;
      position: absolute;
      left: 50px;
      top: 50px;
      border-radius: 20px;
      width: 40px;
      height: 40px;
      background-color: #4c3832;
      cursor: pointer;
    }
    </style>
    <img class="background" src="쿠마.png" width=500px></img>
    <a class="target"> </a>
    <a class="target"> </a>
  </body>
</html>

 

 

Javascript

function MouseDown(event){
  event.preventDefault();

  const el = event.target;
  const classList = el.classList;

  if( !classList.contains("hold")){
    const mouseX = event.clientX;
    const mouseY = event.clientY;

    const targetPos = el.getBoundingClientRect();
    const targetX = targetPos.x;
    const targetY = targetPos.y;
	
    /*타겟의 left, top이 그저 마우스의 좌표로 이동하게 된다면 어떻게 될지 상상해보라.*/
    const gapX = mouseX - targetX;
    const gapY = mouseY - targetY;
	
    el.setAttribute("gap-x", gapX);
    el.setAttribute("gap-y", gapY);

	/*수많은 target 중 클릭의 타겟이 된 하나의 target에 hold 클라스 부여함*/
    classList.add("hold");
  }
}

function MouseMove(event){
  event.preventDefault();

  const el = document.querySelector(".target.hold");
  if( el ){
    const mouseX = event.clientX;
    const mouseY = event.clientY;

    const gapX = el.getAttribute("gap-x");
    const gapY = el.getAttribute("gap-y");

    const targetX = mouseX - gapX;
    const targetY = mouseY - gapY;
    
    el.style.left = targetX+"px";
    el.style.top = targetY+"px";
  }
}

function MouseUp(event){
  event.preventDefault();

  const el = document.querySelector(".target.hold");
  el.removeAttribute("gap-x");
  el.removeAttribute("gap-y");
  el.classList.remove("hold");
}

$(document).ready(function(){
  const targets = document.querySelectorAll(".target");

  targets.forEach(function(target, idx){
    target.addEventListener('mousedown', MouseDown);
  });

  document.addEventListener('mousemove', MouseMove);
  document.addEventListener('mouseup', MouseUp);

});

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