錘子拖拽中心

Question

我爲我的應用使用Hammers庫。如何從我觸摸的任何點拖動我的元素，而不是通過中心拖動？謝謝 ！

var hammertime = Hammer(document.getElementById('contentTab'), { 
    transform_always_block:true, 
    transform_min_scale: 1, 
    drag_block_horizontal: true, 
    drag_block_vertical: true, 
    drag_min_distance: 0, 
    drag_max_touches: 2, 
    release: false 

}); 

var rect = document.getElementById('tabella'); 

var posX=0, posY=0, 
    scale=1, last_scale, 
    rotation= 1, last_rotation, 
    dt =0; 

hammertime.on('touch doubletap drag transform', function(ev) { 
    switch(ev.type) { 

    case 'doubletap': 
     if (dt == 0){ 
      dt=1; 
      scale = 2; 
     }else if (dt ==1){ 
      dt = 0; 
      scale = 1; 
      posX=0; 
      posY=0; 
     } 

     last_rotation = rotation; 
     break; 

     case 'touch': 
      last_scale = scale; 

      last_rotation = rotation; 
      break; 



    case 'drag': 



      posX = ev.gesture.deltaX; 
      posY = ev.gesture.deltaY; 
      break; 

     case 'transform': 
    //   rotation = last_rotation + ev.gesture.rotation; 
      scale = Math.max(1, Math.min(last_scale * ev.gesture.scale, 10)); 
      break; 
    } 

    // transform! 
    var transform = 
      "translate3d("+posX+"px,"+posY+"px, 0) " + 
      "scale3d("+scale+","+scale+", 0) " ; 
      "rotate("+rotation+"deg) "; 

    rect.style.transform = transform; 
    rect.style.oTransform = transform; 
    rect.style.msTransform = transform; 
    rect.style.mozTransform = transform; 
    rect.style.webkitTransform = transform; 
}); 

Answer 1

更改

posX = ev.gesture.deltaX; 
posY = ev.gesture.deltaY; 

到

posX += ev.gesture.deltaX; 
posY += ev.gesture.deltaY; 

可能做的伎倆。