问在AMI医学影像中使用鼠标移动改变级别/窗口ToolKit

EN

var drag =  {
  x: null,
  y: null
}

var shiftDown = false;

function onKeyPressed(event){

  shiftDown = event.shiftKey;

  if(!shiftDown){
    drag.x = null;
    drag.y = null;
  }

}

container.addEventListener('keydown', onKeyPressed);
container.addEventListener('keyup', onKeyPressed);

function onMouseMove(event){

  if(!shiftDown || !stack || !stackHelper){
    return;
  }

  if(drag.x === null){
    drag.x = event.offsetX;
    drag.y = event.offsetY;
  }

  var threshold = 15;
  var dynamicRange = stack.minMax[1] - stack.minMax[0];
  dynamicRange /= container.clientWidth;

  if(Math.abs(event.offsetX - drag.x) > threshold){
    // window width
    stackHelper.slice.windowWidth += dynamicRange * (event.offsetX - drag.x);
    drag.x = event.offsetX;
  }

  if(Math.abs(event.offsetY - drag.y) > threshold){
    // window center
    stackHelper.slice.windowCenter -= dynamicRange * (event.offsetY - drag.y);
    drag.y = event.offsetY;
  }

}
container.addEventListener('mousemove', onMouseMove);