javascript 锤子.js 和 preventDefault();

hammer.js and preventDefault();

提问by myradon

js to also support touch-gestures. I'm bagging my head about prevent default actions. when I set event.preventDefaultor event.gesture.preventDefault()or even apply parameter {prevent_defaults: true }on hammer it just triggers default action on the anchor. How can I prevent that and/or what am I doing wrong?!

js 还支持触摸手势。我正在考虑防止默认操作。当我在锤子上设置event.preventDefault或event.gesture.preventDefault()什至应用参数时{prevent_defaults: true }，它只会触发锚点上的默认操作。我怎样才能防止这种情况和/或我做错了什么？！

Code snippet;

代码片段；

function initializeNavigation() {
    $("nav").hammer({prevent_defaults: true }).on("tap", "a", function(event) {
        event.preventDefault();
        event.gesture.preventDefault();
        var target = $(this.hash);
        scrollToTarget(target, 1200);
        // if there is an open detailItem then close it.
        if (detailItemOpen) {
            $("div." + detailItemOpen).slideUp();
        }
    })

    if (Modernizr.mq('only screen and (max-width: 767px)'))  {
        initializeMobileMenuAndSetButton();
    }
}

回答by Joel Cox

Considering Hammer 2.0+ event.gestureis no longer and Event, but a simple Object.

考虑到 Hammer 2.0+event.gesture不再是和 Event，而是一个简单的 Object。

event.gesture.srcEventwill not be the proper event to stopPropagation on, so it will not work.

event.gesture.srcEvent将不是停止传播的正确事件，因此它将不起作用。

If you are using the tapevent, and want to prevent click/taps on the document you can do something like this. We need to create a global tap handler that will replace the original methods stopPropagationand preventDefault

如果您正在使用该tap事件，并且想要防止单击/点击文档，您可以执行以下操作。我们需要创建一个全局的 tap 处理程序来替换原来的方法stopPropagation和preventDefault

function createHandler(event) {
  return {
    isHandled: false,
    _shouldStopPropagation: false,
    _shoulePreventDefault: false,
    stopPropagation: event.stopPropagation.bind(event),
    preventDefault: event.preventDefault.bind(event),
  }
}


function handleEvent(handler, node) {
  let clickHandler; 


  if (!handler.isHandled) {
    handler.isHandled = true;
    document.addEventListener('click', clickHandler = (event)=> {
      if (handler._shouldStopPropagation) {
        handler.stopPropagation();
        event.stopPropagation();
      }
      
      if (handler._shoulePreventDefault) {
        handler.preventDefault();
        event.preventDefault();
      }
      document.removeEventListener('click', clickHandler, true);
    }, true);
  }
}


// Create a global tap Event so we can replace the original functions
document.addEventListener('tap', (event)=> {
  let handler = createHandler(event);

  event.stopPropagation = function() {
    handler._shouldStopPropagation = true;
    handleEvent(handler);
  };
  event.preventDefault  = function() {
    handler._shoulePreventDefault = true;
    handleEvent(handler);
  }
}, true);

// Now we can use it.
document.addEventListener('tap', (event)=> {
  /* If you want to prevent Default */
  event.preventDefault();

  /* If you want to stop propagation */
  event.stopPropagation();

  /* If you want to do both */
  event.preventDefault();
  event.stopPropagation();
});

回答by Proustibat

I think you can also try event.stopPropagation()and event.gesture.stopPropagation(). But it seems that Hammer gives that method : event.gesture.stopDetect()for a similar case.

我想你也可以尝试event.stopPropagation()和event.gesture.stopPropagation()。但似乎 Hammer 给出了这种方法：event.gesture.stopDetect()对于类似的情况。

source: https://github.com/hammerjs/hammer.js/wiki/Event-delegation-and-how-to-stopPropagation---preventDefaults

来源：https: //github.com/hammerjs/hammer.js/wiki/Event-delegation-and-how-to-stopPropagation---preventDefaults