javascript .click() 在 Mozilla 中不起作用

Question

I have taken the code to access a file on the computer from the browser in Unity from this link:

Unity3D - Upload a image from PC memory to WebGL app

I have set the opacity of the elements with span to 0 and I have added a code call to the click () event to make it transparent to the user and directly show the file selector.

The modified code is as follows:

var getImage = {
    getImageFromBrowser: function(objectNamePtr, funcNamePtr) {
      // Because unity is currently bad at JavaScript we can't use standard
      // JavaScript idioms like closures so we have to use global variables :(
      window.becauseUnitysBadWithJavacript_getImageFromBrowser =
          window.becauseUnitysBadWithJavacript_getImageFromBrowser || {
          busy: false,
          initialized: false,
          rootDisplayStyle: null,  // style to make root element visible
          root_: null,             // root element of form
          ctx_: null,              // canvas for getting image data;
      };
      var g = window.becauseUnitysBadWithJavacript_getImageFromBrowser;
      if (g.busy) {
          // Don't let multiple requests come in
          return;
      }
      g.busy = true;

      var objectName = Pointer_stringify(objectNamePtr);
      var funcName = Pointer_stringify(funcNamePtr);

      if (!g.initialized) {
          g.initialized = true;
          g.ctx = window.document.createElement("canvas").getContext("2d");

          // Append a form to the page (more self contained than editing the HTML?)
          g.root = window.document.createElement("div");
          g.root.innerHTML = [
            '<style>                                                    ',
            '.getimage {                                                ',
            '    position: absolute;                                    ',
            '    left: 0;                                               ',
            '    top: 0;                                                ',
            '    width: 100%;                                           ',
            '    height: 100%;                                          ',
            '    display: -webkit-flex;                                 ',
            '    display: flex;                                         ',
            '    -webkit-flex-flow: column;                             ',
            '    flex-flow: column;                                     ',
            '    -webkit-justify-content: center;                       ',
            '    -webkit-align-content: center;                         ',
            '    -webkit-align-items: center;                           ',
            '                                                           ',
            '    justify-content: center;                               ',
            '    align-content: center;                                 ',
            '    align-items: center;                                   ',
            '                                                           ',
            '    z-index: 2;                                            ',
            '    color: white;                                          ',
            '    background-color: rgba(0,0,0,0.8);                     ',
            '    font: sans-serif;                                      ',
            '    font-size: x-large;                                    ',
            '}                                                          ',
            '.getimage a,                                               ',
            '.getimage label {                                          ',
            '   font-size: x-large;                                     ',
            '   background-color: rgba(0,0,0,0);                        ',
            '   border-radius: 0.5em;                                   ',
            '   border: 0px solid black;                                ',
            '   padding: 0.5em;                                         ',
            '   margin: 0.25em;                                         ',
            '   outline: none;                                          ',
            '   display: inline-block;                                  ',
            '}                                                          ',
            '.getimage input {                                          ',
            '    display: none;                                         ',
            '}                                                          ',
            '</style>                                                   ',
            '<div class="getimage">                                     ',
            '    <div>                                                  ',
            '    <span style="opacity: 0">                              ',
            '      <label for="photo">click to choose an image</label>  ',
            '      <input id="photo" type="file" accept="image/*"/><br/>',
            '      <a>cancel</a>                                        ',
            '    </span>                                                ',
            '    </div>                                                 ',
            '</div>                                                     ',
          ].join('\n');
          var input = g.root.querySelector("input");
          input.addEventListener('change', getPic);

          // prevent clicking in input or label from canceling
          input.addEventListener('click', preventOtherClicks);
          var label = g.root.querySelector("label");
          label.addEventListener('click', preventOtherClicks);

          // clicking cancel or outside cancels
          var cancel = g.root.querySelector("a");  // there's only one
          cancel.addEventListener('click', handleCancel);
          var getImage = g.root.querySelector(".getimage");
          getImage.addEventListener('click', handleCancel);

          // remember the original style
          g.rootDisplayStyle = g.root.style.display;

          window.document.body.appendChild(g.root);
      }

      // make it visible
      g.root.style.display = g.rootDisplayStyle;

      g.root.querySelector("#photo").click();

      function preventOtherClicks(evt) {
          evt.stopPropagation();
      }

      function getPic(evt) {
          evt.stopPropagation();
          var fileInput = evt.target.files;
          if (!fileInput || !fileInput.length) {
              return sendError("no image selected");
          }

          var picURL = window.URL.createObjectURL(fileInput[0]);
          var img = new window.Image();
          img.addEventListener('load', handleImageLoad);
          img.addEventListener('error', handleImageError);
          img.src = picURL;
      }

      function handleCancel(evt) {
          evt.stopPropagation();
          evt.preventDefault();
          sendError("cancelled");
      }

      function handleImageError(evt) {
          sendError("Could not get image");
      }

      function handleImageLoad(evt) {
          var img = evt.target;
          window.URL.revokeObjectURL(img.src);
          // We probably don't want the fullsize image. It might be 3000x2000 pixels or something too big
          g.ctx.canvas.width  = 256;
          g.ctx.canvas.height = 256;
          g.ctx.drawImage(img, 0, 0, g.ctx.canvas.width, g.ctx.canvas.height);

          var dataUrl = g.ctx.canvas.toDataURL();

          // free the canvas memory (could probably be zero)
          g.ctx.canvas.width  = 1;
          g.ctx.canvas.height = 1;

          sendResult(dataUrl);
          g.busy = false;
      }

      function sendError(msg) {
          sendResult("error: " + msg);
      }

      function hide() {
          g.root.style.display = "none";
      }

      function sendResult(result) {
          hide();
          g.busy = false;
          SendMessage(objectName, funcName, result);
      }
    },
};

mergeInto(LibraryManager.library, getImage);

The problem is that it works correctly in Google Chrome and Microsoft Edge Chromium, but in Mozilla Firefox the click () event is not triggered automatically, the invisible element does exist and, if I click on it, the code is executed correctly.

I have verified that the element on which I click () is not null, but I can't get it to launch automatically. Could you tell me how I can solve it either by modifying this code or with a different code?

Thanks in advance.

Greetings.

Answer 1

This is the popup blocker in Firefox preventing async calls from spawning the file picker. https://bugzilla.mozilla.org/show_bug.cgi?id=1678389 should fix this.