Paste image from clipboard to fabric.js canvas?

Question

I'm trying to create a function that pastes an image from the user's clipboard to the canvas as a new fabric.Image(). Any search result I find either describes cloning objects already on the canvas or pasting IText data. This SO question is related to what I'm asking about, but it's 4 years old and the function in the top answer doesn't work:

How to do Copy and paste the image from User system to Canvas using fabric.js

Here's the code I'm currently trying to use. I'm trying to set up a paste function I can call later:

var $wrapper = $('#content'), 
  canvas = new fabric.Canvas('canvas', {
    width: 400,
    height: 550
  }),
pasteImage = function (e) {
    var items=e.originalEvent.clipboardData.items;

    e.preventDefault();
    e.stopPropagation();

    // Fabric.js image function
    function canvasImage(url) {
      var img = new fabric.Image(url);
      img.scale(0.75).center().setCoords();
      canvas.add(img).renderAll();
    }

    //Loop through files
    for(var i=0;i<items.length;i++){
      var file = items.items[i],
          type = file.type;

      if (type.indexOf("image")!=-1) {
        var imageData = file.getAsFile();
        var imageURL=window.webkitURL.createObjectURL(imageData);
        canvasImage(imageURL);
      }
    }
  };
$wrapper.on('paste', pasteImage);

Here's a fiddle to see it in action (or inaction, I guess). This will eventually be part of a Photoshop plugin, so thankfully I only need to worry about this working in Chrome.

Answer 1

I couldn't get your paste event handler to trigger, because i'm not sure if div can natively take the past event unless you make it a contenteditable div, which in your use case i doubt you want to do.

I just recently implemented this in an app of my own, but i wasn't using fabric, just native canvas and js.

You're going to have to rework your code, but try changing

$wrapper.on('paste', pasteImage);

to

$(window).on('paste', pasteImage);

Regardless, I tinkered with your current code, and this is what I got to work, albeit it might not have your settings being triggered completely, but it is pasting the image in:

(function() {
  var $wrapper = $('#content'), 
      canvas = new fabric.Canvas('canvas', {
        width: 400,
        height: 550
      }),
      txtStyles = {
        top: 100,
        left: 200,
        padding: 6,
        fill: '#d6d6d6',
        fontFamily: 'sans-serif',
        fontSize: '24',
        originY: 'center',
        originX: 'center',
        borderColor: '#d6d6d6',
        cornerColor: '#d6d6d6',
        cornerSize: 5,
        cornerStyle: 'circle',
        transparentCorners: false,
        lockUniScaling: true
      },
      imgAttrs = {
        left: 200,
        top: 200,
        originY: 'center',
        originX: 'center',
        borderColor: '#d6d6d6',
        cornerColor: '#d6d6d6',
        cornerSize: 5,
        cornerStyle: 'circle',
        transparentCorners: false,
        lockUniScaling: true
      },
      introTxt = new fabric.Text('Paste images here', txtStyles),
      pasteImage = function (e) {
        var items=e.originalEvent.clipboardData.items;

        e.preventDefault();
        e.stopPropagation();

        //Loop through files
        for(var i=0;i<items.length;i++){
          if (items[i].type.indexOf('image')== -1) continue;
          var file = items[i],
              type = items[i].type;
          var imageData = file.getAsFile();
          var URLobj = window.URL || window.webkitURL;
          var img = new Image();
          img.src = URLobj.createObjectURL(imageData);
          fabric.Image.fromURL(img.src, function(img){
            canvas.add(img);
          });
        }
      },

      //Canvas starter text
      introCanvas = function() {
        canvas.add(introTxt);
      };

  introCanvas();
  $(window).on('paste', pasteImage);
})();

fiddlers: https://jsfiddle.net/c0kw5dbu/3/