Issue with setCropBoxData in cropper js

Question

I have created a function which resizes the size of the crop box. The user enters height and width, clicks "set" and job is done.

$('body').on('click', '#cropImageModal .set_box_size', function () { 
    var width = $(this).parents('.panel-body').find('.width').val();
    var height = $(this).parents('.panel-body').find('.height').val();
    document.getElementById('imageToCrop').cropper.setCropBoxData({width: parseInt(width), height: parseInt(height)});
});

Except we have a problem when, which is when resize is performed for some reason crop box is scaled down depending on the size of the image.

i.e. I have an image 700x385 and I set the box to be 700x300 and click "set"... result? the result is 510x219

I have narrowed down to the issue within cropperJS and it is to do with a code on lines 2662-2667:

if (self.ready && self.cropped) {
  data = {
    x: cropBoxData.left - canvasData.left,
    y: cropBoxData.top - canvasData.top,
    width: cropBoxData.width,
    height: cropBoxData.height
  };

  // issue is below
  ratio = imageData.width / imageData.naturalWidth;

  each(data, function (n, i) {
    n /= ratio;
    data[i] = rounded ? Math.round(n) : n;
  });
}

If I remove "ratio" code above the problem is solved but now getCroppedCanvas doesn't work properly due to the added black background to the cropped image.

---

By the way, same can be seen when using http://fengyuanchen.github.io/cropperjs/, if you are to:

1. click "Get Crop Box Data"
2. adjust the width/height in the box where result presented
3. click "Set Crop Box Data"
4. The Width / Height parameters to the right of the image do not match up

Answer 1

The solution was to figure out the ratio and then perform the calculation of adjusted width and height using calculated ratio:

var width = parseInt($(this).parents('.panel-body').find('.width').val());
var height = parseInt($(this).parents('.panel-body').find('.height').val());

var ratio = document.getElementById('imageToCrop').cropper.imageData.width /  document.getElementById('imageToCrop').cropper.imageData.naturalWidth; 

document.getElementById('imageToCrop').cropper.setCropBoxData({width: width*ratio, height: height*ratio});