Unable to capture content of the scorm present inside the iframe using html2canvas

I am trying to capture the screenshot of the SCORM present inside the iframe but it is capturing content of the iframe, I am using html2canvas for that. All the files of SCORM are present on same server.
This is first slide/page of my scorm.

1) Firstly I have passed $('iframe') and var iframe = document.querySelector("iframe").contentWindow.document.body; to html2canvas but it is not working well.
Output of this is following Img

2) Then I passed e.target.parentNode to html2canvas so it capturing current element's parent.
Output this is following :

Here is my code :

html2canvas($('iframe'), {
    logging: true,
    onrendered: function(canvas){
        before_imgData = canvas.toDataURL('image/png');
        // console.log(before_imgData);
    }
});

But I want screenshot of all the screen how can I achieve that, any help would be appreciated.