javascripthtmlpdfpdf.js

How do I determine the size of a pdf with pdf.js so I can scale to the screen size?


I need to scale a pdf so it fills the height of the screen, but all I've found is the function scale(). How do i know how much to scale it?


Solution

  • To determine the width/height of a page, you need to do the following:

    1. Get the page

    2. In a "promise" function (the page can only be retrieved asynchronously):

      a. Retrieve the viewport with a scale of 1

      b. Call the width property of the viewport

    The Code:

    //Get the page with your callback
    pdf.getPage(1).then( function(page) {
    
        //We need to pass it a scale for "getViewport" to work
        var scale = 1;
    
        //Grab the viewport with original scale
        var viewport = page.getViewport( 1 );
    
        //Here's the width and height
        console.log( "Width: " + viewport.width + ", Height: " + viewport.height );
    });