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

Question

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?

Answer 1

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 );
});