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Pan-zoom a PDF (Javascript)

I'm trying to pan-zoom with the mouse a <div> that contains a PDF document.
I'm using PDF.js and panzoom libraries (but other working alternatives are welcome)
The snippet below basically does this task, but unfortunately, after the <div> is panzoomed, the PDF is not re-rendered, then its image gets blurry (pan the PDF with the mouse and zoom it with the mouse-wheel):
HTML
<script src="https://mozilla.github.io/pdf.js/build/pdf.js"></script>
<script src="https://cdn.jsdelivr.net/npm/#panzoom/panzoom#4.3.2/dist/panzoom.min.js"></script>
<div id="panzoom-container">
<canvas id="the-canvas"></canvas>
</div>
<style>
#the-canvas {
border: 1px solid black;
direction: ltr;
}
</style>
JAVASCRIPT
// Loaded via <script> tag, create shortcut to access PDF.js exports.
var pdfjsLib = window['pdfjs-dist/build/pdf'];
// The workerSrc property shall be specified.
pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://mozilla.github.io/pdf.js/build/pdf.worker.js';
var pdfDoc = null,
canvas = document.getElementById('the-canvas'),
ctx = canvas.getContext('2d');
var container = document.getElementById("panzoom-container")
function renderPage(desiredHeight) {
pdfDoc.getPage(1).then(function(page) {
var viewport = page.getViewport({ scale: 1, });
var scale = desiredHeight / viewport.height;
var scaledViewport = page.getViewport({ scale: scale, });
canvas.height = scaledViewport.height;
canvas.width = scaledViewport.width;
// Render PDF page into canvas context
var renderContext = {
canvasContext: ctx,
viewport: scaledViewport
};
page.render(renderContext);
});
}
// Get the PDF
var url = 'https://raw.githubusercontent.com/mozilla/pdf.js/ba2edeae/web/compressed.tracemonkey-pldi-09.pdf';
pdfjsLib.getDocument(url).promise.then(function(pdfDoc_) {
pdfDoc = pdfDoc_;
// Initial/first page rendering
renderPage(250);
});
var panzoom = Panzoom(container, {
setTransform: (container, { scale, x, y }) => {
// here I can re-render the page, but I don't know how
// renderPage(container.getBoundingClientRect().height);
panzoom.setStyle('transform', `scale(${scale}) translate(${x}px, ${y}px)`)
}
})
container.addEventListener('wheel', zoomWithWheel)
function zoomWithWheel(event) {
panzoom.zoomWithWheel(event)
}
https://jsfiddle.net/9rkh7o0e/5/
I think that the procedure is correct, but unfortunately I'm stuck into two issues that must be fixed (then I ask for your help):
I don't know how to re-render correctly the PDF after the panzoom happened.
consecutive renderings have to be queued in order to make this work properly (so that the PDF doesn't blink when panzooming)
How could I fix 1 and 2 ? I could not find any tool for doing that on a PDF, apart the panzoom lib.
Thanks

After some days of attempts, I solved the problem.
The tricky part was to scale down the contained canvas after the container has been scaled, with a transform-origin CSS attribute set:
canvas.style.transform = "scale("+1/panzoom.getScale()+")"
Here is a fiddle of a PDF that can pan-zoomed. Each new render is done after a small delay (here it is set to 250ms) which corresponds to a sort of "wheel stop event".
function zoomWithWheel(event) {
panzoom.zoomWithWheel(event)
clearTimeout(wheelTimeoutHandler);
wheelTimeoutHandler = setTimeout(function() {
canvas.style.transform = "scale("+1/panzoom.getScale()+")"
if (pdfDoc)
renderPage(panzoom.getScale());
}, wheelTimeout)
}
https://jsfiddle.net/7tmk0z42/

How to view PDF file before uploading

I'm implementing some code to to view a PDF file after selecting it from our computer, but I am getting some errors
I have tried with 'pdf.js' but I'm getting some error that 'PDFJS' or 'pdfjsLib' is not defined
function showInCanvas(url) {
'use strict';
var pdfAsArray = convertDataURIToBinary(url);
pdfjsLib.getDocument(pdfAsArray).then(function (pdf) {
pdf.getPage(1).then(function (page) {
var scale = 1.5;
var viewport = page.getViewport(scale);
var canvas = document.getElementById('the-canvas');
var context = canvas.getContext('2d');
canvas.height = viewport.height;
canvas.width = viewport.width;
var renderContext = {
canvasContext: context,
viewport: viewport
};
page.render(renderContext);
});
});
}
The error message that I get is:
Uncaught ReferenceError: pdfjsLib is not defined

Why are you depend on external library to preview pdf file even you could do it using iframe object.you just need to read file from file control and assign file object to iframe.
var file =document.getElementById("filecontrol").files[0];
var url =URL.createObjectURL(file );
$('#iframeid').attr('src',url);
HTML :
<iframe id="iframeid" width="x" height="y"></iframe>

Convert a PDF to thumbnail using PDF.JS

I am trying to write some code that converts the first page of a PDF to a PNG thumbnail. I have found several examples here on stackoverflow and other place on the web and it seems like a simple thing to do, but I cannot make it work.
I have a HTML file that looks like this
<!DOCTYPE html>
<html>
<head>
<title>JR PDF test</title>
</head>
<body>
<script type="text/javascript" src="/build/pdf.js"></script>
<script type="text/javascript" src="jr-pdf.js"></script>
<script type="text/javascript" src="canvas2image.js"></script>
</body>
<div id="pdf-main-container">
<a id="download-image" href="#">Download PNG</a>
</div>
</div>
</html>
<canvas id="the-canvas"></canvas>
and a the jr-pdf.js looks like this
// URL of PDF document
var url = "REGLEMENT_FOR_RALLY_2012.pdf";
// Asynchronous download PDF
PDFJS.getDocument(url)
.then(function(pdf) {
return pdf.getPage(1);
})
.then(function(page) {
// Set scale (zoom) level
var scale = 1.5;
// Get viewport (dimensions)
var viewport = page.getViewport(scale);
// Get canvas#the-canvas
var canvas = document.getElementById('the-canvas');
// Fetch canvas' 2d context
var context = canvas.getContext('2d');
// Set dimensions to Canvas
canvas.height = viewport.height;
canvas.width = viewport.width;
// Prepare object needed by render method
var renderContext = {
canvasContext: context,
viewport: viewport
};
// Render PDF page
page.render(renderContext);
// JR experiments
console.log('hej');
url = canvas.toDataURL();
downloadButton = document.getElementById('download-image');
downloadButton.setAttribute('download', 'jr.png');
downloadButton.setAttribute('href', url);
});
The first page of the PDF file is rendered correctly to the screen and a jr.png file is generated. When I look at the PNG file the header seems right, but when I try to view the file with an image viewer it is empty (actually it is shown as transparent).
So I guess these lines are wrong:
url = canvas.toDataURL();
downloadButton = document.getElementById('download-image');
downloadButton.setAttribute('download', 'jr.png');
downloadButton.setAttribute('href', url);
Any suggestions on how to make a correct PNG file?

page.render is asynchronous function -- you need to wait until it finishes painting
var renderTask = page.render(renderContext);
renderTask.promise.then(function () {
// use canvas now
var url = canvas.toDataURL();
var downloadButton = document.getElementById('download-image');
downloadButton.setAttribute('download', 'jr.png');
downloadButton.setAttribute('href', url);
});

Export Highcharts to PDF (using javascript and local server - no internet connection)

I am using Highcharts in my application (without any internet connection)
I have multiple charts on a html page, and I want to generate a PDF report that contains all the charts from this page.
How can I do this without sending the data to any server on the internet ?
I will be thankful for any help or any example you can provide.
Thank you in advance :)

Yes this is possible but involves a few different libraries to get working. The first Library is jsPDF which allows the creation of PDF in the browser. The second is canvg which allows for the rendering and parsing of SVG's, the bit that is really cool though is it can render an svg on to canvas element. Lastly is Highcharts export module which will allow us to send the svg to the canvg to turn into a data URL which can then be given to jsPDF to turn into your pdf.
Here is an example http://fiddle.jshell.net/leighking2/dct9tfvn/ you can also see in there source files you will need to include in your project.
So to start highcharts provides an example of using canvg with it's export to save a chart as a png. because you want all the iamges in a pdf this has been slightly altered for our purpose to just return the data url
// create canvas function from highcharts example http://jsfiddle.net/highcharts/PDnmQ/
(function (H) {
H.Chart.prototype.createCanvas = function (divId) {
var svg = this.getSVG(),
width = parseInt(svg.match(/width="([0-9]+)"/)[1]),
height = parseInt(svg.match(/height="([0-9]+)"/)[1]),
canvas = document.createElement('canvas');
canvas.setAttribute('width', width);
canvas.setAttribute('height', height);
if (canvas.getContext && canvas.getContext('2d')) {
canvg(canvas, svg);
return canvas.toDataURL("image/jpeg");
} 
else {
alert("Your browser doesn't support this feature, please use a modern browser");
return false;
}
}
}(Highcharts));
Then for the example i have set up export on a button click. This will look for all elements of a certain class (so choose one to add to all of your chart elements) and then call their highcharts.createCanvas function.
$('#export_all').click(function () {
var doc = new jsPDF();
// chart height defined here so each chart can be palced
// in a different position
var chartHeight = 80;
// All units are in the set measurement for the document
// This can be changed to "pt" (points), "mm" (Default), "cm", "in"
doc.setFontSize(40);
doc.text(35, 25, "My Exported Charts");
//loop through each chart
$('.myChart').each(function (index) {
var imageData = $(this).highcharts().createCanvas();
// add image to doc, if you have lots of charts,
// you will need to check if you have gone bigger
// than a page and do doc.addPage() before adding
// another image.
/**
* addImage(imagedata, type, x, y, width, height)
*/
doc.addImage(imageData, 'JPEG', 45, (index * chartHeight) + 40, 120, chartHeight);
});
//save with name
doc.save('demo.pdf');
});
important to note here that if you have lots of charts you will need to handle placing them on a new page. The documentation for jsPDF looks really outdated (they do have a good demos page though just not a lot to explain all the options possible), there is an addPage() function and then you can just play with widths and heights until you find something that works.
the last part is to just setup the graphs with an extra option to not display the export button on each graph that would normally display.
//charts
$('#chart1').highcharts({
navigation: {
buttonOptions: {
enabled: false
}
},
//this is just normal highcharts setup form here for two graphs see fiddle for full details
The result isn't too bad i'm impressed with the quality of the graphs as I wasn't expecting much from this, with some playing of the pdf positions and sizes could look really good.
Here is a screen shot showing the network requests made before and after the export, when the export is made no requests are made http://i.imgur.com/ppML6Gk.jpg
here is an example of what the pdf looks like http://i.imgur.com/6fQxLZf.png (looks better when view as actual pdf)
quick example to be tried on local https://github.com/leighquince/HighChartLocalExport

You need to setup your own exporting server, locally like in the article

Here is an example using the library pdfmake:
html:
<div id="chart_exchange" style="width: 450px; height: 400px; margin: 0 auto"></div>
<button id="export">export</button>
<canvas id="chart_exchange_canvas" width="450" height="400" style="display: none;"></canvas>
javascript:
function drawInlineSVG(svgElement, canvas_id, callback) {
var can = document.getElementById(canvas_id);
var ctx = can.getContext('2d');
var img = new Image();
img.setAttribute('src', 'data:image/svg+xml;base64,' + btoa(unescape(encodeURIComponent(svgElement))));
img.onload = function() {
ctx.drawImage(img, 0, 0);
callback(can.toDataURL("image/png"));
}
}
full working code:
https://jsfiddle.net/dimitrisscript/f6sbdsps/

Maybe this link can help you out.
http://bit.ly/1IYJIyF
Try refer to the exporting properties (fallbackToExportServer: false) and the necessary file that need to be include (offline-exporting.js).
Whereas for the export all at once part, currently I myself also still trying. Will update here if any.

This question is a bit old but was something i was working on myself recently and had some trouble with it.
I used the jsPDF library: https://github.com/MrRio/jsPDF
Issues i ran into involved jsPDF not supporting the SVG image exported by the high chart + images being blurry and low quality.
Below is the solution I used to get two charts into one pdf document:
function createPDF() {
var doc = new jsPDF('p', 'pt', 'a4'); //Create pdf
if ($('#chart1').length > 0) {
var chartSVG = $('#chart1').highcharts().getSVG();
var chartImg = new Image();
chartImg.onload = function () {
var w = 762;
var h = 600;
var chartCanvas = document.createElement('canvas');
chartCanvas.width = w * 2;
chartCanvas.height = h * 2;
chartCanvas.style.width = w + 'px';
chartCanvas.style.height = h + 'px';
var context = chartCanvas.getContext('2d');
chartCanvas.webkitImageSmoothingEnabled = true;
chartCanvas.mozImageSmoothingEnabled = true;
chartCanvas.imageSmoothingEnabled = true;
chartCanvas.imageSmoothingQuality = "high";
context.scale(2, 2);
chartCanvas.getContext('2d').drawImage(chartImg, 0, 0, 762, 600);
var chartImgData = chartCanvas.toDataURL("image/png");
doc.addImage(chartImgData, 'png', 40, 260, 250, 275);
if ($('#chart2').length > 0) {
var chart2SVG = $('#chart2').highcharts().getSVG(),
chart2Img = new Image();
chart2Img.onload = function () {
var chart2Canvas = document.createElement('canvas');
chart2Canvas.width = w * 2;
chart2Canvas.height = h * 2;
chart2Canvas.style.width = w + 'px';
chart2Canvas.style.height = h + 'px';
var context = chart2Canvas.getContext('2d');
chart2Canvas.webkitImageSmoothingEnabled = true;
chart2Canvas.mozImageSmoothingEnabled = true;
chart2Canvas.imageSmoothingEnabled = true;
chart2Canvas.imageSmoothingQuality = "high";
context.scale(2, 2);
chart2Canvas.getContext('2d').drawImage(chart2Img, 0, 0, 762, 600);
var chart2ImgData = chart2Canvas.toDataURL("image/png");
doc.addImage(chart2ImgData, 'PNG', 300, 260, 250, 275);
doc.save('ChartReport.pdf');
}
chart2Img.src = "data:image/svg+xml;base64," + window.btoa(unescape(encodeURIComponent(chart2SVG)));
}
}
chartImg.src = "data:image/svg+xml;base64," + window.btoa(unescape(encodeURIComponent(chartSVG)));
}
}
scripts to include:
<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/modules/exporting.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.2.61/jspdf.min.js"></script>

programatically change page of PDF using javascript?

I'm trying to display a PDF within an iFrame, for a PHP, HTML and CSS based web "app" on the iPad. However, when viewing a PDF that's either in an object or in an iFrame, on the iPad, you can't change the page you are viewing. The scrolling just doesn't seem to work.
So my thought is that I need to create a next and prev button that uses javascript to change the currently viewed page. However, I can't seem to find any information on how to achieve this without embedding code in the PDF. This is not an option for the app though, as users will obviously not know how to embed code in the PDF's they upload.
I'd really love any information on how to achieve this solution w/o modifying the PDF's. Also, if there is an alternative to using an object or iFrame that will make this work on the iPad, that would be great too.
Thanks in advance.

This can be done using PDF.js
Their webpage can be found here: http://mozilla.github.io/pdf.js/
I didn't want to use their solution at first, because I heard it will have issues rendering some PDF's. However, so far, it appears to render our PDFs perfectly.
Here is some code I used to implement the process
PDFJS.getDocument('FILE_LOCATION').then(function(pdf) {
state = true;
cur_page = 1;
total_pages = pdf.numPages;
pdf.getPage(cur_page).then(function(page) {
var scale = 1.5;
var viewport = page.getViewport(scale);
// Prepare canvas using PDF page dimensions
var canvas = document.getElementById('the-canvas');
var context = canvas.getContext('2d');
canvas.height = viewport.height;
canvas.width = viewport.width;
// Render PDF page into canvas context
var renderContext = {
canvasContext: context,
viewport: viewport
};
page.render(renderContext);
});
$(".pdf_viewer").on("click", ".prev_page", function(e) {
e.preventDefault();
if( state && cur_page > 1 ) {
--cur_page
pdf.getPage(cur_page).then(function(page) {
var scale = 1.5;
var viewport = page.getViewport(scale);
// Prepare canvas using PDF page dimensions
var canvas = document.getElementById('the-canvas');
var context = canvas.getContext('2d');
canvas.height = viewport.height;
canvas.width = viewport.width;
// Render PDF page into canvas context
var renderContext = {
canvasContext: context,
viewport: viewport
};
page.render(renderContext);
});
}
});
$(".pdf_viewer").on("click", ".next_page", function(e) {
e.preventDefault();
if( state && cur_page < total_pages ) {
++cur_page;
pdf.getPage(cur_page).then(function(page) {
var scale = 1.5;
var viewport = page.getViewport(scale);
// Prepare canvas using PDF page dimensions
var canvas = document.getElementById('the-canvas');
var context = canvas.getContext('2d');
canvas.height = viewport.height;
canvas.width = viewport.width;
// Render PDF page into canvas context
var renderContext = {
canvasContext: context,
viewport: viewport
};
page.render(renderContext);
});
}
});
$(".pdf_viewer").on("click", ".close_window", function(e) {
e.preventDefault();
if( state ) {
state = false;
pdf.destroy();
}
});
EDIT: fixed a typo