From 29947b5a570e07ca2ea2c2f14d5a3c7bcb838d4c Mon Sep 17 00:00:00 2001
From: Yury Delendik <ydelendik@mozilla.com>
Date: Thu, 6 Oct 2016 07:51:45 -0500
Subject: [PATCH] Printing canvases at PDF document size.

---
 web/pdf_page_view.js                          | 29 +++++++------------
 ...wer-snippet-mozPrintCallback-polyfill.html |  8 -----
 web/viewer.css                                |  7 +++--
 3 files changed, 15 insertions(+), 29 deletions(-)

diff --git a/web/pdf_page_view.js b/web/pdf_page_view.js
index 8a1d197b7..927d9b0d3 100644
--- a/web/pdf_page_view.js
+++ b/web/pdf_page_view.js
@@ -546,22 +546,18 @@ var PDFPageView = (function PDFPageViewClosure() {
       var pdfPage = this.pdfPage;
 
       var viewport = pdfPage.getViewport(1);
-      // Use the same hack we use for high dpi displays for printing to get
-      // better output until bug 811002 is fixed in FF.
-      var PRINT_OUTPUT_SCALE = 2;
+
       var canvas = document.createElement('canvas');
 
-      // The logical size of the canvas.
-      canvas.width = Math.floor(viewport.width) * PRINT_OUTPUT_SCALE;
-      canvas.height = Math.floor(viewport.height) * PRINT_OUTPUT_SCALE;
+      // The size of the canvas in pixels for printing.
+      var PRINT_RESOLUTION = 150;
+      var PRINT_UNITS = PRINT_RESOLUTION / 72.0;
+      canvas.width = Math.floor(viewport.width * PRINT_UNITS);
+      canvas.height = Math.floor(viewport.height * PRINT_UNITS);
 
-      // The rendered size of the canvas, relative to the size of canvasWrapper.
-      canvas.style.width = (PRINT_OUTPUT_SCALE * 100) + '%';
-
-      var cssScale = 'scale(' + (1 / PRINT_OUTPUT_SCALE) + ', ' +
-                                (1 / PRINT_OUTPUT_SCALE) + ')';
-      CustomStyle.setProp('transform' , canvas, cssScale);
-      CustomStyle.setProp('transformOrigin' , canvas, '0% 0%');
+      // The physical size of the canvas as specified by the PDF document.
+      canvas.style.width = Math.floor(viewport.width * CSS_UNITS) + 'px';
+      canvas.style.height = Math.floor(viewport.height * CSS_UNITS) + 'px';
 
       var canvasWrapper = document.createElement('div');
       canvasWrapper.appendChild(canvas);
@@ -574,15 +570,10 @@ var PDFPageView = (function PDFPageViewClosure() {
         ctx.fillStyle = 'rgb(255, 255, 255)';
         ctx.fillRect(0, 0, canvas.width, canvas.height);
         ctx.restore();
-//#if !(MOZCENTRAL || FIREFOX)
-        // Used by the mozCurrentTransform polyfill in src/display/canvas.js.
-        ctx._transformMatrix =
-          [PRINT_OUTPUT_SCALE, 0, 0, PRINT_OUTPUT_SCALE, 0, 0];
-//#endif
-        ctx.scale(PRINT_OUTPUT_SCALE, PRINT_OUTPUT_SCALE);
 
         var renderContext = {
           canvasContext: ctx,
+          transform: [PRINT_UNITS, 0, 0, PRINT_UNITS, 0, 0],
           viewport: viewport,
           intent: 'print'
         };
diff --git a/web/viewer-snippet-mozPrintCallback-polyfill.html b/web/viewer-snippet-mozPrintCallback-polyfill.html
index c45252371..ebf2e3419 100644
--- a/web/viewer-snippet-mozPrintCallback-polyfill.html
+++ b/web/viewer-snippet-mozPrintCallback-polyfill.html
@@ -1,12 +1,4 @@
 <div id="mozPrintCallback-shim" hidden>
-  <style>
-@media print {
-  #printContainer div {
-    page-break-after: always;
-    page-break-inside: avoid;
-  }
-}
-  </style>
   <style scoped>
 #mozPrintCallback-shim {
   position: fixed;
diff --git a/web/viewer.css b/web/viewer.css
index 898c7921b..66e9e137d 100644
--- a/web/viewer.css
+++ b/web/viewer.css
@@ -1810,8 +1810,11 @@ html[dir='rtl'] #documentPropertiesOverlay .row > * {
     position: relative;
     top: 0;
     left: 0;
-    height: 100%;
-    overflow: hidden;
+    width: 1px;
+    height: 1px;
+    overflow: visible;
+    page-break-after: always;
+    page-break-inside: avoid;
   }
   #printContainer canvas {
     display: block;