commit 85a87a81a9ff95ef538712ace5e5ccf1909d2e2e
author tell-k <ffk2005@gmail.com> Tue Jan 22 16:59:15 2019 +0000
committer Dmitri Shuralyov <dmitshur@golang.org> Wed Jan 23 18:36:29 2019 +0000
tree 869c04e455231ea980be8ba19b158d41b50e7f99
parent 9279ec27fd88b9e004f857564a7b4123cc584f63

cmd/present: fix CSS when printing slides

The existing CSS style was causing slides to not align with page
boundaries when printing slides. The cause of that is the CSS transform
property that is applied to automatically scale size of slides.
This change clears the transform property just before printing.

Fixes golang/go#29480

Change-Id: I6f719ad1b716e9bda8ba83007c3d1d7dece9ce08
GitHub-Last-Rev: d46dfee57601b2e9127c5e8e80e596dc2a2f24fa
GitHub-Pull-Request: golang/tools#67
Reviewed-on: https://go-review.googlesource.com/c/155940
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

cmd/present/static/slides.js

diff --git a/cmd/present/static/slides.js b/cmd/present/static/slides.js
index df10647..ff08b82 100644
--- a/cmd/present/static/slides.js
+++ b/cmd/present/static/slides.js
@@ -442,7 +442,7 @@
 };
 
 function scaleSmallViewports() {
-  var el = document.querySelector('.slides');
+  var el = document.querySelector('section.slides');
   var transform = '';
   var sWidthPx = 1250;
   var sHeightPx = 750;
@@ -468,6 +468,20 @@
       scaleSmallViewports();
     }, 50);
   });
+
+  // Force reset transform property of section.slides when printing page.
+  // Use both onbeforeprint and matchMedia for compatibility with different browsers.
+  var beforePrint = function() {
+    var el = document.querySelector('section.slides');
+    el.style.transform = '';
+  };
+  window.onbeforeprint = beforePrint;
+  if (window.matchMedia) {
+    var mediaQueryList = window.matchMedia('print');
+    mediaQueryList.addListener(function(mql) {
+      if (mql.matches) beforePrint();
+    });
+  }
 }
 
 /* Initialization */