Added matchmedia.js (https://github.com/paulirish/matchMedia.js/) to allows support for IE9.

Author: micahmills

js/matchmedia.js

@@ -0,0 +1,46 @@
+/*! matchMedia() polyfill - Test a CSS media type/query in JS. Authors & copyright (c) 2012: Scott Jehl, Paul Irish, Nicholas Zakas, David Knight. Dual MIT/BSD license */
+
+window.matchMedia || (window.matchMedia = function() {
+    "use strict";
+
+    // For browsers that support matchMedium api such as IE 9 and webkit
+    var styleMedia = (window.styleMedia || window.media);
+
+    // For those that don't support matchMedium
+    if (!styleMedia) {
+        var style       = document.createElement('style'),
+            script      = document.getElementsByTagName('script')[0],
+            info        = null;
+
+        style.type  = 'text/css';
+        style.id    = 'matchmediajs-test';
+
+        script.parentNode.insertBefore(style, script);
+
+        // 'style.currentStyle' is used by IE <= 8 and 'window.getComputedStyle' for all other browsers
+        info = ('getComputedStyle' in window) && window.getComputedStyle(style, null) || style.currentStyle;
+
+        styleMedia = {
+            matchMedium: function(media) {
+                var text = '@media ' + media + '{ #matchmediajs-test { width: 1px; } }';
+
+                // 'style.styleSheet' is used by IE <= 8 and 'style.textContent' for all other browsers
+                if (style.styleSheet) {
+                    style.styleSheet.cssText = text;
+                } else {
+                    style.textContent = text;
+                }
+
+                // Test if media query is true or false
+                return info.width === '1px';
+            }
+        };
+    }
+
+    return function(media) {
+        return {
+            matches: styleMedia.matchMedium(media || 'all'),
+            media: media || 'all'
+        };
+    };
+}());

wp-tevko-responsive-images.php

@@ -14,6 +14,7 @@
 // First we queue the polyfill
 function tevkori_get_picturefill() {
 	wp_enqueue_script( 'picturefill', plugins_url( '/js/picturefill.js', __FILE__ ) );
+	wp_enqueue_script( 'matchmedia', plugins_url( '/js/matchmedia.js', __FILE__ ) );
 }
 add_action( 'wp_enqueue_scripts', 'tevkori_get_picturefill' );