From 196c112243c81ead6a7c7c7013424d8c774cc8e1 Mon Sep 17 00:00:00 2001
From: Frode Petterson <frode.andre.petterson@gmail.com>
Date: Tue, 20 Jun 2017 16:47:07 +0200
Subject: [PATCH] Start improving accessibility

---
 card.js        | 86 +++++++++++++++++++++++++++++++++++++++++++-------
 memory-game.js | 39 +++++++++++++++++++++--
 semantics.json | 17 +++++++++-
 3 files changed, 126 insertions(+), 16 deletions(-)

diff --git a/card.js b/card.js
index 660a9bf..76a1c73 100644
--- a/card.js
+++ b/card.js
@@ -7,10 +7,11 @@
    * @extends H5P.EventDispatcher
    * @param {Object} image
    * @param {number} id
+   * @param {string} alt
    * @param {string} [description]
    * @param {Object} [styles]
    */
-  MemoryGame.Card = function (image, id, description, styles) {
+  MemoryGame.Card = function (image, id, alt, description, styles) {
     /** @alias H5P.MemoryGame.Card# */
     var self = this;
 
@@ -18,7 +19,7 @@
     EventDispatcher.call(self);
 
     var path = H5P.getPath(image.path, id);
-    var width, height, margin, $card;
+    var width, height, margin, $card, $wrapper, removedState, flippedState;
 
     if (image.width !== undefined && image.height !== undefined) {
       if (image.width > image.height) {
@@ -40,6 +41,7 @@
     self.flip = function () {
       $card.addClass('h5p-flipped');
       self.trigger('flip');
+      flippedState = true;
     };
 
     /**
@@ -47,6 +49,7 @@
      */
     self.flipBack = function () {
       $card.removeClass('h5p-flipped');
+      flippedState = false;
     };
 
     /**
@@ -54,6 +57,7 @@
      */
     self.remove = function () {
       $card.addClass('h5p-matched');
+      removedState = true;
     };
 
     /**
@@ -88,27 +92,85 @@
      */
     self.appendTo = function ($container) {
       // TODO: Translate alt attr
-      $card = $('<li class="h5p-memory-wrap"><div class="h5p-memory-card" role="button" tabindex="1">' +
+      $wrapper = $('<li class="h5p-memory-wrap" tabindex="-1" role="button"><div class="h5p-memory-card">' +
                   '<div class="h5p-front"' + (styles && styles.front ? styles.front : '') + '>' + (styles && styles.backImage ? '' : '<span></span>') + '</div>' +
                   '<div class="h5p-back"' + (styles && styles.back ? styles.back : '') + '>' +
-                    '<img src="' + path + '" alt="Memory Card" style="width:' + width + ';height:' + height + '"/>' +
+                    '<img src="' + path + '" alt="' + (alt || 'Memory Image') + '" style="width:' + width + ';height:' + height + '"/>' +
                   '</div>' +
                 '</div></li>')
         .appendTo($container)
-        .children('.h5p-memory-card')
-          .children('.h5p-front')
-            .click(function () {
-              self.flip();
-            })
-            .end();
+        .on('keydown', function (event) {
+          switch (event.which) {
+            case 13: // Enter
+            case 32: // Space
+              if (!flippedState) {
+                self.flip();
+                event.preventDefault();
+              }
+              return;
+            case 39: // Right
+            case 40: // Down
+              // Move focus forward
+              self.trigger('next');
+              event.preventDefault();
+              return;
+            case 37: // Left
+            case 38: // Up
+              // Move focus back
+              self.trigger('prev');
+              event.preventDefault();
+              return;
+          }
+        });
+      $card = $wrapper.children('.h5p-memory-card')
+        .children('.h5p-front')
+          .click(function () {
+            self.flip();
+          })
+          .end();
     };
 
     /**
      * Re-append to parent container
      */
     self.reAppend = function () {
-      var parent = $card[0].parentElement.parentElement;
-      parent.appendChild($card[0].parentElement);
+      var parent = $wrapper[0].parentElement;
+      parent.appendChild($wrapper[0]);
+    };
+
+    /**
+     *
+     */
+    self.makeTabbable = function () {
+      if ($wrapper) {
+        $wrapper.attr('tabindex', '0');
+      }
+    };
+
+    /**
+     *
+     */
+    self.makeUntabbable = function () {
+      if ($wrapper) {
+        $wrapper.attr('tabindex', '-1');
+      }
+    };
+
+    /**
+     *
+     */
+    self.setFocus = function () {
+      self.makeTabbable();
+      if ($wrapper) {
+        $wrapper.focus();
+      }
+    };
+
+    /**
+     *
+     */
+    self.isFlipped = function () {
+      return flippedState;
     };
   };
 
diff --git a/memory-game.js b/memory-game.js
index a0029f6..894f512 100644
--- a/memory-game.js
+++ b/memory-game.js
@@ -220,6 +220,38 @@ H5P.MemoryGame = (function (EventDispatcher, $) {
         counter.increment();
       });
 
+      /**
+       * @private
+       * @param {number} direction
+       */
+      var createCardChangeFocusHandler = function (direction) {
+        return function () {
+          // Locate next card
+          for (var i = 0; i < cards.length; i++) {
+            if (cards[i] === card) {
+              // Found current card
+
+              var nextCard, fails = 0;
+              do {
+                fails++;
+                nextCard = cards[i + (direction * fails)];
+                if (!nextCard) {
+                  return; // No more cards
+                }
+              }
+              while (nextCard.isFlipped());
+
+              card.makeUntabbable();
+              nextCard.setFocus();
+
+              return;
+            }
+          }
+        };
+      };
+
+      card.on('next', createCardChangeFocusHandler(1));
+      card.on('prev', createCardChangeFocusHandler(-1));
       cards.push(card);
     };
 
@@ -277,16 +309,16 @@ H5P.MemoryGame = (function (EventDispatcher, $) {
       var cardParams = cardsToUse[i];
       if (MemoryGame.Card.isValid(cardParams)) {
         // Create first card
-        var cardTwo, cardOne = new MemoryGame.Card(cardParams.image, id, cardParams.description, cardStyles);
+        var cardTwo, cardOne = new MemoryGame.Card(cardParams.image, id, cardParams.imageAlt, cardParams.description, cardStyles);
 
         if (MemoryGame.Card.hasTwoImages(cardParams)) {
           // Use matching image for card two
-          cardTwo = new MemoryGame.Card(cardParams.match, id, cardParams.description, cardStyles);
+          cardTwo = new MemoryGame.Card(cardParams.match, id, cardParams.matchAlt, cardParams.description, cardStyles);
           cardOne.hasTwoImages = cardTwo.hasTwoImages = true;
         }
         else {
           // Add two cards with the same image
-          cardTwo = new MemoryGame.Card(cardParams.image, id, cardParams.description, cardStyles);
+          cardTwo = new MemoryGame.Card(cardParams.image, id, cardParams.imageAlt, cardParams.description, cardStyles);
         }
 
         // Add cards to card list for shuffeling
@@ -314,6 +346,7 @@ H5P.MemoryGame = (function (EventDispatcher, $) {
       for (var i = 0; i < cards.length; i++) {
         cards[i].appendTo($list);
       }
+      cards[0].makeTabbable();
 
       if ($list.children().length) {
         $list.appendTo($container);
diff --git a/semantics.json b/semantics.json
index fd274e2..52a1f10 100644
--- a/semantics.json
+++ b/semantics.json
@@ -26,6 +26,13 @@
           "importance": "high",
           "ratio": 1
         },
+        {
+          "name": "imageAlt",
+          "type": "text",
+          "label": "Alternative text for Image",
+          "importance": "high",
+          "description": "Describe what can be seen in the photo. The text is read by text-to-speech tools needed by visually impaired users."
+        },
         {
           "name": "match",
           "type": "image",
@@ -35,6 +42,14 @@
           "description": "An optional image to match against instead of using two cards with the same image.",
           "ratio": 1
         },
+        {
+          "name": "matchAlt",
+          "type": "text",
+          "label": "Alternative text for Matching Image",
+          "importance": "low",
+          "optional": true,
+          "description": "Describe what can be seen in the photo. The text is read by text-to-speech tools needed by visually impaired users."
+        },
         {
           "name": "description",
           "type": "text",
@@ -146,7 +161,7 @@
         "importance": "low",
         "name": "tryAgain",
         "type": "text",
-        "default": "Try again?"
+        "default": "Reset"
       },
       {
         "label": "Close button label",