Aligns text to braille in chromevox.

chrome/browser/resources/chromeos/chromevox/chromevox/background/braille_captions_background.js

Index: chrome/browser/resources/chromeos/chromevox/chromevox/background/braille_captions_background.js
diff --git a/chrome/browser/resources/chromeos/chromevox/chromevox/background/braille_captions_background.js b/chrome/browser/resources/chromeos/chromevox/chromevox/background/braille_captions_background.js
index a38d3b75dcfd09be1fc67631602dadf25149c574..cab516780d239e161d8ab0f2be84ff0b9c828def 100644
--- a/chrome/browser/resources/chromeos/chromevox/chromevox/background/braille_captions_background.js
+++ b/chrome/browser/resources/chromeos/chromevox/chromevox/background/braille_captions_background.js
@@ -57,19 +57,41 @@ cvox.BrailleCaptionsBackground.isEnabled = function() {
 /**
  * @param {string} text Text of the shown braille.
  * @param {ArrayBuffer} cells Braille cells shown on the display.
+ * @param {Array} brailleToText Map of Braille letters to the first

[dmazzoni, 2016/09/26 04:53:49]

How about {Array<number>} - it's always good to be as specific
as possible

[ultimatedbz, 2016/09/27 22:56:24]

Done.

+ * index of
+ * corresponding text letter.

[dmazzoni, 2016/09/26 04:53:48]

nit: wrap this

[ultimatedbz, 2016/09/27 22:56:24]

Done.

  */
-cvox.BrailleCaptionsBackground.setContent = function(text, cells) {
+cvox.BrailleCaptionsBackground.setContent = function(text, cells,
+    brailleToText) {
   var self = cvox.BrailleCaptionsBackground;
   // Convert the cells to Unicode braille pattern characters.
   var byteBuf = new Uint8Array(cells);
   var brailleChars = '';
-  for (var i = 0; i < byteBuf.length; ++i) {
+  var brailleBuf = '';
+  var textIndex = 0;
+  var groups = [];
+
+  for (var i = 0; i < byteBuf.length - 1; ++i) {

[dmazzoni, 2016/09/26 04:53:48]

Abstract this concept of breaking into groups into its own helper function
so it's ready for unit testing.

[ultimatedbz, 2016/09/27 22:56:24]

Done.

     brailleChars += String.fromCharCode(

[dmazzoni, 2016/09/26 04:53:49]

We're not using brailleChars anymore, so you can just
get rid of it.

Alternatively, do one pass to convert to brailleChars,
then a second pass to convert the text and brailleChars
to text - that might be better so you won't need the
String.fromCharCode line twice.

[ultimatedbz, 2016/09/27 21:15:49]

Isn't brailleChars used below in line 100 though? I wasn't exactly sure what the
extension bridge was so I left it alone.

[dmazzoni, 2016/09/27 21:54:50]

You're right, I missed that. That's for a way to display braille
captions on Chrome on other non-ChromeOS platforms

[ultimatedbz, 2016/09/27 22:56:24]

Done.

         self.BRAILLE_UNICODE_BLOCK_START | byteBuf[i]);
+    if ((i != 0) && ((brailleToText[i] != textIndex))) {
+      groups.push([text.substr(textIndex, brailleToText[i] - textIndex),

[dmazzoni, 2016/09/26 04:53:49]

Instead of each group being an array [text, braille],
make it an object with named fields, like
{text: text, braille: braille}. This makes it harder
to accidentally get them mixed up elsewhere in the code.

+          brailleBuf]);
+      brailleBuf = '';
+      textIndex = brailleToText[i];
+    }
+    brailleBuf += String.fromCharCode(
+        self.BRAILLE_UNICODE_BLOCK_START | byteBuf[i]);
+  }
+  // Puts the rest of the text into the last group.
+  if (byteBuf.length > 0) {
+    brailleChars += String.fromCharCode(
+        self.BRAILLE_UNICODE_BLOCK_START | byteBuf[byteBuf.length - 1]);
+    groups.push([text.substr(textIndex), brailleBuf]);
   }
 
   if (cvox.ChromeVox.isChromeOS) {
-    var data = {text: text, braille: brailleChars};
+    var data = {groups: groups};
     (new PanelCommand(PanelCommandType.UPDATE_BRAILLE, data)).send();
   } else {
     cvox.ExtensionBridge.send({