Implement word wrapping and panning in multiline Braille.

chrome/browser/resources/chromeos/chromevox/braille/braille_display_manager.js

Index: chrome/browser/resources/chromeos/chromevox/braille/braille_display_manager.js
diff --git a/chrome/browser/resources/chromeos/chromevox/braille/braille_display_manager.js b/chrome/browser/resources/chromeos/chromevox/braille/braille_display_manager.js
index 91352693897ff7619798b5995d8ec6485060c439..16a88cb877017822199df28929e0907d77f8db46 100644
--- a/chrome/browser/resources/chromeos/chromevox/braille/braille_display_manager.js
+++ b/chrome/browser/resources/chromeos/chromevox/braille/braille_display_manager.js
@@ -53,7 +53,7 @@ cvox.BrailleDisplayManager = function(translatorManager) {
    * @type {cvox.PanStrategy}
    * @private
    */
-  this.panStrategy_ = new cvox.WrappingPanStrategy();
+  this.panStrategy_ = new cvox.PanStrategy();
   /**
    * @type {function(!cvox.BrailleKeyEvent, !cvox.NavBraille)}
    * @private
@@ -76,16 +76,6 @@ cvox.BrailleDisplayManager = function(translatorManager) {
    * @private
    */
   this.realDisplayState_ = this.displayState_;
-  /**
-   * @type {!Array<number>}
-   * @private
-   */
-  this.textToBraille_ = [];
-  /**
-   * @type {!Array<number>}
-   * @private
-   */
-  this.brailleToText_ = [];
 
   translatorManager.addChangeListener(function() {
     this.translateContent_(this.content_, this.expansionType_);
@@ -170,7 +160,10 @@ cvox.BrailleDisplayManager.prototype.refreshDisplayState_ = function(
   var newSize = this.displayState_.textColumnCount *
                 this.displayState_.textRowCount || 0;
   if (oldSize != newSize) {
-    this.panStrategy_.setDisplaySize(newSize);
+    // TODO might need to change when display is plugged in.

[David Tseng, 2016/11/14 21:05:08]

This is going to break for real devices. Look at the logic dealing with whether
the display is available. Understand how:
- getVirtualDisplayState works above
- after you understand that, reconsider how you get the virtual display params
below

[ultimatedbz, 2016/11/15 18:04:02]

Right, I'm thinking that if a newState is available, I'll also set localStorage
to the physical display's dimensions, so that the localStorage values will be
consistent and won't break for real devices.

+    this.panStrategy_.setDisplaySize(parseInt(
+        localStorage['virtualBrailleRows'], 10),
+        parseInt(localStorage['virtualBrailleColumns'], 10));
   }
   this.refresh_();
 };
@@ -188,26 +181,26 @@ cvox.BrailleDisplayManager.prototype.onCaptionsStateChanged_ = function() {
 };
 
 
-/** @private */
+/**
+ * Refreshes what is shown on the physical braille display and the virtual
+ * braille captions display.
+ * @private */
 cvox.BrailleDisplayManager.prototype.refresh_ = function() {
   if (!this.displayState_.available) {
     return;
   }
-  var viewPort = this.panStrategy_.viewPort;
-  var buf = this.displayedContent_.slice(viewPort.start, viewPort.end);
+  var brailleBuf = this.panStrategy_.getCurrentBrailleSlice();
+  var textBuf = this.panStrategy_.getCurrentTextSlice();
   if (this.realDisplayState_.available) {
-    chrome.brailleDisplayPrivate.writeDots(buf, buf.byteLength, 1);
+    chrome.brailleDisplayPrivate.writeDots(brailleBuf,
+        brailleBuf.byteLength, 1);
   }
   if (cvox.BrailleCaptionsBackground.isEnabled()) {
-    var start = this.brailleToTextPosition_(viewPort.start);
-    var end = this.brailleToTextPosition_(viewPort.end);
-    cvox.BrailleCaptionsBackground.setContent(
-        this.content_.text.toString().substring(start, end), buf,
-        this.brailleToText_);
+    cvox.BrailleCaptionsBackground.setContent(textBuf, brailleBuf,
+        this.panStrategy_.brailleToText, this.panStrategy_.offsetsForSlices);
   }
 };
 
-
 /**
  * @param {!cvox.NavBraille} newContent New display content.
  * @param {cvox.ExpandingBrailleTranslator.ExpansionType} newExpansionType
@@ -220,8 +213,6 @@ cvox.BrailleDisplayManager.prototype.translateContent_ = function(
   var writeTranslatedContent = function(cells, textToBraille, brailleToText) {
     this.content_ = newContent;
     this.expansionType_ = newExpansionType;
-    this.textToBraille_ = textToBraille;
-    this.brailleToText_ = brailleToText;
     var startIndex = this.content_.startIndex;
     var endIndex = this.content_.endIndex;
     var targetPosition;
@@ -232,7 +223,7 @@ cvox.BrailleDisplayManager.prototype.translateContent_ = function(
         // Allow the cells to be extended with one extra cell for
         // a carret after the last character.
         var extCells = new ArrayBuffer(cells.byteLength + 1);
-        new Uint8Array(extCells).set(new Uint8Array(cells));
+        new Uint8Array(extCells).set(cells);
         // Last byte is initialized to 0.
         cells = extCells;
         translatedStartIndex = cells.byteLength - 1;
@@ -251,7 +242,7 @@ cvox.BrailleDisplayManager.prototype.translateContent_ = function(
       // Copy the translated content to a separate buffer and  add the cursor
       // to it.
       this.displayedContent_ = new ArrayBuffer(cells.byteLength);
-      new Uint8Array(this.displayedContent_).set(new Uint8Array(cells));
+      new Uint8Array(this.displayedContent_).set(cells);
       this.writeCursor_(this.displayedContent_,
                         translatedStartIndex, translatedEndIndex);
       targetPosition = translatedStartIndex;
@@ -259,7 +250,9 @@ cvox.BrailleDisplayManager.prototype.translateContent_ = function(
       this.translatedContent_ = this.displayedContent_ = cells;
       targetPosition = 0;
     }
-    this.panStrategy_.setContent(this.translatedContent_, targetPosition);
+    this.panStrategy_.setContent(this.content_.text.toString(),
+        this.translatedContent_, brailleToText);
+
     this.refresh_();
   }.bind(this);
 
@@ -288,9 +281,11 @@ cvox.BrailleDisplayManager.prototype.onKeyEvent_ = function(event) {
       this.panRight_();
       break;
     case cvox.BrailleKeyCommand.ROUTING:
+      /* TODO
       event.displayPosition = this.brailleToTextPosition_(
           event.displayPosition + this.panStrategy_.viewPort.start);
       // fall through
+      // */

[David Tseng, 2016/11/14 21:05:08]

Please don't comment out code like this with a TODO especially because this
breaks routing...

Btw, TODO's are formmated like:
TODO(ultimatedbz) ...

[ultimatedbz, 2016/11/15 00:01:17]

Hey David! Noted, my intentions weren't for this to stay here when the code to
be committed, but only so that I could be reminded to fill this out. This
initial CL was just to get the conversation started and get some comments on
code I've already written, while I continue to work on commenting, cleaning up
the code, and finishing up these  TODO's. Thanks!

     default:
       this.commandListener_(event, this.content_);
       break;
@@ -368,7 +363,8 @@ cvox.BrailleDisplayManager.prototype.writeCursor_ = function(
  */
 cvox.BrailleDisplayManager.prototype.brailleToTextPosition_ =
     function(braillePosition) {
-  var mapping = this.brailleToText_;
+  // TODO I'll need to support this function
+  var mapping = this.panStrategy_.brailleToText;
   if (braillePosition < 0) {
     // This shouldn't happen.
     console.error('WARNING: Braille position < 0: ' + braillePosition);
@@ -389,11 +385,6 @@ cvox.BrailleDisplayManager.prototype.brailleToTextPosition_ =
  * @private
  */
 cvox.BrailleDisplayManager.prototype.updatePanStrategy_ = function(wordWrap) {
-  var newStrategy = wordWrap ? new cvox.WrappingPanStrategy() :
-      new cvox.FixedPanStrategy();
-  newStrategy.setDisplaySize(this.displayState_.textColumnCount || 0);
-  newStrategy.setContent(this.translatedContent_,
-                         this.panStrategy_.viewPort.start);
-  this.panStrategy_ = newStrategy;
+  this.panStrategy_.setPanStrategy(wordWrap);
   this.refresh_();
 };