Display images in multiline Braille

chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview Provides output services for ChromeVox.
  */
 
 goog.provide('Output');
 goog.provide('Output.EventType');
@@ skipping 76 matching lines @@
    * @type {cvox.QueueMode}
    * @private
    */
   this.queueMode_ = cvox.QueueMode.QUEUE;
 
   /**
    * @type {boolean}
    * @private
    */
   this.outputContextFirst_ = false;
+
+  /**
+   * @type {string}
+   * @private
+   */
+  this.imageDataUrl_ = '';
 };
 
 /**
  * Delimiter to use between output values.
  * @type {string}
  */
 Output.SPACE = ' ';
 
 /**
  * Metadata about supported automation roles.
@@ skipping 827 matching lines @@
       var startIndex = -1, endIndex = -1;
       if (selSpan) {
         var valueStart = buff.getSpanStart(selSpan);
         var valueEnd = buff.getSpanEnd(selSpan);
         startIndex = valueStart + selSpan.startIndex;
         endIndex = valueStart + selSpan.endIndex;
         buff.setSpan(new cvox.ValueSpan(0), valueStart, valueEnd);
         buff.setSpan(new cvox.ValueSelectionSpan(), startIndex, endIndex);
       }
 
-      var output = new cvox.NavBraille({
-        text: buff,
-        startIndex: startIndex,
-        endIndex: endIndex
-      });
-
-      cvox.ChromeVox.braille.write(output);
+      if (this.imageDataUrl_) {
+        cvox.ChromeVox.braille.writeRawImage(this.imageDataUrl_);
+      } else {
+        var output = new cvox.NavBraille({
+          text: buff,
+          startIndex: startIndex,
+          endIndex: endIndex
+        });
+        cvox.ChromeVox.braille.write(output);
+      }
     }
 
     // Display.
     if (this.speechCategory_ != cvox.TtsCategory.LIVE)
       chrome.accessibilityPrivate.setFocusRing(this.locations_);
   },
 
   /**
    * Renders the given range using optional context previous range and event
    * type.
@@ skipping 35 matching lines @@
    * @param {string|!Object} format The output format either specified as an
    * output template string or a parsed output format tree.
    * @param {!Array<Spannable>} buff Buffer to receive rendered output.
    * @param {!AutomationNode=} opt_prevNode
    * @private
    */
   format_: function(node, format, buff, opt_prevNode) {
     var tokens = [];
     var args = null;
 
+    if (node != null &&
+        (node.role == RoleType.canvas || node.role == RoleType.image)) {
+      if (node.imageDataUrl)
+        this.imageDataUrl_ = node.imageDataUrl;
+      else
+        node.getImageData(0, 0);

[David Tseng, 2016/12/08 17:09:21]

This is going to be pretty strange in terms of feedback. The user will see
whatever is the default output for an image (e.g. name + role), then get a
non-panning image pattern.

I would hook this up as a command (command_handler.js) that gets triggered via a
keyboard shortcut (e.g. showTactleImage). Add the key binding in
chromevox/background/keymaps/next_keymap.json.

+    }
+
     // Hacky way to support args.
     if (typeof(format) == 'string') {
       format = format.replace(/([,:])\W/g, '$1');
       tokens = format.split(' ');
     } else {
       tokens = [format];
     }
 
     var speechProps = null;
     tokens.forEach(function(token) {
@@ skipping 813 matching lines @@
   /**
    * Gets the output buffer for braille.
    * @return {!Spannable}
    */
   get brailleOutputForTest() {
     return this.mergeBraille_(this.brailleBuffer_);
   }
 };
 
 });  // goog.scope