Display images in multiline Braille

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

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
index d2599e1f2934c41044e31ca0d5707ee712a343c2..03a9ee9732ed469b63f455501a5cf33444f78315 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js
@@ -94,6 +94,12 @@ Output = function() {
    * @private
    */
   this.outputContextFirst_ = false;
+
+  /**
+   * @type {string}
+   * @private
+   */
+  this.imageDataUrl_ = '';
 };
 
 /**
@@ -941,13 +947,16 @@ Output.prototype = {
         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.
@@ -1003,6 +1012,14 @@ Output.prototype = {
     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');