Implement rich editable line output

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

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.js
index b19fb53548fa3932d691b4df9002be96e59215cc..ea0424015a2c0ab473592c46afcaebf5828d3736 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.js
@@ -134,6 +134,21 @@ cursors.Cursor.prototype = {
   },
 
   /**
+   * Compares this cursor with |rhs|.
+   * @param {cursors.Cursor} rhs
+   * @return Dir.BACKWARD if |rhs| comes before this cursor in
+   * document order. Forward otherwise.
+   */
+  compare: function(rhs) {
+    if (!this.node || !rhs.node)
+      return Dir.FORWARD;
+
+    if (rhs.node == this.node)
+      return rhs.index < this.index ? Dir.BACKWARD : Dir.FORWARD;
+    return AutomationUtil.getDirection(this.node, rhs.node);
+  },
+
+  /**
    * Returns the node. If the node is invalid since the last time it
    * was accessed, moves the cursor to the nearest valid ancestor first.
    * @return {AutomationNode}
@@ -364,7 +379,10 @@ cursors.Cursor.prototype = {
         }
         break;
       case Unit.LINE:
-        newIndex = 0;
+        var deepEquivalent = this.deepEquivalent;
+        newNode = deepEquivalent.node || newNode;
+        newIndex = deepEquivalent.index || 0;
+
         switch (movement) {
           case Movement.BOUND:
             newNode = AutomationUtil.findNodeUntil(newNode, dir,
@@ -388,6 +406,44 @@ cursors.Cursor.prototype = {
   },
 
   /**
+   * Returns the deepest equivalent cursor.
+   * @return {cursors.Cursor}
+   */
+  get deepEquivalent() {

[dmazzoni, 2017/05/09 04:49:46]

Might be nice to have a unit test for this?

[David Tseng, 2017/05/09 23:22:51]

Before we get there, do you have any comments on whether this resembles the
version found in Blink for positions/selections? I mostly wrote this to get
something working when trying to arrow through a content editable.

[dmazzoni, 2017/05/10 06:02:52]

I think so. Note that Nektarios has already implemented this
(AXPosition::AsLeafTextPosition), which is in ui/accessibility so we
could use it here. What would you think about adding native bindings
for AXPosition or some subset of it? If we find any bugs we'd only have
to fix them in one place

+    var newNode = this.node;
+    var newIndex = this.index_;
+    while (newNode.firstChild) {
+      if (newNode.role == RoleType.STATIC_TEXT) {
+        // Text offset.
+        // Re-interpret the index as an offset into an inlineTextBox.
+        var target = newNode.firstChild;
+        var length = 0;
+        while (target && length < newIndex) {
+          if (length <= newIndex && newIndex < (length + target.name.length))
+          break;

[dmazzoni, 2017/05/09 04:49:46]

nit: indent

[David Tseng, 2017/05/09 23:22:51]

Done.

+          length += target.name.length;
+          target = target.nextSibling;
+        }
+        if (target) {
+          newNode = target;
+          newIndex = newIndex - length;
+        }
+        break;
+      } else if (newNode.role != RoleType.INLINE_TEXT_BOX &&
+          newNode.children[newIndex]) {
+        // Valid node offset.
+        newNode = newNode.children[newIndex];
+        newIndex = 0;
+      } else {
+        // Invalid offset.
+        break;
+      }
+    }
+
+    return new cursors.Cursor(newNode, newIndex);
+  },
+
+  /**
    * Returns whether this cursor points to a valid position.
    * @return {boolean}
    */