Finish implementing ChromeVox Next active indicator.

chrome/common/extensions/api/automation.idl

 // 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.
 
 // The <code>chrome.automation</code> API allows developers to access the
 // automation (accessibility) tree for the browser. The tree resembles the DOM
 // tree, but only exposes the <em>semantic</em> structure of a page. It can be
 // used to programmatically interact with a page by examining names, roles, and
 // states, listening for events, and performing actions on nodes.
 [nocompile] namespace automation {
@@ skipping 319 matching lines @@
 
     // The role of this node.
     automation.RoleType role;
 
     // The $(ref:automation.StateType)s describing this node.
     object state;
 
     // The rendered location (as a bounding box) of this node within the frame.
     automation.Rect location;
 
+    // Computes the bounding box of a subrange of this node within the frame.

[Peter Lundblad, 2015/11/20 11:15:03]

Sorry for being ignorant about coordinate systems and stuff, but what does 'in
the frame' mean here? It looks to me like you're making the coordinate screen
absolute, but maybe I am missing something. Do you want to be clear that this
only works for inline text boxes?

[dmazzoni, 2015/11/20 23:35:14]

Good catch. Actually this returns global screen coordinates now, when I fixed it
a while ago I forgot to update the docs here. Fixed both.

I think doing the local to global conversion in C++ makes far more sense.

+    // Returns the same as |location| if range information is not available.
+    static automation.Rect boundsForRange(long startIndex, long endIndex);

[Peter Lundblad, 2015/11/20 11:15:03]

Document what the start and end indices index into.

[dmazzoni, 2015/11/20 23:35:14]

Done.

+
     // The purpose of the node, other than the role, if any.
     DOMString description;
 
     // The help text for the node, if any.
     DOMString help;
 
     // The accessible name for this node, via the
     // <a href="http://www.w3.org/TR/wai-aria/roles#namecalculation">
     // Accessible Name Calculation</a> process.
     DOMString name;
@@ skipping 235 matching lines @@
     // Everything in the tree between the two node/offset pairs gets included
     // in the selection. The anchor is where the user started the selection,
     // while the focus is the point at which the selection gets extended
     // e.g. when dragging with a mouse or using the keyboard. For nodes with
     // the role staticText, the offset gives the character offset within
     // the value where the selection starts or ends, respectively.
     [nocompile] static void setDocumentSelection(
         SetDocumentSelectionParams params);
   };
 };