Implement AutomationNode.querySelector().

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 202 matching lines @@
     visited
   };
 
   dictionary Rect {
     long left;
     long top;
     long width;
     long height;
   };
 
+  // The parameters for a <code>query</code>.
+  dictionary QueryInfo {
+    DOMString? querySelector;

[David Tseng, 2014/10/27 20:44:35]

Is this optional?

[aboxhall, 2014/10/28 23:43:56]

See below.

+  };

[David Tseng, 2014/10/27 20:44:35]

Will there be additional info members? If not, then just expose the query info
as a string.

[aboxhall, 2014/10/28 23:43:56]

Right, I guess my CL description was a little misleading :)

This is the proposed API in the linked bug
(https://code.google.com/p/chromium/issues/detail?id=404710)

/**
 * Gets the first node in this node's subtree which matches |queryInfo|.
 * @param {Object} queryInfo A query object with any of the following keys:
 *  - selector {string} a CSS querySelector string
 *  - state {StateType} for example ‘focused’
 *  - role {RoleType}
 * @return {chrome.automation.AutomationNode}
 */
chrome.automation.AutomationNode.query(query);

This change just implements 'selector' (which I somewhat arbitrarily renamed
querySelector here).

My idea was that we could implement the filters which act over the automation
tree in JavaScript, unless there's some more performant way to do it in C++.

I'd love it if you had any suggestions for other attributes we could query on,
too.

[dmazzoni, 2014/10/29 00:00:10]

My vote is to have two separate APIs. I'll comment on the bug.

+
+  // Called when the result for a <code>query</code> is available.
+  callback QueryCallback = void(AutomationNode node);
+
   // An event in the Automation tree.
   [nocompile, noinline_doc] dictionary AutomationEvent {
     // The $(ref:automation.AutomationNode) to which the event was targeted.
     AutomationNode target;
 
     // The type of the event.
     EventType type;
 
     // Stops this event from further processing except for any remaining
     // listeners on $(ref:AutomationEvent.target).
@@ skipping 52 matching lines @@
     // Sets selection within a text field.
     static void setSelection(long startIndex, long endIndex);
 
     // Adds a listener for the given event type and event phase.
     static void addEventListener(
         EventType eventType, AutomationListener listener, boolean capture);
 
     // Removes a listener for the given event type and event phase.
     static void removeEventListener(
         EventType eventType, AutomationListener listener, boolean capture);
+

[David Tseng, 2014/10/27 20:44:35]

nit: Docs?

[aboxhall, 2014/10/28 23:43:56]

Done.

+    static void query(QueryInfo info, QueryCallback callback);
   };
 
   // Called when the <code>AutomationRootNode</code> for the page is available.
   callback RootCallback = void(AutomationRootNode rootNode);
 
   // The root node of the automation tree for a single frame or desktop.
   // This may be:
   // <ul>
   //   <li> The desktop
   //   <li> The top frame of a page
@@ skipping 25 matching lines @@
     // tree with a placeholder root node; listen for the "loadComplete" event to
     // get a notification that the tree has fully loaded (the previous root node
     // reference will stop working at or before this point).
     [nocompile] static void getTree(optional long tabId, RootCallback callback);
 
     // Get the automation tree for the whole desktop which consists of all on
     // screen views. Note this API is currently only supported on Chrome OS.
     [nocompile] static void getDesktop(RootCallback callback);
   };
 };