Modify AccessibilityTreeFormatter to build up an internal representation of the tree

content/browser/accessibility/accessibility_tree_formatter.cc

Index: content/browser/accessibility/accessibility_tree_formatter.cc
diff --git a/content/browser/accessibility/accessibility_tree_formatter.cc b/content/browser/accessibility/accessibility_tree_formatter.cc
index f8b4cc735230a139c6e660a862f3653d8181a2cc..781498833c2a649322ca8a000ce30f60e84df3ae 100644
--- a/content/browser/accessibility/accessibility_tree_formatter.cc
+++ b/content/browser/accessibility/accessibility_tree_formatter.cc
@@ -4,6 +4,7 @@
 
 #include "content/browser/accessibility/accessibility_tree_formatter.h"
 
+#include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string_util.h"
@@ -21,8 +22,8 @@ const char* kSkipString = "@NO_DUMP";
 }
 
 AccessibilityTreeFormatter::AccessibilityTreeFormatter(
-    BrowserAccessibility* node)
-    : node_(node) {
+    BrowserAccessibility* root)
+    : root_(root) {
   Initialize();
 }
 
@@ -45,26 +46,44 @@ AccessibilityTreeFormatter* AccessibilityTreeFormatter::Create(
 AccessibilityTreeFormatter::~AccessibilityTreeFormatter() {
 }
 
+void AccessibilityTreeFormatter::BuildAccessibilityTree(
+    DictionaryValue* dict) {
+  RecursiveBuildAccessibilityTree(root_, dict);
+}
+
 void AccessibilityTreeFormatter::FormatAccessibilityTree(
     string16* contents) {
-  RecursiveFormatAccessibilityTree(node_, contents, 0);
+  DictionaryValue dict;
+  BuildAccessibilityTree(&dict);
+  RecursiveFormatAccessibilityTree(&dict, contents);
 }
 
-void AccessibilityTreeFormatter::RecursiveFormatAccessibilityTree(
-    BrowserAccessibility* node, string16* contents, int indent) {
-  scoped_array<char> prefix(new char[indent + 1]);
-  for (int i = 0; i < indent; ++i)
-    prefix[i] = ' ';
-  prefix[indent] = '\0';
+void AccessibilityTreeFormatter::RecursiveBuildAccessibilityTree(
+    BrowserAccessibility* node, DictionaryValue* dict) {
+  AddProperties(node, dict);
+  ListValue* children = new ListValue;
+  dict->Set("children", children);

[dmazzoni, 2013/04/08 05:46:35]

Put dict field names in a constant at the top of this file, inside the anonymous
namespace, something like:

namespace {
const int kIndentSpaces = 4;
...
const char[] kChildrenDictAttr = "children";
}

[aboxhall, 2013/04/10 03:09:34]

Done (there was actually only this one).

+  for (size_t i = 0; i < node->children().size(); ++i) {
+    BrowserAccessibility* child_node = node->children()[i];
+    DictionaryValue* child_dict = new DictionaryValue;
+    children->Append(child_dict);
+    RecursiveBuildAccessibilityTree(child_node, child_dict);
+  }
+}
 
-  string16 line = ToString(node, prefix.get());
+void AccessibilityTreeFormatter::RecursiveFormatAccessibilityTree(
+    DictionaryValue* dict, string16* contents, int depth) {
+  string16 line = ToString(dict, string16(depth * kIndentSpaces, ' '));

[dmazzoni, 2013/04/08 05:46:35]

Thanks - I didn't realize you could construct a string this way!

[aboxhall, 2013/04/10 03:09:34]

Hehe - I was thinking "surely there's a more efficient way" so I looked up the
STL docs. It's neat!

   if (line.find(ASCIIToUTF16(kSkipString)) != string16::npos)
     return;
 
   *contents += line;
-  for (size_t i = 0; i < node->children().size(); ++i) {
-    RecursiveFormatAccessibilityTree(node->children()[i], contents,
-                                     indent + kIndentSpaces);
+  ListValue* children;
+  dict->GetList("children", &children);

[dmazzoni, 2013/04/08 05:46:35]

Make sure this uses the constant!

[aboxhall, 2013/04/10 03:09:34]

Done.

[aboxhall, 2013/04/10 03:09:34]

Done.

+  DictionaryValue* child_dict;
+  for (size_t i = 0; i < children->GetSize(); i++) {
+    children->GetDictionary(i, &child_dict);
+    RecursiveFormatAccessibilityTree(child_dict, contents, depth + 1);
   }
 }
 
@@ -127,23 +146,15 @@ bool AccessibilityTreeFormatter::MatchesFilters(
   return allow;
 }
 
-void AccessibilityTreeFormatter::StartLine() {
-  line_.clear();
-}
-
-void AccessibilityTreeFormatter::Add(
-    bool include_by_default, const string16& attr) {
+void AccessibilityTreeFormatter::WriteAttribute(
+    bool include_by_default, const string16& attr, string16* line) {
   if (attr.empty())
     return;
   if (!MatchesFilters(attr, include_by_default))
     return;
-  if (!line_.empty())
-    line_ += ASCIIToUTF16(" ");
-  line_ += attr;
-}
-
-string16 AccessibilityTreeFormatter::FinishLine() {
-  return line_;
+  if (!line->empty())
+    *line += ASCIIToUTF16(" ");
+  *line += attr;
 }
 
 }  // namespace content