content/browser/accessibility/accessibility_tree_formatter.cc

// Copyright (c) 2012 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.

#include "content/browser/accessibility/accessibility_tree_formatter.h"

#include <stddef.h>

#include <memory>
#include <utility>

#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/strings/pattern.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "content/browser/accessibility/browser_accessibility_manager.h"
#include "content/browser/renderer_host/render_widget_host_view_base.h"
#include "content/browser/web_contents/web_contents_impl.h"
#include "content/public/browser/web_contents.h"

namespace content {

namespace {

const char kIndentSymbol = '+';
const int kIndentSymbolCount = 2;
const char kSkipString[] = "@NO_DUMP";
const char kSkipChildren[] = "@NO_CHILDREN_DUMP";
const char kChildrenDictAttr[] = "children";

}  // namespace

AccessibilityTreeFormatter::AccessibilityTreeFormatter()
    : show_ids_(false) {
}

AccessibilityTreeFormatter::~AccessibilityTreeFormatter() {
}

std::unique_ptr<base::DictionaryValue>
AccessibilityTreeFormatter::BuildAccessibilityTree(BrowserAccessibility* root) {
  CHECK(root);
  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue);
  RecursiveBuildAccessibilityTree(*root, dict.get());
  return dict;
}

void AccessibilityTreeFormatter::FormatAccessibilityTree(
    BrowserAccessibility* root, base::string16* contents) {
  std::unique_ptr<base::DictionaryValue> dict = BuildAccessibilityTree(root);
  RecursiveFormatAccessibilityTree(*(dict.get()), contents);
}

void AccessibilityTreeFormatter::RecursiveBuildAccessibilityTree(
    const BrowserAccessibility& node, base::DictionaryValue* dict) {
  AddProperties(node, dict);

  base::ListValue* children = new base::ListValue;
  dict->Set(kChildrenDictAttr, children);

  for (size_t i = 0; i < ChildCount(node); ++i) {
    BrowserAccessibility* child_node = GetChild(node, i);
    std::unique_ptr<base::DictionaryValue> child_dict(
        new base::DictionaryValue);
    RecursiveBuildAccessibilityTree(*child_node, child_dict.get());
    children->Append(std::move(child_dict));
  }
}

void AccessibilityTreeFormatter::RecursiveFormatAccessibilityTree(
    const base::DictionaryValue& dict, base::string16* contents, int depth) {
  base::string16 indent = base::string16(depth * kIndentSymbolCount,
                                         kIndentSymbol);
  base::string16 line = indent + ToString(dict);
  if (line.find(base::ASCIIToUTF16(kSkipString)) != base::string16::npos)
    return;

  *contents += line + base::ASCIIToUTF16("\n");
  if (line.find(base::ASCIIToUTF16(kSkipChildren)) != base::string16::npos)
    return;

  const base::ListValue* children;
  dict.GetList(kChildrenDictAttr, &children);
  const base::DictionaryValue* child_dict;
  for (size_t i = 0; i < children->GetSize(); i++) {
    children->GetDictionary(i, &child_dict);
    RecursiveFormatAccessibilityTree(*child_dict, contents, depth + 1);
  }
}

void AccessibilityTreeFormatter::SetFilters(
    const std::vector<Filter>& filters) {
  filters_ = filters;
}

uint32_t AccessibilityTreeFormatter::ChildCount(
    const BrowserAccessibility& node) const {
  return node.PlatformChildCount();
}

BrowserAccessibility* AccessibilityTreeFormatter::GetChild(
    const BrowserAccessibility& node,
    uint32_t i) const {
  return node.PlatformGetChild(i);
}

// static
bool AccessibilityTreeFormatter::MatchesFilters(
    const std::vector<Filter>& filters,
    const base::string16& text,
    bool default_result) {
  std::vector<Filter>::const_iterator iter = filters.begin();
  bool allow = default_result;
  for (iter = filters.begin(); iter != filters.end(); ++iter) {
    if (base::MatchPattern(text, iter->match_str)) {
      if (iter->type == Filter::ALLOW_EMPTY)
        allow = true;
      else if (iter->type == Filter::ALLOW)
        allow = (!base::MatchPattern(text, base::UTF8ToUTF16("*=''")));
      else
        allow = false;
    }
  }
  return allow;
}

bool AccessibilityTreeFormatter::MatchesFilters(
    const base::string16& text, bool default_result) const {
  return MatchesFilters(filters_, text, default_result);
}

base::string16 AccessibilityTreeFormatter::FormatCoordinates(
    const char* name, const char* x_name, const char* y_name,
    const base::DictionaryValue& value) {
  int x, y;
  value.GetInteger(x_name, &x);
  value.GetInteger(y_name, &y);
  std::string xy_str(base::StringPrintf("%s=(%d, %d)", name, x, y));

  return base::UTF8ToUTF16(xy_str);
}

void AccessibilityTreeFormatter::WriteAttribute(
    bool include_by_default, const std::string& attr, base::string16* line) {
  WriteAttribute(include_by_default, base::UTF8ToUTF16(attr), line);
}

void AccessibilityTreeFormatter::WriteAttribute(
    bool include_by_default, const base::string16& attr, base::string16* line) {
  if (attr.empty())
    return;
  if (!MatchesFilters(attr, include_by_default))
    return;
  if (!line->empty())
    *line += base::ASCIIToUTF16(" ");
  *line += attr;
}

}  // namespace content