Relation list properties for Accessibility Object Model phase 1

third_party/WebKit/Source/core/dom/AccessibleNodeList.cpp

+// Copyright 2017 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 "core/dom/AccessibleNodeList.h"
+
+#include "core/dom/AccessibleNode.h"
+
+namespace blink {
+
+// The spec doesn't give a limit, but there's no reason to allow relations
+// between an arbitrarily large number of other accessible nodes.
+static const unsigned kMaxItems = 65536;
+
+// static
+AccessibleNodeList* AccessibleNodeList::Create(
+    const HeapVector<Member<AccessibleNode>>& nodes) {
+  AccessibleNodeList* result = new AccessibleNodeList();
+  result->nodes_ = nodes;
+  return result;
+}
+
+AccessibleNodeList::AccessibleNodeList() {
+  DCHECK(RuntimeEnabledFeatures::AccessibilityObjectModelEnabled());
+}
+
+AccessibleNodeList::~AccessibleNodeList() {}
+
+void AccessibleNodeList::AddOwner(AOMRelationListProperty property,
+                                  AccessibleNode* node) {
+  owners_.push_back(std::make_pair(property, node));
+}
+
+void AccessibleNodeList::RemoveOwner(AOMRelationListProperty property,
+                                     AccessibleNode* node) {
+  for (size_t i = 0; i < owners_.size(); ++i) {
+    auto& item = owners_[i];
+    if (item.first == property && item.second == node) {
+      owners_.erase(i);
+      return;
+    }
+  }
+}
+
+AccessibleNode* AccessibleNodeList::item(unsigned offset) const {
+  if (offset < nodes_.size())
+    return nodes_[offset];
+  return nullptr;
+}
+
+void AccessibleNodeList::add(AccessibleNode* node, AccessibleNode* before) {
+  if (nodes_.size() == kMaxItems)
+    return;
+
+  unsigned index = nodes_.size();
+  if (before) {
+    for (index = 0; index < nodes_.size(); ++index) {
+      if (nodes_[index] == before)
+        break;
+    }
+    if (index == nodes_.size())
+      return;
+  }
+
+  nodes_.insert(index, node);
+}
+
+void AccessibleNodeList::remove(int index) {
+  if (index >= 0 && index < static_cast<int>(nodes_.size()))
+    nodes_.erase(index);
+}
+
+bool AccessibleNodeList::AnonymousIndexedSetter(unsigned index,
+                                                AccessibleNode* node,
+                                                ExceptionState& state) {
+  if (!node) {
+    remove(index);
+    return true;
+  }
+  if (index >= kMaxItems)
+    return false;
+  if (index >= nodes_.size()) {
+    unsigned old_size = nodes_.size();
+    nodes_.resize(index + 1);
+    for (unsigned i = old_size; i < nodes_.size(); ++i)
+      nodes_[i] = nullptr;
+  }
+  nodes_[index] = node;
+  return true;
+}
+
+unsigned AccessibleNodeList::length() const {
+  return nodes_.size();
+}
+
+void AccessibleNodeList::setLength(unsigned new_length) {
+  if (new_length >= kMaxItems)
+    return;
+  nodes_.resize(new_length);
+}
+
+void AccessibleNodeList::NotifyChanged() {
+  for (auto& owner : owners_)
+    owner.second->OnRelationListChanged(owner.first);
+}
+
+DEFINE_TRACE(AccessibleNodeList) {
+  visitor->Trace(nodes_);
+  visitor->Trace(owners_);
+}
+
+}  // namespace blink