Make BrowserAccessibilityManager cross platform. Step 2.

chrome/browser/accessibility/browser_accessibility_manager.cc

 // Copyright (c) 2010 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 "chrome/browser/accessibility/browser_accessibility_manager.h"
 
-#include "chrome/common/render_messages_params.h"
+#include "chrome/browser/accessibility/browser_accessibility.h"
 
 using webkit_glue::WebAccessibility;
 
+// Start child IDs at -1 and decrement each time, because clients use
+// child IDs of 1, 2, 3, ... to access the children of an object by
+// index, so we use negative IDs to clearly distinguish between indices
+// and unique IDs.
+// static
+int32 BrowserAccessibilityManager::next_child_id_ = -1;
 
 BrowserAccessibilityManager::BrowserAccessibilityManager(
-    gfx::NativeWindow parent_window)
-    : parent_window_(parent_window) {
+    gfx::NativeView parent_view,
+      const WebAccessibility& src,
+      BrowserAccessibilityDelegate* delegate,
+      BrowserAccessibilityFactory* factory)
+    : parent_view_(parent_view),
+      delegate_(delegate),
+      factory_(factory),
+      focus_(NULL) {
+  root_ = CreateAccessibilityTree(NULL, GetNextChildID(), src, 0);
+  if (!focus_)
+    focus_ = root_;
+}
+
+// static
+int32 BrowserAccessibilityManager::GetNextChildID() {
+  // Get the next child ID, and wrap around when we get near the end
+  // of a 32-bit integer range. It's okay to wrap around; we just want
+  // to avoid it as long as possible because clients may cache the ID of
+  // an object for a while to determine if they've seen it before.
+  next_child_id_--;
+  if (next_child_id_ == -2000000000)
+    next_child_id_ = -1;
+
+  return next_child_id_;
 }
 
 BrowserAccessibilityManager::~BrowserAccessibilityManager() {
+  // Clients could still hold references to some nodes of the tree, so
+  // calling Inactivate will make sure that as many nodes as possible are
+  // released now, and remaining nodes are marked as inactive so that
+  // calls to any methods on them will return E_FAIL;
+  root_->ReleaseTree();
+  root_->ReleaseReference();
+}
+
+BrowserAccessibility* BrowserAccessibilityManager::GetRoot() {
+  return root_;
+}
+
+BrowserAccessibility* BrowserAccessibilityManager::GetFromChildID(
+    int32 child_id) {
+  base::hash_map<int32, BrowserAccessibility*>::iterator iter =
+      child_id_map_.find(child_id);
+  if (iter != child_id_map_.end()) {
+    return iter->second;
+  } else {
+    return NULL;
+  }
+}
+
+void BrowserAccessibilityManager::Remove(int32 child_id) {
+  child_id_map_.erase(child_id);
 }
 
 void BrowserAccessibilityManager::OnAccessibilityNotifications(
     const std::vector<ViewHostMsg_AccessibilityNotification_Params>& params) {
   for (uint32 index = 0; index < params.size(); index++) {
     const ViewHostMsg_AccessibilityNotification_Params& param = params[index];
 
     switch (param.notification_type) {
       case ViewHostMsg_AccessibilityNotification_Params::
           NOTIFICATION_TYPE_CHECK_STATE_CHANGED:
@@ skipping 19 matching lines @@
           NOTIFICATION_TYPE_SELECTED_TEXT_CHANGED:
         OnAccessibilityObjectTextChange(param.acc_obj);
         break;
       default:
         DCHECK(0);
         break;
     }
   }
 }
 
-gfx::NativeWindow BrowserAccessibilityManager::GetParentWindow() {
-  return parent_window_;
-}
+void BrowserAccessibilityManager::OnAccessibilityObjectStateChange(
+    const WebAccessibility& acc_obj) {
+  BrowserAccessibility* new_browser_acc = UpdateTree(acc_obj);
+  if (!new_browser_acc)
+    return;
+
+  NotifyAccessibilityEvent(
+      ViewHostMsg_AccessibilityNotification_Params::
+          NOTIFICATION_TYPE_CHECK_STATE_CHANGED,
+      new_browser_acc);
+}
+
+void BrowserAccessibilityManager::OnAccessibilityObjectChildrenChange(
+    const WebAccessibility& acc_obj) {
+  BrowserAccessibility* new_browser_acc = UpdateTree(acc_obj);
+  if (!new_browser_acc)
+    return;
+
+  NotifyAccessibilityEvent(
+      ViewHostMsg_AccessibilityNotification_Params::
+          NOTIFICATION_TYPE_CHILDREN_CHANGED,
+      new_browser_acc);
+}
+
+void BrowserAccessibilityManager::OnAccessibilityObjectFocusChange(
+  const WebAccessibility& acc_obj) {
+  BrowserAccessibility* new_browser_acc = UpdateTree(acc_obj);
+  if (!new_browser_acc)
+    return;
+
+  focus_ = new_browser_acc;
+  if (delegate_ && delegate_->HasFocus())
+    GotFocus();
+}
+
+void BrowserAccessibilityManager::OnAccessibilityObjectLoadComplete(
+  const WebAccessibility& acc_obj) {
+  root_->ReleaseTree();
+  root_->ReleaseReference();
+  focus_ = NULL;
+
+  root_ = CreateAccessibilityTree(NULL, GetNextChildID(), acc_obj, 0);
+  if (!focus_)
+    focus_ = root_;
+
+  NotifyAccessibilityEvent(
+      ViewHostMsg_AccessibilityNotification_Params::
+          NOTIFICATION_TYPE_LOAD_COMPLETE,
+      root_);
+  if (delegate_ && delegate_->HasFocus())
+    GotFocus();
+}
+
+void BrowserAccessibilityManager::OnAccessibilityObjectValueChange(
+    const WebAccessibility& acc_obj) {
+  BrowserAccessibility* new_browser_acc = UpdateTree(acc_obj);
+  if (!new_browser_acc)
+    return;
+
+  NotifyAccessibilityEvent(
+      ViewHostMsg_AccessibilityNotification_Params::
+          NOTIFICATION_TYPE_VALUE_CHANGED,
+      root_);
+}
+
+void BrowserAccessibilityManager::OnAccessibilityObjectTextChange(
+    const WebAccessibility& acc_obj) {
+  BrowserAccessibility* new_browser_acc = UpdateTree(acc_obj);
+  if (!new_browser_acc)
+    return;
+
+  NotifyAccessibilityEvent(
+      ViewHostMsg_AccessibilityNotification_Params::
+          NOTIFICATION_TYPE_SELECTED_TEXT_CHANGED,
+      root_);
+}
+
+void BrowserAccessibilityManager::GotFocus() {
+  // TODO(ctguil): Remove when tree update logic handles focus changes.
+  if (!focus_)
+    return;
+
+  NotifyAccessibilityEvent(
+      ViewHostMsg_AccessibilityNotification_Params::
+          NOTIFICATION_TYPE_FOCUS_CHANGED,
+      focus_);
+}
+
+gfx::NativeView BrowserAccessibilityManager::GetParentView() {
+  return parent_view_;
+}
+
+BrowserAccessibility* BrowserAccessibilityManager::GetFocus(
+    BrowserAccessibility* root) {
+  if (focus_ && (!root || focus_->IsDescendantOf(root)))
+    return focus_;
+
+  return NULL;
+}
+
+void BrowserAccessibilityManager::SetFocus(
+    const BrowserAccessibility& node) {
+  if (delegate_)
+    delegate_->SetAccessibilityFocus(node.renderer_id());
+}
+
+void BrowserAccessibilityManager::DoDefaultAction(
+    const BrowserAccessibility& node) {
+  if (delegate_)
+    delegate_->AccessibilityDoDefaultAction(node.renderer_id());
+}
+
+bool BrowserAccessibilityManager::CanModifyTreeInPlace(
+    BrowserAccessibility* current_root,
+    const WebAccessibility& new_root) {
+  if (current_root->renderer_id() != new_root.id)
+    return false;
+  if (current_root->GetChildCount() != new_root.children.size())
+    return false;
+  for (unsigned int i = 0; i < current_root->GetChildCount(); i++) {
+    if (!CanModifyTreeInPlace(current_root->GetChild(i),
+                              new_root.children[i])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+void BrowserAccessibilityManager::ModifyTreeInPlace(
+      BrowserAccessibility* current_root,
+      const WebAccessibility& new_root) {
+  DCHECK_EQ(current_root->renderer_id(), new_root.id);
+  DCHECK_EQ(current_root->GetChildCount(), new_root.children.size());
+  for (unsigned int i = 0; i < current_root->GetChildCount(); i++)
+    ModifyTreeInPlace(current_root->GetChild(i), new_root.children[i]);
+  current_root->Initialize(
+      this,
+      current_root->GetParent(),
+      current_root->child_id(),
+      current_root->index_in_parent(),
+      new_root);
+}
+
+
+BrowserAccessibility* BrowserAccessibilityManager::UpdateTree(
+    const WebAccessibility& acc_obj) {
+  base::hash_map<int, int32>::iterator iter =
+      renderer_id_to_child_id_map_.find(acc_obj.id);
+  if (iter == renderer_id_to_child_id_map_.end())
+    return NULL;
+
+  int32 child_id = iter->second;
+  BrowserAccessibility* old_browser_acc = GetFromChildID(child_id);
+  if (!old_browser_acc)
+    return NULL;
+
+  if (CanModifyTreeInPlace(old_browser_acc, acc_obj)) {
+    ModifyTreeInPlace(old_browser_acc, acc_obj);
+    return old_browser_acc;
+  }
+
+  BrowserAccessibility* new_browser_acc = CreateAccessibilityTree(
+        old_browser_acc->GetParent(),
+        child_id,
+        acc_obj,
+        old_browser_acc->index_in_parent());
+
+    if (old_browser_acc->GetParent()) {
+      old_browser_acc->GetParent()->ReplaceChild(
+          old_browser_acc,
+          new_browser_acc);
+    } else {
+      DCHECK_EQ(old_browser_acc, root_);
+      root_ = new_browser_acc;
+    }
+    old_browser_acc->ReleaseTree();
+    old_browser_acc->ReleaseReference();
+    child_id_map_[child_id] = new_browser_acc;
+
+    return new_browser_acc;
+}
+
+BrowserAccessibility* BrowserAccessibilityManager::CreateAccessibilityTree(
+    BrowserAccessibility* parent,
+    int child_id,
+    const WebAccessibility& src,
+    int index_in_parent) {
+  BrowserAccessibility* instance = factory_->Create();
+
+  instance->Initialize(this, parent, child_id, index_in_parent, src);
+  child_id_map_[child_id] = instance;
+  renderer_id_to_child_id_map_[src.id] = child_id;
+  if ((src.state >> WebAccessibility::STATE_FOCUSED) & 1)
+    focus_ = instance;
+  for (int i = 0; i < static_cast<int>(src.children.size()); ++i) {
+    BrowserAccessibility* child = CreateAccessibilityTree(
+        instance, GetNextChildID(), src.children[i], i);
+    instance->AddChild(child);
+  }
+
+  return instance;
+}