Create accessor for owner's manager to simplify code a bit

content/browser/accessibility/browser_accessibility_com_win.cc

 // Copyright (c) 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 "content/browser/accessibility/browser_accessibility_com_win.h"
 
 #include <UIAutomationClient.h>
 #include <UIAutomationCoreApi.h>
 
 #include <algorithm>
@@ skipping 328 matching lines @@
 }
 
 STDMETHODIMP BrowserAccessibilityRelation::get_target(long target_index,
                                                       IUnknown** target) {
   if (!target)
     return E_INVALIDARG;
 
   if (!owner_->GetOwner())
     return E_FAIL;
 
-  auto* manager = owner_->GetOwner()->manager();
+  auto* manager = owner_->owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (target_index < 0 ||
       target_index >= static_cast<long>(target_ids_.size())) {
     return E_INVALIDARG;
   }
 
   BrowserAccessibility* result = manager->GetFromID(target_ids_[target_index]);
   if (!result || !result->instance_active())
@@ skipping 63 matching lines @@
 // * There are some methods that don't touch any state such as get_toolkitName.
 //   For these rare cases, you may not need to call GetOwner().
 //
 
 HRESULT BrowserAccessibilityComWin::accDoDefaultAction(VARIANT var_id) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_ACC_DO_DEFAULT_ACTION);
 
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   BrowserAccessibilityComWin* target = GetTargetFromChildID(var_id);
   if (!target)
     return E_INVALIDARG;
 
   // Return an error if it's not clickable.
   if (!target->GetOwner()->HasIntAttribute(ui::AX_ATTR_ACTION))
     return DISP_E_MEMBERNOTFOUND;
 
   manager->DoDefaultAction(*target->GetOwner());
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::accHitTest(LONG x_left,
                                                     LONG y_top,
                                                     VARIANT* child) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_ACC_HIT_TEST);
 
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (!child)
     return E_INVALIDARG;
 
   gfx::Point point(x_left, y_top);
   if (!GetOwner()->GetScreenBoundsRect().Contains(point)) {
     // Return S_FALSE and VT_EMPTY when outside the object's boundaries.
     child->vt = VT_EMPTY;
@@ skipping 143 matching lines @@
 
   DCHECK(*desc);
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_accFocus(VARIANT* focus_child) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_ACC_FOCUS);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (!focus_child)
     return E_INVALIDARG;
 
   BrowserAccessibilityWin* focus =
       static_cast<BrowserAccessibilityWin*>(manager->GetFocus());
   if (focus == GetOwner()) {
     focus_child->vt = VT_I4;
@@ skipping 54 matching lines @@
     return E_FAIL;
 
   if (!disp_parent)
     return E_INVALIDARG;
 
   IAccessible* parent_obj =
       ToBrowserAccessibilityComWin(GetOwner()->PlatformGetParent());
   if (parent_obj == NULL) {
     // This happens if we're the root of the tree;
     // return the IAccessible for the window.
-    parent_obj = GetOwner()
-                     ->manager()
+    parent_obj = owners_manager()
                      ->ToBrowserAccessibilityManagerWin()
                      ->GetParentIAccessible();
     // |parent| can only be NULL if the manager was created before the parent
     // IAccessible was known and it wasn't subsequently set before a client
     // requested it. This has been fixed. |parent| may also be NULL during
     // destruction. Possible cases where this could occur include tabs being
     // dragged to a new window, etc.
     if (!parent_obj) {
       DVLOG(1) << "In Function: " << __func__
                << ". Parent IAccessible interface is NULL. Returning failure";
@@ skipping 27 matching lines @@
   }
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_accState(VARIANT var_id,
                                                       VARIANT* state) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_ACC_STATE);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (!state)
     return E_INVALIDARG;
 
   BrowserAccessibilityComWin* target = GetTargetFromChildID(var_id);
   if (!target)
     return E_INVALIDARG;
 
@@ skipping 105 matching lines @@
       static_cast<base::win::IUnknownImpl*>(enum_variant));
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::accSelect(LONG flags_sel,
                                                    VARIANT var_id) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_ACC_SELECT);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (flags_sel & SELFLAG_TAKEFOCUS) {
     manager->SetFocus(*GetOwner());
     return S_OK;
   }
 
   return S_FALSE;
 }
@@ skipping 74 matching lines @@
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_windowHandle(HWND* window_handle) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_WINDOW_HANDLE);
   if (!GetOwner())
     return E_FAIL;
 
   if (!window_handle)
     return E_INVALIDARG;
 
-  *window_handle = GetOwner()
-                       ->manager()
-                       ->ToBrowserAccessibilityManagerWin()
-                       ->GetParentHWND();
+  *window_handle =
+      owners_manager()->ToBrowserAccessibilityManagerWin()->GetParentHWND();
   if (!*window_handle)
     return E_FAIL;
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_indexInParent(
     LONG* index_in_parent) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_INDEX_IN_PARENT);
   if (!GetOwner())
@@ skipping 63 matching lines @@
   }
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::scrollTo(IA2ScrollType scroll_type) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_IA2_SCROLL_TO);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
 
   if (!manager)
     return E_FAIL;
 
   gfx::Rect r = GetOwner()->GetFrameBoundsRect();
   switch (scroll_type) {
     case IA2_SCROLL_TYPE_TOP_LEFT:
       manager->ScrollToMakeVisible(*GetOwner(), gfx::Rect(r.x(), r.y(), 0, 0));
       break;
     case IA2_SCROLL_TYPE_BOTTOM_RIGHT:
@@ skipping 26 matching lines @@
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::scrollToPoint(
     IA2CoordinateType coordinate_type,
     LONG x,
     LONG y) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_SCROLL_TO_POINT);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   gfx::Point scroll_to(x, y);
 
   if (coordinate_type == IA2_COORDTYPE_SCREEN_RELATIVE) {
     scroll_to -= manager->GetViewBounds().OffsetFromOrigin();
   } else if (coordinate_type == IA2_COORDTYPE_PARENT_RELATIVE) {
     if (GetOwner()->PlatformGetParent()) {
       scroll_to += GetOwner()
@@ skipping 1662 matching lines @@
 
 STDMETHODIMP BrowserAccessibilityComWin::doAction(long action_index) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_DO_ACTION);
   AddAccessibilityModeFlags(kScreenReaderAndHTMLAccessibilityModes);
   if (!GetOwner())
     return E_FAIL;
 
   if (!GetOwner()->HasIntAttribute(ui::AX_ATTR_ACTION) || action_index != 0)
     return E_INVALIDARG;
 
-  GetOwner()->manager()->DoDefaultAction(*GetOwner());
+  owners_manager()->DoDefaultAction(*GetOwner());
   return S_OK;
 }
 
 STDMETHODIMP
 BrowserAccessibilityComWin::get_description(long action_index,
                                             BSTR* description) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_IAACTION_GET_DESCRIPTION);
   AddAccessibilityModeFlags(kScreenReaderAndHTMLAccessibilityModes);
   return E_NOTIMPL;
 }
@@ skipping 139 matching lines @@
 
 //
 // ISimpleDOMDocument methods.
 //
 
 STDMETHODIMP BrowserAccessibilityComWin::get_URL(BSTR* url) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_URL);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (!url)
     return E_INVALIDARG;
 
   if (GetOwner() != manager->GetRoot())
     return E_FAIL;
 
   std::string str = manager->GetTreeData().url;
   if (str.empty())
     return S_FALSE;
 
   *url = SysAllocString(base::UTF8ToUTF16(str).c_str());
   DCHECK(*url);
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_title(BSTR* title) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_TITLE);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (!title)
     return E_INVALIDARG;
 
   std::string str = manager->GetTreeData().title;
   if (str.empty())
     return S_FALSE;
 
   *title = SysAllocString(base::UTF8ToUTF16(str).c_str());
   DCHECK(*title);
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_mimeType(BSTR* mime_type) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_MIME_TYPE);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (!mime_type)
     return E_INVALIDARG;
 
   std::string str = manager->GetTreeData().mimetype;
   if (str.empty())
     return S_FALSE;
 
   *mime_type = SysAllocString(base::UTF8ToUTF16(str).c_str());
   DCHECK(*mime_type);
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_docType(BSTR* doc_type) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_DOC_TYPE);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   if (!doc_type)
     return E_INVALIDARG;
 
   std::string str = manager->GetTreeData().doctype;
   if (str.empty())
     return S_FALSE;
 
@@ skipping 416 matching lines @@
 
 STDMETHODIMP BrowserAccessibilityComWin::scrollToSubstring(
     unsigned int start_index,
     unsigned int end_index) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_SCROLL_TO_SUBSTRING);
   AddAccessibilityModeFlags(kScreenReaderAndHTMLAccessibilityModes |
                             AccessibilityMode::kInlineTextBoxes);
   if (!GetOwner())
     return E_FAIL;
 
-  auto* manager = GetOwner()->manager();
+  auto* manager = owners_manager();
   if (!manager)
     return E_FAIL;
 
   unsigned int text_length =
       static_cast<unsigned int>(GetOwner()->GetText().size());
   if (start_index > text_length || end_index > text_length ||
       start_index > end_index) {
     return E_INVALIDARG;
   }
 
@@ skipping 268 matching lines @@
 
   win_attributes_->offset_to_text_attributes.swap(attributes_map);
 }
 
 // |offset| could either be a text character or a child index in case of
 // non-text objects.
 // TODO(nektar): Remove this function once selection bugs are fixed in Blink.
 AXPlatformPosition::AXPositionInstance
 BrowserAccessibilityComWin::CreatePositionForSelectionAt(int offset) const {
   if (!GetOwner()->IsNativeTextControl() && !GetOwner()->IsTextOnlyObject()) {
-    auto* manager = GetOwner()->manager();
+    auto* manager = owners_manager();
     DCHECK(manager);
     const BrowserAccessibilityComWin* child = this;
     // TODO(nektar): Make parents of text-only objects not include the text of
     // children in their hypertext.
     for (size_t i = 0; i < GetOwner()->InternalChildCount(); ++i) {
       int new_offset = offset;
       child = ToBrowserAccessibilityComWin(GetOwner()->InternalGetChild(i));
       DCHECK(child);
       if (child->GetOwner()->IsTextOnlyObject()) {
         new_offset -= child->GetOwner()->GetText().length();
@@ skipping 166 matching lines @@
 
   win_attributes_->name = GetOwner()->GetString16Attribute(ui::AX_ATTR_NAME);
   win_attributes_->description =
       GetOwner()->GetString16Attribute(ui::AX_ATTR_DESCRIPTION);
   StringAttributeToIA2(ui::AX_ATTR_PLACEHOLDER, "placeholder");
 
   base::string16 value = GetOwner()->GetValue();
   // On Windows, the value of a document should be its url.
   if (GetOwner()->GetRole() == ui::AX_ROLE_ROOT_WEB_AREA ||
       GetOwner()->GetRole() == ui::AX_ROLE_WEB_AREA) {
-    value = base::UTF8ToUTF16(GetOwner()->manager()->GetTreeData().url);
+    value = base::UTF8ToUTF16(owners_manager()->GetTreeData().url);
   }
   // If this doesn't have a value and is linked then set its value to the url
   // attribute. This allows screen readers to read an empty link's destination.
   if (value.empty() && (ia_state() & STATE_SYSTEM_LINKED))
     value = GetOwner()->GetString16Attribute(ui::AX_ATTR_URL);
   win_attributes_->value = value;
 
   ClearOwnRelations();
   AddBidirectionalRelations(IA2_RELATION_CONTROLLER_FOR,
                             IA2_RELATION_CONTROLLED_BY,
@@ skipping 146 matching lines @@
         ToBrowserAccessibilityComWin(GetOwner()->PlatformGetParent());
     if (parent && GetOwner()->IsTextOnlyObject() &&
         name() != old_win_attributes_->name) {
       parent->GetOwner()->UpdatePlatformAttributes();
     }
   }
 
   old_win_attributes_.reset(nullptr);
 }
 
+BrowserAccessibilityManager* BrowserAccessibilityComWin::owners_manager()
+    const {
+  auto* owner = GetOwner();
+  if (!owner)

[dmazzoni, 2017/05/10 06:10:04]

Doesn't every single method call GetOwner at the top?

I think we could DCHECK(owner) and similarly DCHECK(manager).
They shouldn't ever be null.

+    return nullptr;
+  return owner->manager();
+}
+
 std::vector<base::string16> BrowserAccessibilityComWin::ComputeTextAttributes()
     const {
   std::vector<base::string16> attributes;
 
   // We include list markers for now, but there might be other objects that are
   // auto generated.
   // TODO(nektar): Compute what objects are auto-generated in Blink.
   if (GetOwner()->GetRole() == ui::AX_ROLE_LIST_MARKER)
     attributes.push_back(L"auto-generated:true");
   else
@@ skipping 276 matching lines @@
 }
 
 void BrowserAccessibilityComWin::SetIA2HypertextSelection(LONG start_offset,
                                                           LONG end_offset) {
   HandleSpecialTextOffset(&start_offset);
   HandleSpecialTextOffset(&end_offset);
   AXPlatformPositionInstance start_position =
       CreatePositionForSelectionAt(static_cast<int>(start_offset));
   AXPlatformPositionInstance end_position =
       CreatePositionForSelectionAt(static_cast<int>(end_offset));
-  GetOwner()->manager()->SetSelection(AXPlatformRange(
+  owners_manager()->SetSelection(AXPlatformRange(
       start_position->AsTextPosition(), end_position->AsTextPosition()));
 }
 
 void BrowserAccessibilityComWin::StringAttributeToIA2(
     ui::AXStringAttribute attribute,
     const char* ia2_attr) {
   base::string16 value;
   if (GetOwner()->GetString16Attribute(attribute, &value)) {
     SanitizeStringAttributeForIA2(value, &value);
     win_attributes_->ia2_attributes.push_back(base::ASCIIToUTF16(ia2_attr) +
@@ skipping 190 matching lines @@
   if (endpoint_index_in_common_parent < index_in_common_parent)
     return 0;
   if (endpoint_index_in_common_parent > index_in_common_parent)
     return GetOwner()->GetText().size();
 
   NOTREACHED();
   return -1;
 }
 
 int BrowserAccessibilityComWin::GetSelectionAnchor() const {
-  int32_t anchor_id = GetOwner()->manager()->GetTreeData().sel_anchor_object_id;
+  int32_t anchor_id = owners_manager()->GetTreeData().sel_anchor_object_id;
   const BrowserAccessibilityComWin* anchor_object = GetFromID(anchor_id);
   if (!anchor_object)
     return -1;
 
-  int anchor_offset = GetOwner()->manager()->GetTreeData().sel_anchor_offset;
+  int anchor_offset = owners_manager()->GetTreeData().sel_anchor_offset;
   return GetHypertextOffsetFromEndpoint(*anchor_object, anchor_offset);
 }
 
 int BrowserAccessibilityComWin::GetSelectionFocus() const {
-  int32_t focus_id = GetOwner()->manager()->GetTreeData().sel_focus_object_id;
+  int32_t focus_id = owners_manager()->GetTreeData().sel_focus_object_id;
   const BrowserAccessibilityComWin* focus_object = GetFromID(focus_id);
   if (!focus_object)
     return -1;
 
-  int focus_offset = GetOwner()->manager()->GetTreeData().sel_focus_offset;
+  int focus_offset = owners_manager()->GetTreeData().sel_focus_offset;
   return GetHypertextOffsetFromEndpoint(*focus_object, focus_offset);
 }
 
 void BrowserAccessibilityComWin::GetSelectionOffsets(int* selection_start,
                                                      int* selection_end) const {
   DCHECK(selection_start && selection_end);
 
   if (GetOwner()->IsSimpleTextControl() &&
       GetOwner()->GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START,
                                   selection_start) &&
@@ skipping 159 matching lines @@
 
 LONG BrowserAccessibilityComWin::FindBoundary(
     const base::string16& text,
     IA2TextBoundaryType ia2_boundary,
     LONG start_offset,
     ui::TextBoundaryDirection direction) {
   // If the boundary is relative to the caret, use the selection
   // affinity, otherwise default to downstream affinity.
   ui::AXTextAffinity affinity =
       start_offset == IA2_TEXT_OFFSET_CARET
-          ? GetOwner()->manager()->GetTreeData().sel_focus_affinity
+          ? owners_manager()->GetTreeData().sel_focus_affinity
           : ui::AX_TEXT_AFFINITY_DOWNSTREAM;
 
   HandleSpecialTextOffset(&start_offset);
   if (ia2_boundary == IA2_TEXT_BOUNDARY_WORD) {
     switch (direction) {
       case ui::FORWARDS_DIRECTION: {
         AXPlatformPositionInstance position = GetOwner()->CreatePositionAt(
             static_cast<int>(start_offset), affinity);
         AXPlatformPositionInstance next_word =
             position->CreateNextWordStartPosition();
@@ skipping 77 matching lines @@
   }
 
   NOTREACHED();
   return start_offset;
 }
 
 BrowserAccessibilityComWin* BrowserAccessibilityComWin::GetFromID(
     int32_t id) const {
   if (!GetOwner())
     return nullptr;
-  return ToBrowserAccessibilityComWin(GetOwner()->manager()->GetFromID(id));
+  return ToBrowserAccessibilityComWin(owners_manager()->GetFromID(id));
 }
 
 bool BrowserAccessibilityComWin::IsListBoxOptionOrMenuListOption() {
   if (!GetOwner()->PlatformGetParent())
     return false;
 
   int32_t role = GetOwner()->GetRole();
   int32_t parent_role = GetOwner()->PlatformGetParent()->GetRole();
 
   if (role == ui::AX_ROLE_LIST_BOX_OPTION &&
@@ skipping 817 matching lines @@
 
 BrowserAccessibilityComWin* ToBrowserAccessibilityComWin(
     BrowserAccessibility* obj) {
   if (!obj || !obj->IsNative())
     return nullptr;
   auto* result = static_cast<BrowserAccessibilityWin*>(obj)->GetCOM();
   return result;
 }
 
 }  // namespace content