Reports the position of the caret and current selection in content editables.

content/browser/accessibility/browser_accessibility_win.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/browser_accessibility_win.h"
 
 #include <UIAutomationClient.h>
 #include <UIAutomationCoreApi.h>
+#include <algorithm>

[dmazzoni, 2015/07/16 19:50:23]

Nit: don't group this with the Microsoft includes, above - put one more blank
line before it.

 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/enum_variant.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/windows_version.h"
 #include "content/browser/accessibility/browser_accessibility_manager_win.h"
 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
@@ skipping 1978 matching lines @@
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_caretOffset(LONG* offset) {
   if (!instance_active())
     return E_FAIL;
 
   if (!offset)
     return E_INVALIDARG;
 
-  // IA2 spec says that caret offset should be -1 if the object is not focused.
-  if (manager()->GetFocus(this) != this) {
-    *offset = -1;
+  int selection_start, selection_end;
+  GetSelectionOffsets(&selection_start, &selection_end);

[dmazzoni, 2015/07/16 19:50:23]

Are you 100% sure that this change isn't going to regress any existing behavior,
like for <input> and <textarea> elements? Please check carefully.

+  *offset = selection_start;
+  if (selection_start < 0)
     return S_FALSE;
-  }
-
-  *offset = 0;
-  if (IsEditableText()) {
-    int sel_start = 0;
-    if (GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START,
-                        &sel_start))
-      *offset = sel_start;
-  }
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_characterExtents(
     LONG offset,
     enum IA2CoordinateType coordinate_type,
     LONG* out_x,
     LONG* out_y,
     LONG* out_width,
@@ skipping 29 matching lines @@
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_nSelections(LONG* n_selections) {
   if (!instance_active())
     return E_FAIL;
 
   if (!n_selections)
     return E_INVALIDARG;
 
   *n_selections = 0;
-  if (IsEditableText()) {
-    int sel_start = 0;
-    int sel_end = 0;
-    if (GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START,
-                        &sel_start) &&
-        GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END, &sel_end) &&
-        sel_start != sel_end)
-      *n_selections = 1;
-  }
+  int selection_start, selection_end;
+  GetSelectionOffsets(&selection_start, &selection_end);
+  if (selection_start >= 0 && selection_end >= 0 &&
+      selection_start != selection_end)
+    *n_selections = 1;
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_selection(LONG selection_index,
                                                     LONG* start_offset,
                                                     LONG* end_offset) {
   if (!instance_active())
     return E_FAIL;
 
   if (!start_offset || !end_offset || selection_index != 0)
     return E_INVALIDARG;
 
   LONG n_selections = 0;
   if (FAILED(get_nSelections(&n_selections)) || n_selections < 1)
     return E_INVALIDARG;
 
   *start_offset = 0;
   *end_offset = 0;
-  if (IsEditableText()) {
-    int sel_start = 0;
-    int sel_end = 0;
-    if (GetIntAttribute(
-            ui::AX_ATTR_TEXT_SEL_START, &sel_start) &&
-        GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END, &sel_end)) {
-      *start_offset = sel_start;
-      *end_offset = sel_end;
-    }
+  int selection_start, selection_end;
+  GetSelectionOffsets(&selection_start, &selection_end);
+  if (selection_start >= 0 && selection_end >= 0) {
+    *start_offset = selection_start;
+    *end_offset = selection_end;
   }
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_text(LONG start_offset,
                                                LONG end_offset,
                                                BSTR* text) {
   if (!instance_active())
     return E_FAIL;
@@ skipping 1530 matching lines @@
     ui::AXIntAttribute attribute,
     const char* ia2_attr) {
   int value;
   if (GetIntAttribute(attribute, &value)) {
     win_attributes_->ia2_attributes.push_back(
         base::ASCIIToUTF16(ia2_attr) + L":" +
         base::IntToString16(value));
   }
 }
 
+int32 BrowserAccessibilityWin::GetHyperlinkIndexFromChild(
+    const BrowserAccessibilityWin& child) const {
+  auto iterator = std::find(
+      hyperlinks().begin(), hyperlinks().end(), child.GetId());
+  if (iterator == hyperlinks().end())
+    return -1;
+
+  return static_cast<int32>(iterator - hyperlinks().begin());
+}
+
+int32 BrowserAccessibilityWin::GetHypertextOffsetFromHyperlinkIndex(
+    int32 hyperlink_index) const {
+  auto& offsets_map = hyperlink_offset_to_index();
+  for (auto& offset_index : offsets_map)

[dmazzoni, 2015/07/16 19:50:23]

Braces around the body of the for loop since there's more than one line inside

+    if (offset_index.second == hyperlink_index)
+      return offset_index.first;
+
+  return -1;
+}
+
+int32 BrowserAccessibilityWin::GetHypertextOffsetFromChild(
+    const BrowserAccessibilityWin& child) const {
+  int32 hyperlink_index = GetHyperlinkIndexFromChild(child);
+  if (hyperlink_index < 0)
+    return -1;
+
+  return GetHypertextOffsetFromHyperlinkIndex(hyperlink_index);
+}
+
+int32 BrowserAccessibilityWin::GetHypertextOffsetFromDescendant(
+    const BrowserAccessibilityWin& descendant) const {
+  auto parent_object = descendant.GetParent()->ToBrowserAccessibilityWin();
+  auto current_object = const_cast<BrowserAccessibilityWin*>(&descendant);
+  while (parent_object && parent_object != this) {
+    current_object = parent_object;
+    parent_object = current_object->GetParent()->ToBrowserAccessibilityWin();
+  }
+  if (!parent_object)
+    return -1;
+
+  return parent_object->GetHypertextOffsetFromChild(*current_object);
+}
+
+int BrowserAccessibilityWin::GetSelectionAnchor() const {
+  BrowserAccessibility* root = manager()->GetRoot();
+  int32 anchor_id;
+  if (!root || !root->GetIntAttribute(ui::AX_ATTR_ANCHOR_OBJECT_ID, &anchor_id))
+    return -1;
+
+  BrowserAccessibilityWin* anchor_object = manager()->GetFromID(
+      anchor_id)->ToBrowserAccessibilityWin();
+  if (!anchor_object)
+    return -1;
+
+  if (anchor_object->IsDescendantOf(this))
+    return GetHypertextOffsetFromDescendant(*anchor_object);
+
+  if (IsDescendantOf(anchor_object)) {
+    int anchor_offset;
+    if (!root->GetIntAttribute(ui::AX_ATTR_ANCHOR_OFFSET, &anchor_offset))
+      return -1;
+
+    return anchor_offset;
+  }
+
+  return -1;
+}
+
+int BrowserAccessibilityWin::GetSelectionFocus() const {
+  BrowserAccessibility* root = manager()->GetRoot();
+  int32 focus_id;
+  if (!root || !root->GetIntAttribute(ui::AX_ATTR_FOCUS_OBJECT_ID, &focus_id))
+    return -1;
+
+  BrowserAccessibilityWin* focus_object = manager()->GetFromID(
+      focus_id)->ToBrowserAccessibilityWin();
+  if (!focus_object)
+    return -1;
+
+  if (focus_object->IsDescendantOf(this))
+    return GetHypertextOffsetFromDescendant(*focus_object);
+
+  if (IsDescendantOf(focus_object)) {
+    int focus_offset;
+    if (!root->GetIntAttribute(ui::AX_ATTR_FOCUS_OFFSET, &focus_offset))
+      return -1;
+
+    return focus_offset;
+  }
+
+  return -1;
+}
+
+void BrowserAccessibilityWin::GetSelectionOffsets(
+    int* selection_start, int* selection_end) const {
+  if (!selection_start || !selection_end)
+    return;
+
+  if (GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START, selection_start) &&
+      GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END, selection_end)) {
+    return;
+  }
+
+  *selection_start = GetSelectionAnchor();
+  *selection_end = GetSelectionFocus();
+  if (*selection_start < 0 || *selection_end < 0)
+    return;
+
+  if (*selection_end < *selection_start)
+    std::swap(*selection_start, *selection_end);

[dmazzoni, 2015/07/16 19:50:23]

Are you sure this is correct? I think IA2 might support the selection start and
end being reversed indicating that the selection focus is at the beginning
rather than the end. Please verify and manually test with selections that go
both directions.

+
+  // IA2 Spec says that the end of the selection should be after the last
+  // embedded object character that is part of the selection.
+  ++(*selection_end);
+}
+
 base::string16 BrowserAccessibilityWin::GetNameRecursive() const {
   if (!name().empty()) {
     return name();
   }
 
   base::string16 result;
   for (uint32 i = 0; i < PlatformChildCount(); ++i) {
     result += PlatformGetChild(i)->ToBrowserAccessibilityWin()->
         GetNameRecursive();
   }
@@ skipping 711 matching lines @@
     ia2_role = ia_role;
 
   win_attributes_->ia_role = ia_role;
   win_attributes_->ia_state = ia_state;
   win_attributes_->role_name = role_name;
   win_attributes_->ia2_role = ia2_role;
   win_attributes_->ia2_state = ia2_state;
 }
 
 }  // namespace content