| // 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_manager_win.h" |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <vector> |
| |
| #include "base/command_line.h" |
| #include "base/win/windows_version.h" |
| #include "content/browser/accessibility/browser_accessibility_state_impl.h" |
| #include "content/browser/accessibility/browser_accessibility_win.h" |
| #include "content/browser/renderer_host/legacy_render_widget_host_win.h" |
| #include "content/common/accessibility_messages.h" |
| #include "ui/base/win/atl_module.h" |
| |
| namespace content { |
| |
| // static |
| BrowserAccessibilityManager* BrowserAccessibilityManager::Create( |
| const ui::AXTreeUpdate& initial_tree, |
| BrowserAccessibilityDelegate* delegate, |
| BrowserAccessibilityFactory* factory) { |
| return new BrowserAccessibilityManagerWin(initial_tree, delegate, factory); |
| } |
| |
| BrowserAccessibilityManagerWin* |
| BrowserAccessibilityManager::ToBrowserAccessibilityManagerWin() { |
| return static_cast<BrowserAccessibilityManagerWin*>(this); |
| } |
| |
| BrowserAccessibilityManagerWin::BrowserAccessibilityManagerWin( |
| const ui::AXTreeUpdate& initial_tree, |
| BrowserAccessibilityDelegate* delegate, |
| BrowserAccessibilityFactory* factory) |
| : BrowserAccessibilityManager(delegate, factory), |
| load_complete_pending_(false) { |
| ui::win::CreateATLModuleIfNeeded(); |
| Initialize(initial_tree); |
| ui::GetIAccessible2UsageObserverList().AddObserver(this); |
| } |
| |
| BrowserAccessibilityManagerWin::~BrowserAccessibilityManagerWin() { |
| // Destroy the tree in the subclass, rather than in the inherited |
| // destructor, otherwise our overrides of functions like |
| // OnNodeWillBeDeleted won't be called. |
| tree_.reset(NULL); |
| ui::GetIAccessible2UsageObserverList().RemoveObserver(this); |
| } |
| |
| // static |
| ui::AXTreeUpdate |
| BrowserAccessibilityManagerWin::GetEmptyDocument() { |
| ui::AXNodeData empty_document; |
| empty_document.id = 0; |
| empty_document.role = ax::mojom::Role::kRootWebArea; |
| empty_document.AddBoolAttribute(ax::mojom::BoolAttribute::kBusy, true); |
| |
| ui::AXTreeUpdate update; |
| update.root_id = empty_document.id; |
| update.nodes.push_back(empty_document); |
| return update; |
| } |
| |
| HWND BrowserAccessibilityManagerWin::GetParentHWND() { |
| BrowserAccessibilityDelegate* delegate = GetDelegateFromRootManager(); |
| if (!delegate) |
| return NULL; |
| return delegate->AccessibilityGetAcceleratedWidget(); |
| } |
| |
| void BrowserAccessibilityManagerWin::OnIAccessible2Used() { |
| // When IAccessible2 APIs have been used elsewhere in the codebase, |
| // enable basic web accessibility support. (Full screen reader support is |
| // detected later when specific more advanced APIs are accessed.) |
| BrowserAccessibilityStateImpl::GetInstance()->AddAccessibilityModeFlags( |
| ui::AXMode::kNativeAPIs | ui::AXMode::kWebContents); |
| } |
| |
| void BrowserAccessibilityManagerWin::UserIsReloading() { |
| if (GetRoot()) |
| FireWinAccessibilityEvent(IA2_EVENT_DOCUMENT_RELOAD, GetRoot()); |
| } |
| |
| BrowserAccessibility* BrowserAccessibilityManagerWin::GetFocus() { |
| BrowserAccessibility* focus = BrowserAccessibilityManager::GetFocus(); |
| return GetActiveDescendant(focus); |
| } |
| |
| void BrowserAccessibilityManagerWin::FireFocusEvent( |
| BrowserAccessibility* node) { |
| BrowserAccessibilityManager::FireFocusEvent(node); |
| DCHECK(node); |
| // On Windows, we always fire a FOCUS event on the root of a frame before |
| // firing a focus event within that frame. |
| if (node->manager() != last_focused_manager_ && |
| node != node->manager()->GetRoot()) { |
| FireWinAccessibilityEvent(EVENT_OBJECT_FOCUS, node->manager()->GetRoot()); |
| } |
| |
| FireWinAccessibilityEvent(EVENT_OBJECT_FOCUS, node); |
| } |
| |
| void BrowserAccessibilityManagerWin::FireBlinkEvent( |
| ax::mojom::Event event_type, |
| BrowserAccessibility* node) { |
| BrowserAccessibilityManager::FireBlinkEvent(event_type, node); |
| switch (event_type) { |
| case ax::mojom::Event::kLocationChanged: |
| FireWinAccessibilityEvent(IA2_EVENT_VISIBLE_DATA_CHANGED, node); |
| break; |
| case ax::mojom::Event::kScrolledToAnchor: |
| FireWinAccessibilityEvent(EVENT_SYSTEM_SCROLLINGSTART, node); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| void BrowserAccessibilityManagerWin::FireGeneratedEvent( |
| AXEventGenerator::Event event_type, |
| BrowserAccessibility* node) { |
| BrowserAccessibilityManager::FireGeneratedEvent(event_type, node); |
| bool can_fire_events = CanFireEvents(); |
| |
| if (event_type == Event::LOAD_COMPLETE && can_fire_events) |
| load_complete_pending_ = false; |
| |
| if (load_complete_pending_ && can_fire_events && GetRoot()) { |
| load_complete_pending_ = false; |
| FireWinAccessibilityEvent(IA2_EVENT_DOCUMENT_LOAD_COMPLETE, GetRoot()); |
| } |
| |
| if (!can_fire_events && !load_complete_pending_ && |
| event_type == Event::LOAD_COMPLETE && GetRoot() && |
| !GetRoot()->IsOffscreen() && GetRoot()->PlatformChildCount() > 0) { |
| load_complete_pending_ = true; |
| } |
| |
| switch (event_type) { |
| case Event::ACTIVE_DESCENDANT_CHANGED: |
| FireWinAccessibilityEvent(IA2_EVENT_ACTIVE_DESCENDANT_CHANGED, node); |
| break; |
| case Event::ALERT: |
| FireWinAccessibilityEvent(EVENT_SYSTEM_ALERT, node); |
| break; |
| case Event::CHILDREN_CHANGED: |
| FireWinAccessibilityEvent(EVENT_OBJECT_REORDER, node); |
| break; |
| case Event::LIVE_REGION_CHANGED: |
| // NVDA and JAWS are inconsistent about speaking this event in content. |
| // Because of this, and because Firefox does not currently fire it, we |
| // are avoiding this event for now. |
| // FireWinAccessibilityEvent(EVENT_OBJECT_LIVEREGIONCHANGED, node); |
| break; |
| case Event::LOAD_COMPLETE: |
| FireWinAccessibilityEvent(IA2_EVENT_DOCUMENT_LOAD_COMPLETE, node); |
| break; |
| case Event::SCROLL_POSITION_CHANGED: |
| FireWinAccessibilityEvent(EVENT_SYSTEM_SCROLLINGEND, node); |
| break; |
| case Event::SELECTED_CHILDREN_CHANGED: |
| FireWinAccessibilityEvent(EVENT_OBJECT_SELECTIONWITHIN, node); |
| break; |
| case Event::DOCUMENT_SELECTION_CHANGED: { |
| // Fire the event on the object where the focus of the selection is. |
| int32_t focus_id = GetTreeData().sel_focus_object_id; |
| BrowserAccessibility* focus_object = GetFromID(focus_id); |
| if (focus_object) |
| FireWinAccessibilityEvent(IA2_EVENT_TEXT_CARET_MOVED, focus_object); |
| break; |
| } |
| case Event::CHECKED_STATE_CHANGED: |
| case Event::COLLAPSED: |
| case Event::DESCRIPTION_CHANGED: |
| case Event::DOCUMENT_TITLE_CHANGED: |
| case Event::EXPANDED: |
| case Event::INVALID_STATUS_CHANGED: |
| case Event::LIVE_REGION_CREATED: |
| case Event::LIVE_REGION_NODE_CHANGED: |
| case Event::MENU_ITEM_SELECTED: |
| case Event::NAME_CHANGED: |
| case Event::OTHER_ATTRIBUTE_CHANGED: |
| case Event::RELATED_NODE_CHANGED: |
| case Event::ROLE_CHANGED: |
| case Event::ROW_COUNT_CHANGED: |
| case Event::SELECTED_CHANGED: |
| case Event::STATE_CHANGED: |
| case Event::VALUE_CHANGED: |
| // There are some notifications that aren't meaningful on Windows. |
| // It's okay to skip them. |
| break; |
| } |
| } |
| |
| void BrowserAccessibilityManagerWin::FireWinAccessibilityEvent( |
| LONG win_event_type, |
| BrowserAccessibility* node) { |
| // If there's no root delegate, this may be a new frame that hasn't |
| // yet been swapped in or added to the frame tree. Suppress firing events |
| // until then. |
| BrowserAccessibilityDelegate* root_delegate = GetDelegateFromRootManager(); |
| if (!root_delegate) |
| return; |
| |
| HWND hwnd = root_delegate->AccessibilityGetAcceleratedWidget(); |
| if (!hwnd) |
| return; |
| |
| // Don't fire events when this document might be stale as the user has |
| // started navigating to a new document. |
| if (user_is_navigating_away_) |
| return; |
| |
| // Inline text boxes are an internal implementation detail, we don't |
| // expose them to Windows. |
| if (node->GetRole() == ax::mojom::Role::kInlineTextBox) |
| return; |
| |
| // Pass the negation of this node's unique id in the |child_id| |
| // argument to NotifyWinEvent; the AT client will then call get_accChild |
| // on the HWND's accessibility object and pass it that same id, which |
| // we can use to retrieve the IAccessible for this node. |
| LONG child_id = -(ToBrowserAccessibilityWin(node)->GetCOM()->GetUniqueId()); |
| ::NotifyWinEvent(win_event_type, hwnd, OBJID_CLIENT, child_id); |
| } |
| |
| bool BrowserAccessibilityManagerWin::CanFireEvents() { |
| BrowserAccessibilityDelegate* root_delegate = GetDelegateFromRootManager(); |
| if (!root_delegate) |
| return false; |
| HWND hwnd = root_delegate->AccessibilityGetAcceleratedWidget(); |
| return hwnd != nullptr; |
| } |
| |
| gfx::Rect BrowserAccessibilityManagerWin::GetViewBounds() { |
| // We have to take the device scale factor into account on Windows. |
| BrowserAccessibilityDelegate* delegate = GetDelegateFromRootManager(); |
| if (delegate) { |
| gfx::Rect bounds = delegate->AccessibilityGetViewBounds(); |
| if (device_scale_factor() > 0.0 && device_scale_factor() != 1.0) |
| bounds = ScaleToEnclosingRect(bounds, device_scale_factor()); |
| return bounds; |
| } |
| return gfx::Rect(); |
| } |
| |
| void BrowserAccessibilityManagerWin::OnAtomicUpdateFinished( |
| ui::AXTree* tree, |
| bool root_changed, |
| const std::vector<ui::AXTreeDelegate::Change>& changes) { |
| BrowserAccessibilityManager::OnAtomicUpdateFinished( |
| tree, root_changed, changes); |
| |
| // Do a sequence of Windows-specific updates on each node. Each one is |
| // done in a single pass that must complete before the next step starts. |
| // The first step moves win_attributes_ to old_win_attributes_ and then |
| // recomputes all of win_attributes_ other than IAccessibleText. |
| for (const auto& change : changes) { |
| const ui::AXNode* changed_node = change.node; |
| DCHECK(changed_node); |
| BrowserAccessibility* obj = GetFromAXNode(changed_node); |
| if (obj && obj->IsNative()) { |
| ToBrowserAccessibilityWin(obj) |
| ->GetCOM() |
| ->UpdateStep1ComputeWinAttributes(); |
| } |
| } |
| |
| // The next step updates the hypertext of each node, which is a |
| // concatenation of all of its child text nodes, so it can't run until |
| // the text of all of the nodes was computed in the previous step. |
| for (const auto& change : changes) { |
| const ui::AXNode* changed_node = change.node; |
| DCHECK(changed_node); |
| BrowserAccessibility* obj = GetFromAXNode(changed_node); |
| if (obj && obj->IsNative()) |
| ToBrowserAccessibilityWin(obj)->GetCOM()->UpdateStep2ComputeHypertext(); |
| } |
| |
| // The third step fires events on nodes based on what's changed - like |
| // if the name, value, or description changed, or if the hypertext had |
| // text inserted or removed. It's able to figure out exactly what changed |
| // because we still have old_win_attributes_ populated. |
| // This step has to run after the previous two steps complete because the |
| // client may walk the tree when it receives any of these events. |
| // At the end, it deletes old_win_attributes_ since they're not needed |
| // anymore. |
| for (const auto& change : changes) { |
| const ui::AXNode* changed_node = change.node; |
| DCHECK(changed_node); |
| BrowserAccessibility* obj = GetFromAXNode(changed_node); |
| if (obj && obj->IsNative()) { |
| ToBrowserAccessibilityWin(obj)->GetCOM()->UpdateStep3FireEvents( |
| change.type == AXTreeDelegate::SUBTREE_CREATED); |
| } |
| } |
| } |
| |
| } // namespace content |