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Diffstat (limited to 'chrome/views/accessibility/view_accessibility.cc')
-rw-r--r-- | chrome/views/accessibility/view_accessibility.cc | 703 |
1 files changed, 703 insertions, 0 deletions
diff --git a/chrome/views/accessibility/view_accessibility.cc b/chrome/views/accessibility/view_accessibility.cc new file mode 100644 index 0000000..c435f1e --- /dev/null +++ b/chrome/views/accessibility/view_accessibility.cc @@ -0,0 +1,703 @@ +// Copyright 2008, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "chrome/views/accessibility/view_accessibility.h" + +#include "base/logging.h" +#include "chrome/browser/view_ids.h" +#include "chrome/browser/views/location_bar_view.h" + +HRESULT ViewAccessibility::Initialize(ChromeViews::View* view) { + if (!view) { + return E_INVALIDARG; + } + + view_ = view; + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accChildCount(LONG* child_count) { + if (!child_count) { + return E_INVALIDARG; + } + + DCHECK(view_); + *child_count = view_->GetChildViewCount(); + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accChild(VARIANT var_child, + IDispatch** disp_child) { + if (var_child.vt != VT_I4 || !disp_child) { + return E_INVALIDARG; + } + + // If var_child is the parent, remain with the same IDispatch. + if (var_child.lVal == CHILDID_SELF) { + return S_OK; + } + + ChromeViews::View* child = NULL; + bool get_iaccessible = false; + + // Check to see if child is out-of-bounds. + if (IsValidChild((var_child.lVal - 1), view_)) { + child = view_->GetChildViewAt(var_child.lVal - 1); + } else { + // Child is further down the hierarchy, get ID and adjust for MSAA. + child = view_->GetViewByID(static_cast<int>(var_child.lVal)); + get_iaccessible = true; + } + // TODO(klink): Add bounds checking for View IDs and an else for OOB error. + + if (!child) { + // No child found. + *disp_child = NULL; + return E_FAIL; + } + + // Sprecial case to handle the AutocompleteEdit MSAA. + if (child->GetID() == VIEW_ID_AUTOCOMPLETE) { + ChromeViews::View* parent = child->GetParent(); + + // Paranoia check, to make sure we are making a correct cast. + if (parent->GetID() == VIEW_ID_LOCATION_BAR) { + LocationBarView* location_bar = + static_cast<LocationBarView*>(parent); + + // Set the custom IAccessible for the HWNDView containing + // AutocompleteEdit. + IAccessible* location_entry_accessibility = + location_bar->location_entry()->GetIAccessible(); + if (!location_entry_accessibility) + return E_NOINTERFACE; + + GetAccessibleWrapper(child)->SetInstance(location_entry_accessibility); + // Setting bool to be true, as we have inserted an IAccessible on a + // leaf, and we need ref counting to happen properly. + get_iaccessible = true; + } + } + + if (get_iaccessible || child->GetChildViewCount() != 0) { + // Retrieve the IUnknown interface for the requested child view, and + // assign the IDispatch returned. + if ((GetAccessibleWrapper(child))-> + GetInstance(IID_IAccessible, + reinterpret_cast<void**>(disp_child)) == S_OK) { + // Increment the reference count for the retrieved interface. + (*disp_child)->AddRef(); + return S_OK; + } else { + // No interface, return failure. + return E_NOINTERFACE; + } + } else { + // When at a leaf, children are handled by the parent object. + *disp_child = NULL; + return S_FALSE; + } +} + +STDMETHODIMP ViewAccessibility::get_accParent(IDispatch** disp_parent) { + if (!disp_parent) { + return E_INVALIDARG; + } + + ChromeViews::View* parent = view_->GetParent(); + + if (!parent) { + // For a View that has no parent (e.g. root), point the accessible parent to + // the default implementation, to interface with Windows' hierarchy and to + // support calls from e.g. WindowFromAccessibleObject. + HRESULT hr = + ::AccessibleObjectFromWindow(view_->GetViewContainer()->GetHWND(), + OBJID_WINDOW, IID_IAccessible, + reinterpret_cast<void**>(disp_parent)); + + if (!SUCCEEDED(hr)) { + *disp_parent = NULL; + return S_FALSE; + } + + return S_OK; + } + + // Retrieve the IUnknown interface for the parent view, and assign the + // IDispatch returned. + if ((GetAccessibleWrapper(parent))-> + GetInstance(IID_IAccessible, + reinterpret_cast<void**>(disp_parent)) == S_OK) { + // Increment the reference count for the retrieved interface. + (*disp_parent)->AddRef(); + return S_OK; + } else { + return E_NOINTERFACE; + } +} + +STDMETHODIMP ViewAccessibility::accNavigate(LONG nav_dir, VARIANT start, + VARIANT* end) { + if (start.vt != VT_I4 || !end) { + return E_INVALIDARG; + } + + switch (nav_dir) { + case NAVDIR_FIRSTCHILD: + case NAVDIR_LASTCHILD: { + if (start.lVal != CHILDID_SELF) { + // Start of navigation must be on the View itself. + return E_INVALIDARG; + } else if (view_->GetChildViewCount() == 0) { + // No children found. + return S_FALSE; + } + + // Set child_id based on first or last child. + int child_id = 0; + if (nav_dir == NAVDIR_LASTCHILD) { + child_id = view_->GetChildViewCount() - 1; + } + + ChromeViews::View* child = view_->GetChildViewAt(child_id); + + if (child->GetChildViewCount() != 0) { + end->vt = VT_DISPATCH; + if ((GetAccessibleWrapper(child))-> + GetInstance(IID_IAccessible, + reinterpret_cast<void**>(&end->pdispVal)) == S_OK) { + // Increment the reference count for the retrieved interface. + end->pdispVal->AddRef(); + return S_OK; + } else { + return E_NOINTERFACE; + } + } else { + end->vt = VT_I4; + // Set return child lVal, adjusted for MSAA indexing. (MSAA + // child indexing starts with 1, whereas View indexing starts with 0). + end->lVal = child_id + 1; + } + break; + } + case NAVDIR_LEFT: + case NAVDIR_UP: + case NAVDIR_PREVIOUS: + case NAVDIR_RIGHT: + case NAVDIR_DOWN: + case NAVDIR_NEXT: { + // Retrieve parent to access view index and perform bounds checking. + ChromeViews::View* parent = view_->GetParent(); + if (!parent) { + return E_FAIL; + } + + if (start.lVal == CHILDID_SELF) { + int view_index = parent->GetChildIndex(view_); + // Check navigation bounds, adjusting for View child indexing (MSAA + // child indexing starts with 1, whereas View indexing starts with 0). + if (!IsValidNav(nav_dir, view_index, -1, + parent->GetChildViewCount())) { + // Navigation attempted to go out-of-bounds. + end->vt = VT_EMPTY; + return S_FALSE; + } else { + if (IsNavDirNext(nav_dir)) { + view_index += 1; + } else { + view_index -=1; + } + } + + ChromeViews::View* child = parent->GetChildViewAt(view_index); + if (child->GetChildViewCount() != 0) { + end->vt = VT_DISPATCH; + // Retrieve IDispatch for non-leaf child. + if ((GetAccessibleWrapper(child))-> + GetInstance(IID_IAccessible, + reinterpret_cast<void**>(&end->pdispVal)) == S_OK) { + // Increment the reference count for the retrieved interface. + end->pdispVal->AddRef(); + return S_OK; + } else { + return E_NOINTERFACE; + } + } else { + end->vt = VT_I4; + // Modifying view_index to give lVal correct MSAA-based value. (MSAA + // child indexing starts with 1, whereas View indexing starts with 0). + end->lVal = view_index + 1; + } + } else { + // Check navigation bounds, adjusting for MSAA child indexing (MSAA + // child indexing starts with 1, whereas View indexing starts with 0). + if (!IsValidNav(nav_dir, start.lVal, 0, + parent->GetChildViewCount() + 1)) { + // Navigation attempted to go out-of-bounds. + end->vt = VT_EMPTY; + return S_FALSE; + } else { + if (IsNavDirNext(nav_dir)) { + start.lVal += 1; + } else { + start.lVal -= 1; + } + } + + HRESULT result = this->get_accChild(start, &end->pdispVal); + if (result == S_FALSE) { + // Child is a leaf. + end->vt = VT_I4; + end->lVal = start.lVal; + } else if (result == E_INVALIDARG) { + return E_INVALIDARG; + } else { + // Child is not a leaf. + end->vt = VT_DISPATCH; + } + } + break; + } + default: + return E_INVALIDARG; + } + // Navigation performed correctly. Global return for this function, if no + // error triggered an escape earlier. + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accFocus(VARIANT* focus_child) { + if (!focus_child) { + return E_INVALIDARG; + } + + if (view_->GetChildViewCount() == 0 && view_->HasFocus()) { + // Parent view has focus. + focus_child->vt = VT_I4; + focus_child->lVal = CHILDID_SELF; + } else { + bool has_focus = false; + int child_count = view_->GetChildViewCount(); + // Search for child view with focus. + for (int child_id = 0; child_id < child_count; ++child_id) { + if (view_->GetChildViewAt(child_id)->HasFocus()) { + focus_child->vt = VT_I4; + focus_child->lVal = child_id + 1; + + // If child view is no leaf, retrieve IDispatch. + if (view_->GetChildViewAt(child_id)->GetChildViewCount() != 0) { + focus_child->vt = VT_DISPATCH; + this->get_accChild(*focus_child, &focus_child->pdispVal); + } + has_focus = true; + break; + } + } + // No current focus on any of the children. + if (!has_focus) { + focus_child->vt = VT_EMPTY; + return S_FALSE; + } + } + + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accName(VARIANT var_id, BSTR* name) { + if (var_id.vt != VT_I4 || !name) { + return E_INVALIDARG; + } + + std::wstring temp_name; + + if (var_id.lVal == CHILDID_SELF) { + // Retrieve the parent view's name. + view_->GetAccessibleName(&temp_name); + } else { + if (!IsValidChild((var_id.lVal - 1), view_)) { + return E_INVALIDARG; + } + // Retrieve the child view's name. + view_->GetChildViewAt(var_id.lVal - 1)->GetAccessibleName(&temp_name); + } + if (!temp_name.empty()) { + // Return name retrieved. + *name = CComBSTR(temp_name.c_str()).Detach(); + } else { + // If view has no name, return S_FALSE. + return S_FALSE; + } + DCHECK(*name); + + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accDescription(VARIANT var_id, BSTR* desc) { + if (var_id.vt != VT_I4 || !desc) { + return E_INVALIDARG; + } + + std::wstring temp_desc; + + if (var_id.lVal == CHILDID_SELF) { + view_->GetTooltipText(0, 0, &temp_desc); + } else { + if (!IsValidChild((var_id.lVal - 1), view_)) { + return E_INVALIDARG; + } + view_->GetChildViewAt(var_id.lVal - 1)->GetTooltipText(0, 0, &temp_desc); + } + if (!temp_desc.empty()) { + *desc = CComBSTR(temp_desc.c_str()).Detach(); + } else { + return S_FALSE; + } + DCHECK(*desc); + + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accState(VARIANT var_id, VARIANT* state) { + if (var_id.vt != VT_I4 || !state) { + return E_INVALIDARG; + } + + state->vt = VT_I4; + + if (var_id.lVal == CHILDID_SELF) { + // Retrieve all currently applicable states of the parent. + this->SetState(state, view_); + } else { + if (!IsValidChild((var_id.lVal - 1), view_)) { + return E_INVALIDARG; + } + // Retrieve all currently applicable states of the child. + this->SetState(state, view_->GetChildViewAt(var_id.lVal - 1)); + } + DCHECK((*state).vt != VT_EMPTY); + + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accRole(VARIANT var_id, VARIANT* role) { + if (var_id.vt != VT_I4 || !role) { + return E_INVALIDARG; + } + + if (var_id.lVal == CHILDID_SELF) { + // Retrieve parent role. + if (!view_->GetAccessibleRole(role)) { + return E_FAIL; + } + } else { + if (!IsValidChild((var_id.lVal - 1), view_)) { + return E_INVALIDARG; + } + // Retrieve child role. + if (!view_->GetChildViewAt(var_id.lVal - 1)->GetAccessibleRole(role)) { + return E_FAIL; + } + } + DCHECK((*role).vt != VT_EMPTY); + + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accDefaultAction(VARIANT var_id, + BSTR* def_action) { + if (var_id.vt != VT_I4 || !def_action) { + return E_INVALIDARG; + } + + std::wstring temp_action; + + if (var_id.lVal == CHILDID_SELF) { + view_->GetAccessibleDefaultAction(&temp_action); + } else { + if (!IsValidChild((var_id.lVal - 1), view_)) { + return E_INVALIDARG; + } + view_->GetChildViewAt(var_id.lVal - 1)-> + GetAccessibleDefaultAction(&temp_action); + } + if (!temp_action.empty()) { + *def_action = CComBSTR(temp_action.c_str()).Detach(); + } else { + return S_FALSE; + } + DCHECK(*def_action); + + return S_OK; +} + +STDMETHODIMP ViewAccessibility::accLocation(LONG* x_left, LONG* y_top, + LONG* width, LONG* height, + VARIANT var_id) { + if (var_id.vt != VT_I4 || !x_left || !y_top || !width || !height) { + return E_INVALIDARG; + } + + CRect view_bounds(0, 0, 0, 0); + // Retrieving the parent View to be used for converting from view-to-screen + // coordinates. + ChromeViews::View* parent = view_->GetParent(); + + if (parent == NULL) { + // If no parent, remain within the same View. + parent = view_; + } + + if (var_id.lVal == CHILDID_SELF) { + // Retrieve active View's bounds. + view_->GetBounds(&view_bounds); + } else { + // Check to see if child is out-of-bounds. + if (!IsValidChild((var_id.lVal - 1), view_)) { + return E_INVALIDARG; + } + // Retrieve child bounds. + view_->GetChildViewAt(var_id.lVal - 1)->GetBounds(&view_bounds); + // Parent View is current View. + parent = view_; + } + + if (!view_bounds.IsRectNull()) { + *width = view_bounds.Width(); + *height = view_bounds.Height(); + + ChromeViews::View::ConvertPointToScreen(parent, &view_bounds.TopLeft()); + *x_left = view_bounds.left; + *y_top = view_bounds.top; + } else { + return E_FAIL; + } + return S_OK; +} + + +// TODO(klink): Handle case where child View is not contained by parent. +STDMETHODIMP ViewAccessibility::accHitTest(LONG x_left, LONG y_top, + VARIANT* child) { + if (!child) { + return E_INVALIDARG; + } + + CPoint pt(x_left, y_top); + ChromeViews::View::ConvertPointToView(NULL, view_, &pt); + + if (!view_->HitTest(pt)) { + // If containing parent is not hit, return with failure. + child->vt = VT_EMPTY; + return S_FALSE; + } + + int child_count = view_->GetChildViewCount(); + bool child_hit = false; + ChromeViews::View* child_view = NULL; + for (int child_id = 0; child_id < child_count; ++child_id) { + // Search for hit within any of the children. + child_view = view_->GetChildViewAt(child_id); + ChromeViews::View::ConvertPointToView(view_, child_view, &pt); + if (child_view->HitTest(pt)) { + // Store child_id (adjusted with +1 to convert to MSAA indexing). + child->lVal = child_id + 1; + child_hit = true; + break; + } + // Convert point back to parent view to test next child. + ChromeViews::View::ConvertPointToView(child_view, view_, &pt); + } + + child->vt = VT_I4; + + if (!child_hit) { + // No child hit, return parent id. + child->lVal = CHILDID_SELF; + } else { + if (child_view == NULL) { + return E_FAIL; + } else if (child_view->GetChildViewCount() != 0) { + // Retrieve IDispatch for child, if it is not a leaf. + child->vt = VT_DISPATCH; + if ((GetAccessibleWrapper(child_view))-> + GetInstance(IID_IAccessible, + reinterpret_cast<void**>(&child->pdispVal)) == S_OK) { + // Increment the reference count for the retrieved interface. + child->pdispVal->AddRef(); + return S_OK; + } else { + return E_NOINTERFACE; + } + } + } + + return S_OK; +} + +STDMETHODIMP ViewAccessibility::get_accKeyboardShortcut(VARIANT var_id, + BSTR* acc_key) { + if (var_id.vt != VT_I4 || !acc_key) { + return E_INVALIDARG; + } + + std::wstring temp_key; + + if (var_id.lVal == CHILDID_SELF) { + view_->GetAccessibleKeyboardShortcut(&temp_key); + } else { + if (!IsValidChild((var_id.lVal - 1), view_)) { + return E_INVALIDARG; + } + view_->GetChildViewAt(var_id.lVal - 1)-> + GetAccessibleKeyboardShortcut(&temp_key); + } + if (!temp_key.empty()) { + *acc_key = CComBSTR(temp_key.c_str()).Detach(); + } else { + return S_FALSE; + } + DCHECK(*acc_key); + + return S_OK; +} + +// Helper functions. + +bool ViewAccessibility::IsValidChild(int child_id, + ChromeViews::View* view) const { + if (((child_id) < 0) || + ((child_id) >= view->GetChildViewCount())) { + return false; + } + return true; +} + +bool ViewAccessibility::IsNavDirNext(int nav_dir) const { + if (nav_dir == NAVDIR_RIGHT || nav_dir == NAVDIR_DOWN || + nav_dir == NAVDIR_NEXT) { + return true; + } + return false; +} + +bool ViewAccessibility::IsValidNav(int nav_dir, int start_id, int lower_bound, + int upper_bound) const { + if (IsNavDirNext(nav_dir)) { + if ((start_id + 1) > upper_bound) { + return false; + } + } else { + if ((start_id - 1) <= lower_bound) { + return false; + } + } + return true; +} + +void ViewAccessibility::SetState(VARIANT* state, ChromeViews::View* view) { + // Default state; all views can have accessibility focus. + state->lVal |= STATE_SYSTEM_FOCUSABLE; + + if (!view) + return; + + if (!view->IsEnabled()) { + state->lVal |= STATE_SYSTEM_UNAVAILABLE; + } + if (!view->IsVisible()) { + state->lVal |= STATE_SYSTEM_INVISIBLE; + } + if (view->IsHotTracked()) { + state->lVal |= STATE_SYSTEM_HOTTRACKED; + } + if (view->IsPushed()) { + state->lVal |= STATE_SYSTEM_PRESSED; + } + // Check both for actual View focus, as well as accessibility focus. + ChromeViews::View* parent = view->GetParent(); + + if (view->HasFocus() || + (parent && parent->GetAccFocusedChildView() == view)) { + state->lVal |= STATE_SYSTEM_FOCUSED; + } + + // Add on any view-specific states. + view->GetAccessibleState(state); +} + +// IAccessible functions not supported. + +HRESULT ViewAccessibility::accDoDefaultAction(VARIANT var_id) { + return DISP_E_MEMBERNOTFOUND; +} + +STDMETHODIMP ViewAccessibility::get_accValue(VARIANT var_id, BSTR* value) { + if (value) + *value = NULL; + return DISP_E_MEMBERNOTFOUND; +} + +STDMETHODIMP ViewAccessibility::get_accSelection(VARIANT* selected) { + if (selected) + selected->vt = VT_EMPTY; + return DISP_E_MEMBERNOTFOUND; +} + +STDMETHODIMP ViewAccessibility::accSelect(LONG flagsSelect, VARIANT var_id) { + return DISP_E_MEMBERNOTFOUND; +} + +STDMETHODIMP ViewAccessibility::get_accHelp(VARIANT var_id, BSTR* help) { + if (help) + *help = NULL; + return DISP_E_MEMBERNOTFOUND; +} + +STDMETHODIMP ViewAccessibility::get_accHelpTopic(BSTR* help_file, + VARIANT var_id, + LONG* topic_id) { + if (help_file) { + *help_file = NULL; + } + if (topic_id) { + *topic_id = static_cast<LONG>(-1); + } + return DISP_E_MEMBERNOTFOUND; +} + +STDMETHODIMP ViewAccessibility::put_accName(VARIANT var_id, BSTR put_name) { + // Deprecated. + return DISP_E_MEMBERNOTFOUND; +} + +STDMETHODIMP ViewAccessibility::put_accValue(VARIANT var_id, BSTR put_val) { + // Deprecated. + return DISP_E_MEMBERNOTFOUND; +} + |