michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim:expandtab:shiftwidth=2:tabstop=2:
michael@0:  */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsTextEquivUtils.h"
michael@0: 
michael@0: #include "Accessible-inl.h"
michael@0: #include "AccIterator.h"
michael@0: #include "nsCoreUtils.h"
michael@0: #include "nsIDOMXULLabeledControlEl.h"
michael@0: 
michael@0: using namespace mozilla::a11y;
michael@0: 
michael@0: /**
michael@0:  * The accessible for which we are computing a text equivalent. It is useful
michael@0:  * for bailing out during recursive text computation, or for special cases
michael@0:  * like step f. of the ARIA implementation guide.
michael@0:  */
michael@0: static Accessible* sInitiatorAcc = nullptr;
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // nsTextEquivUtils. Public.
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::GetNameFromSubtree(Accessible* aAccessible,
michael@0:                                      nsAString& aName)
michael@0: {
michael@0:   aName.Truncate();
michael@0: 
michael@0:   if (sInitiatorAcc)
michael@0:     return NS_OK;
michael@0: 
michael@0:   sInitiatorAcc = aAccessible;
michael@0:   if (GetRoleRule(aAccessible->Role()) == eNameFromSubtreeRule) {
michael@0:     //XXX: is it necessary to care the accessible is not a document?
michael@0:     if (aAccessible->IsContent()) {
michael@0:       nsAutoString name;
michael@0:       AppendFromAccessibleChildren(aAccessible, &name);
michael@0:       name.CompressWhitespace();
michael@0:       if (!nsCoreUtils::IsWhitespaceString(name))
michael@0:         aName = name;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   sInitiatorAcc = nullptr;
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::GetTextEquivFromIDRefs(Accessible* aAccessible,
michael@0:                                          nsIAtom *aIDRefsAttr,
michael@0:                                          nsAString& aTextEquiv)
michael@0: {
michael@0:   aTextEquiv.Truncate();
michael@0: 
michael@0:   nsIContent* content = aAccessible->GetContent();
michael@0:   if (!content)
michael@0:     return NS_OK;
michael@0: 
michael@0:   nsIContent* refContent = nullptr;
michael@0:   IDRefsIterator iter(aAccessible->Document(), content, aIDRefsAttr);
michael@0:   while ((refContent = iter.NextElem())) {
michael@0:     if (!aTextEquiv.IsEmpty())
michael@0:       aTextEquiv += ' ';
michael@0: 
michael@0:     nsresult rv = AppendTextEquivFromContent(aAccessible, refContent,
michael@0:                                              &aTextEquiv);
michael@0:     NS_ENSURE_SUCCESS(rv, rv);
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::AppendTextEquivFromContent(Accessible* aInitiatorAcc,
michael@0:                                              nsIContent *aContent,
michael@0:                                              nsAString *aString)
michael@0: {
michael@0:   // Prevent recursion which can cause infinite loops.
michael@0:   if (sInitiatorAcc)
michael@0:     return NS_OK;
michael@0: 
michael@0:   sInitiatorAcc = aInitiatorAcc;
michael@0: 
michael@0:   // If the given content is not visible or isn't accessible then go down
michael@0:   // through the DOM subtree otherwise go down through accessible subtree and
michael@0:   // calculate the flat string.
michael@0:   nsIFrame *frame = aContent->GetPrimaryFrame();
michael@0:   bool isVisible = frame && frame->StyleVisibility()->IsVisible();
michael@0: 
michael@0:   nsresult rv = NS_ERROR_FAILURE;
michael@0:   bool goThroughDOMSubtree = true;
michael@0: 
michael@0:   if (isVisible) {
michael@0:     Accessible* accessible =
michael@0:       sInitiatorAcc->Document()->GetAccessible(aContent);
michael@0:     if (accessible) {
michael@0:       rv = AppendFromAccessible(accessible, aString);
michael@0:       goThroughDOMSubtree = false;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if (goThroughDOMSubtree)
michael@0:     rv = AppendFromDOMNode(aContent, aString);
michael@0: 
michael@0:   sInitiatorAcc = nullptr;
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::AppendTextEquivFromTextContent(nsIContent *aContent,
michael@0:                                                  nsAString *aString)
michael@0: {
michael@0:   if (aContent->IsNodeOfType(nsINode::eTEXT)) {
michael@0:     bool isHTMLBlock = false;
michael@0: 
michael@0:     nsIContent *parentContent = aContent->GetFlattenedTreeParent();
michael@0:     if (parentContent) {
michael@0:       nsIFrame *frame = parentContent->GetPrimaryFrame();
michael@0:       if (frame) {
michael@0:         // If this text is inside a block level frame (as opposed to span
michael@0:         // level), we need to add spaces around that block's text, so we don't
michael@0:         // get words jammed together in final name.
michael@0:         const nsStyleDisplay* display = frame->StyleDisplay();
michael@0:         if (display->IsBlockOutsideStyle() ||
michael@0:             display->mDisplay == NS_STYLE_DISPLAY_TABLE_CELL) {
michael@0:           isHTMLBlock = true;
michael@0:           if (!aString->IsEmpty()) {
michael@0:             aString->Append(char16_t(' '));
michael@0:           }
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:     
michael@0:     if (aContent->TextLength() > 0) {
michael@0:       nsIFrame *frame = aContent->GetPrimaryFrame();
michael@0:       if (frame) {
michael@0:         nsresult rv = frame->GetRenderedText(aString);
michael@0:         NS_ENSURE_SUCCESS(rv, rv);
michael@0:       } else {
michael@0:         // If aContent is an object that is display: none, we have no a frame.
michael@0:         aContent->AppendTextTo(*aString);
michael@0:       }
michael@0:       if (isHTMLBlock && !aString->IsEmpty()) {
michael@0:         aString->Append(char16_t(' '));
michael@0:       }
michael@0:     }
michael@0:     
michael@0:     return NS_OK;
michael@0:   }
michael@0:   
michael@0:   if (aContent->IsHTML() &&
michael@0:       aContent->NodeInfo()->Equals(nsGkAtoms::br)) {
michael@0:     aString->AppendLiteral("\r\n");
michael@0:     return NS_OK;
michael@0:   }
michael@0:   
michael@0:   return NS_OK_NO_NAME_CLAUSE_HANDLED;
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // nsTextEquivUtils. Private.
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::AppendFromAccessibleChildren(Accessible* aAccessible,
michael@0:                                                nsAString *aString)
michael@0: {
michael@0:   nsresult rv = NS_OK_NO_NAME_CLAUSE_HANDLED;
michael@0: 
michael@0:   uint32_t childCount = aAccessible->ChildCount();
michael@0:   for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
michael@0:     Accessible* child = aAccessible->GetChildAt(childIdx);
michael@0:     rv = AppendFromAccessible(child, aString);
michael@0:     NS_ENSURE_SUCCESS(rv, rv);
michael@0:   }
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::AppendFromAccessible(Accessible* aAccessible,
michael@0:                                        nsAString *aString)
michael@0: {
michael@0:   //XXX: is it necessary to care the accessible is not a document?
michael@0:   if (aAccessible->IsContent()) {
michael@0:     nsresult rv = AppendTextEquivFromTextContent(aAccessible->GetContent(),
michael@0:                                                  aString);
michael@0:     if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
michael@0:       return rv;
michael@0:   }
michael@0: 
michael@0:   bool isEmptyTextEquiv = true;
michael@0: 
michael@0:   // If the name is from tooltip then append it to result string in the end
michael@0:   // (see h. step of name computation guide).
michael@0:   nsAutoString text;
michael@0:   if (aAccessible->Name(text) != eNameFromTooltip)
michael@0:     isEmptyTextEquiv = !AppendString(aString, text);
michael@0: 
michael@0:   // Implementation of f. step.
michael@0:   nsresult rv = AppendFromValue(aAccessible, aString);
michael@0:   NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:   if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
michael@0:     isEmptyTextEquiv = false;
michael@0: 
michael@0:   // Implementation of g) step of text equivalent computation guide. Go down
michael@0:   // into subtree if accessible allows "text equivalent from subtree rule" or
michael@0:   // it's not root and not control.
michael@0:   if (isEmptyTextEquiv) {
michael@0:     uint32_t nameRule = GetRoleRule(aAccessible->Role());
michael@0:     if (nameRule & eNameFromSubtreeIfReqRule) {
michael@0:       rv = AppendFromAccessibleChildren(aAccessible, aString);
michael@0:       NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:       if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
michael@0:         isEmptyTextEquiv = false;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   // Implementation of h. step
michael@0:   if (isEmptyTextEquiv && !text.IsEmpty()) {
michael@0:     AppendString(aString, text);
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::AppendFromValue(Accessible* aAccessible,
michael@0:                                   nsAString *aString)
michael@0: {
michael@0:   if (GetRoleRule(aAccessible->Role()) != eNameFromValueRule)
michael@0:     return NS_OK_NO_NAME_CLAUSE_HANDLED;
michael@0: 
michael@0:   // Implementation of step f. of text equivalent computation. If the given
michael@0:   // accessible is not root accessible (the accessible the text equivalent is
michael@0:   // computed for in the end) then append accessible value. Otherwise append
michael@0:   // value if and only if the given accessible is in the middle of its parent.
michael@0: 
michael@0:   nsAutoString text;
michael@0:   if (aAccessible != sInitiatorAcc) {
michael@0:     aAccessible->Value(text);
michael@0: 
michael@0:     return AppendString(aString, text) ?
michael@0:       NS_OK : NS_OK_NO_NAME_CLAUSE_HANDLED;
michael@0:   }
michael@0: 
michael@0:   //XXX: is it necessary to care the accessible is not a document?
michael@0:   if (aAccessible->IsDoc())
michael@0:     return NS_ERROR_UNEXPECTED;
michael@0: 
michael@0:   nsIContent *content = aAccessible->GetContent();
michael@0: 
michael@0:   for (nsIContent* childContent = content->GetPreviousSibling(); childContent;
michael@0:        childContent = childContent->GetPreviousSibling()) {
michael@0:     // check for preceding text...
michael@0:     if (!childContent->TextIsOnlyWhitespace()) {
michael@0:       for (nsIContent* siblingContent = content->GetNextSibling(); siblingContent;
michael@0:            siblingContent = siblingContent->GetNextSibling()) {
michael@0:         // .. and subsequent text
michael@0:         if (!siblingContent->TextIsOnlyWhitespace()) {
michael@0:           aAccessible->Value(text);
michael@0: 
michael@0:           return AppendString(aString, text) ?
michael@0:             NS_OK : NS_OK_NO_NAME_CLAUSE_HANDLED;
michael@0:           break;
michael@0:         }
michael@0:       }
michael@0:       break;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return NS_OK_NO_NAME_CLAUSE_HANDLED;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::AppendFromDOMChildren(nsIContent *aContent,
michael@0:                                         nsAString *aString)
michael@0: {
michael@0:   for (nsIContent* childContent = aContent->GetFirstChild(); childContent;
michael@0:        childContent = childContent->GetNextSibling()) {
michael@0:     nsresult rv = AppendFromDOMNode(childContent, aString);
michael@0:     NS_ENSURE_SUCCESS(rv, rv);
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsTextEquivUtils::AppendFromDOMNode(nsIContent *aContent, nsAString *aString)
michael@0: {
michael@0:   nsresult rv = AppendTextEquivFromTextContent(aContent, aString);
michael@0:   NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:   if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
michael@0:     return NS_OK;
michael@0: 
michael@0:   if (aContent->IsXUL()) {
michael@0:     nsAutoString textEquivalent;
michael@0:     nsCOMPtr<nsIDOMXULLabeledControlElement> labeledEl =
michael@0:       do_QueryInterface(aContent);
michael@0: 
michael@0:     if (labeledEl) {
michael@0:       labeledEl->GetLabel(textEquivalent);
michael@0:     } else {
michael@0:       if (aContent->NodeInfo()->Equals(nsGkAtoms::label,
michael@0:                                        kNameSpaceID_XUL))
michael@0:         aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::value,
michael@0:                           textEquivalent);
michael@0: 
michael@0:       if (textEquivalent.IsEmpty())
michael@0:         aContent->GetAttr(kNameSpaceID_None,
michael@0:                           nsGkAtoms::tooltiptext, textEquivalent);
michael@0:     }
michael@0: 
michael@0:     AppendString(aString, textEquivalent);
michael@0:   }
michael@0: 
michael@0:   return AppendFromDOMChildren(aContent, aString);
michael@0: }
michael@0: 
michael@0: bool
michael@0: nsTextEquivUtils::AppendString(nsAString *aString,
michael@0:                                const nsAString& aTextEquivalent)
michael@0: {
michael@0:   if (aTextEquivalent.IsEmpty())
michael@0:     return false;
michael@0: 
michael@0:   // Insert spaces to insure that words from controls aren't jammed together.
michael@0:   if (!aString->IsEmpty() && !nsCoreUtils::IsWhitespace(aString->Last()))
michael@0:     aString->Append(char16_t(' '));
michael@0: 
michael@0:   aString->Append(aTextEquivalent);
michael@0: 
michael@0:   if (!nsCoreUtils::IsWhitespace(aString->Last()))
michael@0:     aString->Append(char16_t(' '));
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: uint32_t
michael@0: nsTextEquivUtils::GetRoleRule(role aRole)
michael@0: {
michael@0: #define ROLE(geckoRole, stringRole, atkRole, \
michael@0:              macRole, msaaRole, ia2Role, nameRule) \
michael@0:   case roles::geckoRole: \
michael@0:     return nameRule;
michael@0: 
michael@0:   switch (aRole) {
michael@0: #include "RoleMap.h"
michael@0:     default:
michael@0:       MOZ_CRASH("Unknown role.");
michael@0:   }
michael@0: 
michael@0: #undef ROLE
michael@0: }