1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/accessible/src/base/nsTextEquivUtils.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,362 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim:expandtab:shiftwidth=2:tabstop=2:
1.6 + */
1.7 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.8 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.9 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.10 +
1.11 +#include "nsTextEquivUtils.h"
1.12 +
1.13 +#include "Accessible-inl.h"
1.14 +#include "AccIterator.h"
1.15 +#include "nsCoreUtils.h"
1.16 +#include "nsIDOMXULLabeledControlEl.h"
1.17 +
1.18 +using namespace mozilla::a11y;
1.19 +
1.20 +/**
1.21 + * The accessible for which we are computing a text equivalent. It is useful
1.22 + * for bailing out during recursive text computation, or for special cases
1.23 + * like step f. of the ARIA implementation guide.
1.24 + */
1.25 +static Accessible* sInitiatorAcc = nullptr;
1.26 +
1.27 +////////////////////////////////////////////////////////////////////////////////
1.28 +// nsTextEquivUtils. Public.
1.29 +
1.30 +nsresult
1.31 +nsTextEquivUtils::GetNameFromSubtree(Accessible* aAccessible,
1.32 + nsAString& aName)
1.33 +{
1.34 + aName.Truncate();
1.35 +
1.36 + if (sInitiatorAcc)
1.37 + return NS_OK;
1.38 +
1.39 + sInitiatorAcc = aAccessible;
1.40 + if (GetRoleRule(aAccessible->Role()) == eNameFromSubtreeRule) {
1.41 + //XXX: is it necessary to care the accessible is not a document?
1.42 + if (aAccessible->IsContent()) {
1.43 + nsAutoString name;
1.44 + AppendFromAccessibleChildren(aAccessible, &name);
1.45 + name.CompressWhitespace();
1.46 + if (!nsCoreUtils::IsWhitespaceString(name))
1.47 + aName = name;
1.48 + }
1.49 + }
1.50 +
1.51 + sInitiatorAcc = nullptr;
1.52 +
1.53 + return NS_OK;
1.54 +}
1.55 +
1.56 +nsresult
1.57 +nsTextEquivUtils::GetTextEquivFromIDRefs(Accessible* aAccessible,
1.58 + nsIAtom *aIDRefsAttr,
1.59 + nsAString& aTextEquiv)
1.60 +{
1.61 + aTextEquiv.Truncate();
1.62 +
1.63 + nsIContent* content = aAccessible->GetContent();
1.64 + if (!content)
1.65 + return NS_OK;
1.66 +
1.67 + nsIContent* refContent = nullptr;
1.68 + IDRefsIterator iter(aAccessible->Document(), content, aIDRefsAttr);
1.69 + while ((refContent = iter.NextElem())) {
1.70 + if (!aTextEquiv.IsEmpty())
1.71 + aTextEquiv += ' ';
1.72 +
1.73 + nsresult rv = AppendTextEquivFromContent(aAccessible, refContent,
1.74 + &aTextEquiv);
1.75 + NS_ENSURE_SUCCESS(rv, rv);
1.76 + }
1.77 +
1.78 + return NS_OK;
1.79 +}
1.80 +
1.81 +nsresult
1.82 +nsTextEquivUtils::AppendTextEquivFromContent(Accessible* aInitiatorAcc,
1.83 + nsIContent *aContent,
1.84 + nsAString *aString)
1.85 +{
1.86 + // Prevent recursion which can cause infinite loops.
1.87 + if (sInitiatorAcc)
1.88 + return NS_OK;
1.89 +
1.90 + sInitiatorAcc = aInitiatorAcc;
1.91 +
1.92 + // If the given content is not visible or isn't accessible then go down
1.93 + // through the DOM subtree otherwise go down through accessible subtree and
1.94 + // calculate the flat string.
1.95 + nsIFrame *frame = aContent->GetPrimaryFrame();
1.96 + bool isVisible = frame && frame->StyleVisibility()->IsVisible();
1.97 +
1.98 + nsresult rv = NS_ERROR_FAILURE;
1.99 + bool goThroughDOMSubtree = true;
1.100 +
1.101 + if (isVisible) {
1.102 + Accessible* accessible =
1.103 + sInitiatorAcc->Document()->GetAccessible(aContent);
1.104 + if (accessible) {
1.105 + rv = AppendFromAccessible(accessible, aString);
1.106 + goThroughDOMSubtree = false;
1.107 + }
1.108 + }
1.109 +
1.110 + if (goThroughDOMSubtree)
1.111 + rv = AppendFromDOMNode(aContent, aString);
1.112 +
1.113 + sInitiatorAcc = nullptr;
1.114 + return rv;
1.115 +}
1.116 +
1.117 +nsresult
1.118 +nsTextEquivUtils::AppendTextEquivFromTextContent(nsIContent *aContent,
1.119 + nsAString *aString)
1.120 +{
1.121 + if (aContent->IsNodeOfType(nsINode::eTEXT)) {
1.122 + bool isHTMLBlock = false;
1.123 +
1.124 + nsIContent *parentContent = aContent->GetFlattenedTreeParent();
1.125 + if (parentContent) {
1.126 + nsIFrame *frame = parentContent->GetPrimaryFrame();
1.127 + if (frame) {
1.128 + // If this text is inside a block level frame (as opposed to span
1.129 + // level), we need to add spaces around that block's text, so we don't
1.130 + // get words jammed together in final name.
1.131 + const nsStyleDisplay* display = frame->StyleDisplay();
1.132 + if (display->IsBlockOutsideStyle() ||
1.133 + display->mDisplay == NS_STYLE_DISPLAY_TABLE_CELL) {
1.134 + isHTMLBlock = true;
1.135 + if (!aString->IsEmpty()) {
1.136 + aString->Append(char16_t(' '));
1.137 + }
1.138 + }
1.139 + }
1.140 + }
1.141 +
1.142 + if (aContent->TextLength() > 0) {
1.143 + nsIFrame *frame = aContent->GetPrimaryFrame();
1.144 + if (frame) {
1.145 + nsresult rv = frame->GetRenderedText(aString);
1.146 + NS_ENSURE_SUCCESS(rv, rv);
1.147 + } else {
1.148 + // If aContent is an object that is display: none, we have no a frame.
1.149 + aContent->AppendTextTo(*aString);
1.150 + }
1.151 + if (isHTMLBlock && !aString->IsEmpty()) {
1.152 + aString->Append(char16_t(' '));
1.153 + }
1.154 + }
1.155 +
1.156 + return NS_OK;
1.157 + }
1.158 +
1.159 + if (aContent->IsHTML() &&
1.160 + aContent->NodeInfo()->Equals(nsGkAtoms::br)) {
1.161 + aString->AppendLiteral("\r\n");
1.162 + return NS_OK;
1.163 + }
1.164 +
1.165 + return NS_OK_NO_NAME_CLAUSE_HANDLED;
1.166 +}
1.167 +
1.168 +////////////////////////////////////////////////////////////////////////////////
1.169 +// nsTextEquivUtils. Private.
1.170 +
1.171 +nsresult
1.172 +nsTextEquivUtils::AppendFromAccessibleChildren(Accessible* aAccessible,
1.173 + nsAString *aString)
1.174 +{
1.175 + nsresult rv = NS_OK_NO_NAME_CLAUSE_HANDLED;
1.176 +
1.177 + uint32_t childCount = aAccessible->ChildCount();
1.178 + for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
1.179 + Accessible* child = aAccessible->GetChildAt(childIdx);
1.180 + rv = AppendFromAccessible(child, aString);
1.181 + NS_ENSURE_SUCCESS(rv, rv);
1.182 + }
1.183 +
1.184 + return rv;
1.185 +}
1.186 +
1.187 +nsresult
1.188 +nsTextEquivUtils::AppendFromAccessible(Accessible* aAccessible,
1.189 + nsAString *aString)
1.190 +{
1.191 + //XXX: is it necessary to care the accessible is not a document?
1.192 + if (aAccessible->IsContent()) {
1.193 + nsresult rv = AppendTextEquivFromTextContent(aAccessible->GetContent(),
1.194 + aString);
1.195 + if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
1.196 + return rv;
1.197 + }
1.198 +
1.199 + bool isEmptyTextEquiv = true;
1.200 +
1.201 + // If the name is from tooltip then append it to result string in the end
1.202 + // (see h. step of name computation guide).
1.203 + nsAutoString text;
1.204 + if (aAccessible->Name(text) != eNameFromTooltip)
1.205 + isEmptyTextEquiv = !AppendString(aString, text);
1.206 +
1.207 + // Implementation of f. step.
1.208 + nsresult rv = AppendFromValue(aAccessible, aString);
1.209 + NS_ENSURE_SUCCESS(rv, rv);
1.210 +
1.211 + if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
1.212 + isEmptyTextEquiv = false;
1.213 +
1.214 + // Implementation of g) step of text equivalent computation guide. Go down
1.215 + // into subtree if accessible allows "text equivalent from subtree rule" or
1.216 + // it's not root and not control.
1.217 + if (isEmptyTextEquiv) {
1.218 + uint32_t nameRule = GetRoleRule(aAccessible->Role());
1.219 + if (nameRule & eNameFromSubtreeIfReqRule) {
1.220 + rv = AppendFromAccessibleChildren(aAccessible, aString);
1.221 + NS_ENSURE_SUCCESS(rv, rv);
1.222 +
1.223 + if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
1.224 + isEmptyTextEquiv = false;
1.225 + }
1.226 + }
1.227 +
1.228 + // Implementation of h. step
1.229 + if (isEmptyTextEquiv && !text.IsEmpty()) {
1.230 + AppendString(aString, text);
1.231 + return NS_OK;
1.232 + }
1.233 +
1.234 + return rv;
1.235 +}
1.236 +
1.237 +nsresult
1.238 +nsTextEquivUtils::AppendFromValue(Accessible* aAccessible,
1.239 + nsAString *aString)
1.240 +{
1.241 + if (GetRoleRule(aAccessible->Role()) != eNameFromValueRule)
1.242 + return NS_OK_NO_NAME_CLAUSE_HANDLED;
1.243 +
1.244 + // Implementation of step f. of text equivalent computation. If the given
1.245 + // accessible is not root accessible (the accessible the text equivalent is
1.246 + // computed for in the end) then append accessible value. Otherwise append
1.247 + // value if and only if the given accessible is in the middle of its parent.
1.248 +
1.249 + nsAutoString text;
1.250 + if (aAccessible != sInitiatorAcc) {
1.251 + aAccessible->Value(text);
1.252 +
1.253 + return AppendString(aString, text) ?
1.254 + NS_OK : NS_OK_NO_NAME_CLAUSE_HANDLED;
1.255 + }
1.256 +
1.257 + //XXX: is it necessary to care the accessible is not a document?
1.258 + if (aAccessible->IsDoc())
1.259 + return NS_ERROR_UNEXPECTED;
1.260 +
1.261 + nsIContent *content = aAccessible->GetContent();
1.262 +
1.263 + for (nsIContent* childContent = content->GetPreviousSibling(); childContent;
1.264 + childContent = childContent->GetPreviousSibling()) {
1.265 + // check for preceding text...
1.266 + if (!childContent->TextIsOnlyWhitespace()) {
1.267 + for (nsIContent* siblingContent = content->GetNextSibling(); siblingContent;
1.268 + siblingContent = siblingContent->GetNextSibling()) {
1.269 + // .. and subsequent text
1.270 + if (!siblingContent->TextIsOnlyWhitespace()) {
1.271 + aAccessible->Value(text);
1.272 +
1.273 + return AppendString(aString, text) ?
1.274 + NS_OK : NS_OK_NO_NAME_CLAUSE_HANDLED;
1.275 + break;
1.276 + }
1.277 + }
1.278 + break;
1.279 + }
1.280 + }
1.281 +
1.282 + return NS_OK_NO_NAME_CLAUSE_HANDLED;
1.283 +}
1.284 +
1.285 +nsresult
1.286 +nsTextEquivUtils::AppendFromDOMChildren(nsIContent *aContent,
1.287 + nsAString *aString)
1.288 +{
1.289 + for (nsIContent* childContent = aContent->GetFirstChild(); childContent;
1.290 + childContent = childContent->GetNextSibling()) {
1.291 + nsresult rv = AppendFromDOMNode(childContent, aString);
1.292 + NS_ENSURE_SUCCESS(rv, rv);
1.293 + }
1.294 +
1.295 + return NS_OK;
1.296 +}
1.297 +
1.298 +nsresult
1.299 +nsTextEquivUtils::AppendFromDOMNode(nsIContent *aContent, nsAString *aString)
1.300 +{
1.301 + nsresult rv = AppendTextEquivFromTextContent(aContent, aString);
1.302 + NS_ENSURE_SUCCESS(rv, rv);
1.303 +
1.304 + if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED)
1.305 + return NS_OK;
1.306 +
1.307 + if (aContent->IsXUL()) {
1.308 + nsAutoString textEquivalent;
1.309 + nsCOMPtr<nsIDOMXULLabeledControlElement> labeledEl =
1.310 + do_QueryInterface(aContent);
1.311 +
1.312 + if (labeledEl) {
1.313 + labeledEl->GetLabel(textEquivalent);
1.314 + } else {
1.315 + if (aContent->NodeInfo()->Equals(nsGkAtoms::label,
1.316 + kNameSpaceID_XUL))
1.317 + aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::value,
1.318 + textEquivalent);
1.319 +
1.320 + if (textEquivalent.IsEmpty())
1.321 + aContent->GetAttr(kNameSpaceID_None,
1.322 + nsGkAtoms::tooltiptext, textEquivalent);
1.323 + }
1.324 +
1.325 + AppendString(aString, textEquivalent);
1.326 + }
1.327 +
1.328 + return AppendFromDOMChildren(aContent, aString);
1.329 +}
1.330 +
1.331 +bool
1.332 +nsTextEquivUtils::AppendString(nsAString *aString,
1.333 + const nsAString& aTextEquivalent)
1.334 +{
1.335 + if (aTextEquivalent.IsEmpty())
1.336 + return false;
1.337 +
1.338 + // Insert spaces to insure that words from controls aren't jammed together.
1.339 + if (!aString->IsEmpty() && !nsCoreUtils::IsWhitespace(aString->Last()))
1.340 + aString->Append(char16_t(' '));
1.341 +
1.342 + aString->Append(aTextEquivalent);
1.343 +
1.344 + if (!nsCoreUtils::IsWhitespace(aString->Last()))
1.345 + aString->Append(char16_t(' '));
1.346 +
1.347 + return true;
1.348 +}
1.349 +
1.350 +uint32_t
1.351 +nsTextEquivUtils::GetRoleRule(role aRole)
1.352 +{
1.353 +#define ROLE(geckoRole, stringRole, atkRole, \
1.354 + macRole, msaaRole, ia2Role, nameRule) \
1.355 + case roles::geckoRole: \
1.356 + return nameRule;
1.357 +
1.358 + switch (aRole) {
1.359 +#include "RoleMap.h"
1.360 + default:
1.361 + MOZ_CRASH("Unknown role.");
1.362 + }
1.363 +
1.364 +#undef ROLE
1.365 +}
