NS_IMETHODIMP
nsAccessiblePivot::MoveLast(nsIAccessibleTraversalRule* aRule,
bool* aResult)
{
NS_ENSURE_ARG(aResult);
NS_ENSURE_ARG(aRule);
Accessible* root = GetActiveRoot();
NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE);
*aResult = false;
nsresult rv = NS_OK;
Accessible* lastAccessible = root;
Accessible* accessible = nullptr;
// First go to the last accessible in pre-order
while (lastAccessible->HasChildren())
lastAccessible = lastAccessible->LastChild();
// Search backwards from last accessible and find the last occurrence in the doc
accessible = SearchBackward(lastAccessible, aRule, true, &rv);
NS_ENSURE_SUCCESS(rv, rv);
if (accessible)
*aResult = MovePivotInternal(accessible, nsAccessiblePivot::REASON_LAST);
return NS_OK;
}
bool
HTMLTableAccessible::IsProbablyLayoutTable()
{
// Implement a heuristic to determine if table is most likely used for layout
// XXX do we want to look for rowspan or colspan, especialy that span all but a couple cells
// at the beginning or end of a row/col, and especially when they occur at the edge of a table?
// XXX expose this info via object attributes to AT-SPI
// XXX For now debugging descriptions are always on via SHOW_LAYOUT_HEURISTIC
// This will allow release trunk builds to be used by testers to refine the algorithm
// Change to |#define SHOW_LAYOUT_HEURISTIC DEBUG| before final release
#ifdef SHOW_LAYOUT_HEURISTIC
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) \
{ \
mLayoutHeuristic = isLayout ? \
NS_LITERAL_STRING("layout table: " heuristic) : \
NS_LITERAL_STRING("data table: " heuristic); \
return isLayout; \
}
#else
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) { return isLayout; }
#endif
DocAccessible* docAccessible = Document();
if (docAccessible) {
uint64_t docState = docAccessible->State();
if (docState & states::EDITABLE) { // Need to see all elements while document is being edited
RETURN_LAYOUT_ANSWER(false, "In editable document");
}
}
// Check to see if an ARIA role overrides the role from native markup,
// but for which we still expose table semantics (treegrid, for example).
if (Role() != roles::TABLE)
RETURN_LAYOUT_ANSWER(false, "Has role attribute");
if (mContent->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::role)) {
// Role attribute is present, but overridden roles have already been dealt with.
// Only landmarks and other roles that don't override the role from native
// markup are left to deal with here.
RETURN_LAYOUT_ANSWER(false, "Has role attribute, weak role, and role is table");
}
NS_ASSERTION(mContent->IsHTMLElement(nsGkAtoms::table),
"table should not be built by CSS display:table style");
// Check if datatable attribute has "0" value.
if (mContent->AsElement()->AttrValueIs(kNameSpaceID_None, nsGkAtoms::datatable,
NS_LITERAL_STRING("0"), eCaseMatters)) {
RETURN_LAYOUT_ANSWER(true, "Has datatable = 0 attribute, it's for layout");
}
// Check for legitimate data table attributes.
nsAutoString summary;
if (mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::summary, summary) &&
!summary.IsEmpty())
RETURN_LAYOUT_ANSWER(false, "Has summary -- legitimate table structures");
// Check for legitimate data table elements.
Accessible* caption = FirstChild();
if (caption && caption->Role() == roles::CAPTION && caption->HasChildren())
RETURN_LAYOUT_ANSWER(false, "Not empty caption -- legitimate table structures");
for (nsIContent* childElm = mContent->GetFirstChild(); childElm;
childElm = childElm->GetNextSibling()) {
if (!childElm->IsHTMLElement())
continue;
if (childElm->IsAnyOfHTMLElements(nsGkAtoms::col,
nsGkAtoms::colgroup,
nsGkAtoms::tfoot,
nsGkAtoms::thead)) {
RETURN_LAYOUT_ANSWER(false,
"Has col, colgroup, tfoot or thead -- legitimate table structures");
}
if (childElm->IsHTMLElement(nsGkAtoms::tbody)) {
for (nsIContent* rowElm = childElm->GetFirstChild(); rowElm;
rowElm = rowElm->GetNextSibling()) {
if (rowElm->IsHTMLElement(nsGkAtoms::tr)) {
for (nsIContent* cellElm = rowElm->GetFirstChild(); cellElm;
cellElm = cellElm->GetNextSibling()) {
if (cellElm->IsHTMLElement()) {
if (cellElm->NodeInfo()->Equals(nsGkAtoms::th)) {
RETURN_LAYOUT_ANSWER(false,
"Has th -- legitimate table structures");
}
if (cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::headers) ||
cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::scope) ||
cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::abbr)) {
RETURN_LAYOUT_ANSWER(false,
"Has headers, scope, or abbr attribute -- legitimate table structures");
}
Accessible* cell = mDoc->GetAccessible(cellElm);
if (cell && cell->ChildCount() == 1 &&
cell->FirstChild()->IsAbbreviation()) {
RETURN_LAYOUT_ANSWER(false,
"has abbr -- legitimate table structures");
}
}
}
}
}
}
}
if (HasDescendant(NS_LITERAL_STRING("table"))) {
RETURN_LAYOUT_ANSWER(true, "Has a nested table within it");
}
// If only 1 column or only 1 row, it's for layout
uint32_t colCount = ColCount();
if (colCount <=1) {
RETURN_LAYOUT_ANSWER(true, "Has only 1 column");
}
uint32_t rowCount = RowCount();
if (rowCount <=1) {
RETURN_LAYOUT_ANSWER(true, "Has only 1 row");
}
// Check for many columns
if (colCount >= 5) {
RETURN_LAYOUT_ANSWER(false, ">=5 columns");
}
// Now we know there are 2-4 columns and 2 or more rows
// Check to see if there are visible borders on the cells
// XXX currently, we just check the first cell -- do we really need to do more?
nsTableWrapperFrame* tableFrame = do_QueryFrame(mContent->GetPrimaryFrame());
if (!tableFrame)
RETURN_LAYOUT_ANSWER(false, "table with no frame!");
nsIFrame* cellFrame = tableFrame->GetCellFrameAt(0, 0);
if (!cellFrame)
RETURN_LAYOUT_ANSWER(false, "table's first cell has no frame!");
nsMargin border;
cellFrame->GetXULBorder(border);
if (border.top && border.bottom && border.left && border.right) {
RETURN_LAYOUT_ANSWER(false, "Has nonzero border-width on table cell");
}
/**
* Rules for non-bordered tables with 2-4 columns and 2+ rows from here on forward
*/
// Check for styled background color across rows (alternating background
// color is a common feature for data tables).
uint32_t childCount = ChildCount();
nscolor rowColor = 0;
nscolor prevRowColor;
for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
Accessible* child = GetChildAt(childIdx);
if (child->Role() == roles::ROW) {
prevRowColor = rowColor;
nsIFrame* rowFrame = child->GetFrame();
rowColor = rowFrame->StyleBackground()->BackgroundColor(rowFrame);
if (childIdx > 0 && prevRowColor != rowColor)
RETURN_LAYOUT_ANSWER(false, "2 styles of row background color, non-bordered");
}
}
// Check for many rows
const uint32_t kMaxLayoutRows = 20;
if (rowCount > kMaxLayoutRows) { // A ton of rows, this is probably for data
RETURN_LAYOUT_ANSWER(false, ">= kMaxLayoutRows (20) and non-bordered");
}
// Check for very wide table.
nsIFrame* documentFrame = Document()->GetFrame();
nsSize documentSize = documentFrame->GetSize();
if (documentSize.width > 0) {
nsSize tableSize = GetFrame()->GetSize();
int32_t percentageOfDocWidth = (100 * tableSize.width) / documentSize.width;
if (percentageOfDocWidth > 95) {
// 3-4 columns, no borders, not a lot of rows, and 95% of the doc's width
// Probably for layout
RETURN_LAYOUT_ANSWER(true,
"<= 4 columns, table width is 95% of document width");
}
}
// Two column rules
if (rowCount * colCount <= 10) {
RETURN_LAYOUT_ANSWER(true, "2-4 columns, 10 cells or less, non-bordered");
}
if (HasDescendant(NS_LITERAL_STRING("embed")) ||
HasDescendant(NS_LITERAL_STRING("object")) ||
HasDescendant(NS_LITERAL_STRING("iframe"))) {
RETURN_LAYOUT_ANSWER(true, "Has no borders, and has iframe, object, or iframe, typical of advertisements");
}
RETURN_LAYOUT_ANSWER(false, "no layout factor strong enough, so will guess data");
}
bool
TableAccessible::IsProbablyLayoutTable()
{
// Implement a heuristic to determine if table is most likely used for layout.
// XXX do we want to look for rowspan or colspan, especialy that span all but
// a couple cells at the beginning or end of a row/col, and especially when
// they occur at the edge of a table?
// XXX For now debugging descriptions are always on via SHOW_LAYOUT_HEURISTIC
// This will allow release trunk builds to be used by testers to refine
// the algorithm. Integrate it into Logging.
// Change to |#define SHOW_LAYOUT_HEURISTIC DEBUG| before final release
#ifdef SHOW_LAYOUT_HEURISTIC
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) \
{ \
mLayoutHeuristic = isLayout ? \
NS_LITERAL_STRING("layout table: " heuristic) : \
NS_LITERAL_STRING("data table: " heuristic); \
return isLayout; \
}
#else
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) { return isLayout; }
#endif
Accessible* thisacc = AsAccessible();
// Need to see all elements while document is being edited.
if (thisacc->Document()->State() & states::EDITABLE) {
RETURN_LAYOUT_ANSWER(false, "In editable document");
}
// Check to see if an ARIA role overrides the role from native markup,
// but for which we still expose table semantics (treegrid, for example).
if (thisacc->HasARIARole()) {
RETURN_LAYOUT_ANSWER(false, "Has role attribute");
}
dom::Element* el = thisacc->Elm();
if (el->IsMathMLElement(nsGkAtoms::mtable_)) {
RETURN_LAYOUT_ANSWER(false, "MathML matrix");
}
MOZ_ASSERT(el->IsHTMLElement(nsGkAtoms::table),
"Table should not be built by CSS display:table style");
// Check if datatable attribute has "0" value.
if (el->AttrValueIs(kNameSpaceID_None, nsGkAtoms::datatable,
NS_LITERAL_STRING("0"), eCaseMatters)) {
RETURN_LAYOUT_ANSWER(true, "Has datatable = 0 attribute, it's for layout");
}
// Check for legitimate data table attributes.
nsAutoString summary;
if (el->GetAttr(kNameSpaceID_None, nsGkAtoms::summary, summary) &&
!summary.IsEmpty()) {
RETURN_LAYOUT_ANSWER(false, "Has summary -- legitimate table structures");
}
// Check for legitimate data table elements.
Accessible* caption = thisacc->FirstChild();
if (caption && caption->IsHTMLCaption() && caption->HasChildren()) {
RETURN_LAYOUT_ANSWER(false, "Not empty caption -- legitimate table structures");
}
for (nsIContent* childElm = el->GetFirstChild(); childElm;
childElm = childElm->GetNextSibling()) {
if (!childElm->IsHTMLElement())
continue;
if (childElm->IsAnyOfHTMLElements(nsGkAtoms::col,
nsGkAtoms::colgroup,
nsGkAtoms::tfoot,
nsGkAtoms::thead)) {
RETURN_LAYOUT_ANSWER(false,
"Has col, colgroup, tfoot or thead -- legitimate table structures");
}
if (childElm->IsHTMLElement(nsGkAtoms::tbody)) {
for (nsIContent* rowElm = childElm->GetFirstChild(); rowElm;
rowElm = rowElm->GetNextSibling()) {
if (rowElm->IsHTMLElement(nsGkAtoms::tr)) {
for (nsIContent* cellElm = rowElm->GetFirstChild(); cellElm;
cellElm = cellElm->GetNextSibling()) {
if (cellElm->IsHTMLElement()) {
if (cellElm->NodeInfo()->Equals(nsGkAtoms::th)) {
RETURN_LAYOUT_ANSWER(false,
"Has th -- legitimate table structures");
}
if (cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::headers) ||
cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::scope) ||
cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::abbr)) {
RETURN_LAYOUT_ANSWER(false,
"Has headers, scope, or abbr attribute -- legitimate table structures");
}
Accessible* cell = thisacc->Document()->GetAccessible(cellElm);
if (cell && cell->ChildCount() == 1 &&
cell->FirstChild()->IsAbbreviation()) {
RETURN_LAYOUT_ANSWER(false,
"has abbr -- legitimate table structures");
}
}
}
}
}
}
}
// Check for nested tables.
nsCOMPtr<nsIHTMLCollection> nestedTables =
el->GetElementsByTagName(NS_LITERAL_STRING("table"));
if (nestedTables->Length() > 0) {
RETURN_LAYOUT_ANSWER(true, "Has a nested table within it");
}
// If only 1 column or only 1 row, it's for layout.
auto colCount = ColCount();
if (colCount <= 1) {
RETURN_LAYOUT_ANSWER(true, "Has only 1 column");
}
auto rowCount = RowCount();
if (rowCount <=1) {
RETURN_LAYOUT_ANSWER(true, "Has only 1 row");
}
// Check for many columns.
if (colCount >= 5) {
RETURN_LAYOUT_ANSWER(false, ">=5 columns");
}
// Now we know there are 2-4 columns and 2 or more rows. Check to see if
// there are visible borders on the cells.
// XXX currently, we just check the first cell -- do we really need to do more?
nsTableWrapperFrame* tableFrame = do_QueryFrame(el->GetPrimaryFrame());
if (!tableFrame) {
RETURN_LAYOUT_ANSWER(false, "table with no frame!");
}
nsIFrame* cellFrame = tableFrame->GetCellFrameAt(0, 0);
if (!cellFrame) {
RETURN_LAYOUT_ANSWER(false, "table's first cell has no frame!");
}
nsMargin border;
cellFrame->GetXULBorder(border);
if (border.top && border.bottom && border.left && border.right) {
RETURN_LAYOUT_ANSWER(false, "Has nonzero border-width on table cell");
}
// Rules for non-bordered tables with 2-4 columns and 2+ rows from here on
// forward.
// Check for styled background color across rows (alternating background
// color is a common feature for data tables).
auto childCount = thisacc->ChildCount();
nscolor rowColor = 0;
nscolor prevRowColor;
for (auto childIdx = 0U; childIdx < childCount; childIdx++) {
Accessible* child = thisacc->GetChildAt(childIdx);
if (child->IsHTMLTableRow()) {
prevRowColor = rowColor;
nsIFrame* rowFrame = child->GetFrame();
MOZ_ASSERT(rowFrame, "Table hierarchy got screwed up");
if (!rowFrame) {
RETURN_LAYOUT_ANSWER(false, "Unexpected table hierarchy");
}
rowColor = rowFrame->StyleBackground()->BackgroundColor(rowFrame);
if (childIdx > 0 && prevRowColor != rowColor) {
RETURN_LAYOUT_ANSWER(
false, "2 styles of row background color, non-bordered"
);
}
}
}
// Check for many rows.
const uint32_t kMaxLayoutRows = 20;
if (rowCount > kMaxLayoutRows) { // A ton of rows, this is probably for data
RETURN_LAYOUT_ANSWER(false, ">= kMaxLayoutRows (20) and non-bordered");
}
// Check for very wide table.
nsIFrame* documentFrame = thisacc->Document()->GetFrame();
nsSize documentSize = documentFrame->GetSize();
if (documentSize.width > 0) {
nsSize tableSize = thisacc->GetFrame()->GetSize();
int32_t percentageOfDocWidth = (100 * tableSize.width) / documentSize.width;
if (percentageOfDocWidth > 95) {
// 3-4 columns, no borders, not a lot of rows, and 95% of the doc's width
// Probably for layout
RETURN_LAYOUT_ANSWER(
true, "<= 4 columns, table width is 95% of document width"
);
}
}
// Two column rules.
if (rowCount * colCount <= 10) {
RETURN_LAYOUT_ANSWER(true, "2-4 columns, 10 cells or less, non-bordered");
}
static const nsLiteralString tags[] = {
NS_LITERAL_STRING("embed"),
NS_LITERAL_STRING("object"),
NS_LITERAL_STRING("iframe")
};
for (auto& tag : tags) {
nsCOMPtr<nsIHTMLCollection> descendants = el->GetElementsByTagName(tag);
if (descendants->Length() > 0) {
RETURN_LAYOUT_ANSWER(
true, "Has no borders, and has iframe, object or embed, typical of advertisements"
);
}
}
RETURN_LAYOUT_ANSWER(
false, "No layout factor strong enough, so will guess data"
);
}
