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" ); }