C++ LayoutTableCell::style方法代码示例

bool AXTable::isDataTable() const
{
    if (!m_layoutObject || !node())
        return false;

    // Do not consider it a data table if it has an ARIA role.
    if (hasARIARole())
        return false;

    // When a section of the document is contentEditable, all tables should be
    // treated as data tables, otherwise users may not be able to work with rich
    // text editors that allow creating and editing tables.
    if (node() && node()->hasEditableStyle())
        return true;

    // This employs a heuristic to determine if this table should appear.
    // Only "data" tables should be exposed as tables.
    // Unfortunately, there is no good way to determine the difference
    // between a "layout" table and a "data" table.

    LayoutTable* table = toLayoutTable(m_layoutObject);
    Node* tableNode = table->node();
    if (!isHTMLTableElement(tableNode))
        return false;

    // Do not consider it a data table if any of its descendants have an ARIA role.
    HTMLTableElement* tableElement = toHTMLTableElement(tableNode);
    if (elementHasAriaRole(tableElement->tHead()))
        return false;
    if (elementHasAriaRole(tableElement->tFoot()))
        return false;

    RefPtrWillBeRawPtr<HTMLCollection> bodies = tableElement->tBodies();
    for (unsigned bodyIndex = 0; bodyIndex < bodies->length(); ++bodyIndex) {
        Element* bodyElement = bodies->item(bodyIndex);
        if (elementHasAriaRole(bodyElement))
            return false;
    }

    RefPtrWillBeRawPtr<HTMLTableRowsCollection> rows = tableElement->rows();
    unsigned rowCount = rows->length();
    for (unsigned rowIndex = 0; rowIndex < rowCount; ++rowIndex) {
        HTMLTableRowElement* rowElement = rows->item(rowIndex);
        if (elementHasAriaRole(rowElement))
            return false;
        RefPtrWillBeRawPtr<HTMLCollection> cells = rowElement->cells();
        for (unsigned cellIndex = 0; cellIndex < cells->length(); ++cellIndex) {
            if (elementHasAriaRole(cells->item(cellIndex)))
                return false;
        }
    }

    // If there is a caption element, summary, THEAD, or TFOOT section, it's most certainly a data table
    if (!tableElement->summary().isEmpty() || tableElement->tHead() || tableElement->tFoot() || tableElement->caption())
        return true;

    // if someone used "rules" attribute than the table should appear
    if (!tableElement->rules().isEmpty())
        return true;

    // if there's a colgroup or col element, it's probably a data table.
    if (Traversal<HTMLTableColElement>::firstChild(*tableElement))
        return true;

    // go through the cell's and check for tell-tale signs of "data" table status
    // cells have borders, or use attributes like headers, abbr, scope or axis
    table->recalcSectionsIfNeeded();
    LayoutTableSection* firstBody = table->firstBody();
    if (!firstBody)
        return false;

    int numCols = firstBody->numEffectiveColumns();
    int numRows = firstBody->numRows();

    // If there's only one cell, it's not a good AXTable candidate.
    if (numRows == 1 && numCols == 1)
        return false;

    // If there are at least 20 rows, we'll call it a data table.
    if (numRows >= 20)
        return true;

    // Store the background color of the table to check against cell's background colors.
    const ComputedStyle* tableStyle = table->style();
    if (!tableStyle)
        return false;
    Color tableBGColor = tableStyle->visitedDependentColor(CSSPropertyBackgroundColor);

    // check enough of the cells to find if the table matches our criteria
    // Criteria:
    //   1) must have at least one valid cell (and)
    //   2) at least half of cells have borders (or)
    //   3) at least half of cells have different bg colors than the table, and there is cell spacing
    unsigned validCellCount = 0;
    unsigned borderedCellCount = 0;
    unsigned backgroundDifferenceCellCount = 0;
    unsigned cellsWithTopBorder = 0;
    unsigned cellsWithBottomBorder = 0;
    unsigned cellsWithLeftBorder = 0;
    unsigned cellsWithRightBorder = 0;
//.........这里部分代码省略.........