gecko-dev/accessible/generic/TableAccessible.h
Marco Zehe c0bdc14cea Bug 1525849 - Guard against 0 columns or out of bounds indexes for ARIA grid accessibles, r=Jamie
When returning the column or row index of a given cell, guard against the column count being 0 or the given index being out of bounds of the current grid or table. The MSAA code already did this previously, but now the upper bounds check has been moved to the base classes and an additional guard for the column count been put in place so a division by 0 crash canot happen.

A return value for RowIndexAt and ColIndexAt of -1 indicates an error condition. ATK will automatically deal with this, and the IA2 code has been adjusted to check for this and return an invalid argument error in such cases, too.

Differential Revision: https://phabricator.services.mozilla.com/D18931

--HG--
extra : moz-landing-system : lando
2019-02-07 21:06:42 +00:00

203 lines
5.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef TABLE_ACCESSIBLE_H
#define TABLE_ACCESSIBLE_H
#include "nsString.h"
#include "nsTArray.h"
namespace mozilla {
namespace a11y {
class Accessible;
/**
* Accessible table interface.
*/
class TableAccessible {
public:
/**
* Return the caption accessible if any for this table.
*/
virtual Accessible* Caption() const { return nullptr; }
/**
* Get the summary for this table.
*/
virtual void Summary(nsString& aSummary) { aSummary.Truncate(); }
/**
* Return the number of columns in the table.
*/
virtual uint32_t ColCount() const { return 0; }
/**
* Return the number of rows in the table.
*/
virtual uint32_t RowCount() { return 0; }
/**
* Return the accessible for the cell at the given row and column indices.
*/
virtual Accessible* CellAt(uint32_t aRowIdx, uint32_t aColIdx) {
return nullptr;
}
/**
* Return the index of the cell at the given row and column.
*/
virtual int32_t CellIndexAt(uint32_t aRowIdx, uint32_t aColIdx) {
return ColCount() * aRowIdx + aColIdx;
}
/**
* Return the column index of the cell with the given index.
* This returns -1 if the column count is 0 or an invalid index is being
* passed in.
*/
virtual int32_t ColIndexAt(uint32_t aCellIdx);
/**
* Return the row index of the cell with the given index.
* This returns -1 if the column count is 0 or an invalid index is being
* passed in.
*/
virtual int32_t RowIndexAt(uint32_t aCellIdx);
/**
* Get the row and column indices for the cell at the given index.
* This returns -1 for both output parameters if the column count is 0 or an
* invalid index is being passed in.
*/
virtual void RowAndColIndicesAt(uint32_t aCellIdx, int32_t* aRowIdx,
int32_t* aColIdx);
/**
* Return the number of columns occupied by the cell at the given row and
* column indices.
*/
virtual uint32_t ColExtentAt(uint32_t aRowIdx, uint32_t aColIdx) { return 1; }
/**
* Return the number of rows occupied by the cell at the given row and column
* indices.
*/
virtual uint32_t RowExtentAt(uint32_t aRowIdx, uint32_t aColIdx) { return 1; }
/**
* Get the description of the given column.
*/
virtual void ColDescription(uint32_t aColIdx, nsString& aDescription) {
aDescription.Truncate();
}
/**
* Get the description for the given row.
*/
virtual void RowDescription(uint32_t aRowIdx, nsString& aDescription) {
aDescription.Truncate();
}
/**
* Return true if the given column is selected.
*/
virtual bool IsColSelected(uint32_t aColIdx) { return false; }
/**
* Return true if the given row is selected.
*/
virtual bool IsRowSelected(uint32_t aRowIdx) { return false; }
/**
* Return true if the given cell is selected.
*/
virtual bool IsCellSelected(uint32_t aRowIdx, uint32_t aColIdx) {
return false;
}
/**
* Return the number of selected cells.
*/
virtual uint32_t SelectedCellCount() { return 0; }
/**
* Return the number of selected columns.
*/
virtual uint32_t SelectedColCount() { return 0; }
/**
* Return the number of selected rows.
*/
virtual uint32_t SelectedRowCount() { return 0; }
/**
* Get the set of selected cells.
*/
virtual void SelectedCells(nsTArray<Accessible*>* aCells) = 0;
/**
* Get the set of selected cell indices.
*/
virtual void SelectedCellIndices(nsTArray<uint32_t>* aCells) = 0;
/**
* Get the set of selected column indices.
*/
virtual void SelectedColIndices(nsTArray<uint32_t>* aCols) = 0;
/**
* Get the set of selected row indices.
*/
virtual void SelectedRowIndices(nsTArray<uint32_t>* aRows) = 0;
/**
* Select the given column unselecting any other selected columns.
*/
virtual void SelectCol(uint32_t aColIdx) {}
/**
* Select the given row unselecting all other previously selected rows.
*/
virtual void SelectRow(uint32_t aRowIdx) {}
/**
* Unselect the given column leaving other selected columns selected.
*/
virtual void UnselectCol(uint32_t aColIdx) {}
/**
* Unselect the given row leaving other selected rows selected.
*/
virtual void UnselectRow(uint32_t aRowIdx) {}
/**
* Return true if the table is probably for layout.
*/
virtual bool IsProbablyLayoutTable();
/**
* Convert the table to an Accessible*.
*/
virtual Accessible* AsAccessible() = 0;
protected:
/**
* Return row accessible at the given row index.
*/
Accessible* RowAt(int32_t aRow);
/**
* Return cell accessible at the given column index in the row.
*/
Accessible* CellInRowAt(Accessible* aRow, int32_t aColumn);
};
} // namespace a11y
} // namespace mozilla
#endif