Accessibility/MathML: Difference between revisions

Jump to navigation Jump to search

Accessibility/MathML (view source)

Revision as of 19:05, 21 April 2014

3,021 bytes removed ,  21 April 2014
Remove nsIAccessible interfaces.
(Remove nsIAccessible interfaces.)
Line 544: Line 544:
=Interface=
=Interface=


==nsIAccessibleMathML==
==MathMLAccessible==
Inherit from nsISupports.
Inherit from HyperTextAccessibleWrap.
 
* NativeAttributes - Override Accessible, and append MathML specific attributes if the element accepts them.
* RelationByType - Override Accessible, process MathML specific relations.
 
Attributes of interest might include the following:


<pre>
* accent - Boolean value determining if the operator is an accent over the content.
readonly attribute AString tokenValue;
* accentunder - Boolean value determining if the operator is an accent under the content.
// Get token value for token MathML elements (mi, mo, mn, mtext, mspace, ms,
* actiontype - String value specifying what an maction should do.
// mglyph).  Returns empty string if not a token element.
* align - String value specifying the type of alignment to be used for an mtable, munder, mover, munderover, or mstack.  May be useful for determining logical ordering of an equation.
</pre>
* bevelled - Boolean value determining rendering format of the fraction.  May be useful for word choice (e.g. "one over two" vs. "one divided by two").
* close - String value for the closing delimiter of an mfenced element.
* columnlines - String value for the type of line between table columns.  May be useful for determining table purpose.
* crossout - String value specifying the type of crossout to be used in an mscarry, changing the crossout's meaning.
* dir - String value (ltr, rtl) specifying text direction of the content.
* fence - Boolean value specifying whether an mo is a fence element.
* href - String value for hyperlinking to a URI.
* largeop - Boolean value for determining if an mo should be drawn larger.  May be useful in determining semantics.
* linethickness - String or length value determining thickness of an mfrac line.  May be useful in determining fraction's purpose (e.g. displaying binomial coefficients for a linethickness of 0).
* location - String (cardinal direction) value determining location of an mscarry relative to its anchoring element.  May be useful in determining the carry's purpose.
* longdivstyle - String value controlling the appearance of an mlongdiv.  May be useful in determining its usage.
* mathvariant - String value specifying the logical class of a token element.  May be useful in determining a token's usage.
* notation - String value specifying the style to apply to the contents of an menclose.
* open - String value for the opening delimiter of an mfenced element.
* position - Integer value for mstack and mlongdiv child elements determining horizontal positioning.
* rowlines - String value for the type of line between table rows.
* selection - Integer value for determining which child element of an maction is to be used.
* separator - Boolean value specifying whether an mo is a separator.
* separators - String value containing separator values for an mfenced element.
* shift - Integer value for mstack and mlongdiv child elements determining vertical positioning.
* stretchy - Boolean value determining if an mo stretches to its adjacent elements' size.  May be useful in determining operator usage.


There's several different options for describing relations between MathML elements:
MathML attributes will be added to/from this tentative list to be displayed under the accessible object attributes based on their usefulness to ATs.


Option 1:  Relations linking accessibles based on role, so we won't have attributes/functions in the interface.  An example would be for a fraction structure, as follows.
Relations will link accessibles based on role.  An example would be for a fraction structure, as follows.


<pre>
<pre>
Line 566: Line 591:
</pre>
</pre>


mfrac would have RELATION_NUMERATOR -> mi and RELATION_DENOMINATOR -> mn or similar.
mfrac would have RELATION_NUMERATOR -> mi and RELATION_DENOMINATOR -> mn.
mi would have RELATION_NUMERATOR_OF -> mfrac and mn would have RELATION_DENOMINATOR_OF -> mfrac.
mi would have RELATION_NUMERATOR_OF -> mfrac and mn would have RELATION_DENOMINATOR_OF -> mfrac.


A list of potential relations is as follows:
A list of relations is as follows:


* MATHML_NUMERATOR_OF
* MATHML_NUMERATOR_OF
Line 600: Line 625:
* MATHML_IN_ROW
* MATHML_IN_ROW


Option 2:  Explicit readonly attributes (accessors) for going from parent elements to children and vice versa.  e.g.
==MathMLTableAccessible, MathMLTableRowAccessible, and MathMLTableCellAccessible==
<pre>
Inherit from HTMLTableAccessible, HTMLTableRowAccessible, and HTMLTableCellAccessible respectively.
readonly attribute nsIAccessibleMathML radicand;
readonly attribute nsIAccessibleMathML rootIndex;
readonly attribute nsIAccessibleMathML under;
...
readonly attribute nsIAccessibleMathML parent;
</pre>
 
Returns nullptr if the related accessible doesn't exist.
Note that specialised elements such as mrow or mmultiscripts would return arrays of elements.
 
==nsIAccessibleMathMLTable==
Inherit from nsISupports.
 
<pre>
/**
* Return columns count in the table.
*/
readonly attribute long columnCount;
 
/**
* Return rows count in the table.
*/
readonly attribute long rowCount;
 
/**
* Return the MathML accessible object at the given row and column in the
* table.
*
* @param  rowIndex    [in] the row index to retrieve the cell at
* @param  columnIndex  [in] the column index to retrieve the cell at
*/
nsIAccessibleMathML getCellAt(in long rowIndex, in long columnIndex);
 
/**
* Return the number of columns occupied by the MathML accessible cell at
* the specified row and column in the table. The result differs from 1 if
* the specified cell spans multiple columns.
*
* @param  row    [in] row index of the cell to return the column extent for
* @param  column  [in] column index of the cell to return the column extent
*                  for
*/
long getColumnExtentAt(in long row, in long column);
 
/**
* Return the number of rows occupied by the MathML accessible cell at the
* specified row and column in the table. The result differs from 1 if the
* specified cell spans multiple rows.
*
* @param  row    [in] row index of the cell to return the column extent for
* @param  column  [in] column index of the cell to return the column extent
*                  for
*/
long getRowExtentAt(in long row, in long column);
 
/**
* Return the label MathML accessible of the specified row in the table if
* available (mlabeledtr), or nullptr otherwise.
*
* @param  rowIndex  [in] the row index to retrieve label mtd for
*/
nsIAccessibleMathML getRowLabel(in long rowIndex);
</pre>
 
==nsIAccessibleMathMLTableCell==
Inherit from nsISupports.
 
<pre>
/**
* Return container MathML table accessible.
*/
readonly attribute nsIAccessibleMathMLTable table;
 
/**
* Return column index of this cell.
*/
readonly attribute long columnIndex;
 
/**
* Return row index of this cell.
*/
readonly attribute long rowIndex;
 
/**
* Return the number of columns occupied by this cell. The result differs
* from 1 if the specified cell spans multiple columns.
*/
readonly attribute long columnExtent;
 
/**
* Return the number of rows occupied by this accessible cell. The result
* differs from 1 if the specified cell spans multiple rows.
*/
readonly attribute long rowExtent;
</pre>
 
==MathMLAccessible==
Inherit from AccessibleWrap, and implements nsIAccessibleMathML.
 
* NativeAttributes - Override Accessible, and append MathML specific attributes if the element accepts them.
* RelationByType - Override Accessible, process MathML specific relations if we go that route.
* GetTokenValue - Sets token value string if applicable. (Gets?)
* GetIsToken - Returns true if element is a token element.
 
Attributes of interest might include the following:


* accent - Boolean value determining if the operator is an accent over the content.
Override NativeAttributes and RelationByType as with MathMLAccessible.
* accentunder - Boolean value determining if the operator is an accent under the content.
The table elements can be traversed using the same interface as HTMLTableAccessible (nsIAccessibleTable and nsIAccessibleTableCell).
* actiontype - String value specifying what an maction should do.
* align - String value specifying the type of alignment to be used for an mtable, munder, mover, munderover, or mstack.  May be useful for determining logical ordering of an equation.
* bevelled - Boolean value determining rendering format of the fraction.  May be useful for word choice (e.g. "one over two" vs. "one divided by two").
* close - String value for the closing delimiter of an mfenced element.
* columnlines - String value for the type of line between table columns.  May be useful for determining table purpose.
* crossout - String value specifying the type of crossout to be used in an mscarry, changing the crossout's meaning.
* dir - String value (ltr, rtl) specifying text direction of the content.
* fence - Boolean value specifying whether an mo is a fence element.
* href - String value for hyperlinking to a URI.
* largeop - Boolean value for determining if an mo should be drawn larger.  May be useful in determining semantics.
* linethickness - String or length value determining thickness of an mfrac line.  May be useful in determining fraction's purpose (e.g. displaying binomial coefficients for a linethickness of 0).
* location - String (cardinal direction) value determining location of an mscarry relative to its anchoring element.  May be useful in determining the carry's purpose.
* longdivstyle - String value controlling the appearance of an mlongdiv.  May be useful in determining its usage.
* mathvariant - String value specifying the logical class of a token element.  May be useful in determining a token's usage.
* notation - String value specifying the style to apply to the contents of an menclose.
* open - String value for the opening delimiter of an mfenced element.
* position - Integer value for mstack and mlongdiv child elements determining horizontal positioning.
* rowlines - String value for the type of line between table rows.
* selection - Integer value for determining which child element of an maction is to be used.
* separator - Boolean value specifying whether an mo is a separator.
* separators - String value containing separator values for an mfenced element.
* shift - Integer value for mstack and mlongdiv child elements determining vertical positioning.
* stretchy - Boolean value determining if an mo stretches to its adjacent elements' size.  May be useful in determining operator usage.
 
MathML attributes will be added to/from this tentative list to be displayed under the accessible object attributes based on their usefulness to ATs.


==Roles==
==Roles==
Jwei
29

edits

Retrieved from "https://wiki.mozilla.org/Special:MobileDiff/967112"

Navigation menu