add docs, destroy method

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@719 57a11ea4-9604-0410-9ed3-97b8803252fd

src/register/datecell.c

@@ -367,6 +367,17 @@ xaccInitDateCell (DateCell *cell)
 
 /* ================================================ */
 
+void
+xaccDestroyDateCell (DateCell *cell)
+{
+   cell->date.tm_mday = 0;
+   cell->date.tm_mon = 0;
+   cell->date.tm_year = 0;
+   xaccDestroyBasicCell ( &(cell->cell));
+}
+
+/* ================================================ */
+
 void 
 xaccSetDateCellValue (DateCell *cell, int day, int mon, int year)
 {

src/register/datecell.h

@@ -3,12 +3,57 @@
  * datecell.h
  *
  * FUNCTION:
- * Implements date handling
+ * The DateCell object implements a date handling cell.  It
+ * is able to display dates in several formats, it is also 
+ * able to accept date input, and also supports a number of accelerator
+ * keys.
  *
+ * On output, this cell will display a date as mm/dd/yy
+ * The actual date formate is compile-time configurable.
+ *
+ * hack alert -- make the display format run-time configurable, and 
+ * appropriately internationalized.
+ *
+ * One input, this cell is able to parse dates that are entered.
+ * It rejects any input that is not in the form of a date.  Input
+ * also includes a number of accelerators:  
+ *
+ *     '+':
+ *     '=':    increment day 
+ *
+ *     '_':
+ *     '-':    decrement day 
+ *
+ *     '}':
+ *     ']':    increment month 
+ *
+ *     '{':
+ *     '[':    decrment month 
+ *
+ *     'M':
+ *     'm':    begining of month 
+ *
+ *     'H':
+ *     'h':    end of month 
+ *
+ *     'Y':
+ *     'y':    begining of year 
+ *
+ *     'R':
+ *     'r':    end of year 
+ *
+ *     'T':
+ *     't':    today 
+ *
+ * 
+ * METHODS:
  * The xaccSetDateCellValue() method accepts a numeric date and
  *    sets the contents of the date cell to that value.  The
  *    value day, month, year should follow the regular written
  *    conventions, i.e. day==(1..31), mon==(1..12), year==4 digits
+ *
+ * HISTORY:
+ * Copyright (c) 1998 Linas Vepstas
  */
  
 #ifndef __XACC_DATE_CELL_C__
@@ -25,6 +70,7 @@ typedef struct _DateCell {
 /* installs a callback to handle date recording */
 DateCell * xaccMallocDateCell (void);
 void       xaccInitDateCell (DateCell *);
+void       xaccDestroyDateCell (DateCell *);
 
 void       xaccSetDateCellValue (DateCell *, int day, int mon, int year);