add destroy method

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@727 57a11ea4-9604-0410-9ed3-97b8803252fd

src/register/register.c

@@ -3,7 +3,8 @@
  * register.c
  *
  * FUNCTION:
- * implements the register object
+ * Implements the register object.
+ * See the header file for additional documentation.
  *
  * HISTORY:
  * Copyright (c) 1998 Linas Vepstas
@@ -300,12 +301,16 @@ BasicRegister * xaccMallocBasicRegister (int type)
    xaccAddCell (curs, reg->CN##Cell, CL##_CELL_R, CL##_CELL_C);	\
 }
    
+/* ============================================== */
 
 void xaccInitBasicRegister (BasicRegister *reg, int type)
 {
    Table * table;
    CellBlock *curs, *header;
 
+   reg->user_hook = NULL;
+   reg->destroy = NULL;
+
    /* --------------------------- */
    configLayout (reg, type);
 
@@ -376,6 +381,60 @@ void xaccInitBasicRegister (BasicRegister *reg, int type)
 
 /* ============================================== */
 
+void 
+xaccDestroyBasicRegister (BasicRegister *reg)
+{
+   /* give the user a chance to clean up */
+   if (reg->destroy) {
+      (*(reg->destroy)) (reg);
+   }
+   reg->destroy = NULL;
+   reg->user_hook = NULL;
+
+   xaccDestroyTable (reg->table);
+   reg->table = NULL;
+
+   xaccDestroyCellBlock (reg->header);
+   xaccDestroyCellBlock (reg->cursor);
+   reg->header = NULL;
+   reg->cursor = NULL;
+
+   xaccDestroyDateCell      (reg->dateCell);
+   xaccDestroyBasicCell     (reg->numCell);
+   xaccDestroyQuickFillCell (reg->descCell);
+   xaccDestroyBasicCell     (reg->recnCell);
+   xaccDestroyPriceCell     (reg->creditCell);
+   xaccDestroyPriceCell     (reg->debitCell);
+   xaccDestroyPriceCell     (reg->shrsCell);
+   xaccDestroyPriceCell     (reg->priceCell);
+   xaccDestroyPriceCell     (reg->valueCell);
+   xaccDestroyBasicCell     (reg->memoCell);
+   xaccDestroyComboCell     (reg->actionCell);
+   xaccDestroyComboCell     (reg->xfrmCell);
+   xaccDestroyComboCell     (reg->xtoCell);
+   xaccDestroyPriceCell     (reg->balanceCell);
+
+   reg->dateCell    = NULL;
+   reg->numCell     = NULL;
+   reg->descCell    = NULL;
+   reg->recnCell    = NULL;
+   reg->creditCell  = NULL;
+   reg->debitCell   = NULL;
+   reg->shrsCell    = NULL;
+   reg->priceCell   = NULL;
+   reg->valueCell   = NULL;
+   reg->memoCell    = NULL;
+   reg->actionCell  = NULL;
+   reg->xfrmCell    = NULL;
+   reg->xtoCell     = NULL;
+   reg->balanceCell = NULL;
+
+   /* free the memory itself */
+   free (reg);
+}
+
+/* ============================================== */
+
 unsigned int
 xaccGetChangeFlag (BasicRegister *reg)
 {

src/register/register.h

@@ -77,7 +77,9 @@
 
 #define NUM_CELLS 20
 
-typedef struct _BasicRegister {
+typedef struct _BasicRegister BasicRegister;
+
+struct _BasicRegister {
    /* the table itself that implements the underlying GUI. */
    Table         * table;
 
@@ -110,10 +112,19 @@ typedef struct _BasicRegister {
    short rows[NUM_CELLS];
    short wids[NUM_CELLS];
 
-} BasicRegister;
+   /* user_hook allows users of this object to hang
+    * private data onto it */
+   void *user_hook;
+
+   /* The destroy callback gives user's a chance 
+    * to free up any associated user_hook data */
+   void (* destroy) (BasicRegister *);
+
+};
 
 BasicRegister * xaccMallocBasicRegister (int type);
 void            xaccInitBasicRegister (BasicRegister *, int type);
+void            xaccDestroyBasicRegister (BasicRegister *);
 
 /* returns non-zero value if updates have been made to data */
 unsigned int    xaccGetChangeFlag (BasicRegister *);