|  |  |  | Libcroco Reference Manual |  | 
|---|---|---|---|---|
| Top | Description | ||||
struct CRAtMediaRule; struct CRRuleSet; CRStyleSheet; struct CRAtImportRule; struct CRAtPageRule; struct CRAtCharsetRule; struct CRAtFontFaceRule; CRStatement; gboolean cr_statement_does_buf_parses_against_core (const guchar *a_buf,enum CREncoding a_encoding); CRStatement * cr_statement_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding); CRStatement * cr_statement_new_ruleset (CRStyleSheet *a_sheet,CRSelector *a_sel_list,CRDeclaration *a_decl_list,CRStatement *a_media_rule); CRStatement * cr_statement_ruleset_parse_from_buf (const guchar *a_buf,enum CREncoding a_enc); CRStatement * cr_statement_new_at_import_rule (CRStyleSheet *a_container_sheet,CRString *a_url,GList *a_media_list,CRStyleSheet *a_imported_sheet); CRStatement * cr_statement_at_import_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding); CRStatement * cr_statement_new_at_media_rule (CRStyleSheet *a_sheet,CRStatement *a_ruleset,GList *a_media); CRStatement * cr_statement_at_media_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_enc); CRStatement * cr_statement_new_at_charset_rule (CRStyleSheet *a_sheet,CRString *a_charset); CRStatement * cr_statement_at_charset_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding); CRStatement * cr_statement_new_at_font_face_rule (CRStyleSheet *a_sheet,CRDeclaration *a_font_decls); CRStatement * cr_statement_font_face_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding); CRStatement * cr_statement_new_at_page_rule (CRStyleSheet *a_sheet,CRDeclaration *a_decl_list,CRString *a_name,CRString *a_pseudo); CRStatement * cr_statement_at_page_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding); enum CRStatus cr_statement_set_parent_sheet (CRStatement *a_this,CRStyleSheet *a_sheet); enum CRStatus cr_statement_get_parent_sheet (CRStatement *a_this,CRStyleSheet **a_sheet); CRStatement * cr_statement_append (CRStatement *a_this,CRStatement *a_new); CRStatement * cr_statement_prepend (CRStatement *a_this,CRStatement *a_new); CRStatement * cr_statement_unlink (CRStatement *a_stmt); enum CRStatus cr_statement_ruleset_set_sel_list (CRStatement *a_this,CRSelector *a_sel_list); enum CRStatus cr_statement_ruleset_get_sel_list (CRStatement const *a_this,CRSelector **a_list); enum CRStatus cr_statement_ruleset_set_decl_list (CRStatement *a_this,CRDeclaration *a_list); enum CRStatus cr_statement_ruleset_get_declarations (CRStatement *a_this,CRDeclaration **a_decl_list); enum CRStatus cr_statement_ruleset_append_decl2 (CRStatement *a_this,CRString *a_prop,CRTerm *a_value); enum CRStatus cr_statement_ruleset_append_decl (CRStatement *a_this,CRDeclaration *a_decl); enum CRStatus cr_statement_at_import_rule_set_imported_sheet (CRStatement *a_this,CRStyleSheet *a_sheet); enum CRStatus cr_statement_at_import_rule_get_imported_sheet (CRStatement *a_this,CRStyleSheet **a_sheet); enum CRStatus cr_statement_at_import_rule_set_url (CRStatement *a_this,CRString *a_url); enum CRStatus cr_statement_at_import_rule_get_url (CRStatement const *a_this,CRString **a_url); gint cr_statement_at_media_nr_rules (CRStatement const *a_this); CRStatement * cr_statement_at_media_get_from_list (CRStatement *a_this,int itemnr); enum CRStatus cr_statement_at_page_rule_set_sel (CRStatement *a_this,CRSelector *a_sel); enum CRStatus cr_statement_at_page_rule_get_sel (CRStatement const *a_this,CRSelector **a_sel); enum CRStatus cr_statement_at_page_rule_set_declarations (CRStatement *a_this,CRDeclaration *a_decl_list); enum CRStatus cr_statement_at_page_rule_get_declarations (CRStatement *a_this,CRDeclaration **a_decl_list); enum CRStatus cr_statement_at_charset_rule_set_charset (CRStatement *a_this,CRString *a_charset); enum CRStatus cr_statement_at_charset_rule_get_charset (CRStatement const *a_this,CRString **a_charset); enum CRStatus cr_statement_at_font_face_rule_set_decls (CRStatement *a_this,CRDeclaration *a_decls); enum CRStatus cr_statement_at_font_face_rule_get_decls (CRStatement *a_this,CRDeclaration **a_decls); enum CRStatus cr_statement_at_font_face_rule_add_decl (CRStatement *a_this,CRString *a_prop,CRTerm *a_value); gchar * cr_statement_to_string (CRStatement const *a_this,gulong a_indent); gchar * cr_statement_list_to_string (CRStatement const *a_this,gulong a_indent); void cr_statement_dump (CRStatement const *a_this,FILE *a_fp,gulong a_indent); void cr_statement_dump_ruleset (CRStatement const *a_this,FILE *a_fp,glong a_indent); void cr_statement_dump_font_face_rule (CRStatement const *a_this,FILE *a_fp,glong a_indent); void cr_statement_dump_page (CRStatement const *a_this,FILE *a_fp,gulong a_indent); void cr_statement_dump_media_rule (CRStatement const *a_this,FILE *a_fp,gulong a_indent); void cr_statement_dump_import_rule (CRStatement const *a_this,FILE *a_fp,gulong a_indent); void cr_statement_dump_charset (CRStatement const *a_this,FILE *a_fp,gulong a_indent); gint cr_statement_nr_rules (CRStatement const *a_this); CRStatement * cr_statement_get_from_list (CRStatement *a_this,int itemnr); void cr_statement_destroy (CRStatement *a_this);
struct CRRuleSet {
	/**A list of instances of #CRSimpeSel*/
	CRSelector *sel_list ;
	/**A list of instances of #CRDeclaration*/
	CRDeclaration *decl_list ;
	
	/**
	 *The parent media rule, or NULL if
	 *no parent media rule exists.
	 */
	CRStatement *parent_media_rule ;
};
typedef struct {
	/**The css statements list*/
	CRStatement *statements ;
        enum CRStyleOrigin origin ;
        /*the parent import rule, if any.*/
        CRStatement *parent_import_rule ;
	/**custom data used by libcroco*/
	gpointer croco_data ;
	/**
	 *custom application data pointer
	 *Can be used by applications.
	 */
	gpointer app_data ;
	/**
	 *the reference count of this insance
	 *Please, don't never ever modify it
	 *directly. Use cr_stylesheet_ref()
	 *and cr_stylesheet_unref() instead.
	 */
	gulong ref_count ;
} CRStyleSheet;
struct CRAtImportRule {
	/**the url of the import rule*/
	CRString *url ;
        GList *media_list ;
	/**
	 *the stylesheet fetched from the url, if any.
	 *this is not "owned" by #CRAtImportRule which means
	 *it is not destroyed by the destructor of #CRAtImportRule.
	 */
	CRStyleSheet * sheet;
};
struct CRAtPageRule {
	/**a list of instances of #CRDeclaration*/
	CRDeclaration *decl_list ;
	/**page selector. Is a pseudo selector*/
	CRString *name ;
	CRString *pseudo ;
};
struct CRAtFontFaceRule {
	/*a list of instanaces of #CRDeclaration*/
	CRDeclaration *decl_list ;
};
typedef struct {
	/**
	 *The type of the statement.
	 */
	enum CRStatementType type ;
	union
	{
		CRRuleSet *ruleset ;
		CRAtImportRule *import_rule ;
		CRAtMediaRule *media_rule ;
		CRAtPageRule *page_rule ;
		CRAtCharsetRule *charset_rule ;
		CRAtFontFaceRule *font_face_rule ;
	} kind ;
        /*
         *the specificity of the selector
         *that matched this statement.
         *This is only used by the cascading
         *order determination algorithm.
         */
        gulong specificity ;
        /*
         *the style sheet that contains
         *this css statement.
         */
        CRStyleSheet *parent_sheet ;
	CRStatement *next ;
	CRStatement *prev ;
        CRParsingLocation location ;
        /**
         *a custom pointer useable by
         *applications that use libcroco.
         *libcroco itself will never modify
         *this pointer.
         */        
        gpointer app_data ;
        /**
         *a custom pointer used
         *by the upper layers of libcroco.
         *application should never use this
         *pointer.
         */
        gpointer croco_data ;
} CRStatement;
gboolean cr_statement_does_buf_parses_against_core (const guchar *a_buf,enum CREncoding a_encoding);
a_buf: the buffer to parse.
a_encoding: the character encoding of a_buf.
Tries to parse a buffer and says whether if the content of the buffer is a css statement as defined by the "Core CSS Grammar" (chapter 4 of the css spec) or not.
| Returns : | TRUE if the buffer parses against the core grammar, false otherwise. | 
CRStatement * cr_statement_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding);
a_buf: the buffer to parse.
a_encoding: the character encoding of a_buf.
Parses a buffer that contains a css statement and returns an instance of CRStatement in case of successful parsing. TODO: at support of "@import" rules.
| Returns : | the newly built instance of CRStatement in case of successful parsing, NULL otherwise. | 
CRStatement * cr_statement_new_ruleset (CRStyleSheet *a_sheet,CRSelector *a_sel_list,CRDeclaration *a_decl_list,CRStatement *a_media_rule);
a_sel_list: the list of CRSimpleSel (selectors)
the rule applies to.
a_decl_list: the list of instances of CRDeclaration
that composes the ruleset.
a_media_types: a list of instances of GString that
describe the media list this ruleset applies to.
Creates a new instance of CRStatement of type CRRulSet.
| Returns : | the new instance of CRStatement or NULL if something went wrong. | 
CRStatement * cr_statement_ruleset_parse_from_buf (const guchar *a_buf,enum CREncoding a_enc);
a_buf: the buffer to parse.
a_enc: the character encoding of a_buf.
Parses a buffer that contains a ruleset statement an instanciates a CRStatement of type RULESET_STMT.
| Returns : | the newly built instance of CRStatement in case of successful parsing, NULL otherwise. | 
CRStatement * cr_statement_new_at_import_rule (CRStyleSheet *a_container_sheet,CRString *a_url,GList *a_media_list,CRStyleSheet *a_imported_sheet);
a_url: the url to connect to the get the file
to be imported.
a_sheet: the imported parsed stylesheet.
Creates a new instance of CRStatment of type CRAtImportRule.
| Returns : | the newly built instance of CRStatement. | 
CRStatement * cr_statement_at_import_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding);
a_buf: the buffer to parse.
a_encoding: the encoding of a_buf.
Parses a buffer that contains an "@import" rule and instanciate a CRStatement of type AT_IMPORT_RULE_STMT
| Returns : | the newly built instance of CRStatement in case of a successful parsing, NULL otherwise. | 
CRStatement * cr_statement_new_at_media_rule (CRStyleSheet *a_sheet,CRStatement *a_ruleset,GList *a_media);
a_ruleset: the ruleset statements contained
in the @media rule.
a_media: the media string list. A list of GString pointers.
Instanciates an instance of CRStatement of type AT_MEDIA_RULE_STMT (@media ruleset).
CRStatement * cr_statement_at_media_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_enc);
a_buf: the input to parse.
a_enc: the encoding of the buffer.
Parses a buffer that contains an "@media" declaration and builds an @media css statement.
| Returns : | the @media statement, or NULL if the buffer could not be successfully parsed. | 
CRStatement * cr_statement_new_at_charset_rule (CRStyleSheet *a_sheet,CRString *a_charset);
a_charset: the string representing the charset.
Note that the newly built instance of CRStatement becomes
the owner of a_charset. The caller must not free a_charset !!!.
Creates a new instance of CRStatement of type CRAtCharsetRule.
| Returns : | the newly built instance of CRStatement or NULL if an error arises. | 
CRStatement * cr_statement_at_charset_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding);
a_buf: the buffer to parse.
a_encoding: the character encoding of the buffer.
Parses a buffer that contains an '@charset' rule and creates an instance of CRStatement of type AT_CHARSET_RULE_STMT.
| Returns : | the newly built instance of CRStatement. | 
CRStatement * cr_statement_new_at_font_face_rule (CRStyleSheet *a_sheet,CRDeclaration *a_font_decls);
a_font_decls: a list of instances of CRDeclaration. Each declaration
is actually a font declaration.
Creates an instance of CRStatement of type CRAtFontFaceRule.
| Returns : | the newly built instance of CRStatement. | 
CRStatement * cr_statement_font_face_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding);
a_buf: the buffer to parse.
a_encoding: the character encoding of a_buf.
Parses a buffer that contains an "@font-face" rule and builds an instance of CRStatement of type AT_FONT_FACE_RULE_STMT out of it.
| Returns : | the newly built instance of CRStatement in case of successufull parsing, NULL otherwise. | 
CRStatement * cr_statement_new_at_page_rule (CRStyleSheet *a_sheet,CRDeclaration *a_decl_list,CRString *a_name,CRString *a_pseudo);
a_decl_list: a list of instances of CRDeclarations
which is actually the list of declarations that applies to
this page rule.
a_selector: the page rule selector.
Creates a new instance of CRStatement of type CRAtPageRule.
| Returns : | the newly built instance of CRStatement or NULL in case of error. | 
CRStatement * cr_statement_at_page_rule_parse_from_buf (const guchar *a_buf,enum CREncoding a_encoding);
a_buf: the character buffer to parse.
a_encoding: the character encoding of a_buf.
Parses a buffer that contains an "@page" production and, if the parsing succeeds, builds the page statement.
| Returns : | the newly built at page statement in case of successful parsing, NULL otherwise. | 
enum CRStatus cr_statement_set_parent_sheet (CRStatement *a_this,CRStyleSheet *a_sheet);
a_this: the current instance of CRStatement.
a_sheet: the sheet that contains the current statement.
Sets the container stylesheet.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_get_parent_sheet (CRStatement *a_this,CRStyleSheet **a_sheet);
a_this: the current CRStatement.
a_sheet: out parameter. A pointer to the sheets that
Gets the sheets that contains the current statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
CRStatement * cr_statement_append (CRStatement *a_this,CRStatement *a_new);
a_this: the current instance of the statement list.
a_new: a_new the new instance of CRStatement to append.
Appends a new statement to the statement list.
| Returns : | the new list statement list, or NULL in cas of failure. | 
CRStatement * cr_statement_prepend (CRStatement *a_this,CRStatement *a_new);
a_this: the current instance of CRStatement.
a_new: the new statement to prepend.
Prepends the an instance of CRStatement to the current statement list.
| Returns : | the new list with the new statement prepended, or NULL in case of an error. | 
CRStatement *       cr_statement_unlink                 (CRStatement *a_stmt);
a_this: the current statements list.
a_to_unlink: the statement to unlink from the list.
Unlinks a statement from the statements list.
| Returns : | the new list where a_to_unlink has been unlinked from, or NULL in case of error. | 
enum CRStatus cr_statement_ruleset_set_sel_list (CRStatement *a_this,CRSelector *a_sel_list);
a_this: the current ruleset statement.
a_sel_list: the selector list to set. Note
that this function increments the ref count of a_sel_list.
The sel list will be destroyed at the destruction of the
current instance of CRStatement.
Sets a selector list to a ruleset statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_ruleset_get_sel_list (CRStatement const *a_this,CRSelector **a_list);
a_this: the current ruleset statement.
a_list: out parameter. The returned selector list,
if and only if the function returned CR_OK.
Gets a pointer to the selector list contained in the current ruleset statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_ruleset_set_decl_list (CRStatement *a_this,CRDeclaration *a_list);
a_this: the current ruleset statement.
a_list: the declaration list to be added to the current
ruleset statement.
Sets a declaration list to the current ruleset statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_ruleset_get_declarations (CRStatement *a_this,CRDeclaration **a_decl_list);
a_this: the current instance of CRStatement.
a_decl_list: out parameter. A pointer to the the returned
list of declaration. Must not be NULL.
Gets a pointer to the list of declaration contained in the ruleset statement.
| Returns : | CR_OK upon successful completion, an error code if something bad happened. | 
enum CRStatus cr_statement_ruleset_append_decl2 (CRStatement *a_this,CRString *a_prop,CRTerm *a_value);
a_this: the current statement.
a_prop: the property of the declaration.
a_value: the value of the declaration.
Appends a declaration to the current ruleset statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_ruleset_append_decl (CRStatement *a_this,CRDeclaration *a_decl);
Appends a declaration to the current statement.
a_this: the current statement.
a_declaration: the declaration to append.
| Returns : | CR_OK upon sucessful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_import_rule_set_imported_sheet (CRStatement *a_this,CRStyleSheet *a_sheet);
Sets a stylesheet to the current @import rule.
a_this: the current @import rule.
a_sheet: the stylesheet. The stylesheet is owned
by the current instance of CRStatement, that is, the 
stylesheet will be destroyed when the current instance
of CRStatement is destroyed.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_import_rule_get_imported_sheet (CRStatement *a_this,CRStyleSheet **a_sheet);
a_this: the current @import rule statement.
a_sheet: out parameter. The returned stylesheet if and
only if the function returns CR_OK.
Gets the stylesheet contained by the @import rule statement.
| Returns : | CR_OK upon sucessful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_import_rule_set_url (CRStatement *a_this,CRString *a_url);
a_this: the current @import rule statement.
a_url: the url to set.
Sets an url to the current @import rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_import_rule_get_url (CRStatement const *a_this,CRString **a_url);
a_this: the current @import rule statement.
a_url: out parameter. The returned url if
and only if the function returned CR_OK.
Gets the url of the @import rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
gint                cr_statement_at_media_nr_rules      (CRStatement const *a_this);
a_this: the current instance of CRStatement.
| Returns : | the number of rules in the media rule; | 
CRStatement * cr_statement_at_media_get_from_list (CRStatement *a_this,int itemnr);
a_this: the current instance of CRStatement.
itemnr: the index into the media rule list of rules.
Use an index to get a CRStatement from the media rule list of rules.
| Returns : | CRStatement at position itemnr, if itemnr > number of rules - 1, it will return NULL. | 
enum CRStatus cr_statement_at_page_rule_set_sel (CRStatement *a_this,CRSelector *a_sel);
enum CRStatus cr_statement_at_page_rule_get_sel (CRStatement const *a_this,CRSelector **a_sel);
enum CRStatus cr_statement_at_page_rule_set_declarations (CRStatement *a_this,CRDeclaration *a_decl_list);
a_this: the current @page rule statement.
a_decl_list: the declaration list to add. Will be freed
by the current instance of CRStatement when it is destroyed.
Sets a declaration list to the current @page rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_page_rule_get_declarations (CRStatement *a_this,CRDeclaration **a_decl_list);
a_this: the current @page rule statement.
a_decl_list: out parameter. The returned declaration list.
Gets the declaration list associated to the current @page rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_charset_rule_set_charset (CRStatement *a_this,CRString *a_charset);
a_this: the current @charset rule statement.
a_charset: the charset to set.
Sets the charset of the current @charset rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_charset_rule_get_charset (CRStatement const *a_this,CRString **a_charset);
Gets the charset string associated to the current @charset rule statement.
| 
 | the current @charset rule statement. | 
| 
 | out parameter. The returned charset string if and only if the function returned CR_OK. | 
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_font_face_rule_set_decls (CRStatement *a_this,CRDeclaration *a_decls);
a_this: the current @font-face rule statement.
a_decls: the declarations list to set.
Sets a declaration list to the current @font-face rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_font_face_rule_get_decls (CRStatement *a_this,CRDeclaration **a_decls);
a_this: the current @font-face rule statement.
a_decls: out parameter. The returned declaration list if
and only if this function returns CR_OK.
Gets the declaration list associated to the current instance of @font-face rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
enum CRStatus cr_statement_at_font_face_rule_add_decl (CRStatement *a_this,CRString *a_prop,CRTerm *a_value);
a_this: the current @font-face rule statement.
a_prop: the property of the declaration.
a_value: the value of the declaration.
Adds a declaration to the current @font-face rule statement.
| Returns : | CR_OK upon successful completion, an error code otherwise. | 
gchar * cr_statement_to_string (CRStatement const *a_this,gulong a_indent);
a_this: the current statement to serialize
a_indent: the number of white space of indentation.
Serializes a css statement into a string
| Returns : | the serialized statement. Must be freed by the caller
using g_free(). | 
gchar * cr_statement_list_to_string (CRStatement const *a_this,gulong a_indent);
void cr_statement_dump (CRStatement const *a_this,FILE *a_fp,gulong a_indent);
a_this: the current css2 statement.
a_fp: the destination file pointer.
a_indent: the number of white space indentation characters.
Dumps the css2 statement to a file.
void cr_statement_dump_ruleset (CRStatement const *a_this,FILE *a_fp,glong a_indent);
a_this: the current instance of CRStatement.
a_fp: the destination file pointer.
a_indent: the number of indentation white spaces to add.
Dumps a ruleset statement to a file.
void cr_statement_dump_font_face_rule (CRStatement const *a_this,FILE *a_fp,glong a_indent);
a_this: the current instance of font face rule statement.
a_fp: the destination file pointer.
a_indent: the number of white space indentation.
Dumps a font face rule statement to a file.
void cr_statement_dump_page (CRStatement const *a_this,FILE *a_fp,gulong a_indent);
a_this: the statement to dump on stdout.
a_fp: the destination file pointer.
a_indent: the number of indentation white spaces.
Dumps an @page rule statement on stdout.
void cr_statement_dump_media_rule (CRStatement const *a_this,FILE *a_fp,gulong a_indent);
a_this: the statement to dump.
a_fp: the destination file pointer
a_indent: the number of white spaces indentation.
Dumps an @media rule statement to a file.
void cr_statement_dump_import_rule (CRStatement const *a_this,FILE *a_fp,gulong a_indent);
a_fp: the destination file pointer.
a_indent: the number of white space indentations.
Dumps an @import rule statement to a file.
void cr_statement_dump_charset (CRStatement const *a_this,FILE *a_fp,gulong a_indent);
a_this: the current instance of the @charset rule statement.
a_fp: the destination file pointer.
a_indent: the number of indentation white spaces.
Dumps an @charset rule statement to a file.
gint                cr_statement_nr_rules               (CRStatement const *a_this);
a_this: the current instance of CRStatement.
Gets the number of rules in the statement list;
| Returns : | number of rules in the statement list. | 
CRStatement * cr_statement_get_from_list (CRStatement *a_this,int itemnr);
a_this: the current instance of CRStatement.
itemnr: the index into the statement list.
Use an index to get a CRStatement from the statement list.
| Returns : | CRStatement at position itemnr, if itemnr > number of statements - 1, it will return NULL. | 
void                cr_statement_destroy                (CRStatement *a_this);
a_this: the current instance of CRStatement.
Destructor of CRStatement.