libgdamm: Gnome::Gda::DataProxy Class Reference

Proxy to hold modifications for any DataModel, providing the DataModel interface itself. More...

Inheritance diagram for Gnome::Gda::DataProxy:

Collaboration diagram for Gnome::Gda::DataProxy:

Public Member Functions
virtual	~DataProxy ()
GdaDataProxy*	gobj ()
	Provides access to the underlying C GObject.
const GdaDataProxy*	gobj () const
	Provides access to the underlying C GObject.
GdaDataProxy*	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
get_proxied_model ()
	Fetch the Gda::DataModel which proxy does proxy.
get_proxied_model () const
	Fetch the Gda::DataModel which proxy does proxy.
int	get_proxied_model_n_cols () const
	Get the number of columns in the proxied data model.
int	get_proxied_model_n_rows () const
	Get the number of rows in the proxied data model.
bool	is_read_only () const
ValueVector	get_values (int proxy_row, const std::vector< int >& cols_index) const
	Retrieve a whole list of values from the proxy data model.
ValueAttribute	get_value_attributes (int proxy_row, int col) const
	Get the attributes of the value stored at (proxy_row, col) in proxy, which is an ORed value of Gda::ValueAttribute flags.
void	alter_value_attributes (int proxy_row, int col, ValueAttribute alter_flags)
	Alters the attributes of the value stored at (proxy_row, col) in proxy.
int	get_proxied_model_row (int proxy_row) const
	Get the proxy's proxied model row corresponding to proxy_row.
void	erase (int proxy_row)
	Marks the row proxy_row to be deleted.
void	unerase (int proxy_row)
	Remove the "to be deleted" mark at the row proxy_row, if it existed.
bool	row_is_deleted (int proxy_row) const
	Tells if the row number proxy_row is marked to be deleted.
bool	row_is_inserted (int proxy_row) const
	Tells if the row number proxy_row is a row which has been inserted in proxy (and is thus not in the proxied data model).
void	cancel_row_changes (int proxy_row, int col)
	Resets data at the corresponding row and column.
void	apply_row_changes (int proxy_row)
	Commits the modified data in the proxy back into the Gda::DataModel.
bool	has_changed () const
	Tells if proxy contains any modifications not applied to the proxied data model.
bool	row_has_changed (int proxy_row) const
	Tells if the row number proxy_row has changed.
int	get_n_new_rows () const
	Get the number of rows which have been added to proxy and which are not part of the proxied data model.
int	get_n_modified_rows () const
	Get the number of rows which have been modified in the proxy (the sum of rows existing in the proxied data model which have been modified, and new rows).
void	set_sample_size (int sample_size)
	Sets the size of each chunk of data to display: the maximum number of rows which can be "displayed" at a time (the maximum number of rows which proxy pretends to have).
int	get_sample_size () const
	Get the size of each chunk of data displayed at a time.
void	set_sample_start (int sample_start)
	Sets the number of the first row to be available in proxy (in reference to the proxied data model)
int	get_sample_start () const
	Get the number of the first row to be available in proxy (in reference to the proxied data model)
int	get_sample_end () const
	Get the number of the last row to be available in proxy (in reference to the proxied data model)
bool	apply_all_changes ()
	Apply all the changes stored in the proxy to the proxied data model.
bool	cancel_all_changes ()
	Cancel all the changes stored in the proxy (the proxy will be reset to its state as it was just after creation).
int	get_filtered_n_rows ()
	Get the total number of filtered rows in proxy if a filter has been applied.
get_filter_expr ()
	Get the current filter expression used by proxy.
void	get_filter_expr (const Glib::ustring& filter_expr)
	Sets a filter among the rows presented by proxy.
void	set_ordering_column (int col)
	Orders by the col column.
< property_model ()
	Proxied data model.
< property_model () const
	Proxied data model.
property_prepend_null_entry ()
	Tells if a row composed of NULL values is inserted as the proxy's first row.
< bool >	property_prepend_null_entry () const
	Tells if a row composed of NULL values is inserted as the proxy's first row.
property_defer_sync ()
	Tells if changes to the sample of rows displayed is done in background in several steps or if it's done in one step.
< bool >	property_defer_sync () const
	Tells if changes to the sample of rows displayed is done in background in several steps or if it's done in one step.
property_sample_size ()
	Number of rows which the proxy will contain at any time, like a sliding window on the proxied data model.
property_sample_size () const
	Number of rows which the proxy will contain at any time, like a sliding window on the proxied data model.
bool >	signal_row_delete_changed ()
int >	signal_sample_changed ()
signal_sample_size_changed ()
signal_filter_changed ()
< signal_validate_row_changes ()
int >	signal_row_changes_applied ()
Static Public Member Functions
static DataModel >& model)
Protected Member Functions
	DataProxy (const DataModel >& model)
virtual void	on_row_delete_changed (int row, bool to_be_deleted)
virtual void	on_sample_changed (int sample_start, int sample_end)
virtual void	on_sample_size_changed (int sample_size)
virtual void	on_row_changes_applied (int row, int proxied_row)
Related Functions
(Note that these are not member functions.)
< Gnome::Gda::DataProxy >	wrap (GdaDataProxy* object, bool take_copy=false)
	A

Detailed Description

Proxy to hold modifications for any DataModel, providing the DataModel interface itself.

This object stores modifications made to a DataModel object which is proxied until asked to make the changes inside the DataModel. It also filters the proxied data model to show only a sample (a defined number of continuous rows) of it.

Specifically, for a proxied data model having nb_cols columns and nb_rows rows, the DataProxy object has the following attributes:

2 * nb_cols columns:
- The first (>= 0) nb_cols columns are the current values stored in the proxy (which correspond to the values of the proxied data model if the considered row has not been changed). The associated values are writable.
- The last nb_cols columns are the values stored in the proxied data model, at column col - nb_cols.
A variable number of rows depending on the following attributes:
- Whether the proxy is configured to have an empty row as the first row.
- Whether the proxy only displays parts of the proxied data model.
- Whether new rows have been added to the proxy.

Note that unless explicitely mentioned, the columns are read-only.

Constructor & Destructor Documentation

virtual Gnome::Gda::DataProxy::~DataProxy ( ) [virtual]

Gnome::Gda::DataProxy::DataProxy ( const DataModel >& model ) [explicit, protected]

Member Function Documentation

void Gnome::Gda::DataProxy::alter_value_attributes	(	int	proxy_row,
		int	col,
		ValueAttribute	alter_flags
	)

Alters the attributes of the value stored at (proxy_row, col) in proxy.

the alter_flags can only contain the GDA_VALUE_ATTR_IS_0, GDA_VALUE_ATTR_IS_DEFAULT and GDA_VALUE_ATTR_IS_UNCHANGED flags (other flags are ignored).

Parameters:

proxy_row	A proxy row number.
col	A valid column number.
alter_flags	Flags to alter the attributes.

bool Gnome::Gda::DataProxy::apply_all_changes ( )

Apply all the changes stored in the proxy to the proxied data model.

The changes are done row after row, and if an error occurs, then it is possible that not all the changes to all the rows have been applied.

Returns:: true if no error occurred.

void Gnome::Gda::DataProxy::apply_row_changes ( int proxy_row )

Commits the modified data in the proxy back into the Gda::DataModel.

Parameters:

proxy_row The row number to commit.

Returns:: true if no error occurred.

bool Gnome::Gda::DataProxy::cancel_all_changes ( )

Cancel all the changes stored in the proxy (the proxy will be reset to its state as it was just after creation).

Returns:: true if no error occurred.

void Gnome::Gda::DataProxy::cancel_row_changes	(	int	proxy_row,
		int	col
	)

Resets data at the corresponding row and column.

If proxy_row corresponds to a new row, then that new row is deleted from proxy.

Parameters:

proxy_row	The row to cancel changes.
col	The column to cancel changes, or less than 0 to cancel any change on the row row.

static DataProxy> Gnome::Gda::DataProxy::create ( const DataModel >& model ) [static]

void Gnome::Gda::DataProxy::erase ( int proxy_row )

Marks the row proxy_row to be deleted.

Parameters:

proxy_row A proxy row number.

Glib::ustring Gnome::Gda::DataProxy::get_filter_expr ( )

Get the current filter expression used by proxy.

Returns:: The current filter expression or 0 if no filter has been set.

void Gnome::Gda::DataProxy::get_filter_expr ( const Glib::ustring & filter_expr )

Sets a filter among the rows presented by proxy.

The filter is defined by a filter expression which can be any SQL valid expression using proxy's columns. For instance if proxy has the "id" and "name" columns, then a filter can be "length(name) < 5" to filter only the rows where the length of the name is strictly inferior to 5, or "id >= 1000 and id < 2000 order by name limit 50" to filter only the rows where the id is between 1000 and 2000, ordered by name and limited to 50 rows.

Note about column names: real column names can be used (double quoted if necessary), but columns can also be named "_<column number>" with column numbers starting at 1.

Note that any previous filter expression is replaced with the new filter_expr if no error occurs (if an error occurs, then any previous filter is left unchanged).

Parameters:

filter_expr An SQL based expression which will filter the contents of proxy, or 0 to remove any previous filter.

Returns:: true if no error occurred.

int Gnome::Gda::DataProxy::get_filtered_n_rows ( )

Get the total number of filtered rows in proxy if a filter has been applied.

As new rows (rows added to the proxy and not yet added to the proxied data model) and rows to remove (rows marked for removal but not yet removed from the proxied data model) are also filtered, the returned number also contains references to new rows and rows to be removed.

Returns:: The number of filtered rows in proxy, or -1 if no filter has been applied.

int Gnome::Gda::DataProxy::get_n_modified_rows ( ) const

Get the number of rows which have been modified in the proxy (the sum of rows existing in the proxied data model which have been modified, and new rows).

Returns:: The number of modified rows.

int Gnome::Gda::DataProxy::get_n_new_rows ( ) const

Get the number of rows which have been added to proxy and which are not part of the proxied data model.

Returns:: The number of new rows.

DataModel> Gnome::Gda::DataProxy::get_proxied_model ( )

Fetch the Gda::DataModel which proxy does proxy.

Returns:: The proxied data model.

DataModel> Gnome::Gda::DataProxy::get_proxied_model ( ) const

Fetch the Gda::DataModel which proxy does proxy.

Returns:: The proxied data model.

int Gnome::Gda::DataProxy::get_proxied_model_n_cols ( ) const

Get the number of columns in the proxied data model.

Returns:: The number of columns, or -1 if an error occurred.

int Gnome::Gda::DataProxy::get_proxied_model_n_rows ( ) const

Get the number of rows in the proxied data model.

Returns:: The number of rows, or -1 if the number of rows is not known.

int Gnome::Gda::DataProxy::get_proxied_model_row ( int proxy_row ) const

Get the proxy's proxied model row corresponding to proxy_row.

Parameters:

proxy_row A proxy row number.

Returns:: The proxied model's row, or -1 if proxy row which only exists proxy.

int Gnome::Gda::DataProxy::get_sample_end ( ) const

Get the number of the last row to be available in proxy (in reference to the proxied data model)

Returns:: The number of the last proxied model's row.

int Gnome::Gda::DataProxy::get_sample_size ( ) const

Get the size of each chunk of data displayed at a time.

Returns:: The chunk (or sample) size, or 0 if chunking is disabled.

int Gnome::Gda::DataProxy::get_sample_start ( ) const

Get the number of the first row to be available in proxy (in reference to the proxied data model)

Returns:: The number of the first proxied model's row.

ValueAttribute Gnome::Gda::DataProxy::get_value_attributes	(	int	proxy_row,
		int	col
	)		const

Get the attributes of the value stored at (proxy_row, col) in proxy, which is an ORed value of Gda::ValueAttribute flags.

Parameters:

proxy_row	A proxy row.
col	A valid proxy column.

Returns:: The attribute.

ValueVector Gnome::Gda::DataProxy::get_values	(	int	proxy_row,
		const std::vector< int > &	cols_index
	)		const

Retrieve a whole list of values from the proxy data model.

This function calls gda_data_proxy_get_value() for each column index specified in cols_index, and generates a SList on the way.

Parameters:

proxy_row	A proxy row.
cols_index	Array containing the columns for which the values are requested.
n_cols	Size of cols_index.

Returns:: A new list of values (the list must be freed, not the values), or 0 if an error occurred.

GdaDataProxy* Gnome::Gda::DataProxy::gobj ( ) [inline]

Provides access to the underlying C GObject.

Reimplemented from Gnome::Gda::DataModel.

const GdaDataProxy* Gnome::Gda::DataProxy::gobj ( ) const [inline]

Provides access to the underlying C GObject.

Reimplemented from Gnome::Gda::DataModel.

GdaDataProxy* Gnome::Gda::DataProxy::gobj_copy ( )

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

bool Gnome::Gda::DataProxy::has_changed ( ) const

Tells if proxy contains any modifications not applied to the proxied data model.

Returns:: true if there are some modifications in proxy.

bool Gnome::Gda::DataProxy::is_read_only ( ) const

Returns:: true if the proxied data model is itself read-only.

virtual void Gnome::Gda::DataProxy::on_row_changes_applied	(	int	row,
		int	proxied_row
	)		`[protected, virtual]`

virtual void Gnome::Gda::DataProxy::on_row_delete_changed	(	int	row,
		bool	to_be_deleted
	)		`[protected, virtual]`

virtual void Gnome::Gda::DataProxy::on_sample_changed	(	int	sample_start,
		int	sample_end
	)		`[protected, virtual]`

virtual void Gnome::Gda::DataProxy::on_sample_size_changed ( int sample_size ) [protected, virtual]

Glib::PropertyProxy<bool> Gnome::Gda::DataProxy::property_defer_sync ( )

Tells if changes to the sample of rows displayed is done in background in several steps or if it's done in one step.