GdaDataProxy

GdaDataProxy — Proxy to hold modifications for any GdaDataModel, and provides the GdaDataModel interface itself

Synopsis

                    GdaDataProxy;
                    GdaDataProxyClass;
                    GdaDataProxyPrivate;
GObject*            gda_data_proxy_new                  (GdaDataModel *model);
GdaDataModel*       gda_data_proxy_get_proxied_model    (GdaDataProxy *proxy);
gint                gda_data_proxy_get_proxied_model_n_cols
                                                        (GdaDataProxy *proxy);
gint                gda_data_proxy_get_proxied_model_n_rows
                                                        (GdaDataProxy *proxy);
gboolean            gda_data_proxy_is_read_only         (GdaDataProxy *proxy);
GSList*             gda_data_proxy_get_values           (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint *cols_index,
                                                         gint n_cols);
GdaValueAttribute   gda_data_proxy_get_value_attributes (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint col);
void                gda_data_proxy_alter_value_attributes
                                                        (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint col,
                                                         GdaValueAttribute alter_flags);
gint                gda_data_proxy_get_proxied_model_row
                                                        (GdaDataProxy *proxy,
                                                         gint proxy_row);
void                gda_data_proxy_delete               (GdaDataProxy *proxy,
                                                         gint proxy_row);
void                gda_data_proxy_undelete             (GdaDataProxy *proxy,
                                                         gint proxy_row);
gboolean            gda_data_proxy_row_is_deleted       (GdaDataProxy *proxy,
                                                         gint proxy_row);
gboolean            gda_data_proxy_row_is_inserted      (GdaDataProxy *proxy,
                                                         gint proxy_row);
gint                gda_data_proxy_find_row_from_values (GdaDataProxy *proxy,
                                                         GSList *values,
                                                         gint *cols_index);
void                gda_data_proxy_cancel_row_changes   (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint col);
gboolean            gda_data_proxy_apply_row_changes    (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         GError **error);
gboolean            gda_data_proxy_has_changed          (GdaDataProxy *proxy);
gboolean            gda_data_proxy_row_has_changed      (GdaDataProxy *proxy,
                                                         gint proxy_row);
gint                gda_data_proxy_get_n_new_rows       (GdaDataProxy *proxy);
void                gda_data_proxy_set_sample_size      (GdaDataProxy *proxy,
                                                         gint sample_size);
gint                gda_data_proxy_get_sample_size      (GdaDataProxy *proxy);
void                gda_data_proxy_set_sample_start     (GdaDataProxy *proxy,
                                                         gint sample_start);
gint                gda_data_proxy_get_sample_start     (GdaDataProxy *proxy);
gint                gda_data_proxy_get_sample_end       (GdaDataProxy *proxy);
gboolean            gda_data_proxy_apply_all_changes    (GdaDataProxy *proxy,
                                                         GError **error);
gboolean            gda_data_proxy_cancel_all_changes   (GdaDataProxy *proxy);

Object Hierarchy

  GObject
   +----GdaObject
         +----GdaDataProxy

Implemented Interfaces

GdaDataProxy implements GdaDataModel.

Properties

  "model"                    GdaDataModel*         : Read / Write / Construct
  "prepend-null-entry"       gboolean              : Read / Write

Signals

  "post-changes-applied"                           : Run First
  "pre-changes-applied"                            : Run Last
  "row-delete-changed"                             : Run First
  "sample-changed"                                 : Run First
  "sample-size-changed"                            : Run First

Description

This object stores modifications made to a GdaDataModel object which is proxied until asked to make the changes inside the GdaDataModel, 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 GdaDataProxy 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:

    • if the proxy is configured to have an empty row as the first row

    • if the proxy only displays parts of the proxied data model

    • if new rows have been added to the proxy

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

Details

GdaDataProxy

typedef struct _GdaDataProxy GdaDataProxy;


GdaDataProxyClass

typedef struct {
	GdaObjectClass          parent_class;

	void                 (* row_delete_changed)   (GdaDataProxy *proxy, gint row, gboolean to_be_deleted);

	void                 (* sample_size_changed)  (GdaDataProxy *proxy, gint sample_size);
	void                 (* sample_changed)       (GdaDataProxy *proxy, gint sample_start, gint sample_end);

	gboolean             (* pre_changes_applied)  (GdaDataProxy *proxy, gint row, gint proxied_row);
	void                 (* post_changes_applied) (GdaDataProxy *proxy, gint row, gint proxied_row);
} GdaDataProxyClass;


GdaDataProxyPrivate

typedef struct _GdaDataProxyPrivate GdaDataProxyPrivate;


gda_data_proxy_new ()

GObject*            gda_data_proxy_new                  (GdaDataModel *model);

Creates a new proxy for model

model :

Data model to be proxied

Returns :

a new GdaDataProxy object

gda_data_proxy_get_proxied_model ()

GdaDataModel*       gda_data_proxy_get_proxied_model    (GdaDataProxy *proxy);

Fetch the GdaDataModel which proxy does proxy

proxy :

a GdaDataProxy object

Returns :

the proxied data model

gda_data_proxy_get_proxied_model_n_cols ()

gint                gda_data_proxy_get_proxied_model_n_cols
                                                        (GdaDataProxy *proxy);

Get the number of columns in the proxied data model

proxy :

a GdaDataProxy object

Returns :

the number of columns, or -1 if an error occurred

gda_data_proxy_get_proxied_model_n_rows ()

gint                gda_data_proxy_get_proxied_model_n_rows
                                                        (GdaDataProxy *proxy);

Get the number of rows in the proxied data model

proxy :

a GdaDataProxy object

Returns :

the number of rows, or -1 if the number of rows is not known

gda_data_proxy_is_read_only ()

gboolean            gda_data_proxy_is_read_only         (GdaDataProxy *proxy);

proxy :

a GdaDataProxy object

Returns :

TRUE if the proxied data model is itself read-only

gda_data_proxy_get_values ()

GSList*             gda_data_proxy_get_values           (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint *cols_index,
                                                         gint n_cols);

Retreive a whole list of values from the proxy store. This function calls gda_data_proxy_get_value() for each column index specified in cols_index, and generates a GSlist on the way.

proxy :

a GdaDataProxy object

proxy_row :

a proxy row

cols_index :

n_cols :

Returns :

a new list of values (the list must be freed, not the values), or NULL if an error occurred

gda_data_proxy_get_value_attributes ()

GdaValueAttribute   gda_data_proxy_get_value_attributes (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint col);

Get the attributes of the value stored at (proxy_row, col) in proxy, which is an ORed value of GdaValueAttribute flags

proxy :

a GdaDataProxy object

proxy_row :

a proxy row

col :

a valid proxy column

Returns :

the attribute

gda_data_proxy_alter_value_attributes ()

void                gda_data_proxy_alter_value_attributes
                                                        (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint col,
                                                         GdaValueAttribute 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_NULL, GDA_VALUE_ATTR_IS_DEFAULT and GDA_VALUE_ATTR_IS_UNCHANGED flags (other flags are ignored).

proxy :

a GdaDataProxy object

proxy_row :

A proxy row number

col :

a valid column number

alter_flags :

flags to alter the attributes

gda_data_proxy_get_proxied_model_row ()

gint                gda_data_proxy_get_proxied_model_row
                                                        (GdaDataProxy *proxy,
                                                         gint proxy_row);

Get the proxy's proxied model row corresponding to proxy_row

proxy :

a GdaDataProxy object

proxy_row :

A proxy row number

Returns :

the proxied model's row, or -1 if proxy row which only exists proxy

gda_data_proxy_delete ()

void                gda_data_proxy_delete               (GdaDataProxy *proxy,
                                                         gint proxy_row);

Marks the row proxy_row to be deleted

proxy :

a GdaDataProxy object

proxy_row :

A proxy row number

gda_data_proxy_undelete ()

void                gda_data_proxy_undelete             (GdaDataProxy *proxy,
                                                         gint proxy_row);

Remove the "to be deleted" mark at the row proxy_row, if it existed.

proxy :

a GdaDataProxy object

proxy_row :

A proxy row number

gda_data_proxy_row_is_deleted ()

gboolean            gda_data_proxy_row_is_deleted       (GdaDataProxy *proxy,
                                                         gint proxy_row);

Tells if the row number proxy_row is marked to be deleted.

proxy :

a GdaDataProxy object

proxy_row :

A proxy row number

Returns :

TRUE if the row is marked to be deleted

gda_data_proxy_row_is_inserted ()

gboolean            gda_data_proxy_row_is_inserted      (GdaDataProxy *proxy,
                                                         gint proxy_row);

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).

proxy :

a GdaDataProxy object

proxy_row :

A proxy row number

Returns :

TRUE if the row is an inserted row

gda_data_proxy_find_row_from_values ()

gint                gda_data_proxy_find_row_from_values (GdaDataProxy *proxy,
                                                         GSList *values,
                                                         gint *cols_index);

Find the first row where all the values in values at the columns identified at cols_index match.

NOTE: the cols_index array MUST contain a column index for each value in values

proxy :

a GdaDataProxy object

values :

a list of GValue values

cols_index :

an array of gint containing the column number to match each value of values

Returns :

proxy row number if the row has been identified, or -1 otherwise

gda_data_proxy_cancel_row_changes ()

void                gda_data_proxy_cancel_row_changes   (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         gint col);

Resets data at the corresponding row and column.

proxy :

a GdaDataProxy object

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

gda_data_proxy_apply_row_changes ()

gboolean            gda_data_proxy_apply_row_changes    (GdaDataProxy *proxy,
                                                         gint proxy_row,
                                                         GError **error);

Commits the modified data in the proxy back into the GdaDataModel.

proxy :

a GdaDataProxy object

proxy_row :

the row number to commit

error :

place to store the error, or NULL

Returns :

TRUE if no error occurred.

gda_data_proxy_has_changed ()

gboolean            gda_data_proxy_has_changed          (GdaDataProxy *proxy);

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

proxy :

a GdaDataProxy object

Returns :

TRUE if there are some modifications in proxy

gda_data_proxy_row_has_changed ()

gboolean            gda_data_proxy_row_has_changed      (GdaDataProxy *proxy,
                                                         gint proxy_row);

Tells if the row number proxy_row has changed

proxy :

a GdaDataProxy object

proxy_row :

A proxy row number

Returns :


gda_data_proxy_get_n_new_rows ()

gint                gda_data_proxy_get_n_new_rows       (GdaDataProxy *proxy);

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

proxy :

a GdaDataProxy object

Returns :

the number of new rows

gda_data_proxy_set_sample_size ()

void                gda_data_proxy_set_sample_size      (GdaDataProxy *proxy,
                                                         gint sample_size);

Sets the size of each chunck of fata to display: the maximum number of rows which can be displayed at a time. The default value is arbitrary 300 as it is big enough to be able to display quite a lot of data, but small enough to avoid too much data displayed at the same time.

Note: the rows which have been added but not yet commited will always be displayed regardless of the current chunck of data, and the modified rows which are not visible when the displayed chunck of data changes are still held as modified rows.

To remove the chuncking of the data to display, simply pass sample_size the 0 value.

proxy :

a GdaDataProxy object

sample_size :

the requested size of a chunck, or 0

gda_data_proxy_get_sample_size ()

gint                gda_data_proxy_get_sample_size      (GdaDataProxy *proxy);

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

proxy :

a GdaDataProxy object

Returns :

the chunck (or sample) size, or 0 if chunking is disabled.

gda_data_proxy_set_sample_start ()

void                gda_data_proxy_set_sample_start     (GdaDataProxy *proxy,
                                                         gint sample_start);

Sets the number of the first row to be displayed.

proxy :

a GdaDataProxy object

sample_start :

the number of the first row to be displayed

gda_data_proxy_get_sample_start ()

gint                gda_data_proxy_get_sample_start     (GdaDataProxy *proxy);

Get the row number of the first row to be displayed.

proxy :

a GdaDataProxy object

Returns :

the number of the first row being displayed.

gda_data_proxy_get_sample_end ()

gint                gda_data_proxy_get_sample_end       (GdaDataProxy *proxy);

Get the row number of the last row to be displayed.

proxy :

a GdaDataProxy object

Returns :

the number of the last row being displayed.

gda_data_proxy_apply_all_changes ()

gboolean            gda_data_proxy_apply_all_changes    (GdaDataProxy *proxy,
                                                         GError **error);

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.

proxy :

a GdaDataProxy object

error :

a place to store errors, or NULL

Returns :

TRUE if no error occurred

gda_data_proxy_cancel_all_changes ()

gboolean            gda_data_proxy_cancel_all_changes   (GdaDataProxy *proxy);

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

proxy :

a GdaDataProxy object

Returns :

TRUE if no error occurred

Property Details

The "model" property

  "model"                    GdaDataModel*         : Read / Write / Construct


The "prepend-null-entry" property

  "prepend-null-entry"       gboolean              : Read / Write

Default value: FALSE

Signal Details

The "post-changes-applied" signal

void                user_function                      (GdaDataProxy *gdadataproxy,
                                                        gint          arg1,
                                                        gint          arg2,
                                                        gpointer      user_data)         : Run First

gdadataproxy :

the object which received the signal.

arg1 :

arg2 :

user_data :

user data set when the signal handler was connected.

The "pre-changes-applied" signal

gboolean            user_function                      (GdaDataProxy *gdadataproxy,
                                                        gint          arg1,
                                                        gint          arg2,
                                                        gpointer      user_data)         : Run Last

gdadataproxy :

the object which received the signal.

arg1 :

arg2 :

user_data :

user data set when the signal handler was connected.

Returns :


The "row-delete-changed" signal

void                user_function                      (GdaDataProxy *gdadataproxy,
                                                        gint          arg1,
                                                        gboolean      arg2,
                                                        gpointer      user_data)         : Run First

gdadataproxy :

the object which received the signal.

arg1 :

arg2 :

user_data :

user data set when the signal handler was connected.

The "sample-changed" signal

void                user_function                      (GdaDataProxy *gdadataproxy,
                                                        gint          arg1,
                                                        gint          arg2,
                                                        gpointer      user_data)         : Run First

gdadataproxy :

the object which received the signal.

arg1 :

arg2 :

user_data :

user data set when the signal handler was connected.

The "sample-size-changed" signal

void                user_function                      (GdaDataProxy *gdadataproxy,
                                                        gint          arg1,
                                                        gpointer      user_data)         : Run First

gdadataproxy :

the object which received the signal.

arg1 :

user_data :

user data set when the signal handler was connected.