GdaDataProxy

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

Functions

Properties

gboolean defer-sync Read / Write
GdaDataModel * model Read / Write / Construct
gboolean prepend-null-entry Read / Write
gint sample-size Read / Write / Construct

Signals

void filter-changed Run First
void post-changes-applied Run First
gboolean pre-changes-applied Run Last
void row-delete-changed Run First
void sample-changed Run First
void sample-size-changed Run First

Types and Values

Object Hierarchy

    GObject
    ╰── GdaObject
        ╰── GdaDataProxy

Implemented Interfaces

GdaDataProxy implements GdaDataModel.

Description

This object stores modifications to be made to a GdaDataModel object which is proxied until the modifications are actually written to the GdaDataModel, it can also filter the proxied data model to show only a subset (a defined number of continuous rows or by a filter to apply).

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.

Functions

gda_data_proxy_new ()

GObject *
gda_data_proxy_new (GdaDataModel *model);

Creates a new proxy for model

Parameters

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

Parameters

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

Parameters

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

Parameters

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);

Parameters

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.

Parameters

proxy

a GdaDataProxy object

 

proxy_row

a proxy row

 

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

Parameters

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).

Parameters

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

Parameters

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

Parameters

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.

Parameters

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.

Parameters

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).

Parameters

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

Parameters

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

Parameters

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.

Parameters

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.

Parameters

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

Parameters

proxy

a GdaDataProxy object

 

proxy_row

A proxy row number

 

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.

Parameters

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 chunk 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 chunk of data, and the modified rows which are not visible when the displayed chunk of data changes are still held as modified rows.

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

Parameters

proxy

a GdaDataProxy object

 

sample_size

the requested size of a chunk, 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.

Parameters

proxy

a GdaDataProxy object

 

Returns

the chunk (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.

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

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).

Parameters

proxy

a GdaDataProxy object

 

Returns

TRUE if no error occurred


gda_data_proxy_set_filter_expr ()

gboolean
gda_data_proxy_set_filter_expr (GdaDataProxy *proxy,
                                const gchar *filter_expr,
                                GError **error);

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 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

proxy

a GdaDataProxy object

 

filter_expr

an SQL based expression which will filter the contents of proxy , or NULL to remove any previous filter

 

error

a place to store errors, or NULL

 

Returns

TRUE if no error occurred


gda_data_proxy_get_filter_expr ()

const gchar *
gda_data_proxy_get_filter_expr (GdaDataProxy *proxy);

Get the current filter expression used by proxy .

Parameters

proxy

a GdaDataProxy object

 

Returns

the current filter expression or NULL if no filter has been set


gda_data_proxy_get_filtered_n_rows ()

gint
gda_data_proxy_get_filtered_n_rows (GdaDataProxy *proxy);

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 reefrences to new rows and rows to be removed.

Parameters

proxy

a GdaDataProxy object

 

Returns

the number of filtered rows in proxy , or -1 if no filter has been applied

Types and Values

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;

Property Details

The “defer-sync” property

  “defer-sync”               gboolean

Flags: Read / Write

Default value: TRUE


The “model” property

  “model”                    GdaDataModel *

Flags: Read / Write / Construct


The “prepend-null-entry” property

  “prepend-null-entry”       gboolean

Flags: Read / Write

Default value: FALSE


The “sample-size” property

  “sample-size”              gint

Flags: Read / Write / Construct

Allowed values: [0,2147483646]

Default value: 300

Signal Details

The “filter-changed” signal

void
user_function (GdaDataProxy *gdadataproxy,
               gpointer      user_data)

Parameters

gdadataproxy

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “post-changes-applied” signal

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

Parameters

gdadataproxy

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “pre-changes-applied” signal

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

Parameters

gdadataproxy

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last


The “row-delete-changed” signal

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

Parameters

gdadataproxy

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “sample-changed” signal

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

Parameters

gdadataproxy

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “sample-size-changed” signal

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

Parameters

gdadataproxy

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First