libgdamm Reference Documentation |
Public Types | |
typedef Glib::ListHandle <Value, ValueTraits> | ValueList |
typedef Glib::SListHandle <Value, ValueTraits> | ValueSList |
Public Member Functions | |
bool | append_row () |
Appends a row to the data model (the new row will possibliy have 0 values for all columns, or some other values depending on the data model implementation). | |
int | append_values (const ValueList& values) |
Appends a row to the given data model. | |
Glib::RefPtr<DataModelIter> | create_iter () |
Creates a new iterator object Gda::DataModelIter object which can be used to iterate through rows in model. | |
Glib::RefPtr<const Column> | describe_column (int col) const |
Queries the underlying data model implementation for a description of a given column. | |
Glib::RefPtr<Column> | describe_column (int col) |
Queries the underlying data model implementation for a description of a given column. | |
void | dump (FILE* to_stream) const |
Dumps a textual representation of the model to the to_stream stream. | |
Glib::ustring | dump_as_string () const |
Dumps a textual representation of the model into a new string. | |
bool | export_to_file (DataModelIOFormat format, const std::string& file, const Glib::ArrayHandle<int>& cols, const Glib::ArrayHandle<int>& rows, const Glib::RefPtr<Set>& options) |
Exports data contained in model to the file; the format is specified using the format argument. | |
Glib::ustring | export_to_string (DataModelIOFormat format, const Glib::ArrayHandle<int>& cols, const Glib::ArrayHandle<int>& rows, const Glib::RefPtr<Set>& options) |
Exports data contained in model to the a string; the format is specified using the format argument. | |
void | freeze () |
Disables notifications of changes on the given data model. | |
DataModelAccessFlags | get_access_flags () const |
Get the attributes of model such as how to access the data it contains if it's modifiable, etc. | |
ValueAttribute | get_attributes_at (int col, int row) |
Get the attributes of the value stored at (row, col) in model, which is an ORed value of Gda::ValueAttribute flags. | |
int | get_column_index (const Glib::ustring& name) |
Get the index of the first column named name in model. | |
Glib::ustring | get_column_name (int col) const |
Since: 3.2. | |
Glib::ustring | get_column_title (int col) const |
int | get_n_columns () const |
int | get_n_rows () const |
int | get_row_from_values (const ValueSList& values, const Glib::ArrayHandle<int>& cols_index) |
Returns: the requested row number, of -1 if not found. | |
Value | get_typed_value_at (int col, int row, GType expected_type, bool nullok) const |
This method is similar to get_value_at(), except that it also allows one to specify the expected Type of the value to get: if the data model returned a Value of a type different than the expected one, then this method returns 0 and an error code. | |
Value | get_value_at (int col, int row) const |
Retrieves the data stored in the given position (identified by the col and row parameters) on a data model. | |
const GdaDataModel* | gobj () const |
Provides access to the underlying C GObject. | |
GdaDataModel* | gobj () |
Provides access to the underlying C GObject. | |
bool | import_from_file (const std::string& file, GHashTable* cols_trans, const Glib::RefPtr<const Set>& options) |
Imports data contained in the file file into model; the format is detected. | |
bool | import_from_model (const Glib::RefPtr<DataModel>& from, bool overwrite, GHashTable* cols_trans) |
Copy the contents of the from data model to the to data model. | |
bool | import_from_string (const Glib::ustring& string, GHashTable* cols_trans, const Glib::RefPtr<const Set>& options) |
Loads the data from string into model. | |
bool | iter_move_next_default (const Glib::RefPtr<DataModelIter>& iter) |
bool | iter_move_prev_default (const Glib::RefPtr<DataModelIter>& iter) |
bool | iter_move_to_row_default (const Glib::RefPtr<DataModelIter>& iter, int row) |
bool | remove_row (int row) |
Removes a row from the data model. | |
void | send_hint (DataModelHint hint, const Value& hint_value) |
Sends a hint to the data model. | |
void | set_column_name (int col, const Glib::ustring& name) |
Sets the name of the given col in model, and if its title is not set, also sets the title to name. | |
void | set_column_title (int col, const Glib::ustring& title) |
Sets the title of the given col in model. | |
bool | set_value_at (int col, int row, const Value& value) |
Modifies a value in model, at ( col, row). | |
bool | set_values (int row, const ValueList& values) |
In a similar way to set_value_at(), this method modifies a data model's contents by setting several values at once. | |
Glib::SignalProxy0<void> | signal_changed () |
Glib::SignalProxy0<void> | signal_reset () |
Glib::SignalProxy1<void, int> | signal_row_inserted () |
Glib::SignalProxy1<void, int> | signal_row_removed () |
Glib::SignalProxy1<void, int> | signal_row_updated () |
void | thaw () |
Re-enables notifications of changes on the given data model. | |
virtual | ~DataModel () |
Static Public Member Functions | |
static void | add_interface (GType gtype_implementer) |
Protected Member Functions | |
virtual void | on_changed () |
virtual void | on_reset () |
virtual void | on_row_inserted (int row) |
virtual void | on_row_removed (int row) |
virtual void | on_row_updated (int row) |
Related Functions | |
(Note that these are not member functions.) | |
Glib::RefPtr <Gnome::Gda::DataModel> | wrap (GdaDataModel* object, bool take_copy=false) |
A Glib::wrap() method for this object. |
A DataModel represents an array of values organized in rows and columns. All the data in the same column have the same type, and all the data in each row have the same semantic meaning. The DataModel is actually an interface implemented by other objects to support various kinds of data storage and operations.
Depending on the real implementation, the contents of data models may be modified by the user by using functions provided by the model. The actual operations that a data model permits can be discovered using the get_access_flags() method.
Again, depending on the real implementation, data retreival can be done either by accessing direct random values located by their row and column, or by using a DataModelIter cursor, or both. Use the get_access_flags() method to discover how the data model can be accessed. Note that a Datamodel which can be accessed in a random way can also be accessed using cursors (and several cusrors may be used at the same time), whereas a data model which can only be accessed using cursors can only have one cursor for iterating.
Random access data models are easier to use since picking a value is very simple by using the get_value_at(), but they consume more memory since all the accessible values must generally be present in memory even if they are not used. Thus, if a data model must handle large quantities of data, it is generally wiser to use a data model which can be only accessed using a cursor.
As a side note there are also data models which wrap other data models such as:
typedef Glib::ListHandle<Value, ValueTraits> Gnome::Gda::DataModel::ValueList |
typedef Glib::SListHandle<Value, ValueTraits> Gnome::Gda::DataModel::ValueSList |
virtual Gnome::Gda::DataModel::~DataModel | ( | ) | [virtual] |
static void Gnome::Gda::DataModel::add_interface | ( | GType | gtype_implementer | ) | [static] |
bool Gnome::Gda::DataModel::append_row | ( | ) |
Appends a row to the data model (the new row will possibliy have 0
values for all columns, or some other values depending on the data model implementation).
int Gnome::Gda::DataModel::append_values | ( | const ValueList & | values | ) |
Appends a row to the given data model.
If any value in values is actually 0
, then it is considered as a default value.
values | List of Value* representing the row to add. The length must match model's column count. These Value are value-copied (the user is still responsible for freeing them). |
Glib::RefPtr<DataModelIter> Gnome::Gda::DataModel::create_iter | ( | ) |
Creates a new iterator object Gda::DataModelIter object which can be used to iterate through rows in model.
The row the returned Gda::DataModelIter represents is undefined. For models which can be accessed randomly the corresponding row can be set using Gda::DataModelIter::move_to_row(), and for models which are accessible sequentially only then the first row will be fetched using Gda::DataModelIter::move_next().
0
if an error occurred. Glib::RefPtr<const Column> Gnome::Gda::DataModel::describe_column | ( | int | col | ) | const |
Queries the underlying data model implementation for a description of a given column.
That description is returned in the form of a Gda::Column structure, which contains all the information about the given column in the data model.
WARNING: the returned Gda::Column object belongs to the model model and and should not be destroyed; any modification will affect the whole data model.
col | Column number. |
Glib::RefPtr<Column> Gnome::Gda::DataModel::describe_column | ( | int | col | ) |
Queries the underlying data model implementation for a description of a given column.
That description is returned in the form of a Gda::Column structure, which contains all the information about the given column in the data model.
WARNING: the returned Gda::Column object belongs to the model model and and should not be destroyed; any modification will affect the whole data model.
col | Column number. |
void Gnome::Gda::DataModel::dump | ( | FILE * | to_stream | ) | const |
Dumps a textual representation of the model to the to_stream stream.
The following environment variables can affect the resulting output: <itemizedlist> <listitem>GDA_DATA_MODEL_DUMP_ROW_NUMBERS: if set, the first coulumn of the output will contain row numbers</listitem> <listitem>GDA_DATA_MODEL_DUMP_ATTRIBUTES: if set, also dump the data model's columns' types and value's attributes</listitem> <listitem>GDA_DATA_MODEL_DUMP_TITLE: if set, also dump the data model's title</listitem> <listitem>GDA_DATA_MODEL_DUMP_NULL_AS_EMPTY: if set, replace the '0
' string with an empty string for 0
values </listitem> </itemizedlist>
to_stream | Where to dump the data model. |
Glib::ustring Gnome::Gda::DataModel::dump_as_string | ( | ) | const |
Dumps a textual representation of the model into a new string.
The following environment variables can affect the resulting output: <itemizedlist> <listitem>GDA_DATA_MODEL_DUMP_ROW_NUMBERS: if set, the first coulumn of the output will contain row numbers</listitem> <listitem>GDA_DATA_MODEL_DUMP_TITLE: if set, also dump the data model's title</listitem> <listitem>GDA_DATA_MODEL_DUMP_NULL_AS_EMPTY: if set, replace the '0
' string with an empty string for 0
values </listitem> </itemizedlist>
bool Gnome::Gda::DataModel::export_to_file | ( | DataModelIOFormat | format, | |
const std::string & | file, | |||
const Glib::ArrayHandle< int > & | cols, | |||
const Glib::ArrayHandle< int > & | rows, | |||
const Glib::RefPtr<Set>& | options | |||
) |
Exports data contained in model to the file; the format is specified using the format argument.
Specifically, the parameters in the list can be:
format | The format in which to export data. | |
file | The filename to export to. | |
cols | An array containing which columns of will be exported. | |
rows | An array containing which rows of will be exported. | |
options | List of options for the export. |
Glib::ustring Gnome::Gda::DataModel::export_to_string | ( | DataModelIOFormat | format, | |
const Glib::ArrayHandle< int > & | cols, | |||
const Glib::ArrayHandle< int > & | rows, | |||
const Glib::RefPtr<Set>& | options | |||
) |
Exports data contained in model to the a string; the format is specified using the format argument.
Specifically, the parameters in the list can be:
format | The format in which to export data. | |
cols | An array containing which columns of will be exported. | |
rows | An array containing which rows of will be exported. | |
options | List of options for the export. |
void Gnome::Gda::DataModel::freeze | ( | ) |
Disables notifications of changes on the given data model.
To re-enable notifications again, you should call the gda_data_model_thaw function.
DataModelAccessFlags Gnome::Gda::DataModel::get_access_flags | ( | ) | const |
Get the attributes of model such as how to access the data it contains if it's modifiable, etc.
ValueAttribute Gnome::Gda::DataModel::get_attributes_at | ( | int | col, | |
int | row | |||
) |
Get the attributes of the value stored at (row, col) in model, which is an ORed value of Gda::ValueAttribute flags.
As a special case, if row is -1, then the attributes returned correspond to a "would be" value if a row was added to model.
col | A valid column number. | |
row | A valid row number, or -1. |
int Gnome::Gda::DataModel::get_column_index | ( | const Glib::ustring & | name | ) |
Get the index of the first column named name in model.
name | A column name. |
Glib::ustring Gnome::Gda::DataModel::get_column_name | ( | int | col | ) | const |
Since: 3.2.
col | Column number. |
Glib::ustring Gnome::Gda::DataModel::get_column_title | ( | int | col | ) | const |
int Gnome::Gda::DataModel::get_n_columns | ( | ) | const |
int Gnome::Gda::DataModel::get_n_rows | ( | ) | const |
int Gnome::Gda::DataModel::get_row_from_values | ( | const ValueSList & | values, | |
const Glib::ArrayHandle< int > & | cols_index | |||
) |
Returns: the requested row number, of -1 if not found.
values | A list of Value values (no 0 is allowed). | |
cols_index | An array of int containing the column number to match each value of values. |
Value Gnome::Gda::DataModel::get_typed_value_at | ( | int | col, | |
int | row, | |||
GType | expected_type, | |||
bool | nullok | |||
) | const |
This method is similar to get_value_at(), except that it also allows one to specify the expected Type of the value to get: if the data model returned a Value of a type different than the expected one, then this method returns 0
and an error code.
col | A valid column number. | |
row | A valid row number. | |
expected_type | The expected data type of the returned value. | |
nullok | If true , then 0 values (value of type Gda::TYPE_<tt>0) will not generate any error. |
0
on error (out-of-bound position, wrong data type, etc). Value Gnome::Gda::DataModel::get_value_at | ( | int | col, | |
int | row | |||
) | const |
Retrieves the data stored in the given position (identified by the col and row parameters) on a data model.
This is the main function for accessing data in a model which allows random access to its data. To access data in a data model using a cursor, use a Gda::DataModelIter object, obtained using create_iter().
the returned value may become invalid as soon as any Libgda part is executed again, which means if you want to keep the value, a copy must be made, however it will remain valid as long as the only Libgda usage is calling get_value_at() for different values of the same row.
col | A valid column number. | |
row | A valid row number. |
0
on error (out-of-bound position, etc). const GdaDataModel* Gnome::Gda::DataModel::gobj | ( | ) | const [inline] |
Provides access to the underlying C GObject.
Reimplemented from Glib::Interface.
Reimplemented in Gnome::Gda::DataAccessWrapper, Gnome::Gda::DataComparator, Gnome::Gda::DataModelArray, Gnome::Gda::DataModelImport, Gnome::Gda::DataProxy, and Gnome::Gda::DataSelect.
References Glib::ValueBase::gobject_.
GdaDataModel* Gnome::Gda::DataModel::gobj | ( | ) | [inline] |
Provides access to the underlying C GObject.
Reimplemented from Glib::Interface.
Reimplemented in Gnome::Gda::DataAccessWrapper, Gnome::Gda::DataComparator, Gnome::Gda::DataModelArray, Gnome::Gda::DataModelImport, Gnome::Gda::DataProxy, and Gnome::Gda::DataSelect.
References Glib::ValueBase::gobject_.
bool Gnome::Gda::DataModel::import_from_file | ( | const std::string & | file, | |
GHashTable * | cols_trans, | |||
const Glib::RefPtr<const Set>& | options | |||
) |
Imports data contained in the file file into model; the format is detected.
file | The filename to import from. | |
cols_trans | A HashTable for columns translating, or 0 . | |
options | List of options for the export. |
true
if no error occurred. bool Gnome::Gda::DataModel::import_from_model | ( | const Glib::RefPtr<DataModel>& | from, | |
bool | overwrite, | |||
GHashTable * | cols_trans | |||
) |
Copy the contents of the from data model to the to data model.
The copy stops as soon as an error orrurs.
The cols_trans is a hash table for which keys are to columns numbers and the values are the corresponding column numbers in the from data model. To set the values of a column in to to 0
, create an entry in the hash table with a negative value.
from | The source Gda::DataModel. | |
overwrite | true if to is completely overwritten by from's data, and false if from's data is appended to to. | |
cols_trans | A HashTable for columns translating, or 0 . |
true
if no error occurred. bool Gnome::Gda::DataModel::import_from_string | ( | const Glib::ustring & | string, | |
GHashTable * | cols_trans, | |||
const Glib::RefPtr<const Set>& | options | |||
) |
Loads the data from string into model.
string | The string to import data from. | |
cols_trans | A hash table containing which columns of model will be imported, or 0 for all columns. | |
options | List of options for the export. |
true
if no error occurred. bool Gnome::Gda::DataModel::iter_move_next_default | ( | const Glib::RefPtr<DataModelIter>& | iter | ) |
bool Gnome::Gda::DataModel::iter_move_prev_default | ( | const Glib::RefPtr<DataModelIter>& | iter | ) |
bool Gnome::Gda::DataModel::iter_move_to_row_default | ( | const Glib::RefPtr<DataModelIter>& | iter, | |
int | row | |||
) |
virtual void Gnome::Gda::DataModel::on_changed | ( | ) | [protected, virtual] |
virtual void Gnome::Gda::DataModel::on_reset | ( | ) | [protected, virtual] |
virtual void Gnome::Gda::DataModel::on_row_inserted | ( | int | row | ) | [protected, virtual] |
virtual void Gnome::Gda::DataModel::on_row_removed | ( | int | row | ) | [protected, virtual] |
virtual void Gnome::Gda::DataModel::on_row_updated | ( | int | row | ) | [protected, virtual] |
bool Gnome::Gda::DataModel::remove_row | ( | int | row | ) |
Removes a row from the data model.
row | The row number to be removed. |
true
if successful, false
otherwise. void Gnome::Gda::DataModel::send_hint | ( | DataModelHint | hint, | |
const Value& | hint_value | |||
) |
Sends a hint to the data model.
The hint may or may not be handled by the data model, depending on its implementation
hint | A hint to send to the model. | |
hint_value | An optional value to specify the hint, or 0 . |
void Gnome::Gda::DataModel::set_column_name | ( | int | col, | |
const Glib::ustring & | name | |||
) |
Sets the name of the given col in model, and if its title is not set, also sets the title to name.
Since: 3.2
col | Column number. | |
name | Name for the given column. |
void Gnome::Gda::DataModel::set_column_title | ( | int | col, | |
const Glib::ustring & | title | |||
) |
Sets the title of the given col in model.
col | Column number. | |
title | Title for the given column. |
bool Gnome::Gda::DataModel::set_value_at | ( | int | col, | |
int | row, | |||
const Value& | value | |||
) |
bool Gnome::Gda::DataModel::set_values | ( | int | row, | |
const ValueList & | values | |||
) |
In a similar way to set_value_at(), this method modifies a data model's contents by setting several values at once.
If any value in values is actually 0
, then the value in the corresponding column is left unchanged.
true
if the value in the data model has been updated and no error occurred. Glib::SignalProxy0< void > Gnome::Gda::DataModel::signal_changed | ( | ) |
void on_my_changed()
Glib::SignalProxy0< void > Gnome::Gda::DataModel::signal_reset | ( | ) |
void on_my_reset()
Glib::SignalProxy1< void,int > Gnome::Gda::DataModel::signal_row_inserted | ( | ) |
void on_my_row_inserted(int row)
Glib::SignalProxy1< void,int > Gnome::Gda::DataModel::signal_row_removed | ( | ) |
void on_my_row_removed(int row)
Glib::SignalProxy1< void,int > Gnome::Gda::DataModel::signal_row_updated | ( | ) |
void on_my_row_updated(int row)
void Gnome::Gda::DataModel::thaw | ( | ) |
Re-enables notifications of changes on the given data model.
Glib::RefPtr<Gnome::Gda::DataModel> wrap | ( | GdaDataModel * | object, | |
bool | take_copy = false | |||
) | [related] |
A Glib::wrap() method for this object.
object | The C instance. | |
take_copy | False if the result should take ownership of the C instance. True if it should take a new copy or ref. |