Focus

Inside Macintosh: OpenDoc Class Reference /: Part 1 - Classes and Methods / ODStorageUnit

Focus
The Focus method focuses this storage unit on the specified focus context.
ODStorageUnit Focus (in ODPropertyName propertyName, 
                     in ODPositionCode propertyPosCode, 
                     in ODValueType valueType, 
                     in ODValueIndex valueIndex, 
                     in ODPositionCode valuePosCode);
propertyName
The name of the property in the desired focus context, or kODNULL to ignore this parameter.
propertyPosCode
The position code, relative to the current focus context, of the property in the desired focus context, or kODPosUndefined to ignore this parameter.
valueType
The value type of the value in the desired focus context, or kODNULL to ignore this parameter.
valueIndex
The value index of the value in the desired focus context, or 0 to ignore this parameter.
valuePosCode
The position code, relative to the current focus context, of the value in the desired focus context, or kODPosUndefined to ignore this parameter.
return value
A reference to this storage unit, focused on the specified focus context.

DISCUSSION
Your part calls this method; its parameters specify the desired focus context.

To focus on the entire storage unit, pass kODNULL as the property name parameter, kODPosAll as the property position code parameter, kODTypeAll as the value type parameter, 0 as the value index parameter, and kODPosUndefined as the value position code parameter.
To focus on a property, either pass its name as the property name parameter or pass kODNULL as the property name parameter and the appropriate code as the property position code parameter. Pass kODTypeAll as the value type parameter, 0 as the value index parameter, and kODPosUndefined as the value position code parameter.
To focus on a value, specify the property containing the value using either the property name parameter or the property position code parameter, as described in the previous item. You can specify the value by its type, its index, or its position.

To use type, pass the type of the desired value as the value type parameter, 0 as the value index parameter, and kODPosUndefined as the value position code parameter.
To use index, pass kODNULL as the value type parameter, the index of the desired value as the value index parameter, and kODPosUndefined as the value position code parameter.
To use the position code, pass kODNULL as the value type parameter, 0 as the value index parameter, and the appropriate code as the value position code parameter.

After this method executes successfully, this storage unit's offset is 0.
Before calling this method, you can call the Exists method to check whether the specified focus context exists.

EXCEPTIONS

kODErrIllegalPropertyName
The specified property name is improperly formed or illegal.
kODErrPropertyDoesNotExist
This storage unit does not contain the specified property.
kODErrSUValueDoesNotExist
This storage unit does not contain the specified value.
kODErrUnsupportedPosCode
One of the specified position codes is not supported.
kODErrValueIndexOutOfRange
The specified property has no value at the specified index.
kODErrZeroRefCount
This storage unit has a reference count of 0.

SEE ALSO
The ODPositionCode type (page 915).
The ODPropertyName type (page 904).
The ODValueIndex type (page 904).
The ODValueType type (page 904).
The ODStorageUnit::Exists method (page 681).
The ODStorageUnit::FocusWithCursor method (page 686).
Listing 2-41 on page 100 in OpenDoc Cookbook.
Listing 2-45 on page 106 in OpenDoc Cookbook.
Listing 2-46 on page 108 in OpenDoc Cookbook.
"Focusing a Storage Unit" on page 274 in OpenDoc Programmer's Guide.