The QContactFetchHint class provides hints to the manager about which contact information needs to be retrieved in an asynchronous fetch request or a synchronous function call. More...
#include <QContactFetchHint>This class was introduced in Qt Mobility 1.0.
| enum | OptimizationHint { AllRequired, NoRelationships, NoActionPreferences, NoBinaryBlobs } |
| flags | OptimizationHints |
| QContactFetchHint () | |
| QContactFetchHint ( const QContactFetchHint & other ) | |
| ~QContactFetchHint () | |
| QStringList | detailDefinitionsHint () const |
| int | maxCountHint () const |
| OptimizationHints | optimizationHints () const |
| QSize | preferredImageSize () const |
| QStringList | relationshipTypesHint () const |
| void | setDetailDefinitionsHint ( const QStringList & definitionNames ) |
| void | setMaxCountHint ( int count ) |
| void | setOptimizationHints ( OptimizationHints hints ) |
| void | setPreferredImageSize ( const QSize & size ) |
| void | setRelationshipTypesHint ( const QStringList & relationshipTypes ) |
| QContactFetchHint & | operator= ( const QContactFetchHint & other ) |
The QContactFetchHint class provides hints to the manager about which contact information needs to be retrieved in an asynchronous fetch request or a synchronous function call.
All of the hints may be ignored at the discretion of the manager, however if a manager is able to optimize retrieval of contacts due to hints, it may do so. If a manager ignores a hint, it must retrieve the full set of data that the hint refers to.
The fetch hint contains:
Important note: a client should not make changes to a contact which has been retrieved using a fetch hint other than the default fetch hint. Doing so can result in information loss when saving the contact back to the manager (as the "new" restricted contact will replace the previously saved contact in the backend).
This enum defines flags which may be set to inform the backend that the client does not require certain information. The backend may safely ignore the hint, but then must return the full set of information relating to the optimization hint.
| Constant | Value | Description |
|---|---|---|
| QContactFetchHint::AllRequired | 0x0 | Tells the backend that all information is required |
| QContactFetchHint::NoRelationships | 0x1 | Tells the backend that the client does not require retrieved contacts to include a cache of relationships |
| QContactFetchHint::NoActionPreferences | 0x2 | Tells the backend that the client does not require retrieved contacts to include a cache of action preferences |
| QContactFetchHint::NoBinaryBlobs | 0x4 | Tells the backend that the client does not require retrieved contacts to include binary blobs such as thumbnail images |
The OptimizationHints type is a typedef for QFlags<OptimizationHint>. It stores an OR combination of OptimizationHint values.
Constructs a new contact fetch hint which requests that the backend fetch all information
Constructs a new contact fetch hint as a copy of other
Frees any memory in use by the fetch hint
Returns the list of definition names that identify detail definitions of which details the manager should (at a minimum) retrieve when fetching contacts. This hint may be ignored by the backend, in which case it will return the full set of details for each contact retrieved.
This function was introduced in Qt Mobility 1.0.
See also setDetailDefinitionsHint().
Returns the number of results which the client considers to be the maximum number of useful results. The client is only interested in this number of results, so returning any more results would be superfluous to the client's requirements. Note that this fetch hint only affects operations where the backend would return a list of contacts; this hint specifies the maximum number of contacts in the list which would be useful to the client. The backend may ignore this hint, in which case it must return all contacts which would otherwise have been returned as a result of the operation.
A negative value for count denotes that the client wishes to retrieve all results. The default value is -1.
This function was introduced in Qt Mobility 1.2.
See also setMaxCountHint().
Returns the optimization hint flags specified by the client. These hints may be ignored by the backend, in which case it will return the full set of information accessible in a contact, including relationships, action preferences, and binary blobs.
This function was introduced in Qt Mobility 1.0.
See also setOptimizationHints().
Returns the preferred pixel dimensions for any images returned by the manager for a given request. This hint may be ignored by the manager.
This is useful when the backend supports multiple sizes of an image (or the image is natively scaleable) in order to get an image that will look good at the indicated dimensions.
The caller should be prepared for images of any dimensions, in any case.
This function was introduced in Qt Mobility 1.1.
See also setPreferredImageSize().
Returns the list of relationship types that the manager should (at a minimum) retrieve when fetching contacts. This hint may be ignored by the backend, in which case it will return the full set of relationships for each contact retrieved.
This function was introduced in Qt Mobility 1.0.
See also setRelationshipTypesHint() and QContact::relationships().
Sets the list of definition names that identify detail definitions of which details the manager should (at a minimum) retrieve when fetching contacts to definitionNames. This hint may be ignored by the backend, in which case it will return the full set of details for each contact retrieved.
This function was introduced in Qt Mobility 1.0.
See also detailDefinitionsHint().
Sets the maximum number of results which the client is interested in to count. The client is only interested in this number of results, so returning any more results would be superfluous to the client's requirements. Note that this fetch hint only affects operations where the backend would return a list of contacts; this hint specifies the maximum number of contacts in the list which would be useful to the client. The backend may ignore this hint, in which case it must return all contacts which would otherwise have been returned as a result of the operation.
A negative value for count denotes that the client wishes to retrieve all results. The default value is -1.
This function was introduced in Qt Mobility 1.2.
See also maxCountHint().
Sets the optimization hint flags specified by the client to hints. These hints may be ignored by the backend, in which case it will return the full set of information accessible in a contact, including relationships, action preferences, and binary blobs.
This function was introduced in Qt Mobility 1.0.
See also optimizationHints().
Sets the preferred pixel dimensions for any images returned by the manager for the given request to size. This hint may be ignored by the manager.
This is useful when the backend supports multiple sizes of an image (or the image is natively scaleable) in order to get an image that will look good at the indicated dimensions.
The caller should be prepared for images of any dimensions, in any case.
This function was introduced in Qt Mobility 1.1.
See also preferredImageSize().
Sets the list of relationship types that the manager should (at a minimum) retrieve when fetching contacts to relationshipTypes. This hint may be ignored by the backend, in which case it will return the full set of relationships for each contact retrieved.
This function was introduced in Qt Mobility 1.0.
See also relationshipTypesHint() and QContact::relationships().
Assigns this fetch hint to be equal to the other fetch hint
This function was introduced in Qt Mobility 1.0.