MeeGo 1.2 Harmattan Developer Documentation Develop for the Nokia N9

QGeoSearchManager Class Reference

The QGeoSearchManager class provides support for searching operations related to geographic information. More...

 #include <QGeoSearchManager>

Inherits: QObject.

This class was introduced in Qt Mobility 1.1.

Public Types

enum SearchType { SearchNone, SearchGeocode, SearchLandmarks, SearchAll }
flags SearchTypes

Public Functions

~QGeoSearchManager ()
void addAdditionalLandmarkManager ( QLandmarkManager * landmarkManager )
QList<QLandmarkManager *> additionalLandmarkManagers () const
QLandmarkManager * defaultLandmarkManager () const
QGeoSearchReply * geocode ( const QGeoAddress & address, QGeoBoundingArea * bounds = 0 )
QLocale locale () const
QString managerName () const
int managerVersion () const
QGeoSearchReply * reverseGeocode ( const QGeoCoordinate & coordinate, QGeoBoundingArea * bounds = 0 )
QGeoSearchReply * search ( const QString & searchString, SearchTypes searchTypes = SearchTypes( SearchAll ), int limit = -1, int offset = 0, QGeoBoundingArea * bounds = 0 )
void setAdditionalLandmarkManagers ( const QList<QLandmarkManager *> & landmarkManagers )
void setLocale ( const QLocale & locale )
SearchTypes supportedSearchTypes () const
bool supportsGeocoding () const
bool supportsReverseGeocoding () const
  • 29 public functions inherited from QObject

Signals

void error ( QGeoSearchReply * reply, QGeoSearchReply::Error error, QString errorString = QString() )
void finished ( QGeoSearchReply * reply )

Additional Inherited Members

  • 1 property inherited from QObject
  • 1 public slot inherited from QObject
  • 1 public variable inherited from QObject
  • 4 static public members inherited from QObject
  • 7 protected functions inherited from QObject
  • 2 protected variables inherited from QObject

Detailed Description

The QGeoSearchManager class provides support for searching operations related to geographic information.

The geocode(), reverseGeocode() and search() functions return QGeoSearchReply objects, which manage these operations and report on the result of the operations and any errors which may have occurred.

The geocode() and reverseGeocode() functions can be used to convert QGeoAddress instances to QGeoCoordinate instances and vice-versa.

The search() function allows a user to perform a free text search for place information. If the string provided can be interpreted as an address it can be geocoded to coordinate information, and the string can also be used to search a landmarks database, depending on the level of support supplied by the service provider.

The defaultLandmarkManager() function will return a QLandmarkManager instance if access to the service providers landmark database is available outside of the search() method.

A user can supply other QLandmarkManager instances to be searched during the execution of search() with setAdditionalLandmarkManagers(). This means that a personal database store can be combined with a public source of database information with very little effort.

Note: At present the additional landmark managers only search for the search string in the name of the landmarks.

Instances of QGeoSearchManager can be accessed with QGeoServiceProvider::searchManager().

A small example of the usage of QGeoSearchManager and the handling of QLandmark results follows:

 class MySearchHandler : public QObject
 {
     Q_OBJECT
 public:
     MySearchHandler(QGeoSearchManager *searchManager, QString searchString)
     {
         QGeoSearchReply *reply = searchManager->search(searchString);

         if (reply->isFinished()) {
             if (reply->error() == QGeoSearchReply::NoError) {
                 searchResults(reply);
             else
                 searchError(reply, reply->error(), reply->errorString());
             return;
         }

         connect(searchManager,
                 SIGNAL(finished(QGeoSearchReply*)),
                 this,
                 SLOT(searchResults(QGeoSearchReply*)));

         connect(searchManager,
                 SIGNAL(error(QGeoSearchReply*,QGeoSearchReply::Error,QString)),
                 this
                 SLOT(searchError(QGeoSearchReply*,QGeoSearchReply::Error,QString)));
     }

 private slots:
     void searchResults(QGeoSearchReply *reply)
     {
         // The QLandmark results can be created from the simpler
         // QGeoPlace results if that is required.
         QList<QLandmark> landmarks;
         for (int i = 0; i < reply->places().size(); ++i) {
             if (reply->places().at(i).isLandmark())
                 landmarks.append(QLandmark(reply->places().at(i)));
         }

         // ... now we have to make use of the places and landmarks ...
         reply->deleteLater();
     }

     void searchError(QGeoSearchReply *reply, QGeoSearchReply::Error error, const QString &errorString)
     {
         // ... inform the user that an error has occurred ...
         reply->deleteLater();
     }
 };

Member Type Documentation

enum QGeoSearchManager::SearchType
flags QGeoSearchManager::SearchTypes

Describes the type of search that should be performed by search().

Constant Value Description
QGeoSearchManager::SearchNone 0x0000 Do not use the search string.
QGeoSearchManager::SearchGeocode 0x0001 Use the search string as a textual address in a geocoding operation.
QGeoSearchManager::SearchLandmarks 0x0002 Use the search string for free-text search against the available landmark information sources.
QGeoSearchManager::SearchAll 0xFFFF All available information sources should be used as part of the search.

The SearchTypes type is a typedef for QFlags<SearchType>. It stores an OR combination of SearchType values.

Member Function Documentation

QGeoSearchManager::~QGeoSearchManager ()

Destroys this manager.

void QGeoSearchManager::addAdditionalLandmarkManager ( QLandmarkManager * landmarkManager )

Adds landmarkManager to the list of landmark managers that will be used with search().

These landmark managers will be used along with the landmark manager returned by defaultLandmarkManager().

This function was introduced in Qt Mobility 1.1.

QList<QLandmarkManager *> QGeoSearchManager::additionalLandmarkManagers () const

Returns the landmark managers that will be used with search().

These landmark managers will be used along with the landmark manager returned by defaultLandmarkManager().

This function was introduced in Qt Mobility 1.1.

See also setAdditionalLandmarkManagers().

QLandmarkManager * QGeoSearchManager::defaultLandmarkManager () const

Returns the landmark manager provided by the service provider for use with search().

Will return 0 if the no landmark manager is associated with the service provider. This does not indicate that search() does not support landmark searching, only that any landmark searching which occurs within in search() is done without the use of a QLandmarkManager.

This function was introduced in Qt Mobility 1.1.

void QGeoSearchManager::error ( QGeoSearchReply * reply, QGeoSearchReply::Error error, QString errorString = QString() ) [signal]

This signal is emitted when an error has been detected in the processing of reply. The QGeoSearchManager::finished() signal will probably follow.

The error will be described by the error code error. If errorString is not empty it will contain a textual description of the error.

This signal and QGeoSearchReply::error() will be emitted at the same time.

Note: Do no delete the reply object in the slot connected to this signal. Use deleteLater() instead.

This function was introduced in Qt Mobility 1.1.

void QGeoSearchManager::finished ( QGeoSearchReply * reply ) [signal]

This signal is emitted when reply has finished processing.

If reply::error() equals QGeoSearchReply::NoError then the processing finished successfully.

This signal and QGeoSearchReply::finished() will be emitted at the same time.

Note: Do no delete the reply object in the slot connected to this signal. Use deleteLater() instead.

This function was introduced in Qt Mobility 1.1.

QGeoSearchReply * QGeoSearchManager::geocode ( const QGeoAddress & address, QGeoBoundingArea * bounds = 0 )

Begins the geocoding of address. Geocoding is the process of finding a coordinate that corresponds to a given address.

A QGeoSearchReply object will be returned, which can be used to manage the geocoding operation and to return the results of the operation.

This manager and the returned QGeoSearchReply object will emit signals indicating if the operation completes or if errors occur.

If supportsGeocoding() returns false an QGeoSearchReply::UnsupportedOptionError will occur.

Once the operation has completed, QGeoSearchReply::places() can be used to retrieve the results, which will consist of a list of QGeoPlace objects. These object represent a combination of coordinate and address data.

The address data returned in the results may be different from address. This will usually occur if the geocoding service backend uses a different canonical form of addresses or if address was only partially filled out.

If bounds is non-null and valid QGeoBoundingArea it will be used to limit the results to thos that are contained within bounds. This is particularly useful if address is only partially filled out, as the service will attempt to geocode all matches for the specified data.

The user is responsible for deleting the returned reply object, although this can be done in the slot connected to QGeoSearchManager::finished(), QGeoSearchManager::error(), QGeoSearchReply::finished() or QGeoSearchReply::error() with deleteLater().

This function was introduced in Qt Mobility 1.1.

QLocale QGeoSearchManager::locale () const

Returns the locale used to hint to this search manager about what language to use for the results.

This function was introduced in Qt Mobility 1.1.

See also setLocale().

QString QGeoSearchManager::managerName () const

Returns the name of the engine which implements the behaviour of this search manager.

The combination of managerName() and managerVersion() should be unique amongst the plugin implementations.

This function was introduced in Qt Mobility 1.1.

int QGeoSearchManager::managerVersion () const

Returns the version of the engine which implements the behaviour of this search manager.

The combination of managerName() and managerVersion() should be unique amongst the plugin implementations.

This function was introduced in Qt Mobility 1.1.

QGeoSearchReply * QGeoSearchManager::reverseGeocode ( const QGeoCoordinate & coordinate, QGeoBoundingArea * bounds = 0 )

Begins the reverse geocoding of coordinate. Reverse geocoding is the process of finding an address that corresponds to a given coordinate.

A QGeoSearchReply object will be returned, which can be used to manage the reverse geocoding operation and to return the results of the operation.

This manager and the returned QGeoSearchReply object will emit signals indicating if the operation completes or if errors occur.

If supportsReverseGeocoding() returns false an QGeoSearchReply::UnsupportedOptionError will occur.

At that point QGeoSearchReply::places() can be used to retrieve the results, which will consist of a list of QGeoPlace objects. These object represent a combination of coordinate and address data.

The coordinate data returned in the results may be different from coordinate. This will usually occur if the reverse geocoding service backend shifts the coordinates to be closer to the matching addresses, or if the backend returns results at multiple levels of detail.

If multiple results are returned by the reverse geocoding service backend they will be provided in order of specificity. This normally occurs if the backend is configured to reverse geocode across multiple levels of detail. As an example, some services will return address and coordinate pairs for the street address, the city, the state and the country.

If bounds is non-null and a valid QGeoBoundingBox it will be used to limit the results to thos that are contained within bounds.

The user is responsible for deleting the returned reply object, although this can be done in the slot connected to QGeoSearchManager::finished(), QGeoSearchManager::error(), QGeoSearchReply::finished() or QGeoSearchReply::error() with deleteLater().

This function was introduced in Qt Mobility 1.1.

QGeoSearchReply * QGeoSearchManager::search ( const QString & searchString, SearchTypes searchTypes = SearchTypes( SearchAll ), int limit = -1, int offset = 0, QGeoBoundingArea * bounds = 0 )

Begins searching for a place matching searchString. The value of searchTypes will determine whether the search is for addresses only, for landmarks only or for both.

A QGeoSearchReply object will be returned, which can be used to manage the geocoding operation and to return the results of the operation.

This manager and the returned QGeoSearchReply object will emit signals indicating if the operation completes or if errors occur.

If supportsGeocoding() returns false and searchTypes is QGeoSearchManager::SearchGeocode an QGeoSearchReply::UnsupportedOptionError will occur.

Once the operation has completed, QGeoSearchReply::places() can be used to retrieve the results, which will consist of a list of QGeoPlace objects. These object represent a combination of coordinate and address data.

If any of the QGeoPlace instances in the results have landmark associated data, QGeoPlace::isLandmark() will return true and QLandmark::QLandmark(const QGeoPlace &place) can be used to convert the QGeoPlace instance into a QLandmark instance.

If searchTypes is QGeoSearchManager::SearchLandmarks or QGeoSearchManager::SearchAll, a free text landmark search will be performed. The results will be a combination of the backend specific landmark search and the same free text search applied to each of the QLandmarkManager instances in additionalLandmarkManagers().

Note: At present the additional landmark managers only search for the search string in the name of the landmarks.

If limit is -1 the entire result set will be returned, otherwise at most limit results will be returned.

The offset parameter is used to ask the search service to not return the first offset results.

The limit and offset results are used together to implement paging.

If additional landmark managers have been setup the number of results returned will be at most (1 + number of additional landmark managers) * limit. This happens because the results are requested from all sources, combined, and returned once all sources have responded.

If bounds is non-null and a valid QGeoBoundingArea it will be used to limit the results to thos that are contained within bounds.

The user is responsible for deleting the returned reply object, although this can be done in the slot connected to QGeoSearchManager::finished(), QGeoSearchManager::error(), QGeoSearchReply::finished() or QGeoSearchReply::error() with deleteLater().

This function was introduced in Qt Mobility 1.1.

void QGeoSearchManager::setAdditionalLandmarkManagers ( const QList<QLandmarkManager *> & landmarkManagers )

Sets the landmark managers to be used with search() to landmarkManagers.

These landmark managers will be used along with the landmark manager returned by defaultLandmarkManager().

This function was introduced in Qt Mobility 1.1.

See also additionalLandmarkManagers().

void QGeoSearchManager::setLocale ( const QLocale & locale )

Sets the locale to be used by the this manager to locale.

If this search manager supports returning the results in different languages, they will be returned in the language of locale.

The locale used defaults to the system locale if this is not set.

This function was introduced in Qt Mobility 1.1.

See also locale().

SearchTypes QGeoSearchManager::supportedSearchTypes () const

Returns the search types supported by the search() function with this manager.

This function was introduced in Qt Mobility 1.1.

bool QGeoSearchManager::supportsGeocoding () const

Returns whether this manager supports geocoding.

This function was introduced in Qt Mobility 1.1.

bool QGeoSearchManager::supportsReverseGeocoding () const

Returns whether this manager supports reverse geocoding.

This function was introduced in Qt Mobility 1.1.