QGIS API Documentation  3.6.0-Noosa (5873452)
Public Types | Signals | Public Member Functions | Static Public Member Functions | List of all members
QgsLocatorFilter Class Referenceabstract

Abstract base class for filters which collect locator results. More...

#include <qgslocatorfilter.h>

Inheritance diagram for QgsLocatorFilter:
Inheritance graph
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Public Types

enum  Flag { FlagFast = 1 << 1 }
 Flags for locator behavior. More...
 
enum  Priority {
  Highest, High, Medium, Low,
  Lowest
}
 Filter priority. Controls the order of results in the locator. More...
 

Signals

void finished ()
 Emitted when the filter finishes fetching results. More...
 
void resultFetched (const QgsLocatorResult &result)
 Should be emitted by filters whenever they encounter a matching result during within their fetchResults() implementation. More...
 

Public Member Functions

 QgsLocatorFilter (QObject *parent=nullptr)
 Constructor for QgsLocatorFilter. More...
 
QString activePrefix () const
 Returns the prefix in use in the locator is entered. More...
 
virtual void clearPreviousResults ()
 This method will be called on main thread on the original filter (not a clone) before fetching results or before triggering a result to clear any change made by a former call to triggerResult. More...
 
virtual QgsLocatorFilterclone () const =0
 Creates a clone of the filter. More...
 
virtual QString displayName () const =0
 Returns a translated, user-friendly name for the filter. More...
 
bool enabled () const
 Returns true if the filter is enabled. More...
 
virtual void fetchResults (const QString &string, const QgsLocatorContext &context, QgsFeedback *feedback)=0
 Retrieves the filter results for a specified search string. More...
 
virtual QgsLocatorFilter::Flags flags () const
 Returns flags which specify the filter's behavior. More...
 
virtual bool hasConfigWidget () const
 Should return true if the filter has a configuration widget. More...
 
void logMessage (const QString &message, Qgis::MessageLevel level=Qgis::Info)
 Logs a message to the log panel. More...
 
virtual QString name () const =0
 Returns the unique name for the filter. More...
 
virtual void openConfigWidget (QWidget *parent=nullptr)
 Opens the configuration widget for the filter (if it has one), with the specified parent widget. More...
 
virtual QString prefix () const
 Returns the search prefix character(s) for this filter. More...
 
virtual void prepare (const QString &string, const QgsLocatorContext &context)
 Prepares the filter instance for an upcoming search for the specified string. More...
 
virtual Priority priority () const
 Returns the priority for the filter, which controls how results are ordered in the locator. More...
 
void setActivePrefix (const QString &activePrefix)
 Sets the prefix as being used by the locator. More...
 
void setEnabled (bool enabled)
 Sets whether the filter is enabled. More...
 
void setUseWithoutPrefix (bool useWithoutPrefix)
 Sets whether the filter should be used when no prefix is entered. More...
 
virtual void triggerResult (const QgsLocatorResult &result)=0
 Triggers a filter result from this filter. More...
 
virtual void triggerResultFromAction (const QgsLocatorResult &result, const int actionId)
 Triggers a filter result from this filter for an entry in the context menu. More...
 
bool useWithoutPrefix () const
 Returns true if the filter should be used when no prefix is entered. More...
 

Static Public Member Functions

static bool stringMatches (const QString &candidate, const QString &search)
 Tests a candidate string to see if it should be considered a match for a specified search string. More...
 

Detailed Description

Abstract base class for filters which collect locator results.

Note
If the configuration of the filter is changed outside of the main application settings, one needs to invalidate current results of the locator widget:
See also
QgisInterface::invalidateLocatorResults
Since
QGIS 3.0

Definition at line 145 of file qgslocatorfilter.h.

Member Enumeration Documentation

◆ Flag

Flags for locator behavior.

Enumerator
FlagFast 

Filter finds results quickly and can be safely run in the main thread.

Definition at line 163 of file qgslocatorfilter.h.

◆ Priority

Filter priority. Controls the order of results in the locator.

Enumerator
Highest 

Highest priority.

High 

High priority.

Medium 

Medium priority.

Low 

Low priority.

Lowest 

Lowest priority.

Definition at line 152 of file qgslocatorfilter.h.

Constructor & Destructor Documentation

◆ QgsLocatorFilter()

QgsLocatorFilter::QgsLocatorFilter ( QObject *  parent = nullptr)

Constructor for QgsLocatorFilter.

Definition at line 26 of file qgslocatorfilter.cpp.

Member Function Documentation

◆ activePrefix()

QString QgsLocatorFilter::activePrefix ( ) const

Returns the prefix in use in the locator is entered.

See also
setActivePrefix()
Since
QGIS 3.2

Definition at line 77 of file qgslocatorfilter.cpp.

◆ clearPreviousResults()

virtual void QgsLocatorFilter::clearPreviousResults ( )
inlinevirtual

This method will be called on main thread on the original filter (not a clone) before fetching results or before triggering a result to clear any change made by a former call to triggerResult.

For instance, this can be used to remove any on-canvas rubber bands which have been created when a previous search result was triggered.

Since
QGIS 3.2

Definition at line 268 of file qgslocatorfilter.h.

◆ clone()

virtual QgsLocatorFilter* QgsLocatorFilter::clone ( ) const
pure virtual

Creates a clone of the filter.

New requests are always executed in a clone of the original filter.

◆ displayName()

virtual QString QgsLocatorFilter::displayName ( ) const
pure virtual

Returns a translated, user-friendly name for the filter.

See also
name()

◆ enabled()

bool QgsLocatorFilter::enabled ( ) const

Returns true if the filter is enabled.

See also
setEnabled()

Definition at line 47 of file qgslocatorfilter.cpp.

◆ fetchResults()

virtual void QgsLocatorFilter::fetchResults ( const QString &  string,
const QgsLocatorContext context,
QgsFeedback feedback 
)
pure virtual

Retrieves the filter results for a specified search string.

The context argument encapsulates the context relating to the search (such as a map extent to prioritize).

Implementations of fetchResults() should emit the resultFetched() signal whenever they encounter a matching result.

Subclasses should periodically check the feedback object to determine whether the query has been canceled. If so, the subclass should return from this method as soon as possible.

This will be called from a background thread unless flags() returns the QgsLocatorFilter::FlagFast flag.

◆ finished

void QgsLocatorFilter::finished ( )
signal

Emitted when the filter finishes fetching results.

◆ flags()

QgsLocatorFilter::Flags QgsLocatorFilter::flags ( ) const
virtual

Returns flags which specify the filter's behavior.

Definition at line 31 of file qgslocatorfilter.cpp.

◆ hasConfigWidget()

bool QgsLocatorFilter::hasConfigWidget ( ) const
virtual

Should return true if the filter has a configuration widget.

See also
openConfigWidget()

Definition at line 57 of file qgslocatorfilter.cpp.

◆ logMessage()

void QgsLocatorFilter::logMessage ( const QString &  message,
Qgis::MessageLevel  level = Qgis::Info 
)

Logs a message to the log panel.

Warning
in Python, do not use print() method as it might result in crashes since fetching results does not happen in the main thread.
Since
QGIS 3.2

Definition at line 93 of file qgslocatorfilter.cpp.

◆ name()

virtual QString QgsLocatorFilter::name ( ) const
pure virtual

Returns the unique name for the filter.

This should be an untranslated string identifying the filter.

See also
displayName()

◆ openConfigWidget()

void QgsLocatorFilter::openConfigWidget ( QWidget *  parent = nullptr)
virtual

Opens the configuration widget for the filter (if it has one), with the specified parent widget.

The base class implementation does nothing. Subclasses can override this to show their own custom configuration widget.

Note
hasConfigWidget() must return true to indicate that the filter supports configuration.

Definition at line 62 of file qgslocatorfilter.cpp.

◆ prefix()

virtual QString QgsLocatorFilter::prefix ( ) const
inlinevirtual

Returns the search prefix character(s) for this filter.

Prefix a search with these characters will restrict the locator search to only include results from this filter.

Note
Plugins are not permitted to utilize prefixes with < 3 characters, as these are reserved for core QGIS functions. If a plugin registers a filter with a prefix shorter than 3 characters then the prefix will be ignored.
Prefixes might be overridden by user preferences.
See also
activePrefix()

Definition at line 215 of file qgslocatorfilter.h.

◆ prepare()

virtual void QgsLocatorFilter::prepare ( const QString &  string,
const QgsLocatorContext context 
)
inlinevirtual

Prepares the filter instance for an upcoming search for the specified string.

This method is always called from the main thread, and individual filter subclasses should perform whatever tasks are required in order to allow a subsequent search to safely execute on a background thread.

Definition at line 223 of file qgslocatorfilter.h.

◆ priority()

virtual Priority QgsLocatorFilter::priority ( ) const
inlinevirtual

Returns the priority for the filter, which controls how results are ordered in the locator.

Definition at line 202 of file qgslocatorfilter.h.

◆ resultFetched

void QgsLocatorFilter::resultFetched ( const QgsLocatorResult result)
signal

Should be emitted by filters whenever they encounter a matching result during within their fetchResults() implementation.

◆ setActivePrefix()

void QgsLocatorFilter::setActivePrefix ( const QString &  activePrefix)

Sets the prefix as being used by the locator.

See also
activePrefix()
Note
If activePrefix is empty, no prefix is used. If activePrefix is NULL, the default prefix is used.
Since
QGIS 3.2

Definition at line 88 of file qgslocatorfilter.cpp.

◆ setEnabled()

void QgsLocatorFilter::setEnabled ( bool  enabled)

Sets whether the filter is enabled.

See also
enabled()

Definition at line 52 of file qgslocatorfilter.cpp.

◆ setUseWithoutPrefix()

void QgsLocatorFilter::setUseWithoutPrefix ( bool  useWithoutPrefix)

Sets whether the filter should be used when no prefix is entered.

See also
useWithoutPrefix()

Definition at line 72 of file qgslocatorfilter.cpp.

◆ stringMatches()

bool QgsLocatorFilter::stringMatches ( const QString &  candidate,
const QString &  search 
)
static

Tests a candidate string to see if it should be considered a match for a specified search string.

Filter subclasses should use this method when comparing strings instead of directly using QString::contains() or Python 'in' checks.

Definition at line 42 of file qgslocatorfilter.cpp.

◆ triggerResult()

virtual void QgsLocatorFilter::triggerResult ( const QgsLocatorResult result)
pure virtual

Triggers a filter result from this filter.

This is called when one of the results obtained by a call to fetchResults() is triggered by a user. The filter subclass must implement logic here to perform the desired operation for the search result. E.g. a file search filter would open file associated with the triggered result.

◆ triggerResultFromAction()

void QgsLocatorFilter::triggerResultFromAction ( const QgsLocatorResult result,
const int  actionId 
)
virtual

Triggers a filter result from this filter for an entry in the context menu.

The entry is identified by its actionId as specified in the result of this filter.

See also
triggerResult()
Since
QGIS 3.6

Definition at line 36 of file qgslocatorfilter.cpp.

◆ useWithoutPrefix()

bool QgsLocatorFilter::useWithoutPrefix ( ) const

Returns true if the filter should be used when no prefix is entered.

See also
setUseWithoutPrefix()

Definition at line 67 of file qgslocatorfilter.cpp.


The documentation for this class was generated from the following files: