QGIS API Documentation  3.13.0-Master (13337b20cd)
qgsdataprovider.h
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1 /***************************************************************************
2  qgsdataprovider.h - DataProvider Interface class
3  --------------------------------------
4  Date : 09-Sep-2003
5  Copyright : (C) 2003 by Gary E.Sherman
6  email : sherman at mrcc.com
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
16 #ifndef QQGSDATAPROVIDER_H
17 #define QQGSDATAPROVIDER_H
18 
19 #include "qgis_core.h"
20 #include <QDateTime>
21 #include <QObject>
22 #include <QString>
23 #include <QStringList>
24 #include <QMutex>
25 
26 //#include "qgsdataitem.h"
27 #include "qgsdatasourceuri.h"
29 #include "qgslayermetadata.h"
30 #include "qgserror.h"
31 
32 class QgsRectangle;
34 
35 
40 class CORE_EXPORT QgsDataProvider : public QObject
41 {
42 
43 #ifdef SIP_RUN
45  if ( qobject_cast<QgsVectorDataProvider *>( sipCpp ) )
46  {
47  sipType = sipType_QgsVectorDataProvider;
48  }
49  else if ( qobject_cast<QgsRasterDataProvider *>( sipCpp ) )
50  {
51  sipType = sipType_QgsRasterDataProvider;
52  }
53  else if ( qobject_cast<QgsMeshDataProvider *>( sipCpp ) )
54  {
55  sipType = sipType_QgsMeshDataProvider;
56  }
57  else
58  {
59  sipType = 0;
60  }
61  SIP_END
62 #endif
63  Q_OBJECT
64 
65  public:
66 
67  // TODO QGIS 4: (re)move DataCapability as this enum is really meant for data items rather than data providers
68 
73  {
74  NoDataCapabilities = 0,
75  File = 1,
76  Dir = 1 << 1,
77  Database = 1 << 2,
78  Net = 1 << 3 // Internet source
79  };
80  Q_DECLARE_FLAGS( DataCapabilities, DataCapability )
81 
82 
90  {
92  CustomData = 3000
93  };
94 
95 
104  {
106  };
107 
113  QgsDataProvider( const QString &uri = QString(), const QgsDataProvider::ProviderOptions &providerOptions = QgsDataProvider::ProviderOptions() );
114 
120  virtual QgsCoordinateReferenceSystem crs() const = 0;
121 
127  virtual void setDataSourceUri( const QString &uri )
128  {
129  mDataSourceURI = uri;
130  }
131 
141  virtual QString dataSourceUri( bool expandAuthConfig = false ) const
142  {
143  if ( expandAuthConfig && mDataSourceURI.contains( QLatin1String( "authcfg" ) ) )
144  {
145  QgsDataSourceUri uri( mDataSourceURI );
146  return uri.uri( expandAuthConfig );
147  }
148  else
149  {
150  return mDataSourceURI;
151  }
152  }
153 
159  void setUri( const QgsDataSourceUri &uri )
160  {
161  mDataSourceURI = uri.uri( true );
162  }
163 
170  {
171  return QgsDataSourceUri( mDataSourceURI );
172  }
173 
178  virtual QgsRectangle extent() const = 0;
179 
180 
185  virtual bool isValid() const = 0;
186 
187 
191  virtual void updateExtents()
192  {
193  // NOP by default
194  }
195 
196 
203  virtual bool setSubsetString( const QString &subset, bool updateFeatureCount = true )
204  {
205  // NOP by default
206  Q_UNUSED( subset )
207  Q_UNUSED( updateFeatureCount )
208  return false;
209  }
210 
211 
215  virtual bool supportsSubsetString() const { return false; }
216 
223  virtual QString subsetString() const
224  {
225  return QString();
226  }
227 
228 
237  virtual QStringList subLayers() const
238  {
239  return QStringList(); // Empty
240  }
241 
249  virtual QStringList subLayerStyles() const
250  {
251  return QStringList(); // Empty
252  }
253 
254 
258  virtual uint subLayerCount() const
259  {
260  return 0;
261  }
262 
263 
269  virtual void setLayerOrder( const QStringList &layers )
270  {
271  //prevent unused var warnings
272  if ( layers.count() < 1 )
273  {
274  return;
275  }
276  // NOOP
277  }
278 
279 
283  virtual void setSubLayerVisibility( const QString &name, bool vis )
284  {
285  //prevent unused var warnings
286  if ( name.isEmpty() || !vis )
287  {
288  return;
289  }
290  // NOOP
291  }
292 
293 
309  virtual QString name() const = 0;
310 
311 
324  virtual QString description() const = 0;
325 
326 
337  virtual QString fileVectorFilters() const
338  {
339  return QString();
340  }
341 
342 
353  virtual QString fileRasterFilters() const
354  {
355  return QString();
356  }
357 
364  virtual void reloadData();
365 
367  virtual QDateTime timestamp() const { return mTimestamp; }
368 
370  virtual QDateTime dataTimestamp() const { return QDateTime(); }
371 
377  virtual QgsError error() const { return mError; }
378 
383  virtual void invalidateConnections( const QString &connection ) { Q_UNUSED( connection ) }
384 
407  virtual bool enterUpdateMode() { return true; }
408 
426  virtual bool leaveUpdateMode() { return true; }
427 
434  void setProviderProperty( ProviderProperty property, const QVariant &value );
435 
442  void setProviderProperty( int property, const QVariant &value ); // SIP_SKIP
443 
450  QVariant providerProperty( ProviderProperty property, const QVariant &defaultValue = QVariant() ) const;
451 
458  QVariant providerProperty( int property, const QVariant &defaultValue ) const; // SIP_SKIP
459 
470  virtual void setListening( bool isListening );
471 
472 #ifndef SIP_RUN
473 
480  {
482  double lastRenderingTimeMs = -1;
483 
485  double maxRenderingTimeMs = MAXIMUM_LAYER_PREVIEW_TIME_MS;
486  };
487 #endif
488 
501  virtual bool renderInPreview( const QgsDataProvider::PreviewContext &context ); // SIP_SKIP
502 
511  virtual QgsLayerMetadata layerMetadata() const { return QgsLayerMetadata(); }
512 
521  virtual bool writeLayerMetadata( const QgsLayerMetadata &metadata ) { Q_UNUSED( metadata ) return false; }
522 
530  QgsCoordinateTransformContext transformContext() const SIP_SKIP;
531 
542  virtual void setTransformContext( const QgsCoordinateTransformContext &transformContext ) SIP_SKIP;
543 
550  static QString sublayerSeparator();
551 
552  signals:
553 
560  void fullExtentCalculated();
561 
574  void dataChanged();
575 
583  void notify( const QString &msg );
584 
585 
586  protected:
587 
591  QDateTime mTimestamp;
592 
595 
597  void appendError( const QgsErrorMessage &message ) { mError.append( message ); }
598 
600  void setError( const QgsError &error ) { mError = error;}
601 
602  private:
603 
608  QString mDataSourceURI;
609 
610  QMap< int, QVariant > mProviderProperties;
611 
613 
617  mutable QMutex mOptionsMutex;
618 
623  virtual void reloadProviderData() {}
624 };
625 
626 
627 #endif
virtual void setSubLayerVisibility(const QString &name, bool vis)
Set the visibility of the given sublayer name.
virtual bool setSubsetString(const QString &subset, bool updateFeatureCount=true)
Set the subset string used to create a subset of features in the layer.
A rectangle specified with double values.
Definition: qgsrectangle.h:41
virtual QString subsetString() const
Returns the subset definition string (typically sql) currently in use by the layer and used by the pr...
virtual void updateExtents()
Update the extents of the layer.
virtual QgsError error() const
Gets current status error.
virtual QString fileRasterFilters() const
Returns raster file filter string.
QDateTime mTimestamp
Timestamp of data in the moment when the data were loaded by provider.
virtual QStringList subLayers() const
Sub-layers handled by this provider, in order from bottom to top.
virtual uint subLayerCount() const
Returns the number of layers for the current data source.
Abstract base class for spatial data provider implementations.
const QgsCoordinateReferenceSystem & crs
DataCapability
Used in browser model to understand which items for which providers should be populated.
virtual QgsLayerMetadata layerMetadata() const
Returns layer metadata collected from the provider&#39;s source.
virtual QDateTime dataTimestamp() const
Current time stamp of data source.
#define SIP_SKIP
Definition: qgis_sip.h:126
void setUri(const QgsDataSourceUri &uri)
Set the data source specification.
virtual QString dataSourceUri(bool expandAuthConfig=false) const
Gets the data source specification.
QgsDataSourceUri uri() const
Gets the data source specification.
#define SIP_END
Definition: qgis_sip.h:189
void appendError(const QgsErrorMessage &message)
Add error message.
virtual void setLayerOrder(const QStringList &layers)
Reorder the list of layer names to be rendered by this provider (in order from bottom to top) ...
virtual bool supportsSubsetString() const
Returns true if the provider supports setting of subset strings.
QgsErrorMessage represents single error message.
Definition: qgserror.h:32
virtual void setDataSourceUri(const QString &uri)
Set the data source specification.
void append(const QString &message, const QString &tag)
Append new error message.
Definition: qgserror.cpp:39
Contains information about the context in which a coordinate transform is executed.
QgsCoordinateTransformContext transformContext
QString uri(bool expandAuthConfig=true) const
Returns the complete URI as a string.
A structured metadata store for a map layer.
Setting options for creating vector data providers.
virtual QDateTime timestamp() const
Time stamp of data source in the moment when data/metadata were loaded by provider.
QgsError is container for error messages (report).
Definition: qgserror.h:80
virtual QString fileVectorFilters() const
Returns vector file filter string.
void setError(const QgsError &error)
Sets error message.
This class represents a coordinate reference system (CRS).
QgsError mError
Error.
#define SIP_CONVERT_TO_SUBCLASS_CODE(code)
Definition: qgis_sip.h:172
virtual bool enterUpdateMode()
Enter update mode.
virtual QStringList subLayerStyles() const
Sub-layer styles for each sub-layer handled by this provider, in order from bottom to top...
virtual bool writeLayerMetadata(const QgsLayerMetadata &metadata)
Writes layer metadata to the underlying provider source.
Class for storing the component parts of a RDBMS data source URI (e.g.
virtual void invalidateConnections(const QString &connection)
Invalidate connections corresponding to specified name.
Stores settings related to the context in which a preview job runs.
ProviderProperty
Properties are used to pass custom configuration options into data providers.
Evaluate default values on provider side when calling QgsVectorDataProvider::defaultValue( int index ...
virtual bool leaveUpdateMode()
Leave update mode.