-
-
Notifications
You must be signed in to change notification settings - Fork 3k
/
qgsvectorlayerutils.h
346 lines (305 loc) · 15.7 KB
/
qgsvectorlayerutils.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
/***************************************************************************
qgsvectorlayerutils.h
---------------------
Date : October 2016
Copyright : (C) 2016 by Nyall Dawson
Email : nyall dot dawson at gmail dot com
***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#ifndef QGSVECTORLAYERUTILS_H
#define QGSVECTORLAYERUTILS_H
#include "qgis_core.h"
#include "qgsgeometry.h"
#include "qgsvectorlayerfeatureiterator.h"
#include "qgssymbollayerreference.h"
class QgsFeatureRenderer;
class QgsSymbolLayer;
/**
* \ingroup core
* \class QgsVectorLayerUtils
* \brief Contains utility methods for working with QgsVectorLayers.
*
* \since QGIS 3.0
*/
class CORE_EXPORT QgsVectorLayerUtils
{
public:
/**
* \ingroup core
* \class QgsDuplicateFeatureContext
* \brief Contains mainly the QMap with QgsVectorLayer and QgsFeatureIds do list all the duplicated features
*
* \since QGIS 3.0
*/
class CORE_EXPORT QgsDuplicateFeatureContext
{
public:
//! Constructor for QgsDuplicateFeatureContext
QgsDuplicateFeatureContext() = default;
/**
* Returns all the layers on which features have been duplicated
* \since QGIS 3.0
*/
QList<QgsVectorLayer *> layers() const;
/**
* Returns the duplicated features in the given layer
* \since QGIS 3.0
*/
QgsFeatureIds duplicatedFeatures( QgsVectorLayer *layer ) const;
private:
QMap<QgsVectorLayer *, QgsFeatureIds> mDuplicatedFeatures;
friend class QgsVectorLayerUtils;
/**
* To set info about duplicated features to the function feedback (layout and ids)
* \since QGIS 3.0
*/
void setDuplicatedFeatures( QgsVectorLayer *layer, const QgsFeatureIds &ids );
};
/**
* \ingroup core
* \class QgsFeatureData
* \brief Encapsulate geometry and attributes for new features, to be passed to createFeatures
* \see createFeatures()
* \since QGIS 3.6
*/
class CORE_EXPORT QgsFeatureData
{
public:
/**
* Constructs a new QgsFeatureData with given \a geometry and \a attributes
*/
QgsFeatureData( const QgsGeometry &geometry = QgsGeometry(), const QgsAttributeMap &attributes = QgsAttributeMap() );
//! Returns geometry
QgsGeometry geometry() const;
//! Returns attributes
QgsAttributeMap attributes() const;
private:
QgsGeometry mGeometry;
QgsAttributeMap mAttributes;
};
// SIP does not like "using", use legacy typedef
//! Alias for list of QgsFeatureData
typedef QList<QgsVectorLayerUtils::QgsFeatureData> QgsFeaturesDataList;
/**
* Create a feature iterator for a specified field name or expression.
* \param layer vector layer to retrieve values from
* \param fieldOrExpression field name or an expression string
* \param ok will be set to FALSE if field or expression is invalid, otherwise TRUE
* \param selectedOnly set to TRUE to get values from selected features only
* \returns feature iterator
* \since QGIS 3.0
*/
static QgsFeatureIterator getValuesIterator( const QgsVectorLayer *layer, const QString &fieldOrExpression, bool &ok, bool selectedOnly );
/**
* Fetches all values from a specified field name or expression.
* \param layer vector layer to retrieve values from
* \param fieldOrExpression field name or an expression string
* \param ok will be set to FALSE if field or expression is invalid, otherwise TRUE
* \param selectedOnly set to TRUE to get values from selected features only
* \param feedback optional feedback object to allow cancellation
* \returns list of fetched values
* \see getDoubleValues
* \since QGIS 3.0
*/
static QList< QVariant > getValues( const QgsVectorLayer *layer, const QString &fieldOrExpression, bool &ok, bool selectedOnly = false, QgsFeedback *feedback = nullptr );
/**
* Fetches all double values from a specified field name or expression. Null values or
* invalid expression results are skipped.
* \param layer vector layer to retrieve values from
* \param fieldOrExpression field name or an expression string evaluating to a double value
* \param ok will be set to FALSE if field or expression is invalid, otherwise TRUE
* \param selectedOnly set to TRUE to get values from selected features only
* \param nullCount optional pointer to integer to store number of null values encountered in
* \param feedback optional feedback object to allow cancellation
* \returns list of fetched values
* \see getValues
* \since QGIS 3.0
*/
static QList< double > getDoubleValues( const QgsVectorLayer *layer, const QString &fieldOrExpression, bool &ok, bool selectedOnly = false, int *nullCount = nullptr, QgsFeedback *feedback = nullptr );
/**
* Returns TRUE if the specified value already exists within a field. This method can be used to test for uniqueness
* of values inside a layer's attributes. An optional list of ignored feature IDs can be provided, if so, any features
* with IDs within this list are ignored when testing for existence of the value.
* \see createUniqueValue()
*/
static bool valueExists( const QgsVectorLayer *layer, int fieldIndex, const QVariant &value, const QgsFeatureIds &ignoreIds = QgsFeatureIds() );
/**
* Returns a new attribute value for the specified field index which is guaranteed to be unique. The optional seed
* value can be used as a basis for generated values.
* \see valueExists()
*/
static QVariant createUniqueValue( const QgsVectorLayer *layer, int fieldIndex, const QVariant &seed = QVariant() );
/**
* Returns a new attribute value for the specified field index which is guaranteed to
* be unique within regard to \a existingValues.
* The optional seed value can be used as a basis for generated values.
* \since QGIS 3.6
*/
static QVariant createUniqueValueFromCache( const QgsVectorLayer *layer, int fieldIndex, const QSet<QVariant> &existingValues, const QVariant &seed = QVariant() );
/**
* Tests an attribute value to check whether it passes all constraints which are present on the corresponding field.
* Returns TRUE if the attribute value is valid for the field. Any constraint failures will be reported in the errors argument.
* If the strength or origin parameter is set then only constraints with a matching strength/origin will be checked.
*/
static bool validateAttribute( const QgsVectorLayer *layer, const QgsFeature &feature, int attributeIndex, QStringList &errors SIP_OUT,
QgsFieldConstraints::ConstraintStrength strength = QgsFieldConstraints::ConstraintStrengthNotSet,
QgsFieldConstraints::ConstraintOrigin origin = QgsFieldConstraints::ConstraintOriginNotSet );
/**
* Tests an attribute \a value for type compatibility, i.e. checks whether it can be converted
* to the \a destinationType.
* NULL values (and QVariant invalid values because they are usually converted to NULLs) are considered valid.
*
* \see validateAttribute()
* \since QGIS 3.14
*/
static bool canConvert( const QVariant &value, const QVariant::Type destinationType );
/**
* Creates a new feature ready for insertion into a layer. Default values and constraints
* (e.g., unique constraints) will automatically be handled. An optional attribute map can be
* passed for the new feature to copy as many attribute values as possible from the map,
* assuming that they respect the layer's constraints. Note that the created feature is not
* automatically inserted into the layer.
* \see createFeatures()
*/
static QgsFeature createFeature( const QgsVectorLayer *layer,
const QgsGeometry &geometry = QgsGeometry(),
const QgsAttributeMap &attributes = QgsAttributeMap(),
QgsExpressionContext *context = nullptr );
/**
* Creates a set of new features ready for insertion into a layer. Default values and constraints
* (e.g., unique constraints) will automatically be handled. Note that the created features are not
* automatically inserted into the layer.
* \see createFeature()
* \since QGIS 3.6
*/
static QgsFeatureList createFeatures( const QgsVectorLayer *layer,
const QgsFeaturesDataList &featuresData,
QgsExpressionContext *context = nullptr );
/**
* Duplicates a feature and it's children (one level deep). It calls CreateFeature, so
* default values and constraints (e.g., unique constraints) will automatically be handled.
* The duplicated feature will be automatically inserted into the layer.
* \a depth the higher this number the deeper the level - With depth > 0 the children of the feature are not duplicated
* \a duplicateFeatureContext stores all the layers and the featureids of the duplicated features (incl. children)
* \since QGIS 3.0
*/
static QgsFeature duplicateFeature( QgsVectorLayer *layer, const QgsFeature &feature, QgsProject *project, int depth, QgsDuplicateFeatureContext &duplicateFeatureContext SIP_OUT );
/**
* Gets the feature source from a QgsVectorLayer pointer.
* This method is thread-safe but will block the main thread for execution. Executing it from the main
* thread is safe too.
* This should be used in scenarios, where a ``QWeakPointer<QgsVectorLayer>`` is kept in a thread
* and features should be fetched from this layer. Using the layer directly is not safe to do.
* The result will be ``NULLPTR`` if the layer has been deleted.
* If \a feedback is specified, the call will return if the feedback is canceled.
* Returns a new feature source for the \a layer. The source may be NULLPTR if the layer no longer
* exists or if the feedback is canceled.
*
* \note Requires Qt >= 5.10 to make use of the thread-safe implementation
* \since QGIS 3.4
*/
static std::unique_ptr<QgsVectorLayerFeatureSource> getFeatureSource( QPointer<QgsVectorLayer> layer, QgsFeedback *feedback = nullptr ) SIP_SKIP;
/**
* Matches the attributes in \a feature to the specified \a fields.
*
* This causes the attributes contained within the given \a feature to be rearranged (or in
* some cases dropped) in order to match the fields and order indicated by \a fields.
*
* The exact behavior depends on whether or not \a feature has a valid fields container
* set (see QgsFeature::fields()). If a fields container is set, then the names of the
* feature's fields are matched to \a fields. In this case attributes from \a feature
* will be rearranged or dropped in order to match the field names from \a fields.
*
* If the \a feature does not have a valid fields container set, then the feature's attributes
* are simply truncated to match the number of fields present in \a fields (or if
* less attributes are present in \a feature than in \a fields, the feature's attributes
* are padded with NULL values to match the required length).
* Finally, the feature's fields are set to \a fields.
*
* \since QGIS 3.4
*/
static void matchAttributesToFields( QgsFeature &feature, const QgsFields &fields );
/**
* Converts input \a feature to be compatible with the given \a layer.
*
* This function returns a new list of transformed features compatible with the input
* layer, note that the number of features returned might be greater than one when
* converting a multi part geometry to single part
*
* The following operations will be performed to convert the input features:
*
* - convert single geometries to multi part
* - drop additional attributes
* - drop geometry if layer is geometry-less
* - add missing attribute fields
* - add back M/Z values (initialized to 0)
* - drop Z/M
* - convert multi part geometries to single part
*
* \since QGIS 3.4
*/
static QgsFeatureList makeFeatureCompatible( const QgsFeature &feature, const QgsVectorLayer *layer );
/**
* Converts input \a features to be compatible with the given \a layer.
*
* This function returns a new list of transformed features compatible with the input
* layer, note that the number of features returned might be greater than the number
* of input features.
*
* The following operations will be performed to convert the input features:
*
* - convert single geometries to multi part
* - drop additional attributes
* - drop geometry if layer is geometry-less
* - add missing attribute fields
* - add back M/Z values (initialized to 0)
* - drop Z/M
* - convert multi part geometries to single part
*
* \since QGIS 3.4
*/
static QgsFeatureList makeFeaturesCompatible( const QgsFeatureList &features, const QgsVectorLayer *layer );
/**
* \return true if the \param feature field at index \param fieldIndex from \param layer
* is editable, false if the field is readonly
*
* \since QGIS 3.10
*/
static bool fieldIsEditable( const QgsVectorLayer *layer, int fieldIndex, const QgsFeature &feature );
/**
* Returns masks defined in labeling options of a layer.
* The returned type associates a labeling rule identifier to a set of layers that are masked given by their layer id,
* and a set of masked symbol layers if associated to each masked layers.
* \note Not available in Python bindings
* \since QGIS 3.12
*/
static QHash<QString, QHash<QString, QSet<QgsSymbolLayerId>>> labelMasks( const QgsVectorLayer * ) SIP_SKIP;
/**
* Returns all masks that may be defined on symbol layers for a given vector layer.
* The hash key is a layer id.
* The hash value is the set of symbol layers masked in the key's layer.
* \note Not available in Python bindings
* \since QGIS 3.12
*/
static QHash<QString, QSet<QgsSymbolLayerId>> symbolLayerMasks( const QgsVectorLayer * ) SIP_SKIP;
/**
* \returns a descriptive string for a \a feature, suitable for displaying to the user.
* The definition is taken from the ``displayExpression`` property of \a layer.
* \since QGIS 3.12
*/
static QString getFeatureDisplayString( const QgsVectorLayer *layer, const QgsFeature &feature );
/**
* \returns TRUE if at least one feature of the \a fids on \a layer is connected as parent in at
* least one composition relation of the \a project or contains joins, where cascade delete is set.
* Details about cascading effects will be written to \a context.
* \since QGIS 3.14
*/
static bool impactsCascadeFeatures( const QgsVectorLayer *layer, const QgsFeatureIds &fids, const QgsProject *project, QgsDuplicateFeatureContext &context SIP_OUT );
};
#endif // QGSVECTORLAYERUTILS_H