File: qgspallabeling.sip

package info (click to toggle)
qgis 2.18.28%2Bdfsg-2
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 1,007,948 kB
  • sloc: cpp: 671,774; python: 158,539; xml: 35,690; ansic: 8,346; sh: 1,766; perl: 1,669; sql: 999; yacc: 836; lex: 461; makefile: 292
file content (991 lines) | stat: -rw-r--r-- 36,963 bytes parent folder | download
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
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
// QMap<QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined*> is implemented as a Python dictionary.
%MappedType QMap<QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined*>
{
%TypeHeaderCode
#include <qmap.h>
#include <qgspallabeling.h>
#include <qgsdatadefined.h>
%End
%ConvertFromTypeCode
    // Create the dictionary.
    PyObject *d = PyDict_New();
    if (!d)
        return NULL;
    // Set the dictionary elements.
    QMap<QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined*>::const_iterator i = sipCpp->constBegin();
    while (i != sipCpp->constEnd())
    {
      QgsDataDefined *t = i.value();
      PyObject *kobj = sipConvertFromEnum(i.key(), sipType_QgsPalLayerSettings_DataDefinedProperties);
      PyObject *tobj = sipConvertFromType(t, sipType_QgsDataDefined, sipTransferObj);
      if (kobj == NULL || tobj == NULL || PyDict_SetItem(d, kobj, tobj) < 0)
      {
	Py_DECREF(d);
	if (kobj)
	{
	  Py_DECREF(kobj);
	}
	if (tobj)
	{
	  Py_DECREF(tobj);
	}
	else
	{
	  delete t;
	}
	return NULL;
      }
      Py_DECREF(kobj);
      Py_DECREF(tobj);
      ++i;
    }
    return d;
%End
%ConvertToTypeCode
    PyObject *kobj, *tobj;
    SIP_SSIZE_T i = 0;
    // Check the type if that is all that is required.
    if (sipIsErr == NULL)
    {
        if (!PyDict_Check(sipPy))
            return 0;
        while (PyDict_Next(sipPy, &i, &kobj, &tobj))
            if (!sipCanConvertToType(tobj, sipType_QgsDataDefined, SIP_NOT_NONE))
                return 0;
        return 1;
    }
    QMap<QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined*> *qm = new QMap<QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined*>;

    while (PyDict_Next(sipPy, &i, &kobj, &tobj))
    {
        int state, k = SIPLong_AsLong(kobj);
        QgsDataDefined *t = reinterpret_cast<QgsDataDefined *>(sipConvertToType(tobj, sipType_QgsDataDefined, sipTransferObj, SIP_NOT_NONE, &state, sipIsErr));

        if (*sipIsErr)
        {
            sipReleaseType(t, sipType_QgsDataDefined, state);
            delete qm;
            return 0;
        }
        qm->insert(QgsPalLayerSettings::DataDefinedProperties(k), t);
        sipReleaseType(t, sipType_QgsDataDefined, state);
    }

    *sipCppPtr = qm;

    return sipGetState(sipTransferObj);
%End
};

class QgsPalLayerSettings
{
%TypeHeaderCode
#include <qgspallabeling.h>
#include <qgsdiagramrendererv2.h>
%End
  public:
    QgsPalLayerSettings();
    QgsPalLayerSettings( const QgsPalLayerSettings& s );
    ~QgsPalLayerSettings();

    //! @note added in 2.4
    static QgsPalLayerSettings fromLayer( QgsVectorLayer* layer );

    /** Placement modes which determine how label candidates are generated for a feature.
     */
    //TODO QGIS 3.0 - move to QgsLabelingEngineV2
    enum Placement
    {
      AroundPoint, /**< Arranges candidates in a circle around a point (or centroid of a polygon). Applies to point or polygon layers only.*/
      OverPoint, /**  Arranges candidates over a point (or centroid of a polygon), or at a preset offset from the point. Applies to point or polygon layers only.*/
      Line, /**< Arranges candidates parallel to a generalised line representing the feature or parallel to a polygon's perimeter. Applies to line or polygon layers only. */
      Curved, /** Arranges candidates following the curvature of a line feature. Applies to line layers only.*/
      Horizontal, /**< Arranges horizontal candidates scattered throughout a polygon feature. Applies to polygon layers only.*/
      Free, /**< Arranges candidates scattered throughout a polygon feature. Candidates are rotated to respect the polygon's orientation. Applies to polygon layers only.*/
      OrderedPositionsAroundPoint, /**< Candidates are placed in predefined positions around a point. Peference is given to positions with greatest cartographic appeal, eg top right, bottom right, etc. Applies to point layers only.*/
      PerimeterCurved, /** Arranges candidates following the curvature of a polygon's boundary. Applies to polygon layers only.*/
    };

    //! Positions for labels when using the QgsPalLabeling::OrderedPositionsAroundPoint placement mode
    //TODO QGIS 3.0 - move to QgsLabelingEngineV2
    enum PredefinedPointPosition
    {
      TopLeft, //!< Label on top-left of point
      TopSlightlyLeft, //! Label on top of point, slightly left of center
      TopMiddle, //!< Label directly above point
      TopSlightlyRight, //! Label on top of point, slightly right of center
      TopRight, //!< Label on top-right of point
      MiddleLeft, //!< Label on left of point
      MiddleRight, //!< Label on right of point
      BottomLeft, //!< Label on bottom-left of point
      BottomSlightlyLeft, //! Label below point, slightly left of center
      BottomMiddle, //!< Label directly below point
      BottomSlightlyRight, //! Label below point, slightly right of center
      BottomRight, //!< Label on bottom right of point
    };

    //! Behaviour modifier for label offset and distance, only applies in some
    //! label placement modes.
    //TODO QGIS 3.0 - move to QgsLabelingEngineV2
    enum OffsetType
    {
      FromPoint, //!< Offset distance applies from point geometry
      FromSymbolBounds, //!< Offset distance applies from rendered symbol bounds
    };

    /** Line placement flags, which control how candidates are generated for a linear feature.
     */
    //TODO QGIS 3.0 - move to QgsLabelingEngineV2, rename to LinePlacementFlag, use Q_DECLARE_FLAGS to make
    //LinePlacementFlags type, and replace use of pal::LineArrangementFlag
    enum LinePlacementFlags
    {
      OnLine,          /**< Labels can be placed directly over a line feature.*/
      AboveLine,       /**< Labels can be placed above a line feature. Unless MapOrientation is also specified this mode
                            respects the direction of the line feature, so a line from right to left labels will have labels
                            placed placed below the line feature. */
      BelowLine,       /**< Labels can be placed below a line feature. Unless MapOrientation is also specified this mode
                            respects the direction of the line feature, so a line from right to left labels will have labels
                            placed placed above the line feature. */
      MapOrientation,  /**< Signifies that the AboveLine and BelowLine flags should respect the map's orientation rather
                            than the feature's orientation. Eg, AboveLine will always result in label's being placed
                            above a line, regardless of the line's direction. */
    };

    enum QuadrantPosition
    {
      QuadrantAboveLeft,
      QuadrantAbove,
      QuadrantAboveRight,
      QuadrantLeft,
      QuadrantOver,
      QuadrantRight,
      QuadrantBelowLeft,
      QuadrantBelow,
      QuadrantBelowRight
    };

    enum UpsideDownLabels
    {
      Upright, /*!< upside-down labels (90 <= angle < 270) are shown upright */
      ShowDefined, /*!< show upside down when rotation is layer- or data-defined */
      ShowAll /*!< show upside down for all labels, including dynamic ones */
    };

    enum DirectionSymbols
    {
      SymbolLeftRight, /*!< place direction symbols on left/right of label */
      SymbolAbove, /*!< place direction symbols on above label */
      SymbolBelow /*!< place direction symbols on below label */
    };

    enum MultiLineAlign
    {
      MultiLeft,
      MultiCenter,
      MultiRight,
      MultiFollowPlacement /*!< Alignment follows placement of label, eg labels to the left of a feature
                               will be drawn with right alignment*/
    };

    /** Valid obstacle types, which affect how features within the layer will act as obstacles
     * for labels.
     */
    //TODO QGIS 3.0 - Move to QgsLabelingEngineV2
    enum ObstacleType
    {
      PolygonInterior, /*!< avoid placing labels over interior of polygon (prefer placing labels totally
       outside or just slightly inside polygon) */
      PolygonBoundary, /*!< avoid placing labels over boundary of polygon (prefer placing outside or
       completely inside polygon) */
      PolygonWhole /*!< avoid placing labels over ANY part of polygon. Where PolygonInterior will prefer
       to place labels with the smallest area of intersection between the label and the polygon,
       PolygonWhole will penalise any label which intersects with the polygon by an equal amount, so that
       placing labels over any part of the polygon is avoided.*/
    };

    enum ShapeType
    {
      ShapeRectangle,
      ShapeSquare,
      ShapeEllipse,
      ShapeCircle,
      ShapeSVG
    };

    enum SizeType
    {
      SizeBuffer,
      SizeFixed,
      SizePercent
    };

    enum RotationType
    {
      RotationSync,
      RotationOffset,
      RotationFixed
    };

    /** Units used for option sizes, before being converted to rendered sizes */
    enum SizeUnit
    {
      Points,
      MM,
      MapUnits,
      Percent
    };

    enum ShadowType
    {
      ShadowLowest,
      ShadowText,
      ShadowBuffer,
      ShadowShape
    };

    // update mDataDefinedNames QMap in constructor when adding/deleting enum value
    enum DataDefinedProperties
    {
      // text style
      Size,
      Bold,
      Italic,
      Underline,
      Color,
      Strikeout,
      Family,
      FontStyle,
      FontSizeUnit,
      FontTransp,
      FontCase,
      FontLetterSpacing,
      FontWordSpacing,
      FontBlendMode,

      // text formatting
      MultiLineWrapChar,
      MultiLineHeight,
      MultiLineAlignment,
      DirSymbDraw,
      DirSymbLeft,
      DirSymbRight,
      DirSymbPlacement,
      DirSymbReverse,
      NumFormat,
      NumDecimals,
      NumPlusSign,

      // text buffer
      BufferDraw,
      BufferSize,
      BufferUnit,
      BufferColor,
      BufferTransp,
      BufferJoinStyle,
      BufferBlendMode,

      // background
      ShapeDraw,
      ShapeKind,
      ShapeSVGFile,
      ShapeSizeType,
      ShapeSizeX,
      ShapeSizeY,
      ShapeSizeUnits,
      ShapeRotationType,
      ShapeRotation,
      ShapeOffset,
      ShapeOffsetUnits,
      ShapeRadii,
      ShapeRadiiUnits,
      ShapeTransparency,
      ShapeBlendMode,
      ShapeFillColor,
      ShapeBorderColor,
      ShapeBorderWidth,
      ShapeBorderWidthUnits,
      ShapeJoinStyle,

      // drop shadow
      ShadowDraw,
      ShadowUnder,
      ShadowOffsetAngle,
      ShadowOffsetDist,
      ShadowOffsetUnits,
      ShadowRadius,
      ShadowRadiusUnits,
      ShadowTransparency,
      ShadowScale,
      ShadowColor,
      ShadowBlendMode,

      // placement
      CentroidWhole,
      OffsetQuad,
      OffsetXY,
      OffsetUnits,
      LabelDistance,
      DistanceUnits,
      OffsetRotation,
      CurvedCharAngleInOut,
      // (data defined only)
      PositionX, //x-coordinate data defined label position
      PositionY, //y-coordinate data defined label position
      Hali, //horizontal alignment for data defined label position (Left, Center, Right)
      Vali, //vertical alignment for data defined label position (Bottom, Base, Half, Cap, Top)
      Rotation, //data defined rotation
      RepeatDistance,
      RepeatDistanceUnit,
      Priority,
      PredefinedPositionOrder,

      // rendering
      ScaleVisibility,
      MinScale,
      MaxScale,
      FontLimitPixel,
      FontMinPixel,
      FontMaxPixel,
      IsObstacle,
      ObstacleFactor,
      ZIndex,

      // (data defined only)
      Show,
      AlwaysShow
    };

    // whether to label this layer
    bool enabled;

    /** Whether to draw labels for this layer. For some layers it may be desirable
     * to register their features as obstacles for other labels without requiring
     * labels to be drawn for the layer itself. In this case drawLabels can be set
     * to false and obstacle set to true, which will result in the layer acting
     * as an obstacle but having no labels of its own.
     * @note added in QGIS 2.12
     */
    bool drawLabels;

    //-- text style

    QString fieldName;

    /** Is this label made from a expression string eg FieldName || 'mm'
      */
    bool isExpression;

    /** Returns the QgsExpression for this label settings.
      */
    QgsExpression* getLabelExpression();

    QFont textFont;
    QString textNamedStyle;
    bool fontSizeInMapUnits; //true if font size is in map units (otherwise in points)
    QgsMapUnitScale fontSizeMapUnitScale; // scale range for map units for font size
    QColor textColor;
    int textTransp;
    QPainter::CompositionMode blendMode;
    QColor previewBkgrdColor;

    //! Substitution collection for automatic text substitution with labels
    QgsStringReplacementCollection substitutions;
    //! True if substitutions should be applied
    bool useSubstitutions;

    //-- text formatting

    QString wrapChar;
    double multilineHeight; //0.0 to 10.0, leading between lines as multiplyer of line height
    MultiLineAlign multilineAlign; // horizontal alignment of multi-line labels

    // Adds '<' or '>', or user-defined symbol to the label string pointing to the
    // direction of the line / polygon ring
    // Works only if Placement == Line
    bool addDirectionSymbol;
    QString leftDirectionSymbol;
    QString rightDirectionSymbol;
    DirectionSymbols placeDirectionSymbol; // whether to place left/right, above or below label
    bool reverseDirectionSymbol;

    bool formatNumbers;
    int decimals;
    bool plusSign;

    //-- text buffer

    bool bufferDraw;
    double bufferSize; // buffer size
    bool bufferSizeInMapUnits; //true if buffer is in map units (otherwise in mm)
    QgsMapUnitScale bufferSizeMapUnitScale; // scale range for map units for buffer size
    QColor bufferColor;
    bool bufferNoFill; //set interior of buffer to 100% transparent
    int bufferTransp;
    Qt::PenJoinStyle bufferJoinStyle;
    QPainter::CompositionMode bufferBlendMode;

    //-- shape background

    bool shapeDraw;
    ShapeType shapeType;
    QString shapeSVGFile;
    SizeType shapeSizeType;
    QPointF shapeSize;
    SizeUnit shapeSizeUnits;
    QgsMapUnitScale shapeSizeMapUnitScale;
    RotationType shapeRotationType;
    double shapeRotation;
    QPointF shapeOffset;
    SizeUnit shapeOffsetUnits;
    QgsMapUnitScale shapeOffsetMapUnitScale;
    QPointF shapeRadii;
    SizeUnit shapeRadiiUnits;
    QgsMapUnitScale shapeRadiiMapUnitScale;
    int shapeTransparency;
    QPainter::CompositionMode shapeBlendMode;
    QColor shapeFillColor;
    QColor shapeBorderColor;
    double shapeBorderWidth;
    SizeUnit shapeBorderWidthUnits;
    QgsMapUnitScale shapeBorderWidthMapUnitScale;
    Qt::PenJoinStyle shapeJoinStyle;

    //-- drop shadow

    bool shadowDraw;
    ShadowType shadowUnder;
    int shadowOffsetAngle;
    double shadowOffsetDist;
    SizeUnit shadowOffsetUnits;
    QgsMapUnitScale shadowOffsetMapUnitScale;
    bool shadowOffsetGlobal;
    double shadowRadius;
    SizeUnit shadowRadiusUnits;
    QgsMapUnitScale shadowRadiusMapUnitScale;
    bool shadowRadiusAlphaOnly;
    int shadowTransparency;
    int shadowScale;
    QColor shadowColor;
    QPainter::CompositionMode shadowBlendMode;

    //-- placement

    Placement placement;
    unsigned int placementFlags;

    bool centroidWhole; // whether centroid calculated from whole or visible polygon
    bool centroidInside; // whether centroid-point calculated must be inside polygon

    /** Ordered list of predefined label positions for points. Positions earlier
     * in the list will be prioritised over later positions. Only used when the placement
     * is set to QgsPalLayerSettings::OrderedPositionsAroundPoint.
     * @note not available in Python bindings
     */
    //QVector< QgsPalLayerSettings::PredefinedPointPosition > predefinedPositionOrder;

    /** True if only labels which completely fit within a polygon are allowed.
     */
    bool fitInPolygonOnly;
    double dist; // distance from the feature (in mm)
    bool distInMapUnits; //true if distance is in map units (otherwise in mm)
    QgsMapUnitScale distMapUnitScale;
    //! Offset type for layer (only applies in certain placement modes)
    OffsetType offsetType;

    double repeatDistance;
    SizeUnit repeatDistanceUnit;
    QgsMapUnitScale repeatDistanceMapUnitScale;

    // offset labels of point/centroid features default to center
    // move label to quadrant: left/down, don't move, right/up (-1, 0, 1)
    QuadrantPosition quadOffset;

    double xOffset; // offset from point in mm or map units
    double yOffset; // offset from point in mm or map units
    bool labelOffsetInMapUnits; //true if label offset is in map units (otherwise in mm)
    QgsMapUnitScale labelOffsetMapUnitScale;
    double angleOffset; // rotation applied to offset labels
    bool preserveRotation; // preserve predefined rotation data during label pin/unpin operations

    double maxCurvedCharAngleIn; // maximum angle between inside curved label characters (defaults to 20.0, range 20.0 to 60.0)
    double maxCurvedCharAngleOut; // maximum angle between outside curved label characters (defaults to -20.0, range -20.0 to -95.0)

    int priority; // 0 = low, 10 = high

    //-- rendering

    bool scaleVisibility;
    int scaleMin;
    int scaleMax;

    bool fontLimitPixelSize; // true is label should be limited by fontMinPixelSize/fontMaxPixelSize
    int fontMinPixelSize; // minimum pixel size for showing rendered map unit labels (1 - 1000)
    int fontMaxPixelSize; // maximum pixel size for showing rendered map unit labels (1 - 10000)

    bool displayAll;  // if true, all features will be labelled even though overlaps occur
    UpsideDownLabels upsidedownLabels; // whether, or how, to show upsidedown labels

    bool labelPerPart; // whether to label every feature's part or only the biggest one
    bool mergeLines;

    bool limitNumLabels; // whether to limit the number of labels to be drawn
    int maxNumLabels; // maximum number of labels to be drawn

    double minFeatureSize; // minimum feature size to be labelled (in mm)
    bool obstacle; // whether features for layer are obstacles to labels of other layers

    /** Obstacle factor, where 1.0 = default, < 1.0 more likely to be covered by labels,
     * > 1.0 less likely to be covered
     */
    double obstacleFactor;

    /** Controls how features act as obstacles for labels
     */
    ObstacleType obstacleType;

    //! Z-Index of label, where labels with a higher z-index are rendered on top of labels with a lower z-index
    double zIndex;

    //-- scale factors
    double vectorScaleFactor; //scale factor painter units->pixels
    double rasterCompressFactor; //pixel resolution scale factor

    // called from register feature hook
    void calculateLabelSize( const QFontMetricsF* fm, QString text, double& labelX, double& labelY, QgsFeature* f = 0, QgsRenderContext* context = 0 );

    /** Register a feature for labelling.
     * @param f feature to label
     * @param context render context. The QgsExpressionContext contained within the render context
     * must have already had the feature and fields sets prior to calling this method.
     * @param labelFeature if using QgsLabelingEngineV2, this will receive the label feature. Not available
     * in Python bindings.
     * @param obstacleGeometry optional obstacle geometry, if a different geometry to the feature's geometry
     * should be used as an obstacle for labels (eg, if the feature has been rendered with an offset point
     * symbol, the obstacle geometry should represent the bounds of the offset symbol). If not set,
     * the feature's original geometry will be used as an obstacle for labels. Not available
     * in Python bindings.
     */
    void registerFeature( QgsFeature& f, QgsRenderContext& context );

    void readFromLayer( QgsVectorLayer* layer );
    void writeToLayer( QgsVectorLayer* layer );

    /** Read settings from a DOM element
     * @note added in 2.12
     */
    void readXml( QDomElement& elem );

    /** Write settings into a DOM element
     * @note added in 2.12
     */
    QDomElement writeXml( QDomDocument& doc );

    /** Get a data defined property pointer
     * @note helpful for Python access
     */
    QgsDataDefined* dataDefinedProperty( QgsPalLayerSettings::DataDefinedProperties p );

    /** Set a property as data defined
     * @note helpful for Python access
     */
    void setDataDefinedProperty( QgsPalLayerSettings::DataDefinedProperties p,
                                 bool active, bool useExpr, const QString& expr, const QString& field );

    /** Set a property to static instead data defined */
    void removeDataDefinedProperty( QgsPalLayerSettings::DataDefinedProperties p );

    /** Clear all data-defined properties
     * @note added in QGIS 2.12
     */
    void removeAllDataDefinedProperties();

    /** Convert old property value to new one as delimited values
     * @note not available in python bindings; as temporary solution until refactoring of project settings
     */
    QString updateDataDefinedString( const QString& value );

    /** Get property value as separate values split into Qmap
     * @note not available in python bindings
     */
    QMap<QString, QString> dataDefinedMap( QgsPalLayerSettings::DataDefinedProperties p ) const;

    /** Get data defined property value from expression string or attribute field name
     * @returns value inside QVariant
     * @note not available in python bindings
     */
    //QVariant dataDefinedValue( QgsPalLayerSettings::DataDefinedProperties p, QgsFeature& f, const QgsFields& fields,
    //                           const QgsExpressionContext* context = 0 ) const;

    /** Get data defined property value from expression string or attribute field name
     * @returns true/false whether result is null or invalid
     * @note not available in python bindings
     */
    //bool dataDefinedEvaluate( QgsPalLayerSettings::DataDefinedProperties p, QVariant& exprVal, const QgsExpressionContext* context = 0 ) const;

    /** Whether data definition is active
     */
    bool dataDefinedIsActive( QgsPalLayerSettings::DataDefinedProperties p ) const;

    /** Whether data definition is set to use an expression
     */
    bool dataDefinedUseExpression( QgsPalLayerSettings::DataDefinedProperties p ) const;

    /** Map of current data defined properties
     *
     * Pointers to QgsDataDefined should never be null, the pointers are owned by this class
     */
    QMap< QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined* > dataDefinedProperties;


    /** Calculates pixel size (considering output size should be in pixel or map units, scale factors and optionally oversampling)
     * @param size size to convert
     * @param c rendercontext
     * @param unit SizeUnit enum value of size
     * @param rasterfactor whether to consider oversampling
     * @param mapUnitScale a mapUnitScale clamper
     * @return font pixel size
     */
    int sizeToPixel( double size, const QgsRenderContext& c, SizeUnit unit, bool rasterfactor = false, const QgsMapUnitScale& mapUnitScale = QgsMapUnitScale() ) const;

    /** Calculates size (considering output size should be in pixel or map units, scale factors and optionally oversampling)
     * @param size size to convert
     * @param c rendercontext
     * @param unit SizeUnit enum value of size
     * @param rasterfactor whether to consider oversampling
     * @param mapUnitScale a mapUnitScale clamper
     * @return size that will render, as double
     */
    double scaleToPixelContext( double size, const QgsRenderContext& c, SizeUnit unit, bool rasterfactor = false, const QgsMapUnitScale& mapUnitScale = QgsMapUnitScale() ) const;

    /** Map of data defined enum to names and old-style indecies
     * The QPair contains a new string for layer property key, and a reference to old-style numeric key (< QGIS 2.0)
     * @note not available in python bindings;
     */
    // QMap<QgsPalLayerSettings::DataDefinedProperties, QPair<QString, int> > dataDefinedNames() const;

    // temporary stuff: set when layer gets prepared or labeled
    QgsFeature* mCurFeat;
    QgsFields mCurFields;
    int fieldIndex;
    const QgsMapToPixel* xform;
    const QgsCoordinateTransform* ct;

    QgsPoint ptZero;
    QgsPoint ptOne;
    QgsGeometry* extentGeom;
    int mFeaturesToLabel; // total features that will probably be labeled, may be less (figured before PAL)
    int mFeatsSendingToPal; // total features tested for sending into PAL (relative to maxNumLabels)
    int mFeatsRegPal; // number of features registered in PAL, when using limitNumLabels

    QString mTextFontFamily;
    bool mTextFontFound;

    bool showingShadowRects; // whether to show debug rectangles for drop shadows
};

class QgsLabelCandidate
{
%TypeHeaderCode
#include <qgspallabeling.h>
%End

  public:
    QgsLabelCandidate( const QRectF& r, double c );

    QRectF rect;
    double cost;
};

/** \ingroup core
  * Maintains current state of more grainular and temporal values when creating/painting
  * component parts of an individual label (e.g. buffer, background, shadow, etc.).
  */
class QgsLabelComponent
{
%TypeHeaderCode
#include <qgspallabeling.h>
%End

  public:
    QgsLabelComponent();

    // methods

    QString text() const;
    void setText( const QString& text );

    const QgsPoint& origin() const;
    void setOrigin( const QgsPoint& point );

    bool useOrigin() const;
    void setUseOrigin( const bool use );

    double rotation() const;
    void setRotation( const double rotation );

    double rotationOffset() const;
    void setRotationOffset( const double rotation );

    bool useRotation() const;
    void setUseRotation( const bool use );

    const QgsPoint& center() const;
    void setCenter( const QgsPoint& point );

    bool useCenter() const;
    void setUseCenter( const bool use );

    const QgsPoint& size() const;
    void setSize( const QgsPoint& point );

    const QgsPoint& offset() const;
    void setOffset( const QgsPoint& point );

    const QPicture* picture() const;
    void setPicture( QPicture* picture );

    double pictureBuffer() const;
    void setPictureBuffer( const double buffer );

    double dpiRatio() const;
    void setDpiRatio( const double ratio );
};


/**
 * Class that stores computed placement from labeling engine.
 * @note added in 2.4
 */
class QgsLabelingResults
{
%TypeHeaderCode
#include <qgspallabeling.h>
%End

  public:
    QgsLabelingResults();
    ~QgsLabelingResults();

    //! return infos about labels at a given (map) position
    QList<QgsLabelPosition> labelsAtPosition( const QgsPoint& p ) const;
    //! return infos about labels within a given (map) rectangle
    QList<QgsLabelPosition> labelsWithinRect( const QgsRectangle& r ) const;

  private:
    QgsLabelingResults( const QgsLabelingResults& );
};


class QgsPalLabeling : QgsLabelingEngineInterface
{
%TypeHeaderCode
#include <qgspallabeling.h>
%End

  public:
    enum DrawLabelType
    {
      LabelText,
      LabelBuffer,
      LabelShape,
      LabelSVG,
      LabelShadow
    };

    QgsPalLabeling();
    ~QgsPalLabeling();

    //! @deprecated since 2.12 - if direct access to QgsPalLayerSettings is necessary, use QgsPalLayerSettings::fromLayer()
    QgsPalLayerSettings& layer( const QString& layerName ) /Deprecated/;

    void numCandidatePositions( int& candPoint, int& candLine, int& candPolygon );
    void setNumCandidatePositions( int candPoint, int candLine, int candPolygon );

    enum Search { Chain, Popmusic_Tabu, Popmusic_Chain, Popmusic_Tabu_Chain, Falp };

    void setSearchMethod( Search s );
    Search searchMethod() const;

    bool isShowingCandidates() const;
    void setShowingCandidates( bool showing );
    //! @deprecated since 2.12
    const QList<QgsLabelCandidate>& candidates() /Deprecated/;

    bool isShowingShadowRectangles() const;
    void setShowingShadowRectangles( bool showing );

    bool isShowingAllLabels() const;
    void setShowingAllLabels( bool showing );

    bool isShowingPartialsLabels() const;
    void setShowingPartialsLabels( bool showing );

    //! @note added in 2.4
    bool isDrawingOutlineLabels() const;
    void setDrawingOutlineLabels( bool outline );

    /** Returns whether the engine will only draw the outline rectangles of labels,
     * not the label contents themselves. Used for debugging and testing purposes.
     * @see setDrawLabelRectOnly
     * @note added in QGIS 2.12
     */
    bool drawLabelRectOnly() const;

    /** Sets whether the engine should only draw the outline rectangles of labels,
     * not the label contents themselves. Used for debugging and testing purposes.
     * @param drawRect set to true to enable rect drawing only
     * @see drawLabelRectOnly
     * @note added in QGIS 2.12
     */
    void setDrawLabelRectOnly( bool drawRect );

    // implemented methods from labeling engine interface

    //! called when we're going to start with rendering
    //! @deprecated since 2.4 - use override with QgsMapSettings
    virtual void init( QgsMapRenderer* mr ) /Deprecated/;
    //! called when we're going to start with rendering
    virtual void init( const QgsMapSettings& mapSettings );
    //! called to find out whether the layer is used for labeling
    virtual bool willUseLayer( QgsVectorLayer* layer );

    //! called to find out whether the layer is used for labeling
    //! @note added in 2.4
    static bool staticWillUseLayer( QgsVectorLayer* layer );
    static bool staticWillUseLayer( const QString& layerID );

    //! clears all PAL layer settings for registered layers
    virtual void clearActiveLayers();
    //! clears data defined objects from PAL layer settings for a registered layer
    virtual void clearActiveLayer( const QString& layerID );
    //! hook called when drawing layer before issuing select()
    virtual int prepareLayer( QgsVectorLayer* layer, QStringList &attrNames, QgsRenderContext& ctx );
    //! adds a diagram layer to the labeling engine
    //! @note added in QGIS 2.12
    virtual int prepareDiagramLayer( QgsVectorLayer* layer, QStringList& attrNames, QgsRenderContext& ctx );
    //! adds a diagram layer to the labeling engine
    //! @deprecated since 2.12 - use prepareDiagramLayer()
    virtual int addDiagramLayer( QgsVectorLayer* layer, const QgsDiagramLayerSettings *s ) /Deprecated/;

    /** Register a feature for labelling.
     * @param layerID string identifying layer associated with label
     * @param feat feature to label
     * @param context render context. The QgsExpressionContext contained within the render context
     * must have already had the feature and fields sets prior to calling this method.
     */
    virtual void registerFeature( const QString& layerID, QgsFeature& feat, QgsRenderContext& context );

    virtual void registerDiagramFeature( const QString& layerID, QgsFeature& feat, QgsRenderContext& context );
    //! called when the map is drawn and labels should be placed
    virtual void drawLabeling( QgsRenderContext& context );
    //! called when we're done with rendering
    virtual void exit();

    //! return infos about labels at a given (map) position
    //! @deprecated since 2.4 - use takeResults() and methods of QgsLabelingResults
    virtual QList<QgsLabelPosition> labelsAtPosition( const QgsPoint& p ) /Deprecated/;
    //! return infos about labels within a given (map) rectangle
    //! @deprecated since 2.4 - use takeResults() and methods of QgsLabelingResults
    virtual QList<QgsLabelPosition> labelsWithinRect( const QgsRectangle& r ) /Deprecated/;

    //! Return pointer to recently computed results (in drawLabeling()) and pass the ownership of results to the caller
    //! @note added in 2.4
    QgsLabelingResults* takeResults() /TransferBack/;

    //! called when passing engine among map renderers
    virtual QgsPalLabeling* clone() /Factory/;

    //! @note not available in python bindings
    // void drawLabelCandidateRect( pal::LabelPosition* lp, QPainter* painter, const QgsMapToPixel* xform );

    static void drawLabelBuffer( QgsRenderContext& context,
                                 const QgsLabelComponent &component,
                                 const QgsPalLayerSettings& tmpLyr );

    static void drawLabelBackground( QgsRenderContext& context,
                                     QgsLabelComponent component,
                                     const QgsPalLayerSettings& tmpLyr );

    static void drawLabelShadow( QgsRenderContext &context,
                                 const QgsLabelComponent &component,
                                 const QgsPalLayerSettings& tmpLyr );

    //! load/save engine settings to project file
    void loadEngineSettings();
    void saveEngineSettings();
    void clearEngineSettings();
    //! @deprecated since 2.4 - settings are always stored in project
    bool isStoredWithProject() const /Deprecated/;
    //! @deprecated since 2.4 - settings are always stored in project
    void setStoredWithProject( bool store ) /Deprecated/;

    /** Prepares a geometry for registration with PAL. Handles reprojection, rotation, clipping, etc.
     * @param geometry geometry to prepare
     * @param context render context
     * @param ct coordinate transform
     * @param clipGeometry geometry to clip features to, if applicable
     * @returns prepared geometry, the caller takes ownership
     * @note added in QGIS 2.9
     */
    static QgsGeometry* prepareGeometry( const QgsGeometry *geometry, QgsRenderContext &context, const QgsCoordinateTransform *ct, QgsGeometry *clipGeometry = 0 ) /Factory/;

    /** Checks whether a geometry requires preparation before registration with PAL
     * @param geometry geometry to prepare
     * @param context render context
     * @param ct coordinate transform
     * @param clipGeometry geometry to clip features to, if applicable
     * @returns true if geometry requires preparation
     * @note added in QGIS 2.9
     */
    static bool geometryRequiresPreparation( const QgsGeometry *geometry, QgsRenderContext &context, const QgsCoordinateTransform *ct, QgsGeometry *clipGeometry = 0 );

    /** Splits a text string to a list of separate lines, using a specified wrap character.
     * The text string will be split on either newline characters or the wrap character.
     * @param text text string to split
     * @param wrapCharacter additional character to wrap on
     * @returns list of text split to lines
     * @note added in QGIS 2.9
     */
    static QStringList splitToLines( const QString& text, const QString& wrapCharacter );

    /** Splits a text string to a list of graphemes, which are the smallest allowable character
     * divisions in the string. This accounts for scripts were individual characters are not
     * allowed to be split apart (eg Arabic and Indic based scripts)
     * @param text string to split
     * @returns list of graphemes
     * @note added in QGIS 2.10
     */
    static QStringList splitToGraphemes( const QString& text );

  protected:
    // update temporary QgsPalLayerSettings with any data defined text style values
    void dataDefinedTextStyle( QgsPalLayerSettings& tmpLyr,
                               const QMap< QgsPalLayerSettings::DataDefinedProperties, QVariant >& ddValues );

    // update temporary QgsPalLayerSettings with any data defined text formatting values
    void dataDefinedTextFormatting( QgsPalLayerSettings& tmpLyr,
                                    const QMap< QgsPalLayerSettings::DataDefinedProperties, QVariant >& ddValues );

    // update temporary QgsPalLayerSettings with any data defined text buffer values
    void dataDefinedTextBuffer( QgsPalLayerSettings& tmpLyr,
                                const QMap< QgsPalLayerSettings::DataDefinedProperties, QVariant >& ddValues );

    // update temporary QgsPalLayerSettings with any data defined shape background values
    void dataDefinedShapeBackground( QgsPalLayerSettings& tmpLyr,
                                     const QMap< QgsPalLayerSettings::DataDefinedProperties, QVariant >& ddValues );

    // update temporary QgsPalLayerSettings with any data defined drop shadow values
    void dataDefinedDropShadow( QgsPalLayerSettings& tmpLyr,
                                const QMap< QgsPalLayerSettings::DataDefinedProperties, QVariant >& ddValues );

    void deleteTemporaryData();

    /** Checks whether a geometry exceeds the minimum required size for a geometry to be labeled.
     * @param context render context
     * @param geom geometry
     * @param minSize minimum size for geometry
     * @returns true if geometry exceeds minimum size
     * @note added in QGIS 2.9
     */
    static bool checkMinimumSizeMM( const QgsRenderContext &context, const QgsGeometry *geom, double minSize );
};