summaryrefslogtreecommitdiffstats
path: root/slideshow/source/engine/slideview.cxx
blob: 6db623468ac790e3d533ffd0ab69ddb1b3d3a94c (plain)
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
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#include <comphelper/diagnose_ex.hxx>
#include <canvas/canvastools.hxx>

#include <eventqueue.hxx>
#include <eventmultiplexer.hxx>
#include <slideview.hxx>
#include <delayevent.hxx>
#include <unoview.hxx>

#include <cppuhelper/basemutex.hxx>
#include <cppuhelper/compbase.hxx>
#include <comphelper/make_shared_from_uno.hxx>

#include <cppcanvas/spritecanvas.hxx>
#include <cppcanvas/customsprite.hxx>
#include <cppcanvas/vclfactory.hxx>
#include <cppcanvas/basegfxfactory.hxx>

#include <basegfx/range/b1drange.hxx>
#include <basegfx/range/b2drange.hxx>
#include <basegfx/range/b2irange.hxx>
#include <basegfx/point/b2dpoint.hxx>
#include <basegfx/polygon/b2dpolygon.hxx>
#include <basegfx/matrix/b2dhommatrix.hxx>
#include <basegfx/polygon/b2dpolygontools.hxx>
#include <basegfx/polygon/b2dpolypolygontools.hxx>
#include <basegfx/utils/canvastools.hxx>
#include <basegfx/polygon/b2dpolygonclipper.hxx>
#include <basegfx/polygon/b2dpolypolygoncutter.hxx>

#include <com/sun/star/awt/XPaintListener.hpp>
#include <com/sun/star/presentation/XSlideShowView.hpp>
#include <com/sun/star/rendering/CompositeOperation.hpp>
#include <com/sun/star/util/XModifyListener.hpp>

#include <memory>
#include <utility>
#include <vector>
#include <algorithm>

using namespace com::sun::star;

namespace slideshow::internal {

namespace {

/** Sprite entry, to store sprite plus priority

    The operator<() defines a strict weak ordering of sprites, sort
    key is the sprite priority.
 */
struct SpriteEntry
{
    SpriteEntry( const cppcanvas::CustomSpriteSharedPtr& rSprite,
                 double                                  nPrio ) :
        mpSprite( rSprite ),
        mnPriority( nPrio )
    {
    }

    bool operator<(const SpriteEntry& rRHS) const
    {
        return mnPriority < rRHS.mnPriority;
    }

    std::weak_ptr< cppcanvas::CustomSprite > mpSprite;
    double                                     mnPriority;
};

typedef std::vector< SpriteEntry > SpriteVector;


/** Create a clip polygon for slide views

    @param rClip
    Clip to set (can be empty)

    @param rCanvas
    Canvas to create the clip polygon for

    @param rUserSize
    The size of the view. Note that the returned clip will
    <em>always</em> clip to at least the rect defined herein.

    @return the view clip polygon, in view coordinates, which is
    guaranteed to at least clip to the view size.
 */
basegfx::B2DPolyPolygon createClipPolygon( const basegfx::B2DPolyPolygon&    rClip,
                                           const cppcanvas::CanvasSharedPtr& /*rCanvas*/,
                                           const basegfx::B2DSize&           rUserSize )
{
    // setup canvas clipping
    // =====================

    // AW: Simplified
    const basegfx::B2DRange aClipRange(0, 0, rUserSize.getWidth(), rUserSize.getHeight());

    if(rClip.count())
    {
        return basegfx::utils::clipPolyPolygonOnRange(rClip, aClipRange, true, false);
    }
    else
    {
        return basegfx::B2DPolyPolygon(basegfx::utils::createPolygonFromRect(aClipRange));
    }
}

/** Prepare given clip polygon to be stored as the current clip

    Note that this is separate from createClipPolygon(), to allow
    SlideView implementations to store this intermediate result
    (createClipPolygon() has to be called every time the view size
    changes)
 */
basegfx::B2DPolyPolygon prepareClip( const basegfx::B2DPolyPolygon& rClip )
{
    basegfx::B2DPolyPolygon aClip( rClip );

    // normalize polygon, preparation for clipping
    // in updateCanvas()
    aClip = basegfx::utils::correctOrientations(aClip);
    aClip = basegfx::utils::solveCrossovers(aClip);
    aClip = basegfx::utils::stripNeutralPolygons(aClip);
    aClip = basegfx::utils::stripDispensablePolygons(aClip);

    return aClip;
}


void clearRect( ::cppcanvas::CanvasSharedPtr const& pCanvas,
                basegfx::B2IRange const&            rArea )
{
    // convert clip polygon to device coordinate system
    ::basegfx::B2DPolyPolygon const* pClipPoly( pCanvas->getClip() );
    if( pClipPoly )
    {
        ::basegfx::B2DPolyPolygon aClipPoly( *pClipPoly );
        aClipPoly.transform( pCanvas->getTransformation() );
        pCanvas->setClip( aClipPoly );
    }

    // set transformation to identity (->device pixel)
    pCanvas->setTransformation( ::basegfx::B2DHomMatrix() );

    // #i42440# Fill the _full_ background in
    // black. Since we had to extend the bitmap by one
    // pixel, and the bitmap is initialized white,
    // depending on the slide content a one pixel wide
    // line will show to the bottom and the right.
    const ::basegfx::B2DPolygon aPoly(
        ::basegfx::utils::createPolygonFromRect(
            basegfx::B2DRange(rArea)));

    ::cppcanvas::PolyPolygonSharedPtr pPolyPoly(
        ::cppcanvas::BaseGfxFactory::createPolyPolygon( pCanvas, aPoly ) );

    if( pPolyPoly )
    {
        pPolyPoly->setCompositeOp( css::rendering::CompositeOperation::SOURCE );
        pPolyPoly->setRGBAFillColor( 0xFFFFFF00U );
        pPolyPoly->draw();
    }

#if defined(DBG_UTIL)
    ::cppcanvas::CanvasSharedPtr pCliplessCanvas( pCanvas->clone() );
    pCliplessCanvas->setClip();

    if( pCanvas->getClip() )
    {
        ::cppcanvas::PolyPolygonSharedPtr pPolyPoly2(
            ::cppcanvas::BaseGfxFactory::createPolyPolygon( pCliplessCanvas, aPoly ));
        if( pPolyPoly2 )
        {
            pPolyPoly2->setRGBALineColor( 0x008000FFU );
            pPolyPoly2->draw();
        }
    }
#endif
}

/** Get bounds in pixel

    @param rLayerBounds
    Bound rect, in user space coordinates

    @param rTransformation
    User space to device pixel transformation

    @return the layer bounds in pixel, extended by one pixel to the
    right and bottom
 */
basegfx::B2IRange getLayerBoundsPixel( basegfx::B2DRange const&     rLayerBounds,
                                       basegfx::B2DHomMatrix const& rTransformation )
{
    ::basegfx::B2DRange aTmpRect;
    ::canvas::tools::calcTransformedRectBounds( aTmpRect,
                                                rLayerBounds,
                                                rTransformation );

    if( aTmpRect.isEmpty() )
        return ::basegfx::B2IRange();

    // #i42440# Returned layer size is one pixel too small, as
    // rendering happens one pixel to the right and below the
    // actual bound rect.
    return ::basegfx::B2IRange( ::basegfx::fround(aTmpRect.getMinX()),
                                ::basegfx::fround(aTmpRect.getMinY()),
                                ::basegfx::fround(aTmpRect.getMaxX()) + 1,
                                ::basegfx::fround(aTmpRect.getMaxY()) + 1 );
}


/** Container class for sprites issued by a ViewLayer

    This class handles the sprite prioritization issues, that are
    needed for layer sprites (e.g. the need to re-prioritize sprites
    when the layer changes prio).
 */
class LayerSpriteContainer
{
    /** Max fill level of maSprites, before we try to prune it from
        deceased sprites
    */
    enum{ SPRITE_ULLAGE=256 };

    /** All sprites that have been issued by this container (pruned
        from time to time, for invalid references). This vector is
        kept sorted with increasing sprite priority.
    */
    SpriteVector       maSprites;

    /// Priority of this layer, relative to other view layers
    basegfx::B1DRange  maLayerPrioRange;

    double getSpritePriority( std::size_t nSpriteNum ) const
    {
        // divide the available layer range equally between all
        // sprites, assign upper bound of individual sprite range as
        // sprite prio (the layer itself gets assigned the lower bound
        // of sprite 0's individual range):

        // | layer 0                    | layer 1                    | ...
        // |    sprite 0 |    sprite 1  |    sprite 0 |    sprite 1  | ...
        return maLayerPrioRange.getMinimum() + maLayerPrioRange.getRange()*(nSpriteNum+1)/(maSprites.size()+1);
    }

    /** Rescan sprite vector, and remove deceased sprites (and reset
        sprite prio)

        @param aBegin
        Iterator to the first entry to rescan
     */
    void updateSprites()
    {
        SpriteVector aValidSprites;

        // check all sprites for validity and set new priority
        for( const auto& rSprite : maSprites )
        {
            cppcanvas::CustomSpriteSharedPtr pCurrSprite( rSprite.mpSprite.lock() );

            if( pCurrSprite )
            {
                // only copy still valid sprites over to the refreshed
                // sprite vector.
                aValidSprites.push_back( rSprite );

                pCurrSprite->setPriority(
                    getSpritePriority( aValidSprites.size()-1 ));
            }
        }

        // replace sprite list with pruned one
        maSprites.swap( aValidSprites );
    }

public:
    LayerSpriteContainer() :
        maSprites(),
        maLayerPrioRange()
    {
    }

    const basegfx::B1DRange& getLayerPriority() const
    {
        return maLayerPrioRange;
    }

    void setLayerPriority( const basegfx::B1DRange& rRange )
    {
        if( rRange != maLayerPrioRange )
        {
            maLayerPrioRange = rRange;

            // prune and recalc sprite prios
            updateSprites();
        }
    }

    void addSprite( const cppcanvas::CustomSpriteSharedPtr& pSprite,
                    double                                  nPriority )
    {
        if( !pSprite )
            return;

        SpriteEntry aEntry( pSprite,nPriority );

        // insert new sprite, such that vector stays sorted
        SpriteVector::iterator aInsertPos(
            maSprites.insert(
                std::lower_bound( maSprites.begin(),
                                  maSprites.end(),
                                  aEntry ),
                aEntry ));

        const std::size_t nNumSprites( maSprites.size() );
        if( nNumSprites > SPRITE_ULLAGE ||
            maSprites.end() - aInsertPos > 1 )
        {
            // updateSprites() also updates all sprite prios
            updateSprites();
        }
        else
        {
            // added sprite to the end, and not too many sprites in
            // vector - perform optimized update (only need to set
            // prio). This basically caters for the common case of
            // iterated character animations, which generate lots of
            // sprites, all added to the end.
            pSprite->setPriority(
                getSpritePriority( nNumSprites-1 ));
        }
    }

    void clear()
    {
        maSprites.clear();
    }
};


/** This class provides layers for a slide view

    Layers are used to render animations with the correct z order -
    because sprites are always in front of the static canvas
    background, shapes that must appear <em<before</em> an animation
    must also be displayed as a sprite.

    Each layer has a priority assigned to it (valid range [0,1]), which
    also affects all sprites created for this specific layer - i.e. if
    the layer priority changes, the sprites change z order together
    with their parent.
 */
class SlideViewLayer : public ViewLayer
{
    /// Smart container for all sprites issued by this layer
    mutable LayerSpriteContainer             maSpriteContainer;

    /// Bounds of this layer in user space coordinates
    basegfx::B2DRange                        maLayerBounds;

    /// Bounds of this layer in device pixel
    mutable basegfx::B2IRange                maLayerBoundsPixel;

    /// Current clip polygon in user coordinates
    basegfx::B2DPolyPolygon                  maClip;

    /// Current size of the view in user coordinates
    basegfx::B2DSize                         maUserSize;

    /// Current overall view transformation
    basegfx::B2DHomMatrix                    maTransformation;

    /// 'parent' canvas, this viewlayer is associated with
    const cppcanvas::SpriteCanvasSharedPtr   mpSpriteCanvas;

    /** output surface (necessarily a sprite, won't otherwise be able
        to display anything <em>before</em> other sprites)
    */
    mutable cppcanvas::CustomSpriteSharedPtr mpSprite;

    /// actual output canvas retrieved from a sprite
    mutable cppcanvas::CanvasSharedPtr       mpOutputCanvas;

    /// ptr back to owning view. needed for isOnView() method
    View const* const                        mpParentView;

public:
    /** Create a new layer

        @param pCanvas
        Sprite canvas to create the layer on

        @param rTransform
        Initial overall canvas transformation

        @param rLayerBounds
        Initial layer bounds, in view coordinate system
     */
    SlideViewLayer( cppcanvas::SpriteCanvasSharedPtr        pCanvas,
                    basegfx::B2DHomMatrix                   aTransform,
                    const basegfx::B2DRange&                rLayerBounds,
                    const basegfx::B2DSize&                 rUserSize,
                    View const* const                       pParentView) :
        maSpriteContainer(),
        maLayerBounds(rLayerBounds),
        maLayerBoundsPixel(),
        maClip(),
        maUserSize(rUserSize),
        maTransformation(std::move(aTransform)),
        mpSpriteCanvas(std::move(pCanvas)),
        mpSprite(),
        mpOutputCanvas(),
        mpParentView(pParentView)
    {
    }

    SlideViewLayer(const SlideViewLayer&) = delete;
    SlideViewLayer& operator=(const SlideViewLayer&) = delete;

    void updateView( const basegfx::B2DHomMatrix& rMatrix,
                     const basegfx::B2DSize&      rUserSize )
    {
        maTransformation = rMatrix;
        maUserSize = rUserSize;

        // limit layer bounds to visible screen
        maLayerBounds.intersect( basegfx::B2DRange(0.0,
                                                   0.0,
                                                   maUserSize.getWidth(),
                                                   maUserSize.getHeight()) );

        basegfx::B2IRange const& rNewLayerPixel(
            getLayerBoundsPixel(maLayerBounds,
                                maTransformation) );
        if( rNewLayerPixel != maLayerBoundsPixel )
        {
            // re-gen sprite with new size
            mpOutputCanvas.reset();
            mpSprite.reset();
        }
    }

    virtual css::geometry::IntegerSize2D getTranslationOffset() const override
    {
        basegfx::B2DRectangle aTmpRect;
        canvas::tools::calcTransformedRectBounds( aTmpRect,
                                                  maLayerBounds,
                                                  maTransformation );
        geometry::IntegerSize2D offset(0, 0);

        // Add translation according to the origin of aTmpRect.  Ignore the
        // translation when aTmpRect was not properly initialized.
        if ( ! aTmpRect.isEmpty())
        {
            offset.Width  = basegfx::fround(aTmpRect.getMinX());
            offset.Height = basegfx::fround(aTmpRect.getMinY());
        }
        return offset;
    }

private:
    // ViewLayer interface


    virtual cppcanvas::CustomSpriteSharedPtr createSprite(
        const ::basegfx::B2DSize& rSpriteSizePixel,
        double                    nPriority ) const override
    {
        cppcanvas::CustomSpriteSharedPtr pSprite(
            mpSpriteCanvas->createCustomSprite( rSpriteSizePixel ) );

        maSpriteContainer.addSprite( pSprite,
                                     nPriority );

        return pSprite;
    }

    virtual void setPriority( const basegfx::B1DRange& rRange ) override
    {
        OSL_ENSURE( !rRange.isEmpty() &&
                    rRange.getMinimum() >= 1.0,
                    "SlideViewLayer::setPriority(): prio MUST be larger than 1.0 (because "
                    "the background layer already lies there)" );

        maSpriteContainer.setLayerPriority( rRange );

        if( mpSprite )
            mpSprite->setPriority( rRange.getMinimum() );
    }

    virtual basegfx::B2DHomMatrix getTransformation() const override
    {
        // Offset given transformation by left, top border of given
        // range (after transformation through given transformation)
        basegfx::B2DRectangle aTmpRect;
        canvas::tools::calcTransformedRectBounds( aTmpRect,
                                                  maLayerBounds,
                                                  maTransformation );

        basegfx::B2DHomMatrix aMatrix( maTransformation );

        // Add translation according to the origin of aTmpRect.  Ignore the
        // translation when aTmpRect was not properly initialized.
        if ( ! aTmpRect.isEmpty())
        {
            aMatrix.translate( -basegfx::fround(aTmpRect.getMinX()),
                               -basegfx::fround(aTmpRect.getMinY()) );
        }

        return aMatrix;
    }

    virtual basegfx::B2DHomMatrix getSpriteTransformation() const override
    {
        return maTransformation;
    }

    virtual void clear() const override
    {
        // grab canvas - that also lazy-initializes maLayerBoundsPixel
        cppcanvas::CanvasSharedPtr pCanvas=getCanvas()->clone();

        // clear whole canvas
        const basegfx::B2I64Tuple& rSpriteSize(maLayerBoundsPixel.getRange());
        clearRect(pCanvas,
                  basegfx::B2IRange(0,0,rSpriteSize.getX(),rSpriteSize.getY()));
    }

    virtual void clearAll() const override
    {
        // grab canvas - that also lazy-initializes maLayerBoundsPixel
        ::cppcanvas::CanvasSharedPtr pCanvas( getCanvas()->clone() );

        // clear layer clip, to clear whole area
        pCanvas->setClip();

        // clear whole canvas
        const basegfx::B2I64Tuple& rSpriteSize(maLayerBoundsPixel.getRange());
        clearRect(pCanvas,
                  basegfx::B2IRange(0,0,rSpriteSize.getX(),rSpriteSize.getY()));
    }

    virtual bool isOnView(ViewSharedPtr const& rView) const override
    {
        return rView.get() == mpParentView;
    }

    virtual cppcanvas::CanvasSharedPtr getCanvas() const override
    {
        if( !mpOutputCanvas )
        {
            if( !mpSprite )
            {
                maLayerBoundsPixel = getLayerBoundsPixel(maLayerBounds,
                                                         maTransformation);

                // HACK: ensure at least 1x1 pixel size. clients might
                // need an actual canvas (e.g. for bound rect
                // calculations) without rendering anything. Better
                // solution: introduce something like a reference
                // canvas for ViewLayers, which is always available.
                if( maLayerBoundsPixel.isEmpty() )
                    maLayerBoundsPixel = basegfx::B2IRange(0,0,1,1);

                const basegfx::B2I64Tuple& rSpriteSize(maLayerBoundsPixel.getRange());
                mpSprite = mpSpriteCanvas->createCustomSprite(
                    basegfx::B2DSize(sal::static_int_cast<sal_Int32>(rSpriteSize.getX()),
                                       sal::static_int_cast<sal_Int32>(rSpriteSize.getY())) );

                mpSprite->setPriority(
                    maSpriteContainer.getLayerPriority().getMinimum() );

#if defined(DBG_UTIL)
                mpSprite->movePixel(
                    basegfx::B2DPoint(maLayerBoundsPixel.getMinimum()) +
                    basegfx::B2DPoint(10,10) );

                mpSprite->setAlpha(0.5);
#else
                mpSprite->movePixel(
                    basegfx::B2DPoint(maLayerBoundsPixel.getMinimum()) );

                mpSprite->setAlpha(1.0);
#endif
                mpSprite->show();
            }

            ENSURE_OR_THROW( mpSprite,
                              "SlideViewLayer::getCanvas(): no layer sprite" );

            mpOutputCanvas = mpSprite->getContentCanvas();

            ENSURE_OR_THROW( mpOutputCanvas,
                              "SlideViewLayer::getCanvas(): sprite doesn't yield a canvas" );

            // new canvas retrieved - setup transformation and clip
            mpOutputCanvas->setTransformation( getTransformation() );
            mpOutputCanvas->setClip(
                createClipPolygon( maClip,
                                   mpOutputCanvas,
                                   maUserSize ));
        }

        return mpOutputCanvas;
    }

    virtual void setClip( const basegfx::B2DPolyPolygon& rClip ) override
    {
        basegfx::B2DPolyPolygon aNewClip = prepareClip( rClip );

        if( aNewClip != maClip )
        {
            maClip = aNewClip;

            if(mpOutputCanvas )
                mpOutputCanvas->setClip(
                    createClipPolygon( maClip,
                                       mpOutputCanvas,
                                       maUserSize ));
        }
    }

    virtual bool resize( const ::basegfx::B2DRange& rArea ) override
    {
        const bool bRet( maLayerBounds != rArea );
        maLayerBounds = rArea;
        updateView( maTransformation,
                    maUserSize );

        return bRet;
    }
};


typedef cppu::WeakComponentImplHelper<
      css::util::XModifyListener,
      css::awt::XPaintListener> SlideViewBase;

/** SlideView class

    This class implements the View interface, encapsulating
    <em>one</em> view a slideshow is displayed on.
 */
class SlideView : private cppu::BaseMutex,
                  public SlideViewBase,
                  public UnoView
{
public:
    SlideView( const uno::Reference<presentation::XSlideShowView>& xView,
               EventQueue&                                         rEventQueue,
               EventMultiplexer&                                   rEventMultiplexer );
    void updateCanvas();

private:
    // View:
    virtual ViewLayerSharedPtr createViewLayer( const basegfx::B2DRange& rLayerBounds ) const override;
    virtual bool updateScreen() const override;
    virtual bool paintScreen() const override;
    virtual void setViewSize( const ::basegfx::B2DSize& ) override;
    virtual void setCursorShape( sal_Int16 nPointerShape ) override;

    // ViewLayer interface
    virtual bool isOnView(ViewSharedPtr const& rView) const override;
    virtual void clear() const override;
    virtual void clearAll() const override;
    virtual cppcanvas::CanvasSharedPtr getCanvas() const override;
    virtual cppcanvas::CustomSpriteSharedPtr createSprite( const ::basegfx::B2DSize& rSpriteSizePixel,
                                                           double                    nPriority ) const override;
    virtual void setPriority( const basegfx::B1DRange& rRange ) override;
    virtual geometry::IntegerSize2D getTranslationOffset() const override;
    virtual ::basegfx::B2DHomMatrix getTransformation() const override;
    virtual basegfx::B2DHomMatrix getSpriteTransformation() const override;
    virtual void setClip( const ::basegfx::B2DPolyPolygon& rClip ) override;
    virtual bool resize( const ::basegfx::B2DRange& rArea ) override;

    // UnoView:
    virtual void _dispose() override;
    virtual uno::Reference<presentation::XSlideShowView> getUnoView()const override;
    virtual void setIsSoundEnabled (const bool bValue) override;
    virtual bool isSoundEnabled() const override;

    // XEventListener:
    virtual void SAL_CALL disposing( lang::EventObject const& evt ) override;
    // XModifyListener:
    virtual void SAL_CALL modified( const lang::EventObject& aEvent ) override;
    // XPaintListener:
    virtual void SAL_CALL windowPaint( const awt::PaintEvent& e ) override;

    // WeakComponentImplHelperBase:
    virtual void SAL_CALL disposing() override;

    void updateClip();

private:
    typedef std::vector< std::weak_ptr<SlideViewLayer> > ViewLayerVector;

    /// Prune viewlayers from deceased ones, optionally update them
    void pruneLayers( bool bWithViewLayerUpdate=false ) const;

    /** Max fill level of maViewLayers, before we try to prune it from
        deceased layers
    */
    enum{ LAYER_ULLAGE=8 };

    uno::Reference<presentation::XSlideShowView>              mxView;
    cppcanvas::SpriteCanvasSharedPtr                          mpCanvas;

    EventMultiplexer&                                         mrEventMultiplexer;
    EventQueue&                                               mrEventQueue;

    mutable LayerSpriteContainer                              maSprites;
    mutable ViewLayerVector                                   maViewLayers;

    basegfx::B2DPolyPolygon                                   maClip;

    basegfx::B2DHomMatrix                                     maViewTransform;
    basegfx::B2DSize                                          maUserSize;
    bool mbIsSoundEnabled;
};


SlideView::SlideView( const uno::Reference<presentation::XSlideShowView>& xView,
                      EventQueue&                                         rEventQueue,
                      EventMultiplexer&                                   rEventMultiplexer ) :
    SlideViewBase( m_aMutex ),
    mxView( xView ),
    mpCanvas(),
    mrEventMultiplexer( rEventMultiplexer ),
    mrEventQueue( rEventQueue ),
    maSprites(),
    maViewLayers(),
    maClip(),
    maViewTransform(),
    maUserSize( 1.0, 1.0 ), // default size: one-by-one rectangle
    mbIsSoundEnabled(true)
{
    // take care not constructing any UNO references to this _inside_
    // ctor, shift that code to createSlideView()!
    ENSURE_OR_THROW( mxView.is(),
                      "SlideView::SlideView(): Invalid view" );

    mpCanvas = cppcanvas::VCLFactory::createSpriteCanvas(
        xView->getCanvas() );
    ENSURE_OR_THROW( mpCanvas,
                      "Could not create cppcanvas" );

    geometry::AffineMatrix2D aViewTransform(
        xView->getTransformation() );

    if( basegfx::fTools::equalZero(
            basegfx::B2DVector(aViewTransform.m00,
                               aViewTransform.m10).getLength()) ||
        basegfx::fTools::equalZero(
            basegfx::B2DVector(aViewTransform.m01,
                               aViewTransform.m11).getLength()) )
    {
        OSL_FAIL( "SlideView::SlideView(): Singular matrix!" );

        canvas::tools::setIdentityAffineMatrix2D(aViewTransform);
    }

    basegfx::unotools::homMatrixFromAffineMatrix(
        maViewTransform, aViewTransform );

    // once and forever: set fixed prio to this 'layer' (we're always
    // the background layer)
    maSprites.setLayerPriority( basegfx::B1DRange(0.0,1.0) );
}

void SlideView::disposing()
{
    osl::MutexGuard aGuard( m_aMutex );

    maViewLayers.clear();
    maSprites.clear();
    mpCanvas.reset();

    // additionally, also de-register from XSlideShowView
    if (mxView.is())
    {
        mxView->removeTransformationChangedListener( this );
        mxView->removePaintListener( this );
        mxView.clear();
    }
}

ViewLayerSharedPtr SlideView::createViewLayer( const basegfx::B2DRange& rLayerBounds ) const
{
    osl::MutexGuard aGuard( m_aMutex );

    ENSURE_OR_THROW( mpCanvas,
                      "SlideView::createViewLayer(): Disposed" );

    const std::size_t nNumLayers( maViewLayers.size() );

    // avoid filling up layer vector with lots of deceased layer weak
    // ptrs
    if( nNumLayers > LAYER_ULLAGE )
        pruneLayers();

    auto xViewLayer = std::make_shared<SlideViewLayer>(mpCanvas,
                                                       getTransformation(),
                                                       rLayerBounds,
                                                       maUserSize,
                                                       this);
    maViewLayers.push_back(xViewLayer);

    return xViewLayer;
}

bool SlideView::updateScreen() const
{
    osl::MutexGuard aGuard( m_aMutex );

    ENSURE_OR_RETURN_FALSE( mpCanvas,
                       "SlideView::updateScreen(): Disposed" );

    return mpCanvas->updateScreen( false );
}

bool SlideView::paintScreen() const
{
    osl::MutexGuard aGuard( m_aMutex );

    ENSURE_OR_RETURN_FALSE( mpCanvas,
                       "SlideView::paintScreen(): Disposed" );

    return mpCanvas->updateScreen( true );
}

void SlideView::clear() const
{
    osl::MutexGuard aGuard( m_aMutex );

    OSL_ENSURE( mxView.is() && mpCanvas,
                "SlideView::clear(): Disposed" );
    if( !mxView.is() || !mpCanvas )
        return;

    // keep layer clip
    clearRect(getCanvas()->clone(),
              getLayerBoundsPixel(
                  basegfx::B2DRange(0,0,
                                    maUserSize.getWidth(),
                                    maUserSize.getHeight()),
                  getTransformation()));
}

void SlideView::clearAll() const
{
    osl::MutexGuard aGuard( m_aMutex );

    OSL_ENSURE( mxView.is() && mpCanvas,
                "SlideView::clear(): Disposed" );
    if( !mxView.is() || !mpCanvas )
        return;

    mpCanvas->clear(); // this is unnecessary, strictly speaking. but
                       // it makes the SlideView behave exactly like a
                       // sprite-based SlideViewLayer, because those
                       // are created from scratch after a resize

    // clear whole view
    mxView->clear();
}

void SlideView::setViewSize( const basegfx::B2DSize& rSize )
{
    osl::MutexGuard aGuard( m_aMutex );

    maUserSize = rSize;
    updateCanvas();
}

void SlideView::setCursorShape( sal_Int16 nPointerShape )
{
    osl::MutexGuard const guard( m_aMutex );

    if (mxView.is())
        mxView->setMouseCursor( nPointerShape );
}

bool SlideView::isOnView(ViewSharedPtr const& rView) const
{
    return rView.get() == this;
}

cppcanvas::CanvasSharedPtr SlideView::getCanvas() const
{
    osl::MutexGuard aGuard( m_aMutex );

    ENSURE_OR_THROW( mpCanvas,
                      "SlideView::getCanvas(): Disposed" );

    return mpCanvas;
}

cppcanvas::CustomSpriteSharedPtr SlideView::createSprite(
    const basegfx::B2DSize& rSpriteSizePixel,
    double                  nPriority ) const
{
    osl::MutexGuard aGuard( m_aMutex );

    ENSURE_OR_THROW( mpCanvas, "SlideView::createSprite(): Disposed" );

    cppcanvas::CustomSpriteSharedPtr pSprite(
        mpCanvas->createCustomSprite( rSpriteSizePixel ) );

    maSprites.addSprite( pSprite,
                         nPriority );

    return pSprite;
}

void SlideView::setPriority( const basegfx::B1DRange& /*rRange*/ )
{
    OSL_FAIL( "SlideView::setPriority() is a NOOP for slide view - "
                "content will always be shown in the background" );
}

basegfx::B2DHomMatrix SlideView::getTransformation() const
{
    osl::MutexGuard aGuard( m_aMutex );

    basegfx::B2DHomMatrix aMatrix;
    aMatrix.scale( 1.0 / maUserSize.getWidth(), 1.0 / maUserSize.getHeight() );

    return maViewTransform * aMatrix;
}

geometry::IntegerSize2D SlideView::getTranslationOffset() const
{
    return mxView->getTranslationOffset();
}

basegfx::B2DHomMatrix SlideView::getSpriteTransformation() const
{
    return getTransformation();
}

void SlideView::setClip( const basegfx::B2DPolyPolygon& rClip )
{
    osl::MutexGuard aGuard( m_aMutex );

    basegfx::B2DPolyPolygon aNewClip = prepareClip( rClip );

    if( aNewClip != maClip )
    {
        maClip = aNewClip;

        updateClip();
    }
}

bool SlideView::resize( const ::basegfx::B2DRange& /*rArea*/ )
{
    OSL_FAIL( "SlideView::resize(): ignored for the View, can't change size "
                "effectively, anyway" );

    return false;
}

uno::Reference<presentation::XSlideShowView> SlideView::getUnoView() const
{
    osl::MutexGuard aGuard( m_aMutex );
    return mxView;
}

void SlideView::setIsSoundEnabled (const bool bValue)
{
    mbIsSoundEnabled = bValue;
}

bool SlideView::isSoundEnabled() const
{
    return mbIsSoundEnabled;
}

void SlideView::_dispose()
{
    dispose();
}

// XEventListener
void SlideView::disposing( lang::EventObject const& evt )
{
    // no deregistration necessary anymore, XView has left:
    osl::MutexGuard const guard( m_aMutex );

    if (mxView.is())
    {
        OSL_ASSERT( evt.Source == mxView );
        mxView.clear();
    }

    dispose();
}

// silly wrapper to check that event handlers don't touch dead SlideView
struct WeakRefWrapper
{
    SlideView & m_rObj;
    uno::WeakReference<uno::XInterface> const m_wObj;
    std::function<void (SlideView&)> const m_func;

    WeakRefWrapper(SlideView & rObj, std::function<void (SlideView&)> func)
        : m_rObj(rObj)
        , m_wObj(rObj.getXWeak())
        , m_func(std::move(func))
    {
    }

    void operator()()
    {
        uno::Reference<uno::XInterface> const xObj(m_wObj);
        if (xObj.is())
        {
            m_func(m_rObj);
        }
    }
};

// XModifyListener
void SlideView::modified( const lang::EventObject& /*aEvent*/ )
{
    osl::MutexGuard const guard( m_aMutex );

    OSL_ENSURE( mxView.is(), "SlideView::modified(): "
                "Disposed, but event received from XSlideShowView?!");

    if( !mxView.is() )
        return;

    geometry::AffineMatrix2D aViewTransform(
        mxView->getTransformation() );

    if( basegfx::fTools::equalZero(
            basegfx::B2DVector(aViewTransform.m00,
                               aViewTransform.m10).getLength()) ||
        basegfx::fTools::equalZero(
            basegfx::B2DVector(aViewTransform.m01,
                               aViewTransform.m11).getLength()) )
    {
        OSL_FAIL( "SlideView::modified(): Singular matrix!" );

        canvas::tools::setIdentityAffineMatrix2D(aViewTransform);
    }

    // view transformation really changed?
    basegfx::B2DHomMatrix aNewTransform;
    basegfx::unotools::homMatrixFromAffineMatrix(
        aNewTransform,
        aViewTransform );

    if( aNewTransform == maViewTransform )
        return; // No change, nothing to do

    maViewTransform = aNewTransform;

    updateCanvas();

    // notify view change. Don't call EventMultiplexer directly, this
    // might not be the main thread!
    mrEventQueue.addEvent(
        makeEvent( WeakRefWrapper(*this,
            [] (SlideView & rThis) { rThis.mrEventMultiplexer.notifyViewChanged(rThis.mxView); }),
                   "EventMultiplexer::notifyViewChanged"));
}

// XPaintListener
void SlideView::windowPaint( const awt::PaintEvent& /*e*/ )
{
    osl::MutexGuard aGuard( m_aMutex );

    OSL_ENSURE( mxView.is() && mpCanvas, "Disposed, but event received?!" );

    // notify view clobbering. Don't call EventMultiplexer directly,
    // this might not be the main thread!
    mrEventQueue.addEvent(
        makeEvent( WeakRefWrapper(*this,
            [] (SlideView & rThis) { rThis.mrEventMultiplexer.notifyViewClobbered(rThis.mxView); }),
                   "EventMultiplexer::notifyViewClobbered") );
}

void SlideView::updateCanvas()
{
    OSL_ENSURE( mpCanvas,
                "SlideView::updateCanvasTransform(): Disposed" );

    if( !mpCanvas || !mxView.is())
        return;

    clearAll();
    mpCanvas->setTransformation( getTransformation() );
    mpCanvas->setClip(
        createClipPolygon( maClip,
                           mpCanvas,
                           maUserSize ));

    // forward update to viewlayers
    pruneLayers( true );
}

void SlideView::updateClip()
{
    OSL_ENSURE( mpCanvas,
                "SlideView::updateClip(): Disposed" );

    if( !mpCanvas )
        return;

    mpCanvas->setClip(
        createClipPolygon( maClip,
                           mpCanvas,
                           maUserSize ));

    pruneLayers();
}

void SlideView::pruneLayers( bool bWithViewLayerUpdate ) const
{
    ViewLayerVector aValidLayers;

    const basegfx::B2DHomMatrix& rCurrTransform(
        getTransformation() );

    // check all layers for validity, and retain only the live ones
    for( const auto& rView : maViewLayers )
    {
        std::shared_ptr< SlideViewLayer > xCurrLayer( rView.lock() );

        if ( xCurrLayer )
        {
            aValidLayers.push_back( xCurrLayer );

            if( bWithViewLayerUpdate )
                xCurrLayer->updateView( rCurrTransform,
                                        maUserSize );
        }
    }

    // replace layer list with pruned one
    maViewLayers.swap( aValidLayers );
}

} // anonymous namespace

UnoViewSharedPtr createSlideView( uno::Reference< presentation::XSlideShowView> const& xView,
                                  EventQueue&                                          rEventQueue,
                                  EventMultiplexer&                                    rEventMultiplexer )
{
    std::shared_ptr<SlideView> const that(
        comphelper::make_shared_from_UNO(
            new SlideView(xView,
                          rEventQueue,
                          rEventMultiplexer)));

    // register listeners with XSlideShowView
    xView->addTransformationChangedListener( that.get() );
    xView->addPaintListener( that.get() );

    // set new transformation
    that->updateCanvas();

    return that;
}

} // namespace slideshow

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */