summaryrefslogtreecommitdiffstats
path: root/src/gui/graphicsview/qgraphicsanchorlayout_p.h
blob: 24b25de42d66963d89ae87afad7ccf5bd39e5875 (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
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QGRAPHICSANCHORLAYOUT_P_H
#define QGRAPHICSANCHORLAYOUT_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QGraphicsWidget>
#include <private/qobject_p.h>

#include "qgraphicslayout_p.h"
#include "qgraphicsanchorlayout.h"
#include "qgraph_p.h"
#include "qsimplex_p.h"

QT_BEGIN_NAMESPACE

/*
  The public QGraphicsAnchorLayout interface represents an anchorage point
  as a pair of a <QGraphicsLayoutItem *> and a <Qt::AnchorPoint>.

  Internally though, it has a graph of anchorage points (vertices) and
  anchors (edges), represented by the AnchorVertex and AnchorData structs
  respectively.
*/

/*!
  \internal

  Represents a vertex (anchorage point) in the internal graph
*/
struct AnchorVertex {
    AnchorVertex(QGraphicsLayoutItem *item, Qt::AnchorPoint edge)
        : m_item(item), m_edge(edge) {}

    AnchorVertex()
        : m_item(0), m_edge(Qt::AnchorPoint(0)) {}

#ifdef QT_DEBUG
    inline QString toString() const;
#endif
    QGraphicsLayoutItem *m_item;
    Qt::AnchorPoint m_edge;

    // Current distance from this vertex to the layout edge (Left or Top)
    // Value is calculated from the current anchors sizes.
    qreal distance;
};

#ifdef QT_DEBUG
inline QString AnchorVertex::toString() const
{
    if (!this || !m_item) {
        return QLatin1String("NULL");
    }
    QString edge;
    switch (m_edge) {
    case Qt::AnchorLeft:
        edge = QLatin1String("Left");
        break;
    case Qt::AnchorHorizontalCenter:
        edge = QLatin1String("HorizontalCenter");
        break;
    case Qt::AnchorRight:
        edge = QLatin1String("Right");
        break;
    case Qt::AnchorTop:
        edge = QLatin1String("Top");
        break;
    case Qt::AnchorVerticalCenter:
        edge = QLatin1String("VerticalCenter");
        break;
    case Qt::AnchorBottom:
        edge = QLatin1String("Bottom");
        break;
    default:
        edge = QLatin1String("None");
        break;
    }
    QString itemName;
    if (m_item->isLayout()) {
        itemName = QLatin1String("layout");
    } else {
        if (QGraphicsItem *item = m_item->graphicsItem()) {
            itemName = item->data(0).toString();
        }
    }
    edge.insert(0, QLatin1String("%1_"));
    return edge.arg(itemName);
}
#endif

/*!
  \internal

  Represents an edge (anchor) in the internal graph.
*/
struct AnchorData : public QSimplexVariable {
    enum Type {
        Normal = 0,
        Sequential,
        Parallel
    };

    AnchorData()
        : QSimplexVariable(), from(0), to(0),
          minSize(0), prefSize(0), expSize(0), maxSize(0),
          sizeAtMinimum(0), sizeAtPreferred(0),
          sizeAtExpanding(0), sizeAtMaximum(0),
          graphicsAnchor(0), skipInPreferred(0),
          type(Normal), hasSize(true), isLayoutAnchor(false) {}

    virtual void updateChildrenSizes() {}
    virtual void refreshSizeHints(qreal effectiveSpacing);

    virtual ~AnchorData() {}

#ifdef QT_DEBUG
    void dump(int indent = 2);
    inline QString toString() const;
    QString name;
#endif

    inline void setFixedSize(qreal size)
    {
        minSize = size;
        prefSize = size;
        expSize = size;
        maxSize = size;
        sizeAtMinimum = size;
        sizeAtPreferred = size;
        sizeAtExpanding = size;
        sizeAtMaximum = size;
        hasSize = true;
    }

    inline void unsetSize()
    {
        hasSize = false;
    }

    // Anchor is semantically directed
    AnchorVertex *from;
    AnchorVertex *to;

    // Size restrictions of this edge. For anchors internal to items, these
    // values are derived from the respective item size hints. For anchors
    // that were added by users, these values are equal to the specified anchor
    // size.
    qreal minSize;
    qreal prefSize;
    qreal expSize;
    qreal maxSize;

    // These attributes define which sizes should that anchor be in when the
    // layout is at its minimum, preferred or maximum sizes. Values are
    // calculated by the Simplex solver based on the current layout setup.
    qreal sizeAtMinimum;
    qreal sizeAtPreferred;
    qreal sizeAtExpanding;
    qreal sizeAtMaximum;
    QGraphicsAnchor *graphicsAnchor;

    uint skipInPreferred : 1;
    uint type : 2;            // either Normal, Sequential or Parallel
    uint hasSize : 1;         // if false, get size from style.
    uint isLayoutAnchor : 1;  // if this anchor is connected to a layout 'edge'
};

#ifdef QT_DEBUG
inline QString AnchorData::toString() const
{
    return QString::fromAscii("Anchor(%1)").arg(name);
}
#endif

struct SequentialAnchorData : public AnchorData
{
    SequentialAnchorData() : AnchorData()
    {
        type = AnchorData::Sequential;
#ifdef QT_DEBUG
        name = QLatin1String("SequentialAnchorData");
#endif
    }

    virtual void updateChildrenSizes();
    virtual void refreshSizeHints(qreal effectiveSpacing);

    void refreshSizeHints_helper(qreal effectiveSpacing, bool refreshChildren = true);

    void setVertices(const QVector<AnchorVertex*> &vertices)
    {
        m_children = vertices;
#ifdef QT_DEBUG
        name = QString::fromAscii("%1 -- %2").arg(vertices.first()->toString(), vertices.last()->toString());
#endif
    }

    QVector<AnchorVertex*> m_children;          // list of vertices in the sequence
    QVector<AnchorData*> m_edges;               // keep the list of edges too.
};

struct ParallelAnchorData : public AnchorData
{
    ParallelAnchorData(AnchorData *first, AnchorData *second)
        : AnchorData(), firstEdge(first), secondEdge(second)
    {
        type = AnchorData::Parallel;

        // ### Those asserts force that both child anchors have the same direction,
        // but can't we simplify a pair of anchors in opposite directions?
        Q_ASSERT(first->from == second->from);
        Q_ASSERT(first->to == second->to);
        from = first->from;
        to = first->to;
#ifdef QT_DEBUG
        name = QString::fromAscii("%1 | %2").arg(first->toString(), second->toString());
#endif
    }

    virtual void updateChildrenSizes();
    virtual void refreshSizeHints(qreal effectiveSpacing);

    void refreshSizeHints_helper(qreal effectiveSpacing, bool refreshChildren = true);

    AnchorData* firstEdge;
    AnchorData* secondEdge;
};

/*!
  \internal

  Representation of a valid path for a given vertex in the graph.
  In this struct, "positives" is the set of anchors that have been
  traversed in the forward direction, while "negatives" is the set
  with the ones walked backwards.

  This paths are compared against each other to produce LP Constraints,
  the exact order in which the anchors were traversed is not relevant.
*/
class GraphPath
{
public:
    GraphPath() {}

    QSimplexConstraint *constraint(const GraphPath &path) const;
#ifdef QT_DEBUG
    QString toString() const;
#endif
    QSet<AnchorData *> positives;
    QSet<AnchorData *> negatives;
};

class QGraphicsAnchorLayoutPrivate;
/*!
    \internal
*/
class QGraphicsAnchorPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QGraphicsAnchor)

public:
    explicit QGraphicsAnchorPrivate(int version = QObjectPrivateVersion);
    ~QGraphicsAnchorPrivate();

    void setSpacing(qreal value);
    void unsetSpacing();
    qreal spacing() const;

    QGraphicsAnchorLayoutPrivate *layoutPrivate;
    AnchorData *data;
};




/*!
  \internal

  QGraphicsAnchorLayout private methods and attributes.
*/
class Q_AUTOTEST_EXPORT QGraphicsAnchorLayoutPrivate : public QGraphicsLayoutPrivate
{
    Q_DECLARE_PUBLIC(QGraphicsAnchorLayout)

public:
    // When the layout geometry is different from its Minimum, Preferred
    // or Maximum values, interpolation is used to calculate the geometries
    // of the items.
    //
    // Interval represents which interpolation interval are we operating in.
    enum Interval {
        MinToPreferred = 0,
        PreferredToExpanding,
        ExpandingToMax
    };

    // Several structures internal to the layout are duplicated to handle
    // both Horizontal and Vertical restrictions.
    //
    // Orientation is used to reference the right structure in each context
    enum Orientation {
        Horizontal = 0,
        Vertical,
        NOrientations
    };

    QGraphicsAnchorLayoutPrivate();

    static QGraphicsAnchorLayoutPrivate *get(QGraphicsAnchorLayout *q)
    {
        return q ? q->d_func() : 0;
    }

    static Qt::AnchorPoint oppositeEdge(
        Qt::AnchorPoint edge);

    static Orientation edgeOrientation(Qt::AnchorPoint edge);

    static Qt::AnchorPoint pickEdge(Qt::AnchorPoint edge, Orientation orientation)
    {
        if (orientation == Vertical && int(edge) <= 2)
            return (Qt::AnchorPoint)(edge + 3);
        else if (orientation == Horizontal && int(edge) >= 3) {
            return (Qt::AnchorPoint)(edge - 3);
        }
        return edge;
    }

    // Init methods
    void createLayoutEdges();
    void deleteLayoutEdges();
    void createItemEdges(QGraphicsLayoutItem *item);
    void createCenterAnchors(QGraphicsLayoutItem *item, Qt::AnchorPoint centerEdge);
    void removeCenterAnchors(QGraphicsLayoutItem *item, Qt::AnchorPoint centerEdge, bool substitute = true);
    void removeCenterConstraints(QGraphicsLayoutItem *item, Orientation orientation);

    QGraphicsAnchor *acquireGraphicsAnchor(AnchorData *data)
    {
        Q_Q(QGraphicsAnchorLayout);
        if (!data->graphicsAnchor) {
            data->graphicsAnchor = new QGraphicsAnchor(q);
            data->graphicsAnchor->d_func()->data = data;
        }
        return data->graphicsAnchor;
    }

    // function used by the 4 API functions
    QGraphicsAnchor *addAnchor(QGraphicsLayoutItem *firstItem,
                            Qt::AnchorPoint firstEdge,
                            QGraphicsLayoutItem *secondItem,
                            Qt::AnchorPoint secondEdge,
                            qreal *spacing = 0);

    // Helper for Anchor Manipulation methods
    void addAnchor_helper(QGraphicsLayoutItem *firstItem,
                   Qt::AnchorPoint firstEdge,
                   QGraphicsLayoutItem *secondItem,
                   Qt::AnchorPoint secondEdge,
                   AnchorData *data);

    QGraphicsAnchor *getAnchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                               QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge);

    void removeAnchor(AnchorVertex *firstVertex, AnchorVertex *secondVertex);
    void removeAnchor_helper(AnchorVertex *v1, AnchorVertex *v2);
    void setAnchorSize(AnchorData *data, const qreal *anchorSize);
    void anchorSize(const AnchorData *data,
                    qreal *minSize = 0,
                    qreal *prefSize = 0,
                    qreal *maxSize = 0) const;

    void removeAnchors(QGraphicsLayoutItem *item);

    void removeVertex(QGraphicsLayoutItem *item, Qt::AnchorPoint edge);

    void correctEdgeDirection(QGraphicsLayoutItem *&firstItem,
                              Qt::AnchorPoint &firstEdge,
                              QGraphicsLayoutItem *&secondItem,
                              Qt::AnchorPoint &secondEdge);
    // for getting the actual spacing (will query the style if the
    // spacing is not explicitly set).
    qreal effectiveSpacing(Orientation orientation) const;

    // Activation methods
    void simplifyGraph(Orientation orientation);
    bool simplifyGraphIteration(Orientation orientation);
    void restoreSimplifiedGraph(Orientation orientation);

    void calculateGraphs();
    void calculateGraphs(Orientation orientation);
    void setAnchorSizeHintsFromItems(Orientation orientation);
    void findPaths(Orientation orientation);
    void constraintsFromPaths(Orientation orientation);
    QList<QSimplexConstraint *> constraintsFromSizeHints(const QList<AnchorData *> &anchors);
    QList<QList<QSimplexConstraint *> > getGraphParts(Orientation orientation);
    void identifyNonFloatItems(QSet<AnchorData *> visited, Orientation orientation);
    void identifyNonFloatItems_helper(const AnchorData *ad, Orientation orientation);

    inline AnchorVertex *internalVertex(const QPair<QGraphicsLayoutItem*, Qt::AnchorPoint> &itemEdge) const
    {
        return m_vertexList.value(itemEdge).first;
    }

    inline AnchorVertex *internalVertex(const QGraphicsLayoutItem *item, Qt::AnchorPoint edge) const
    {
        return internalVertex(qMakePair(const_cast<QGraphicsLayoutItem *>(item), edge));
    }

    AnchorVertex *addInternalVertex(QGraphicsLayoutItem *item, Qt::AnchorPoint edge);
    void removeInternalVertex(QGraphicsLayoutItem *item, Qt::AnchorPoint edge);

    // Geometry interpolation methods
    void setItemsGeometries(const QRectF &geom);

    void calculateVertexPositions(Orientation orientation);
    void setupEdgesInterpolation(Orientation orientation);
    void interpolateEdge(AnchorVertex *base, AnchorData *edge, Orientation orientation);
    void interpolateSequentialEdges(AnchorVertex *base, SequentialAnchorData *edge,
                                    Orientation orientation);
    void interpolateParallelEdges(AnchorVertex *base, ParallelAnchorData *edge,
                                  Orientation orientation);

    // Linear Programming solver methods
    bool solveMinMax(QList<QSimplexConstraint *> constraints,
                     GraphPath path, qreal *min, qreal *max);
    bool solvePreferred(QList<QSimplexConstraint *> constraints);
    void solveExpanding(QList<QSimplexConstraint *> constraints);
    bool hasConflicts() const;

#ifdef QT_DEBUG
    void dumpGraph();
#endif


    qreal spacings[NOrientations];
    // Size hints from simplex engine
    qreal sizeHints[2][3];
    qreal sizeAtExpanding[2];

    // Items
    QVector<QGraphicsLayoutItem *> items;

    // Mapping between high level anchorage points (Item, Edge) to low level
    // ones (Graph Vertices)

    QHash<QPair<QGraphicsLayoutItem*, Qt::AnchorPoint>, QPair<AnchorVertex *, int> > m_vertexList;

    // Internal graph of anchorage points and anchors, for both orientations
    Graph<AnchorVertex, AnchorData> graph[2];

    // Graph paths and constraints, for both orientations
    QMultiHash<AnchorVertex *, GraphPath> graphPaths[2];
    QList<QSimplexConstraint *> constraints[2];
    QList<QSimplexConstraint *> itemCenterConstraints[2];

    // The interpolation interval and progress based on the current size
    // as well as the key values (minimum, preferred and maximum)
    Interval interpolationInterval[2];
    qreal interpolationProgress[2];

    // ###
    bool graphSimplified[2];
    bool graphHasConflicts[2];
    QSet<QGraphicsLayoutItem *> m_nonFloatItems[2];

    uint calculateGraphCacheDirty : 1;
};

QT_END_NAMESPACE

#endif