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Diffstat (limited to 'src/gui/graphicsview/qgraphicsanchorlayout_p.h')
| -rw-r--r-- | src/gui/graphicsview/qgraphicsanchorlayout_p.h | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h new file mode 100644 index 0000000..e17bd28 --- /dev/null +++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h @@ -0,0 +1,474 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QGraphicsWidget> + +#include "qgraphicslayout_p.h" +#include "qgraphicsanchorlayout.h" +#include "qgraph_p.h" +#include "qsimplex_p.h" + +/* + 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(qreal minimumSize, qreal preferredSize, qreal maximumSize) + : QSimplexVariable(), from(0), to(0), + minSize(minimumSize), prefSize(preferredSize), + maxSize(maximumSize), sizeAtMinimum(preferredSize), + sizeAtPreferred(preferredSize), sizeAtMaximum(preferredSize), + skipInPreferred(0), type(Normal), hasSize(true), + isLayoutAnchor(false) {} + + AnchorData(qreal size) + : QSimplexVariable(), from(0), to(0), + minSize(size), prefSize(size), maxSize(size), + sizeAtMinimum(size), sizeAtPreferred(size), sizeAtMaximum(size), + skipInPreferred(0), type(Normal), hasSize(true), + isLayoutAnchor(false) {} + + AnchorData() + : QSimplexVariable(), from(0), to(0), + minSize(0), prefSize(0), maxSize(0), + sizeAtMinimum(0), sizeAtPreferred(0), sizeAtMaximum(0), + skipInPreferred(0), type(Normal), hasSize(false), + 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; + maxSize = size; + sizeAtMinimum = size; + sizeAtPreferred = 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 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 sizeAtMaximum; + + 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' +protected: + AnchorData(Type type, qreal size = 0) + : QSimplexVariable(), from(0), to(0), + minSize(size), prefSize(size), + maxSize(size), sizeAtMinimum(size), + sizeAtPreferred(size), sizeAtMaximum(size), + skipInPreferred(0), type(type), hasSize(true), + isLayoutAnchor(false) {} +}; + +#ifdef QT_DEBUG +inline QString AnchorData::toString() const +{ + return QString::fromAscii("Anchor(%1)").arg(name); +} +#endif + +struct SequentialAnchorData : public AnchorData +{ + SequentialAnchorData() : AnchorData(AnchorData::Sequential) + { +#ifdef QT_DEBUG + name = QLatin1String("SequentialAnchorData"); +#endif + } + + virtual void updateChildrenSizes(); + virtual void refreshSizeHints(qreal effectiveSpacing); + + 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(AnchorData::Parallel), + firstEdge(first), secondEdge(second) + { + // ### 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); + + 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; +}; + + +/*! + \internal + + QGraphicsAnchorLayout private methods and attributes. +*/ +class 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, + PreferredToMax + }; + + // 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 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); + + // helper function used by the 4 API functions + void anchor(QGraphicsLayoutItem *firstItem, + Qt::AnchorPoint firstEdge, + QGraphicsLayoutItem *secondItem, + Qt::AnchorPoint secondEdge, + qreal *spacing = 0); + + // Anchor Manipulation methods + void addAnchor(QGraphicsLayoutItem *firstItem, + Qt::AnchorPoint firstEdge, + QGraphicsLayoutItem *secondItem, + Qt::AnchorPoint secondEdge, + AnchorData *data); + + void removeAnchor(QGraphicsLayoutItem *firstItem, + Qt::AnchorPoint firstEdge, + QGraphicsLayoutItem *secondItem, + Qt::AnchorPoint secondEdge); + + bool setAnchorSize(const QGraphicsLayoutItem *firstItem, + Qt::AnchorPoint firstEdge, + const QGraphicsLayoutItem *secondItem, + Qt::AnchorPoint secondEdge, + const qreal *anchorSize); + + bool anchorSize(const QGraphicsLayoutItem *firstItem, + Qt::AnchorPoint firstEdge, + const QGraphicsLayoutItem *secondItem, + Qt::AnchorPoint secondEdge, + 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); + + 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(); + + 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 + QPair<qreal, qreal> solveMinMax(QList<QSimplexConstraint *> constraints, + GraphPath path); + void solvePreferred(QList<QSimplexConstraint *> constraints); + +#ifdef QT_DEBUG + void dumpGraph(); +#endif + + + qreal spacings[NOrientations]; + // Size hints from simplex engine + qreal sizeHints[2][3]; + + // 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]; + + uint calculateGraphCacheDirty : 1; +}; + |