diff options
| -rw-r--r-- | src/gui/graphicsview/qgraphicsanchorlayout_p.cpp | 99 | ||||
| -rw-r--r-- | src/gui/graphicsview/qgraphicsanchorlayout_p.h | 6 | ||||
| -rw-r--r-- | tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp | 51 |
3 files changed, 122 insertions, 34 deletions
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp index 8b7ff08..8d13b2b 100644 --- a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp +++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp @@ -648,15 +648,17 @@ static AnchorData *createSequence(Graph<AnchorVertex, AnchorData> *graph, 2. Go to (1) 3. Done + When creating the parallel anchors, the algorithm might identify unfeasible situations. In this + case the simplification process stops and returns false. Otherwise returns true. */ -void QGraphicsAnchorLayoutPrivate::simplifyGraph(Orientation orientation) +bool QGraphicsAnchorLayoutPrivate::simplifyGraph(Orientation orientation) { static bool noSimplification = !qgetenv("QT_ANCHORLAYOUT_NO_SIMPLIFICATION").isEmpty(); if (noSimplification || items.isEmpty()) - return; + return true; if (graphSimplified[orientation]) - return; + return true; graphSimplified[orientation] = true; #if 0 @@ -665,12 +667,18 @@ void QGraphicsAnchorLayoutPrivate::simplifyGraph(Orientation orientation) #endif if (!graph[orientation].rootVertex()) - return; + return true; bool dirty; + bool feasible = true; do { - dirty = simplifyGraphIteration(orientation); - } while (dirty); + dirty = simplifyGraphIteration(orientation, &feasible); + } while (dirty && feasible); + + if (!feasible) + graphSimplified[orientation] = false; + + return feasible; } /*! @@ -687,7 +695,8 @@ void QGraphicsAnchorLayoutPrivate::simplifyGraph(Orientation orientation) Note that there are some catches to this that are not covered by the above explanation, see the function comments for more details. */ -bool QGraphicsAnchorLayoutPrivate::simplifyGraphIteration(QGraphicsAnchorLayoutPrivate::Orientation orientation) +bool QGraphicsAnchorLayoutPrivate::simplifyGraphIteration(QGraphicsAnchorLayoutPrivate::Orientation orientation, + bool *feasible) { Q_Q(QGraphicsAnchorLayout); Graph<AnchorVertex, AnchorData> &g = graph[orientation]; @@ -835,6 +844,11 @@ bool QGraphicsAnchorLayoutPrivate::simplifyGraphIteration(QGraphicsAnchorLayoutP // create a parallel anchor between the new sequence and the old anchor. AnchorData *newAnchor = addAnchorMaybeParallel(&g, sequence); + if (!newAnchor) { + *feasible = false; + return false; + } + // When a new parallel anchor is create in the graph, we finish the iteration and return // true to indicate a new iteration is needed. This happens because a parallel anchor // changes the number of adjacents one vertex has, possibly opening up oportunities for @@ -1679,38 +1693,52 @@ QList<AnchorData *> getVariables(QList<QSimplexConstraint *> constraints) } /*! - \internal + \internal - Calculate graphs is the method that puts together all the helper routines - so that the AnchorLayout can calculate the sizes of each item. + Calculate graphs is the method that puts together all the helper routines + so that the AnchorLayout can calculate the sizes of each item. - In a nutshell it should do: + In a nutshell it should do: - 1) Update anchor nominal sizes, that is, the size that each anchor would - have if no other restrictions applied. This is done by quering the - layout style and the sizeHints of the items belonging to the layout. + 1) Refresh anchor nominal sizes, that is, the size that each anchor would + have if no other restrictions applied. This is done by quering the + layout style and the sizeHints of the items belonging to the layout. - 2) Simplify the graph by grouping together parallel and sequential anchors - into "group anchors". These have equivalent minimum, preferred and maximum - sizeHints as the anchors they replace. + 2) Simplify the graph by grouping together parallel and sequential anchors + into "group anchors". These have equivalent minimum, preferred and maximum + sizeHints as the anchors they replace. - 3) Check if we got to a trivial case. In some cases, the whole graph can be - simplified into a single anchor. If so, use this information. If not, - then call the Simplex solver to calculate the anchors sizes. + 3) Check if we got to a trivial case. In some cases, the whole graph can be + simplified into a single anchor. If so, use this information. If not, + then call the Simplex solver to calculate the anchors sizes. - 4) Once the root anchors had its sizes calculated, propagate that to the - anchors they represent. + 4) Once the root anchors had its sizes calculated, propagate that to the + anchors they represent. */ void QGraphicsAnchorLayoutPrivate::calculateGraphs( QGraphicsAnchorLayoutPrivate::Orientation orientation) { Q_Q(QGraphicsAnchorLayout); - // Simplify the graph - simplifyGraph(orientation); +#if defined(QT_DEBUG) || defined(Q_AUTOTEST_EXPORT) + lastCalculationUsedSimplex[orientation] = false; +#endif + + // Reset the nominal sizes of each anchor based on the current item sizes. This function + // works with both simplified and non-simplified graphs, so it'll work when the + // simplification is going to be reused. + if (!refreshAllSizeHints(orientation)) { + qWarning("QGraphicsAnchorLayout: anchor setup is not feasible."); + graphHasConflicts[orientation] = true; + return; + } - // Reset the nominal sizes of each anchor based on the current item sizes - setAnchorSizeHintsFromItems(orientation); + // Simplify the graph + if (!simplifyGraph(orientation)) { + qWarning("QGraphicsAnchorLayout: anchor setup is not feasible."); + graphHasConflicts[orientation] = true; + return; + } // Traverse all graph edges and store the possible paths to each vertex findPaths(orientation); @@ -1878,12 +1906,16 @@ bool QGraphicsAnchorLayoutPrivate::calculateNonTrunk(const QList<QSimplexConstra } /*! - \internal + \internal - For graph edges ("anchors") that represent items, this method updates their - intrinsic size restrictions, based on the item size hints. + Traverse the graph refreshing the size hints. Complex anchors will call the + refresh method of their children anchors. Simple anchors, if are internal + anchors, will query the associated item for their size hints. + + Returns false if some unfeasibility was found in the graph regarding the + complex anchors. */ -void QGraphicsAnchorLayoutPrivate::setAnchorSizeHintsFromItems(Orientation orientation) +bool QGraphicsAnchorLayoutPrivate::refreshAllSizeHints(Orientation orientation) { Graph<AnchorVertex, AnchorData> &g = graph[orientation]; QList<QPair<AnchorVertex *, AnchorVertex *> > vertices = g.connections(); @@ -1893,8 +1925,13 @@ void QGraphicsAnchorLayoutPrivate::setAnchorSizeHintsFromItems(Orientation orien for (int i = 0; i < vertices.count(); ++i) { AnchorData *data = g.edgeData(vertices.at(i).first, vertices.at(i).second);; Q_ASSERT(data->from && data->to); - data->refreshSizeHints(spacing); + + // During the traversal we check the feasibility of the complex anchors. + if (!data->refreshSizeHints(spacing)) + return false; } + + return true; } /*! diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h index d4eb2d4..a3de6f6 100644 --- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h +++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h @@ -428,8 +428,8 @@ public: qreal effectiveSpacing(Orientation orientation) const; // Activation methods - void simplifyGraph(Orientation orientation); - bool simplifyGraphIteration(Orientation orientation); + bool simplifyGraph(Orientation orientation); + bool simplifyGraphIteration(Orientation orientation, bool *feasible); void restoreSimplifiedGraph(Orientation orientation); void calculateGraphs(); @@ -441,7 +441,7 @@ public: bool calculateNonTrunk(const QList<QSimplexConstraint *> &constraints, const QList<AnchorData *> &variables); - void setAnchorSizeHintsFromItems(Orientation orientation); + bool refreshAllSizeHints(Orientation orientation); void findPaths(Orientation orientation); void constraintsFromPaths(Orientation orientation); void updateAnchorSizes(Orientation orientation); diff --git a/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp b/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp index 7b87969..facc1ef 100644 --- a/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp +++ b/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp @@ -82,6 +82,7 @@ private slots: void expandingParallel(); void floatConflict(); void infiniteMaxSizes(); + void simplifiableUnfeasible(); }; class RectWidget : public QGraphicsWidget @@ -1755,5 +1756,55 @@ void tst_QGraphicsAnchorLayout::infiniteMaxSizes() QCOMPARE(d->geometry(), QRectF(QWIDGETSIZE_MAX - 50, 0, 50, 10)); } +void tst_QGraphicsAnchorLayout::simplifiableUnfeasible() +{ + QGraphicsWidget *a = createItem(QSizeF(70.0, 100.0), + QSizeF(100.0, 100.0), + QSizeF(100.0, 100.0), "A"); + + QGraphicsWidget *b = createItem(QSizeF(110.0, 100.0), + QSizeF(150.0, 100.0), + QSizeF(190.0, 100.0), "B"); + + QGraphicsAnchorLayout *l = new QGraphicsAnchorLayout; + l->setContentsMargins(0, 0, 0, 0); + l->setSpacing(0); + + l->addAnchor(l, Qt::AnchorTop, a, Qt::AnchorTop); + l->addAnchor(a, Qt::AnchorBottom, b, Qt::AnchorTop); + l->addAnchor(b, Qt::AnchorBottom, l, Qt::AnchorBottom); + + l->addAnchors(l, a, Qt::Horizontal); + l->addAnchor(l, Qt::AnchorLeft, b, Qt::AnchorLeft); + l->addAnchor(b, Qt::AnchorRight, a, Qt::AnchorRight); + + QCOMPARE(l->count(), 2); + + QGraphicsWidget p; + p.setLayout(l); + + l->invalidate(); + QVERIFY(layoutHasConflict(l)); + if (hasSimplification) + QVERIFY(!usedSimplex(l, Qt::Horizontal)); + + // Now we make it valid again + b->setMinimumWidth(100); + + l->invalidate(); + QVERIFY(!layoutHasConflict(l)); + if (hasSimplification) + QVERIFY(!usedSimplex(l, Qt::Horizontal)); + + // And make it invalid again + a->setPreferredWidth(70); + a->setMaximumWidth(70); + + l->invalidate(); + QVERIFY(layoutHasConflict(l)); + if (hasSimplification) + QVERIFY(!usedSimplex(l, Qt::Horizontal)); +} + QTEST_MAIN(tst_QGraphicsAnchorLayout) #include "tst_qgraphicsanchorlayout.moc" |