Respect the per-item layoutSpacing() if the style uses that feature.

We move the QLayoutStyleInfo class out of the gridlayout engine to a
common header file so that anchor layout also can utilize it.

Due to that we now can have a per-item spacing we have to change the
'effectiveSpacing' argument of refreshSizeHints to just take a
QLayoutStyleInfo pointer that we will later query for the actual
spacing used.

5 files changed, 109 insertions, 69 deletions

diff --git a/src/gui/graphicsview/qgraphicsanchorlayout.cpp b/src/gui/graphicsview/qgraphicsanchorlayout.cpp
index 081572f..00d3478 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout.cpp
@@ -400,7 +400,7 @@ void QGraphicsAnchorLayout::setSpacing(qreal spacing)
 qreal QGraphicsAnchorLayout::horizontalSpacing() const
 {
     Q_D(const QGraphicsAnchorLayout);
-    return d->effectiveSpacing(QGraphicsAnchorLayoutPrivate::Horizontal);
+    return d->styleInfo().defaultSpacing(Qt::Horizontal);
 }
 
 /*!
@@ -411,7 +411,7 @@ qreal QGraphicsAnchorLayout::horizontalSpacing() const
 qreal QGraphicsAnchorLayout::verticalSpacing() const
 {
     Q_D(const QGraphicsAnchorLayout);
-    return d->effectiveSpacing(QGraphicsAnchorLayoutPrivate::Vertical);
+    return d->styleInfo().defaultSpacing(Qt::Vertical);
 }
 
 /*!
@@ -481,7 +481,8 @@ void QGraphicsAnchorLayout::invalidate()
 {
     Q_D(QGraphicsAnchorLayout);
     QGraphicsLayout::invalidate();
-    d->calculateGraphCacheDirty = 1;
+    d->calculateGraphCacheDirty = true;
+    d->styleInfoDirty = true;
 }
 
 /*!
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
index 8c8c303..5bc6708 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
@@ -141,7 +141,7 @@ static void internalSizeHints(QSizePolicy::Policy policy,
         *expSize = *prefSize;
 }
 
-void AnchorData::refreshSizeHints(qreal effectiveSpacing)
+void AnchorData::refreshSizeHints(const QLayoutStyleInfo *styleInfo)
 {
     const bool isInternalAnchor = from->m_item == to->m_item;
 
@@ -196,7 +196,20 @@ void AnchorData::refreshSizeHints(qreal effectiveSpacing)
             // their effective size hints might be narrowed down due to their size policies.
             prefSizeHint = prefSize;
         } else {
-            prefSizeHint = effectiveSpacing;
+            const Qt::Orientation orient = Qt::Orientation(QGraphicsAnchorLayoutPrivate::edgeOrientation(from->m_edge) + 1);
+            qreal s = styleInfo->defaultSpacing(orient);
+            if (s < 0) {
+                QSizePolicy::ControlType controlTypeFrom = from->m_item->sizePolicy().controlType();
+                QSizePolicy::ControlType controlTypeTo = to->m_item->sizePolicy().controlType();
+                s = styleInfo->perItemSpacing(controlTypeFrom, controlTypeTo, orient);
+
+                // ### Currently we do not support negative anchors inside the graph.
+                // To avoid those being created by a negative style spacing, we must
+                // make this test.
+                if (s < 0)
+                    s = 0;
+            }
+            prefSizeHint = s;
         }
         maxSizeHint = QWIDGETSIZE_MAX;
     }
@@ -227,17 +240,17 @@ void ParallelAnchorData::updateChildrenSizes()
     secondEdge->updateChildrenSizes();
 }
 
-void ParallelAnchorData::refreshSizeHints(qreal effectiveSpacing)
+void ParallelAnchorData::refreshSizeHints(const QLayoutStyleInfo *styleInfo)
 {
-    refreshSizeHints_helper(effectiveSpacing);
+    refreshSizeHints_helper(styleInfo);
 }
 
-void ParallelAnchorData::refreshSizeHints_helper(qreal effectiveSpacing,
+void ParallelAnchorData::refreshSizeHints_helper(const QLayoutStyleInfo *styleInfo,
                                                  bool refreshChildren)
 {
     if (refreshChildren) {
-        firstEdge->refreshSizeHints(effectiveSpacing);
-        secondEdge->refreshSizeHints(effectiveSpacing);
+        firstEdge->refreshSizeHints(styleInfo);
+        secondEdge->refreshSizeHints(styleInfo);
     }
 
     // ### should we warn if the parallel connection is invalid?
@@ -362,12 +375,12 @@ void SequentialAnchorData::updateChildrenSizes()
     }
 }
 
-void SequentialAnchorData::refreshSizeHints(qreal effectiveSpacing)
+void SequentialAnchorData::refreshSizeHints(const QLayoutStyleInfo *styleInfo)
 {
-    refreshSizeHints_helper(effectiveSpacing);
+    refreshSizeHints_helper(styleInfo);
 }
 
-void SequentialAnchorData::refreshSizeHints_helper(qreal effectiveSpacing,
+void SequentialAnchorData::refreshSizeHints_helper(const QLayoutStyleInfo *styleInfo,
                                                    bool refreshChildren)
 {
     minSize = 0;
@@ -380,7 +393,7 @@ void SequentialAnchorData::refreshSizeHints_helper(qreal effectiveSpacing,
 
         // If it's the case refresh children information first
         if (refreshChildren)
-            edge->refreshSizeHints(effectiveSpacing);
+            edge->refreshSizeHints(styleInfo);
 
         minSize += edge->minSize;
         prefSize += edge->prefSize;
@@ -458,7 +471,7 @@ QString GraphPath::toString() const
 #endif
 
 QGraphicsAnchorLayoutPrivate::QGraphicsAnchorLayoutPrivate()
-    : calculateGraphCacheDirty(1)
+    : calculateGraphCacheDirty(true), styleInfoDirty(true)
 {
     for (int i = 0; i < NOrientations; ++i) {
         for (int j = 0; j < 3; ++j) {
@@ -1565,34 +1578,32 @@ void QGraphicsAnchorLayoutPrivate::correctEdgeDirection(QGraphicsLayoutItem *&fi
     }
 }
 
-qreal QGraphicsAnchorLayoutPrivate::effectiveSpacing(Orientation orientation) const
+QLayoutStyleInfo &QGraphicsAnchorLayoutPrivate::styleInfo() const
 {
-    Q_Q(const QGraphicsAnchorLayout);
-    qreal s = spacings[orientation];
-    if (s < 0) {
-        // ### make sure behaviour is the same as in QGraphicsGridLayout
+    if (styleInfoDirty) {
+        Q_Q(const QGraphicsAnchorLayout);
+        //### Fix this if QGV ever gets support for Metal style or different Aqua sizes.
+        QWidget *wid = 0;
+
         QGraphicsLayoutItem *parent = q->parentLayoutItem();
         while (parent && parent->isLayout()) {
             parent = parent->parentLayoutItem();
         }
+        QGraphicsWidget *w = 0;
         if (parent) {
             QGraphicsItem *parentItem = parent->graphicsItem();
-            if (parentItem && parentItem->isWidget()) {
-                QGraphicsWidget *w = static_cast<QGraphicsWidget*>(parentItem);
-                s = w->style()->pixelMetric(orientation == Horizontal
-                                            ? QStyle::PM_LayoutHorizontalSpacing
-                                            : QStyle::PM_LayoutVerticalSpacing);
-            }
+            if (parentItem && parentItem->isWidget())
+                w = static_cast<QGraphicsWidget*>(parentItem);
         }
-    }
 
-    // ### Currently we do not support negative anchors inside the graph.
-    // To avoid those being created by a negative style spacing, we must
-    // make this test.
-    if (s < 0)
-        s = 0;
+        QStyle *style = w ? w->style() : QApplication::style();
+        cachedStyleInfo = QLayoutStyleInfo(style, wid);
+        cachedStyleInfo.setDefaultSpacing(Qt::Horizontal, spacings[0]);
+        cachedStyleInfo.setDefaultSpacing(Qt::Vertical, spacings[1]);
 
-    return s;
+        styleInfoDirty = false;
+    }
+    return cachedStyleInfo;
 }
 
 /*!
@@ -1620,7 +1631,7 @@ void QGraphicsAnchorLayoutPrivate::calculateGraphs()
     dumpGraph(QString::fromAscii("%1-after").arg(count));
 #endif
 
-    calculateGraphCacheDirty = 0;
+    calculateGraphCacheDirty = false;
 }
 
 // ### Maybe getGraphParts could return the variables when traversing, at least
@@ -1847,12 +1858,11 @@ void QGraphicsAnchorLayoutPrivate::setAnchorSizeHintsFromItems(Orientation orien
     Graph<AnchorVertex, AnchorData> &g = graph[orientation];
     QList<QPair<AnchorVertex *, AnchorVertex *> > vertices = g.connections();
 
-    qreal spacing = effectiveSpacing(orientation);
-
+    QLayoutStyleInfo styleInf = styleInfo();
     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);
+        data->refreshSizeHints(&styleInf);
     }
 }
 
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
index d45c004..9b7d41e 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
@@ -159,7 +159,7 @@ struct AnchorData : public QSimplexVariable {
           type(Normal), hasSize(true), isLayoutAnchor(false) {}
 
     virtual void updateChildrenSizes() {}
-    virtual void refreshSizeHints(qreal effectiveSpacing);
+    virtual void refreshSizeHints(const QLayoutStyleInfo *styleInfo);
 
     virtual ~AnchorData() {}
 
@@ -226,9 +226,9 @@ struct SequentialAnchorData : public AnchorData
     }
 
     virtual void updateChildrenSizes();
-    virtual void refreshSizeHints(qreal effectiveSpacing);
+    virtual void refreshSizeHints(const QLayoutStyleInfo *styleInfo);
 
-    void refreshSizeHints_helper(qreal effectiveSpacing, bool refreshChildren = true);
+    void refreshSizeHints_helper(const QLayoutStyleInfo *styleInfo, bool refreshChildren = true);
 
     void setVertices(const QVector<AnchorVertex*> &vertices)
     {
@@ -261,9 +261,9 @@ struct ParallelAnchorData : public AnchorData
     }
 
     virtual void updateChildrenSizes();
-    virtual void refreshSizeHints(qreal effectiveSpacing);
+    virtual void refreshSizeHints(const QLayoutStyleInfo *styleInfo);
 
-    void refreshSizeHints_helper(qreal effectiveSpacing, bool refreshChildren = true);
+    void refreshSizeHints_helper(const QLayoutStyleInfo *styleInfo, bool refreshChildren = true);
 
     AnchorData* firstEdge;
     AnchorData* secondEdge;
@@ -423,9 +423,8 @@ public:
                               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;
+
+    QLayoutStyleInfo &styleInfo() const;
 
     // Activation methods
     void simplifyGraph(Orientation orientation);
@@ -524,6 +523,8 @@ public:
 #endif
 
     uint calculateGraphCacheDirty : 1;
+    mutable uint styleInfoDirty : 1;
+    mutable QLayoutStyleInfo cachedStyleInfo;
 
     friend class QGraphicsAnchorPrivate;
 };
diff --git a/src/gui/graphicsview/qgraphicslayout_p.h b/src/gui/graphicsview/qgraphicslayout_p.h
index 59c6dba..4aeae39 100644
--- a/src/gui/graphicsview/qgraphicslayout_p.h
+++ b/src/gui/graphicsview/qgraphicslayout_p.h
@@ -60,6 +60,8 @@
 #include "qgraphicslayout.h"
 #include "qgraphicslayoutitem_p.h"
 #include <QtGui/qstyle.h>
+#include <QtGui/qwidget.h>
+#include <QtGui/qstyleoption.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -76,6 +78,55 @@ inline bool qt_graphicsLayoutDebug()
 }
 #endif
 
+
+class QLayoutStyleInfo
+{
+public:
+    inline QLayoutStyleInfo() { invalidate(); }
+    inline QLayoutStyleInfo(QStyle *style, QWidget *widget)
+        : m_valid(true), m_style(style), m_widget(widget) 
+    {
+        Q_ASSERT(style);
+        if (widget) //###
+            m_styleOption.initFrom(widget);
+        m_defaultSpacing[0] = style->pixelMetric(QStyle::PM_LayoutHorizontalSpacing);
+        m_defaultSpacing[1] = style->pixelMetric(QStyle::PM_LayoutVerticalSpacing);
+    }
+
+    inline void invalidate() { m_valid = false; m_style = 0; m_widget = 0; }
+
+    inline QStyle *style() const { return m_style; }
+    inline QWidget *widget() const { return m_widget; }
+
+    inline bool operator==(const QLayoutStyleInfo &other)
+        { return m_style == other.m_style && m_widget == other.m_widget; }
+    inline bool operator!=(const QLayoutStyleInfo &other)
+        { return !(*this == other); }
+
+    inline void setDefaultSpacing(Qt::Orientation o, qreal spacing){
+        if (spacing >= 0)
+            m_defaultSpacing[o - 1] = spacing;
+    }
+
+    inline qreal defaultSpacing(Qt::Orientation o) const {
+        return m_defaultSpacing[o - 1];
+    }
+
+    inline qreal perItemSpacing(QSizePolicy::ControlType control1, 
+                                  QSizePolicy::ControlType control2,
+                                  Qt::Orientation orientation) const
+    {
+        Q_ASSERT(style());
+        return style()->layoutSpacing(control1, control2, orientation, &m_styleOption, widget());
+    }
+private:
+    bool m_valid;
+    QStyle *m_style;
+    QWidget *m_widget;
+    QStyleOption m_styleOption;
+    qreal m_defaultSpacing[2];
+};
+
 class Q_AUTOTEST_EXPORT QGraphicsLayoutPrivate : public QGraphicsLayoutItemPrivate
 {
     Q_DECLARE_PUBLIC(QGraphicsLayout)
diff --git a/src/gui/graphicsview/qgridlayoutengine_p.h b/src/gui/graphicsview/qgridlayoutengine_p.h
index a42a537..ed335a8 100644
--- a/src/gui/graphicsview/qgridlayoutengine_p.h
+++ b/src/gui/graphicsview/qgridlayoutengine_p.h
@@ -59,7 +59,7 @@
 #include "qmap.h"
 #include "qpair.h"
 #include "qvector.h"
-
+#include "qgraphicslayout_p.h"
 #include <float.h>
 
 QT_BEGIN_NAMESPACE
@@ -128,29 +128,6 @@ public:
 
 };
 
-class QLayoutStyleInfo
-{
-public:
-    inline QLayoutStyleInfo() { invalidate(); }
-    inline QLayoutStyleInfo(QStyle *style, QWidget *widget)
-        : q_valid(true), q_style(style), q_widget(widget) {}
-
-    inline void invalidate() { q_valid = false; q_style = 0; q_widget = 0; }
-
-    inline QStyle *style() const { return q_style; }
-    inline QWidget *widget() const { return q_widget; }
-
-    inline bool operator==(const QLayoutStyleInfo &other)
-        { return q_style == other.q_style && q_widget == other.q_widget; }
-    inline bool operator!=(const QLayoutStyleInfo &other)
-        { return !(*this == other); }
-
-private:
-    bool q_valid;
-    QStyle *q_style;
-    QWidget *q_widget;
-};
-
 class QGridLayoutBox
 {
 public: