QHeaderView - move ishidden into the section

Since we already have the section there is no need to have an
extra structure. It simplifies the code itself and the code
is overall more efficient.

The benchmark seems to show overall performance increasement
various places (e.g insert, swapSection).

Change-Id: I623453b69a9a830908e8d9d5f3816ccebe073c9f
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

2 files changed, 47 insertions, 59 deletions

diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index 75a513fb67..75ca1e656e 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -751,7 +751,7 @@ void QHeaderView::moveSection(int from, int to)
     //int oldHeaderLength = length(); // ### for debugging; remove later
     d->initializeIndexMapping();
 
-    QBitArray sectionHidden = d->sectionHidden;
+    QBitArray sectionHidden = d->sectionsHiddenToBitVector();
     int *visualIndices = d->visualIndices.data();
     int *logicalIndices = d->logicalIndices.data();
     int logical = logicalIndices[from];
@@ -788,8 +788,8 @@ void QHeaderView::moveSection(int from, int to)
         }
     }
     if (!sectionHidden.isEmpty()) {
-        sectionHidden.setBit(to, d->sectionHidden.testBit(from));
-        d->sectionHidden = sectionHidden;
+        sectionHidden.setBit(to, d->isVisualIndexHidden(from));
+        d->setHiddenSectionsFromBitVector(sectionHidden);
     }
     visualIndices[logical] = to;
     logicalIndices[to] = logical;
@@ -860,11 +860,11 @@ void QHeaderView::swapSections(int first, int second)
     d->visualIndices[secondLogical] = first;
     d->logicalIndices[first] = secondLogical;
 
-    if (!d->sectionHidden.isEmpty()) {
-        bool firstHidden = d->sectionHidden.testBit(first);
-        bool secondHidden = d->sectionHidden.testBit(second);
-        d->sectionHidden.setBit(first, secondHidden);
-        d->sectionHidden.setBit(second, firstHidden);
+    if (!d->hiddenSectionSize.isEmpty()) {
+        bool firstHidden = d->isVisualIndexHidden(first);
+        bool secondHidden = d->isVisualIndexHidden(second);
+        d->setVisualIndexHidden(first, secondHidden);
+        d->setVisualIndexHidden(second, firstHidden);
     }
 
     d->viewport->update();
@@ -992,11 +992,11 @@ bool QHeaderView::isSectionHidden(int logicalIndex) const
 {
     Q_D(const QHeaderView);
     d->executePostedLayout();
-    if (logicalIndex >= d->sectionHidden.count() || logicalIndex < 0 || logicalIndex >= d->sectionCount())
+    if (d->hiddenSectionSize.isEmpty() || logicalIndex < 0 || logicalIndex >= d->sectionCount())
         return false;
     int visual = visualIndex(logicalIndex);
     Q_ASSERT(visual != -1);
-    return d->sectionHidden.testBit(visual);
+    return d->isVisualIndexHidden(visual);
 }
 
 /*!
@@ -1035,20 +1035,13 @@ void QHeaderView::setSectionHidden(int logicalIndex, bool hide)
         if (!d->hasAutoResizeSections())
             resizeSection(logicalIndex, 0);
         d->hiddenSectionSize.insert(logicalIndex, size);
-        if (d->sectionHidden.count() < count())
-            d->sectionHidden.resize(count());
-        d->sectionHidden.setBit(visual, true);
+        d->setVisualIndexHidden(visual, true);
         if (d->hasAutoResizeSections())
             d->doDelayedResizeSections();
     } else {
         int size = d->hiddenSectionSize.value(logicalIndex, d->defaultSectionSize);
         d->hiddenSectionSize.remove(logicalIndex);
-        if (d->hiddenSectionSize.isEmpty()) {
-            d->sectionHidden.clear();
-        } else {
-            Q_ASSERT(visual <= d->sectionHidden.count());
-            d->sectionHidden.setBit(visual, false);
-        }
+        d->setVisualIndexHidden(visual, false);
         resizeSection(logicalIndex, size);
     }
 }
@@ -1901,17 +1894,6 @@ void QHeaderView::sectionsInserted(const QModelIndex &parent,
         }
     }
 
-    // insert sections into sectionsHidden
-    if (!d->sectionHidden.isEmpty()) {
-        QBitArray sectionHidden(d->sectionHidden);
-        sectionHidden.resize(sectionHidden.count() + insertCount);
-        sectionHidden.fill(false, logicalFirst, logicalLast + 1);
-        for (int j = logicalLast + 1; j < sectionHidden.count(); ++j)
-            //here we simply copy the old sectionHidden
-            sectionHidden.setBit(j, d->sectionHidden.testBit(j - insertCount));
-        d->sectionHidden = sectionHidden;
-    }
-
     // insert sections into hiddenSectionSize
     QHash<int, int> newHiddenSectionSize; // from logical index to section size
     for (int i = 0; i < logicalFirst; ++i)
@@ -1960,19 +1942,6 @@ void QHeaderViewPrivate::updateHiddenSections(int logicalFirst, int logicalLast)
         if (q->isSectionHidden(j))
             newHiddenSectionSize[j - changeCount] = hiddenSectionSize[j];
     hiddenSectionSize = newHiddenSectionSize;
-
-    // remove sections from sectionsHidden
-    if (!sectionHidden.isEmpty()) {
-        const int newsize = qMin(sectionCount() - changeCount, sectionHidden.size());
-        QBitArray newSectionHidden(newsize);
-        for (int j = 0, k = 0; j < sectionHidden.size(); ++j) {
-            const int logical = logicalIndex(j);
-            if (logical < logicalFirst || logical > logicalLast) {
-                newSectionHidden[k++] = sectionHidden[j];
-            }
-        }
-        sectionHidden = newSectionHidden;
-    }
 }
 
 void QHeaderViewPrivate::_q_sectionsRemoved(const QModelIndex &parent,
@@ -2061,8 +2030,11 @@ void QHeaderViewPrivate::_q_layoutAboutToBeChanged()
         || model->columnCount(root) == 0)
         return;
 
-    for (int i = 0; i < sectionHidden.count(); ++i)
-        if (sectionHidden.testBit(i)) // ### note that we are using column or row 0
+    if (hiddenSectionSize.count() == 0)
+        return;
+
+    for (int i = 0; i < sectionItems.count(); ++i)
+        if (isVisualIndexHidden(i)) // ### note that we are using column or row 0
             persistentHiddenSections.append(orientation == Qt::Horizontal
                                             ? model->index(0, logicalIndex(i), root)
                                             : model->index(logicalIndex(i), 0, root));
@@ -2079,7 +2051,8 @@ void QHeaderViewPrivate::_q_layoutChanged()
         return;
     }
 
-    QBitArray oldSectionHidden = sectionHidden;
+    QBitArray oldSectionHidden = sectionsHiddenToBitVector();
+    oldSectionHidden.resize(sectionItems.size());
     bool sectionCountChanged = false;
 
     for (int i = 0; i < persistentHiddenSections.count(); ++i) {
@@ -2193,8 +2166,6 @@ void QHeaderView::initializeSections(int start, int end)
         d->stretchSections = newSectionCount;
     else if (d->globalResizeMode == ResizeToContents)
          d->contentsSections = newSectionCount;
-    if (!d->sectionHidden.isEmpty())
-        d->sectionHidden.resize(newSectionCount);
 
     if (newSectionCount > oldCount)
         d->createSectionItems(start, end, (end - start + 1) * d->defaultSectionSize, d->globalResizeMode);
@@ -3385,7 +3356,6 @@ void QHeaderViewPrivate::clear()
     visualIndices.clear();
     logicalIndices.clear();
     sectionSelected.clear();
-    sectionHidden.clear();
     hiddenSectionSize.clear();
     sectionItems.clear();
     invalidateCachedSizeHint();
@@ -3526,7 +3496,7 @@ void QHeaderViewPrivate::setDefaultSectionSize(int size)
         preventCursorChangeInSetOffset = true;
     for (int i = 0; i < sectionItems.count(); ++i) {
         QHeaderViewPrivate::SectionItem &section = sectionItems[i];
-        if (sectionHidden.isEmpty() || !sectionHidden.testBit(i)) { // resize on not hidden.
+        if (hiddenSectionSize.isEmpty() || !isVisualIndexHidden(i)) { // resize on not hidden.
             const int newSize = size;
             if (newSize != section.size) {
                 length += newSize - section.size; //the whole length is changed
@@ -3629,11 +3599,11 @@ int QHeaderViewPrivate::viewSectionSizeHint(int logical) const
 
 int QHeaderViewPrivate::adjustedVisualIndex(int visualIndex) const
 {
-    if (!sectionHidden.isEmpty()) {
+    if (!hiddenSectionSize.isEmpty()) {
         int adjustedVisualIndex = visualIndex;
         int currentVisualIndex = 0;
         for (int i = 0; i < sectionItems.count(); ++i) {
-            if (sectionHidden.testBit(i))
+            if (isVisualIndexHidden(i))
                 ++adjustedVisualIndex;
             else
                 ++currentVisualIndex;
@@ -3669,7 +3639,7 @@ void QHeaderViewPrivate::write(QDataStream &out) const
     out << visualIndices;
     out << logicalIndices;
 
-    out << sectionHidden;
+    out << sectionsHiddenToBitVector();
     out << hiddenSectionSize;
 
     out << length;
@@ -3706,6 +3676,7 @@ bool QHeaderViewPrivate::read(QDataStream &in)
     in >> visualIndices;
     in >> logicalIndices;
 
+    QBitArray sectionHidden;
     in >> sectionHidden;
     in >> hiddenSectionSize;
 
@@ -3739,6 +3710,7 @@ bool QHeaderViewPrivate::read(QDataStream &in)
             newSectionItems.append(sectionItems[u]);
     }
     sectionItems = newSectionItems;
+    setHiddenSectionsFromBitVector(sectionHidden);
     recalcSectionStartPos();
 
     int tmpint;
diff --git a/src/widgets/itemviews/qheaderview_p.h b/src/widgets/itemviews/qheaderview_p.h
index b2af821e9b..81f1b176ee 100644
--- a/src/widgets/itemviews/qheaderview_p.h
+++ b/src/widgets/itemviews/qheaderview_p.h
@@ -171,11 +171,11 @@ public:
     }
 
     inline bool isVisualIndexHidden(int visual) const {
-        return !sectionHidden.isEmpty() && sectionHidden.at(visual);
+        return sectionItems.at(visual).isHidden;
     }
 
     inline void setVisualIndexHidden(int visual, bool hidden) {
-        if (!sectionHidden.isEmpty()) sectionHidden.setBit(visual, hidden);
+        sectionItems[visual].isHidden = hidden;
     }
 
     inline bool hasAutoResizeSections() const {
@@ -258,7 +258,6 @@ public:
     mutable QVector<int> visualIndices; // visualIndex = visualIndices.at(logicalIndex)
     mutable QVector<int> logicalIndices; // logicalIndex = row or column in the model
     mutable QBitArray sectionSelected; // from logical index to bit
-    mutable QBitArray sectionHidden; // from visual index to bit
     mutable QHash<int, int> hiddenSectionSize; // from logical index to section size
     mutable QHash<int, int> cascadingSectionSize; // from visual index to section size
     mutable QSize cachedSizeHint;
@@ -301,7 +300,7 @@ public:
 
     struct SectionItem {
         uint size : 20;
-        uint reservedForIsHidden : 1;
+        uint isHidden : 1;
         uint resizeMode : 5;  // (holding QHeaderView::ResizeMode)
         uint currentlyUnusedPadding : 6;
 
@@ -311,9 +310,9 @@ public:
             int tmpDataStreamSectionCount; // recalcSectionStartPos() or set sectionStartposRecalc to true
         };                                 // to ensure that calculated_startpos will be calculated afterwards.
 
-        inline SectionItem() : size(0), resizeMode(QHeaderView::Interactive) {}
+        inline SectionItem() : size(0), isHidden(0), resizeMode(QHeaderView::Interactive) {}
         inline SectionItem(int length, QHeaderView::ResizeMode mode)
-            : size(length), resizeMode(mode), calculated_startpos(-1) {}
+            : size(length), isHidden(0), resizeMode(mode), calculated_startpos(-1) {}
         inline int sectionSize() const { return size; }
         inline int calculatedEndPos() const { return calculated_startpos + size; }
 #ifndef QT_NO_DATASTREAM
@@ -339,6 +338,23 @@ public:
         return len;
     }
 
+    QBitArray sectionsHiddenToBitVector() const
+    {
+        QBitArray sectionHidden;
+        if (!hiddenSectionSize.isEmpty()) {
+            sectionHidden.resize(sectionItems.size());
+            for (int u = 0; u < sectionItems.size(); ++u)
+                sectionHidden[u] = sectionItems.at(u).isHidden;
+        }
+        return sectionHidden;
+    }
+
+    void setHiddenSectionsFromBitVector(const QBitArray &sectionHidden) {
+        SectionItem *sectionData = sectionItems.data();
+        for (int i = 0; i < sectionHidden.count(); ++i)
+            sectionData[i].isHidden = sectionHidden.at(i);
+    }
+
     int headerSectionSize(int visual) const;
     int headerSectionPosition(int visual) const;
     int headerVisualIndexAt(int position) const;