Interface cleanups to prepare the return of "grouped sorting"

- Rename setCategorizedSorting() to setGroupedSorting()
- Change the model interface to allow enabling/disabling grouping
  without the need to declare a role (the sort role will be taken).
- Add dummy group role implementation in KFileItemModel

The grouping code itself requires some cleanups and might crash
at the moment or lead to weird layouts.

7 files changed, 76 insertions, 100 deletions

diff --git a/src/kitemviews/kfileitemmodel.cpp b/src/kitemviews/kfileitemmodel.cpp
index ddb89533c..3a49135f9 100644
--- a/src/kitemviews/kfileitemmodel.cpp
+++ b/src/kitemviews/kfileitemmodel.cpp
@@ -31,11 +31,10 @@
 #define KFILEITEMMODEL_DEBUG
 
 KFileItemModel::KFileItemModel(KDirLister* dirLister, QObject* parent) :
-    KItemModelBase(QByteArray(), "name", parent),
+    KItemModelBase("name", parent),
     m_dirLister(dirLister),
     m_naturalSorting(true),
     m_sortFoldersFirst(true),
-    m_groupRole(NoRole),
     m_sortRole(NameRole),
     m_caseSensitivity(Qt::CaseInsensitive),
     m_sortedItems(),
@@ -127,16 +126,6 @@ bool KFileItemModel::setData(int index, const QHash<QByteArray, QVariant>& value
     return false;
 }
 
-bool KFileItemModel::supportsGrouping() const
-{
-    return true;
-}
-
-bool KFileItemModel::supportsSorting() const
-{
-    return true;
-}
-
 void KFileItemModel::setSortFoldersFirst(bool foldersFirst)
 {
     if (foldersFirst != m_sortFoldersFirst) {
@@ -234,6 +223,20 @@ QString KFileItemModel::roleDescription(const QByteArray& role) const
     return descr;
 }
 
+QList<QPair<int, QVariant> > KFileItemModel::groups() const
+{
+    // TODO:
+    QPair<int, QVariant> group1(0, "Group 1");
+    QPair<int, QVariant> group2(5, "Group 2");
+    QPair<int, QVariant> group3(10, "Group 3");
+
+    QList<QPair<int, QVariant> > groups;
+    groups.append(group1);
+    groups.append(group2);
+    groups.append(group3);
+    return groups;
+}
+
 KFileItem KFileItemModel::fileItem(int index) const
 {
     if (index >= 0 && index < count()) {
@@ -403,10 +406,9 @@ void KFileItemModel::restoreExpandedUrls(const QSet<KUrl>& urls)
     m_restoredExpandedUrls = urls;
 }
 
-void KFileItemModel::onGroupRoleChanged(const QByteArray& current, const QByteArray& previous)
+void KFileItemModel::onGroupedSortingChanged(bool current)
 {
-    Q_UNUSED(previous);
-    m_groupRole = roleIndex(current);
+    Q_UNUSED(current);
 }
 
 void KFileItemModel::onSortRoleChanged(const QByteArray& current, const QByteArray& previous)
diff --git a/src/kitemviews/kfileitemmodel.h b/src/kitemviews/kfileitemmodel.h
index 4c36a2c21..7d10aad8e 100644
--- a/src/kitemviews/kfileitemmodel.h
+++ b/src/kitemviews/kfileitemmodel.h
@@ -55,18 +55,6 @@ public:
     virtual bool setData(int index, const QHash<QByteArray, QVariant>& values);
 
     /**
-     * @return True
-     * @reimp
-     */
-    virtual bool supportsGrouping() const;
-
-    /**
-     * @return True
-     * @reimp
-     */
-    virtual bool supportsSorting() const;
-
-    /**
      * Sets a separate sorting with folders first (true) or a mixed sorting of files and folders (false).
      */
     void setSortFoldersFirst(bool foldersFirst);
@@ -84,6 +72,9 @@ public:
     /** @reimp */
     virtual QString roleDescription(const QByteArray& role) const;
 
+    /** @reimp */
+    virtual QList<QPair<int, QVariant> > groups() const;
+
     /**
      * @return The file-item for the index \a index. If the index is in a valid
      *         range it is assured that the file-item is not null. The runtime
@@ -135,7 +126,7 @@ signals:
     void loadingCompleted();
 
 protected:
-    virtual void onGroupRoleChanged(const QByteArray& current, const QByteArray& previous);
+    virtual void onGroupedSortingChanged(bool current);
     virtual void onSortRoleChanged(const QByteArray& current, const QByteArray& previous);
     virtual void onSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 
@@ -209,7 +200,6 @@ private:
     bool m_naturalSorting;
     bool m_sortFoldersFirst;
 
-    Role m_groupRole;
     Role m_sortRole;
     Qt::CaseSensitivity m_caseSensitivity;
 
diff --git a/src/kitemviews/kitemlistview.cpp b/src/kitemviews/kitemlistview.cpp
index 6d1aeca24..a4cb4b041 100644
--- a/src/kitemviews/kitemlistview.cpp
+++ b/src/kitemviews/kitemlistview.cpp
@@ -845,6 +845,11 @@ void KItemListView::slotItemsChanged(const KItemRangeList& itemRanges,
     }
 }
 
+void KItemListView::slotGroupedSortingChanged(bool current)
+{
+    m_grouped = current;
+}
+
 void KItemListView::slotCurrentChanged(int current, int previous)
 {
     Q_UNUSED(previous);
@@ -1101,11 +1106,13 @@ void KItemListView::setModel(KItemModelBase* model)
                    this,    SLOT(slotItemsRemoved(KItemRangeList)));
         disconnect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
                    this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
+        disconnect(m_model, SIGNAL(groupedSortingChanged(bool)),
+                   this,    SLOT(slotGroupedSortingChanged(bool)));
     }
 
     m_model = model;
     m_layouter->setModel(model);
-    m_grouped = !model->groupRole().isEmpty();
+    m_grouped = model->groupedSorting();
 
     if (m_model) {
         connect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
@@ -1116,6 +1123,8 @@ void KItemListView::setModel(KItemModelBase* model)
                 this,    SLOT(slotItemsRemoved(KItemRangeList)));
         connect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
                 this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
+        connect(m_model, SIGNAL(groupedSortingChanged(bool)),
+                this,    SLOT(slotGroupedSortingChanged(bool)));
     }
 
     onModelChanged(model, previous);
diff --git a/src/kitemviews/kitemlistview.h b/src/kitemviews/kitemlistview.h
index e1678145d..c18f8cb84 100644
--- a/src/kitemviews/kitemlistview.h
+++ b/src/kitemviews/kitemlistview.h
@@ -253,6 +253,7 @@ protected slots:
                                   const QSet<QByteArray>& roles);
 
 private slots:
+    void slotGroupedSortingChanged(bool current);
     void slotCurrentChanged(int current, int previous);
     void slotSelectionChanged(const QSet<int>& current, const QSet<int>& previous);
     void slotAnimationFinished(QGraphicsWidget* widget,
diff --git a/src/kitemviews/kitemlistviewlayouter.cpp b/src/kitemviews/kitemlistviewlayouter.cpp
index f829824f0..30881abfd 100644
--- a/src/kitemviews/kitemlistviewlayouter.cpp
+++ b/src/kitemviews/kitemlistviewlayouter.cpp
@@ -332,18 +332,16 @@ void KItemListViewLayouter::doLayout()
             m_maximumItemOffset = 0;
         }
 
-        m_grouped = !m_model->groupRole().isEmpty();
-        /*if (m_grouped) {
+        m_grouped = m_model->groupedSorting();
+        if (m_grouped) {
             createGroupHeaders();
 
             const int lastGroupItemCount = m_model->count() - m_groups.last().firstItemIndex;
-            m_maximumOffset = m_groups.last().y + (lastGroupItemCount / m_columnCount) * m_rowHeight;
+            m_maximumScrollOffset = m_groups.last().y + (lastGroupItemCount / m_columnCount) * itemSize.height();
             if (lastGroupItemCount % m_columnCount != 0) {
-                m_maximumOffset += m_rowHeight;
+                m_maximumScrollOffset += itemSize.height();
             }
-        } else {*/
-         //   m_maximumOffset = m_minimumRowHeight * rowCount;
-        //}
+        }
 
 #ifdef KITEMLISTVIEWLAYOUTER_DEBUG
         kDebug() << "[TIME] doLayout() for " << m_model->count() << "items:" << timer.elapsed();
@@ -480,7 +478,6 @@ void KItemListViewLayouter::updateGroupedVisibleIndexes()
             m_lastVisibleIndex = nextGroupIndex - 1;
         }
     }
-    //Q_ASSERT(m_lastVisibleIndex < m_model->count());
     m_lastVisibleIndex = qBound(0, m_lastVisibleIndex, maxIndex);
 
     m_visibleIndexesDirty = false;
@@ -491,14 +488,13 @@ void KItemListViewLayouter::createGroupHeaders()
     m_groups.clear();
     m_groupIndexes.clear();
 
-    // TODO:
-    QList<int> numbers;
-    numbers << 0 << 5 << 6 << 13 << 20 << 25 << 30 << 35 << 50;
+    const QList<QPair<int, QVariant> > groups = m_model->groups();
 
     qreal y = 0;
-    for (int i = 0; i < numbers.count(); ++i) {
+    for (int i = 0; i < groups.count(); ++i) {
+        const int firstItemIndex = groups.at(i).first;
         if (i > 0) {
-            const int previousGroupItemCount = numbers[i] - m_groups.last().firstItemIndex;
+            const int previousGroupItemCount = firstItemIndex - m_groups.last().firstItemIndex;
             int previousGroupRowCount = previousGroupItemCount / m_columnCount;
             if (previousGroupItemCount % m_columnCount != 0) {
                 ++previousGroupRowCount;
@@ -509,11 +505,11 @@ void KItemListViewLayouter::createGroupHeaders()
         y += HeaderHeight;
 
         ItemGroup itemGroup;
-        itemGroup.firstItemIndex = numbers[i];
+        itemGroup.firstItemIndex = firstItemIndex;
         itemGroup.y = y;
 
         m_groups.append(itemGroup);
-        m_groupIndexes.insert(itemGroup.firstItemIndex);
+        m_groupIndexes.insert(firstItemIndex);
     }
 }
 
diff --git a/src/kitemviews/kitemmodelbase.cpp b/src/kitemviews/kitemmodelbase.cpp
index 7bfe607a4..3e6114027 100644
--- a/src/kitemviews/kitemmodelbase.cpp
+++ b/src/kitemviews/kitemmodelbase.cpp
@@ -35,15 +35,15 @@ bool KItemRange::operator == (const KItemRange& other) const
 
 KItemModelBase::KItemModelBase(QObject* parent) :
     QObject(parent),
-    m_groupRole(),
+    m_groupedSorting(false),
     m_sortRole(),
     m_sortOrder(Qt::AscendingOrder)
 {
 }
 
-KItemModelBase::KItemModelBase(const QByteArray& groupRole, const QByteArray& sortRole, QObject* parent) :
+KItemModelBase::KItemModelBase(const QByteArray& sortRole, QObject* parent) :
     QObject(parent),
-    m_groupRole(groupRole),
+    m_groupedSorting(false),
     m_sortRole(sortRole),
     m_sortOrder(Qt::AscendingOrder)
 {
@@ -60,34 +60,23 @@ bool KItemModelBase::setData(int index, const QHash<QByteArray, QVariant> &value
     return false;
 }
 
-bool KItemModelBase::supportsGrouping() const
+void KItemModelBase::setGroupedSorting(bool grouped)
 {
-    return false;
-}
-
-void KItemModelBase::setGroupRole(const QByteArray& role)
-{
-    if (supportsGrouping() && role != m_groupRole) {
-        const QByteArray previous = m_groupRole;
-        m_groupRole = role;
-        onGroupRoleChanged(role, previous);
-        emit groupRoleChanged(role, previous);
+    if (m_groupedSorting != grouped) {
+        m_groupedSorting = grouped;
+        onGroupedSortingChanged(grouped);
+        emit groupedSortingChanged(grouped);
     }
 }
 
-QByteArray KItemModelBase::groupRole() const
-{
-    return m_groupRole;
-}
-
-bool KItemModelBase::supportsSorting() const
+bool KItemModelBase::groupedSorting() const
 {
-    return false;
+    return m_groupedSorting;
 }
 
 void KItemModelBase::setSortRole(const QByteArray& role)
 {
-    if (supportsSorting() && role != m_sortRole) {
+    if (role != m_sortRole) {
         const QByteArray previous = m_sortRole;
         m_sortRole = role;
         onSortRoleChanged(role, previous);
@@ -102,7 +91,7 @@ QByteArray KItemModelBase::sortRole() const
 
 void KItemModelBase::setSortOrder(Qt::SortOrder order)
 {
-    if (supportsSorting() && order != m_sortOrder) {
+    if (order != m_sortOrder) {
         const Qt::SortOrder previous = m_sortOrder;
         m_sortOrder = order;
         onSortOrderChanged(order, previous);
@@ -115,6 +104,11 @@ QString KItemModelBase::roleDescription(const QByteArray& role) const
     return role;
 }
 
+QList<QPair<int, QVariant> > KItemModelBase::groups() const
+{
+    return QList<QPair<int, QVariant> >();
+}
+
 QMimeData* KItemModelBase::createMimeData(const QSet<int>& indexes) const
 {
     Q_UNUSED(indexes);
@@ -134,10 +128,9 @@ bool KItemModelBase::supportsDropping(int index) const
     return false;
 }
 
-void KItemModelBase::onGroupRoleChanged(const QByteArray& current, const QByteArray& previous)
+void KItemModelBase::onGroupedSortingChanged(bool current)
 {
     Q_UNUSED(current);
-    Q_UNUSED(previous);
 }
 
 void KItemModelBase::onSortRoleChanged(const QByteArray& current, const QByteArray& previous)
diff --git a/src/kitemviews/kitemmodelbase.h b/src/kitemviews/kitemmodelbase.h
index 763a02efd..693ffb763 100644
--- a/src/kitemviews/kitemmodelbase.h
+++ b/src/kitemviews/kitemmodelbase.h
@@ -52,7 +52,7 @@ typedef QList<KItemRange> KItemRangeList;
  *
  * One item consists of a variable number of role/value-pairs.
  *
- * A model can optionally provide sorting- and/or grouping-capabilities.
+ * A model can optionally provide sorting- and grouping-capabilities.
  */
 class LIBDOLPHINPRIVATE_EXPORT KItemModelBase : public QObject
 {
@@ -60,7 +60,7 @@ class LIBDOLPHINPRIVATE_EXPORT KItemModelBase : public QObject
 
 public:
     KItemModelBase(QObject* parent = 0);
-    KItemModelBase(const QByteArray& groupRole, const QByteArray& sortRole, QObject* parent = 0);
+    KItemModelBase(const QByteArray& sortRole, QObject* parent = 0);
     virtual ~KItemModelBase();
 
     /** @return The number of items. */
@@ -78,26 +78,13 @@ public:
     virtual bool setData(int index, const QHash<QByteArray, QVariant>& values);
 
     /**
-     * @return True if the model supports grouping of data. Per default false is returned.
-     *         If the model should support grouping it is necessary to overwrite
-     *         this method to return true and to implement KItemModelBase::onGroupRoleChanged().
+     * Enables/disables the grouped sorting. The method KItemModelBase::onGroupedSortingChanged() will be
+     * called so that model-implementations can react on the grouped-sorting change. Afterwards the
+     * signal groupedSortingChanged() will be emitted. If the grouped sorting is enabled, the method
+     * KItemModelBase::groups() must be implemented.
      */
-    virtual bool supportsGrouping() const;
-
-    /**
-     * Sets the group-role to \a role. The method KItemModelBase::onGroupRoleChanged() will be
-     * called so that model-implementations can react on the group-role change. Afterwards the
-     * signal groupRoleChanged() will be emitted.
-     */
-    void setGroupRole(const QByteArray& role);
-    QByteArray groupRole() const;
-
-    /**
-     * @return True if the model supports sorting of data. Per default false is returned.
-     *         If the model should support sorting it is necessary to overwrite
-     *         this method to return true and to implement KItemModelBase::onSortRoleChanged().
-     */
-    virtual bool supportsSorting() const;
+    void setGroupedSorting(bool grouped);
+    bool groupedSorting() const;
 
     /**
      * Sets the sort-role to \a role. The method KItemModelBase::onSortRoleChanged() will be
@@ -121,6 +108,8 @@ public:
      */
     virtual QString roleDescription(const QByteArray& role) const;
 
+    virtual QList<QPair<int, QVariant> > groups() const;
+
     /**
      * @return MIME-data for the items given by \a indexes. The default implementation
      *         returns 0. The ownership of the returned instance is in the hand of the
@@ -192,20 +181,16 @@ signals:
 
     void itemsChanged(const KItemRangeList& itemRanges, const QSet<QByteArray>& roles);
 
-    void groupRoleChanged(const QByteArray& current, const QByteArray& previous);
+    void groupedSortingChanged(bool current);
     void sortRoleChanged(const QByteArray& current, const QByteArray& previous);
     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 
 protected:
     /**
-     * Is invoked if the group role has been changed by KItemModelBase::setGroupRole(). Allows
-     * to react on the changed group role before the signal groupRoleChanged() will be emitted.
-     * The implementation must assure that the items are sorted in a way that they are grouped
-     * by the role given by \a current. Usually the most efficient way is to emit a
-     * itemsRemoved() signal for all items, reorder the items internally and to emit a
-     * itemsInserted() signal afterwards.
+     * Is invoked if the grouped sorting has been changed by KItemModelBase::setGroupedSorting(). Allows
+     * to react on the changed grouped sorting  before the signal groupedSortingChanged() will be emitted.
      */
-    virtual void onGroupRoleChanged(const QByteArray& current, const QByteArray& previous);
+    virtual void onGroupedSortingChanged(bool current);
 
     /**
      * Is invoked if the sort role has been changed by KItemModelBase::setSortRole(). Allows
@@ -228,7 +213,7 @@ protected:
     virtual void onSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 
 private:
-    QByteArray m_groupRole;
+    bool m_groupedSorting;
     QByteArray m_sortRole;
     Qt::SortOrder m_sortOrder;
 };