X-Git-Url: https://cloud.milkyroute.net/gitweb/dolphin.git/blobdiff_plain/59723fca41a44e4d1ee753e93589027cbdf8d20d..6bfa0ccfc701df5af5f043fce3168b3840858212:/src/kitemviews/kfileitemmodel.cpp

diff --git a/src/kitemviews/kfileitemmodel.cpp b/src/kitemviews/kfileitemmodel.cpp
index c0dedff39..eb7b16461 100644
--- a/src/kitemviews/kfileitemmodel.cpp
+++ b/src/kitemviews/kfileitemmodel.cpp
@@ -192,8 +192,30 @@ bool KFileItemModel::setData(int index, const QHash<QByteArray, QVariant>& value
 
     emit itemsChanged(KItemRangeList() << KItemRange(index, 1), changedRoles);
 
-    if (changedRoles.contains(sortRole())) {
-        m_resortAllItemsTimer->start();
+    // Trigger a resorting if the item's correct position has changed. Note
+    // that this can happen even if the sort role has not changed at all
+    // because the file name can be used as a fallback.
+    if (changedRoles.contains(sortRole()) || changedRoles.contains(roleForType(NameRole))) {
+        // Compare the changed item with its neighbors to see
+        // if an expensive resorting is needed at all.
+        const ItemData* changedItem = m_itemData.at(index);
+        const ItemData* previousItem = (index == 0) ? 0 : m_itemData.at(index - 1);
+        const ItemData* nextItem = (index == m_itemData.count() - 1) ? 0 : m_itemData.at(index + 1);
+
+        if ((previousItem && lessThan(changedItem, previousItem))
+            || (nextItem && lessThan(nextItem, changedItem))) {
+            m_resortAllItemsTimer->start();
+        } else if (groupedSorting() && changedRoles.contains(sortRole())) {
+            // The position is still correct, but the groups might have changed
+            // if the changed item is either the first or the last item in a
+            // group.
+            // In principle, we could try to find out if the item really is the
+            // first or last one in its group and then update the groups
+            // (possibly with a delayed timer to make sure that we don't
+            // re-calculate the groups very often if items are updated one by
+            // one), but starting m_resortAllItemsTimer is easier.
+            m_resortAllItemsTimer->start();
+        }
     }
 
     return true;
@@ -689,7 +711,6 @@ void KFileItemModel::resortAllItems()
         oldUrls.append(itemData->item.url());
     }
 
-    m_groups.clear();
     m_items.clear();
 
     // Resort the items
@@ -698,20 +719,45 @@ void KFileItemModel::resortAllItems()
         m_items.insert(m_itemData.at(i)->item.url(), i);
     }
 
-    // Determine the indexes that have been moved
-    QList<int> movedToIndexes;
-    movedToIndexes.reserve(itemCount);
-    for (int i = 0; i < itemCount; i++) {
-        const int newIndex = m_items.value(oldUrls.at(i));
-        movedToIndexes.append(newIndex);
+    // Determine the first index that has been moved.
+    int firstMovedIndex = 0;
+    while (firstMovedIndex < itemCount
+           && firstMovedIndex == m_items.value(oldUrls.at(firstMovedIndex))) {
+        ++firstMovedIndex;
     }
 
-    // Don't check whether items have really been moved and always emit a
-    // itemsMoved() signal after resorting: In case of grouped items
-    // the groups might change even if the items themselves don't change their
-    // position. Let the receiver of the signal decide whether a check for moved
-    // items makes sense.
-    emit itemsMoved(KItemRange(0, itemCount), movedToIndexes);
+    const bool itemsHaveMoved = firstMovedIndex < itemCount;
+    if (itemsHaveMoved) {
+        m_groups.clear();
+
+        int lastMovedIndex = itemCount - 1;
+        while (lastMovedIndex > firstMovedIndex
+               && lastMovedIndex == m_items.value(oldUrls.at(lastMovedIndex))) {
+            --lastMovedIndex;
+        }
+
+        Q_ASSERT(firstMovedIndex <= lastMovedIndex);
+
+        // Create a list movedToIndexes, which has the property that
+        // movedToIndexes[i] is the new index of the item with the old index
+        // firstMovedIndex + i.
+        const int movedItemsCount = lastMovedIndex - firstMovedIndex + 1;
+        QList<int> movedToIndexes;
+        movedToIndexes.reserve(movedItemsCount);
+        for (int i = firstMovedIndex; i <= lastMovedIndex; ++i) {
+            const int newIndex = m_items.value(oldUrls.at(i));
+            movedToIndexes.append(newIndex);
+        }
+
+        emit itemsMoved(KItemRange(firstMovedIndex, movedItemsCount), movedToIndexes);
+    } else if (groupedSorting()) {
+        // The groups might have changed even if the order of the items has not.
+        const QList<QPair<int, QVariant> > oldGroups = m_groups;
+        m_groups.clear();
+        if (groups() != oldGroups) {
+            emit groupsChanged();
+        }
+    }
 
 #ifdef KFILEITEMMODEL_DEBUG
     kDebug() << "[TIME] Resorting of" << itemCount << "items:" << timer.elapsed();