return;
}
- // Order the items in a way that the preview for the visible items
- // is generated first, as this improves the feeled performance a lot.
- // Implementation note: using KDirModel::itemForUrl() would lead to a more
- // readable code, but it is a lot slower in comparison to itemListContains().
- const QRect visibleArea = m_view->viewport()->rect();
- KFileItemList orderedItems;
- const int rowCount = m_proxyModel->rowCount();
- for (int row = 0; row < rowCount; ++row) {
- const QModelIndex proxyIndex = m_proxyModel->index(row, 0);
- const QRect itemRect = m_view->visualRect(proxyIndex);
- const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex);
- KFileItem item = m_dolphinModel->itemForIndex(dirIndex);
- const KUrl url = item.url();
- if (itemListContains(items, url)) {
- if (itemRect.intersects(visibleArea)) {
- orderedItems.insert(0, item);
- m_pendingItems.insert(0, url);
- } else {
- orderedItems.append(item);
- m_pendingItems.append(url);
- }
- }
+ KFileItemList orderedItems = items;
+ orderItems(orderedItems);
+
+ foreach (const KFileItem& item, orderedItems) {
+ m_pendingItems.append(item);
}
startPreviewJob(orderedItems);
preview.pixmap = pixmap;
m_previews.append(preview);
- m_dispatchedItems.append(item.url());
+ m_dispatchedItems.append(item);
}
void IconManager::slotPreviewJobFinished(KJob* job)
// queue is usually equal. So even when having a lot of elements the
// nested loop is no performance bottle neck, as the inner loop is only
// entered once in most cases.
- foreach (const KUrl& url, m_dispatchedItems) {
- QList<KUrl>::iterator begin = m_pendingItems.begin();
- QList<KUrl>::iterator end = m_pendingItems.end();
- for (QList<KUrl>::iterator it = begin; it != end; ++it) {
- if ((*it) == url) {
+ foreach (const KFileItem& item, m_dispatchedItems) {
+ KFileItemList::iterator begin = m_pendingItems.begin();
+ KFileItemList::iterator end = m_pendingItems.end();
+ for (KFileItemList::iterator it = begin; it != end; ++it) {
+ if ((*it).url() == item.url()) {
m_pendingItems.erase(it);
break;
}
}
m_dispatchedItems.clear();
- // Create a new preview job for the remaining items.
- // Order the items in a way that the preview for the visible items
- // is generated first, as this improves the feeled performance a lot.
- // Implementation note: using KDirModel::itemForUrl() would lead to a more
- // readable code, but it is a lot slower in comparison
- // to m_pendingItems.contains().
- const QRect visibleArea = m_view->viewport()->rect();
- KFileItemList orderedItems;
-
- const int rowCount = m_proxyModel->rowCount();
- for (int row = 0; row < rowCount; ++row) {
- const QModelIndex proxyIndex = m_proxyModel->index(row, 0);
- const QRect itemRect = m_view->visualRect(proxyIndex);
- const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex);
- KFileItem item = m_dolphinModel->itemForIndex(dirIndex);
- const KUrl url = item.url();
- if (m_pendingItems.contains(url)) {
- if (itemRect.intersects(visibleArea)) {
- orderedItems.insert(0, item);
- } else {
- orderedItems.append(item);
- }
- }
- }
+ KFileItemList orderedItems = m_pendingItems;
+ orderItems(orderedItems);
// Kill all suspended preview jobs. Usually when a preview job
// has been finished, slotPreviewJobFinished() clears all item queues.
m_previewJobs.clear();
}
-bool IconManager::itemListContains(const KFileItemList& items, const KUrl& url) const
+void IconManager::orderItems(KFileItemList& items)
{
- foreach (const KFileItem& item, items) {
- if (url == item.url()) {
- return true;
+ // Order the items in a way that the preview for the visible items
+ // is generated first, as this improves the feeled performance a lot.
+ //
+ // Implementation note: 2 different algorithms are used for the sorting.
+ // Algorithm 1 is faster when having a lot of items in comparison
+ // to the number of rows in the model. Algorithm 2 is faster
+ // when having quite less items in comparison to the number of rows in
+ // the model. Choosing the right algorithm is important when having directories
+ // with several hundreds or thousands of items.
+
+ const int itemCount = items.count();
+ const int rowCount = m_proxyModel->rowCount();
+ const QRect visibleArea = m_view->viewport()->rect();
+
+ if (itemCount * 10 > rowCount) {
+ // Algorithm 1: The number of items is > 10 % of the row count. Parse all rows
+ // and check whether the received row is part of the item list.
+ for (int row = 0; row < rowCount; ++row) {
+ const QModelIndex proxyIndex = m_proxyModel->index(row, 0);
+ const QRect itemRect = m_view->visualRect(proxyIndex);
+ const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex);
+
+ KFileItem item = m_dolphinModel->itemForIndex(dirIndex); // O(1)
+ const KUrl url = item.url();
+
+ // check whether the item is part of the item list 'items'
+ int index = -1;
+ for (int i = 0; i < itemCount; ++i) {
+ if (items[i].url() == url) {
+ index = i;
+ break;
+ }
+ }
+
+ if ((index > 0) && itemRect.intersects(visibleArea)) {
+ // The current item is (at least partly) visible. Move it
+ // to the front of the list, so that the preview is
+ // generated earlier.
+ items.removeAt(index);
+ items.insert(0, item);
+ }
+ }
+ } else {
+ // Algorithm 2: The number of items is <= 10 % of the row count. In this case iterate
+ // all items and receive the corresponding row from the item.
+ for (int i = 0; i < itemCount; ++i) {
+ const QModelIndex dirIndex = m_dolphinModel->indexForItem(items[i]); // O(n) (n = number of rows)
+ const QModelIndex proxyIndex = m_proxyModel->mapFromSource(dirIndex);
+ const QRect itemRect = m_view->visualRect(proxyIndex);
+
+ if (itemRect.intersects(visibleArea)) {
+ // The current item is (at least partly) visible. Move it
+ // to the front of the list, so that the preview is
+ // generated earlier.
+ items.insert(0, items[i]);
+ items.removeAt(i + 1);
+ }
}
}
- return false;
}
#include "iconmanager.moc"
projects / dolphin.git / blobdiff