KDirectoryContentsCounter: show intermediate dir size counting results, improve stopping, improve data caching

Two user visible changes:
 * we can see the dir size changing as it is updated.
 * This makes the file counting a lot more reactive, when changing directories for instance.

`KDirectoryContentsCounterWorker::walkDir` is not recursive anymore.

The cache is now shared and only a single thread is used to count size recursively.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/kitemviews/kfileitemmodel.cpp b/src/kitemviews/kfileitemmodel.cpp
index 0d61775ad..6617fbec6 100644
--- a/src/kitemviews/kfileitemmodel.cpp
+++ b/src/kitemviews/kfileitemmodel.cpp
@@ -129,6 +129,8 @@ void KFileItemModel::refreshDirectory(const QUrl &url)
     }
 
     m_dirLister->openUrl(url, KDirLister::Reload);
+
+    Q_EMIT directoryRefreshing();
 }
 
 QUrl KFileItemModel::directory() const