Fixed performance issues related to selections and deleting of files:

- Don't connect to KDirLister::itemDeleted(const KFileItem&), but KDirLister::itemsDeleted(const KFileItemList&). Otherwise Dolphin is informed about each single file deletion instead of getting the deleted items as a list. Thanks to David Faure for the hint!

- DolphinViewContainer::updateStatusBar() can be expensive when a lot of files are selected, as the file size must get retrieved. Assure that fast calls for updateStatusBar() don't trigger a synchronous update, do the update after 300 ms where no further update has been triggered.

- Dolphin provides a list of file items when emitting the selectionChanged() signal. Collecting the file items is a quite expensive operation, so use the same approach as when updating the statusbar: only emit the selection changed signal when no change has been done within 300 ms. This improves the performance when doing huge selections a lot.

- Make updateStatusBar() a private method, the main window should not need to take care about updating the statusbar (this is done internally now by DolphinViewContainer).

BUG: 199090
BUG: 195787
CCBUG: 199352
CCBUG: 188218

svn path=/trunk/KDE/kdebase/apps/; revision=995015

1 files changed, 16 insertions, 6 deletions

diff --git a/src/dolphinviewcontainer.h b/src/dolphinviewcontainer.h
index db6ee69d5..1f8f1caf6 100644
--- a/src/dolphinviewcontainer.h
+++ b/src/dolphinviewcontainer.h
@@ -120,20 +120,28 @@ public slots:
      */
     void showFilterBar(bool show);
 
+signals:
+    /**
+     * Is emitted whenever the filter bar has changed its visibility state.
+     */
+    void showFilterBarChanged(bool shown);
+
+private slots: 
     /**
      * Updates the number of items (= number of files + number of
      * directories) in the statusbar. If files are selected, the number
-     * of selected files and the sum of the filesize is shown.
+     * of selected files and the sum of the filesize is shown. The update
+     * is done asynchronously, as getting the sum of the
+     * filesizes can be an expensive operation.
      */
-    void updateStatusBar();
+    void delayedStatusBarUpdate();
 
-signals:
     /**
-     * Is emitted whenever the filter bar has changed its visibility state.
+     * Is invoked by DolphinViewContainer::delayedStatusBarUpdate() and
+     * updates the status bar synchronously.
      */
-    void showFilterBarChanged(bool shown);
+    void updateStatusBar();
 
-private slots:
     void updateProgress(int percent);
 
     /**
@@ -256,7 +264,9 @@ private:
     DolphinView* m_view;
 
     FilterBar* m_filterBar;
+
     DolphinStatusBar* m_statusBar;
+    QTimer* m_statusBarTimer;
 
     DolphinModel* m_dolphinModel;
     DolphinDirLister* m_dirLister;