Improve the performance of the code part which checks which items are visible. Although the code is less readable now, it requires only 0,5 seconds for 2500 items instead of 2 seconds.

svn path=/trunk/KDE/kdebase/apps/; revision=819663

1 files changed, 15 insertions, 1 deletions

diff --git a/src/iconmanager.h b/src/iconmanager.h
index 85538f87d..b5a822175 100644
--- a/src/iconmanager.h
+++ b/src/iconmanager.h
@@ -60,10 +60,18 @@ public:
     bool showPreview() const;
 
     /**
-     * Updates the previews for all already available items.
+     * Updates the previews for all already available items. It is only necessary
+     * to invoke this method when the icon size of the abstract item view has
+     * been changed.
      */
     void updatePreviews();
 
+    /**
+     * Cancels all pending previews. Should be invoked when the URL of the item
+     * view has been changed.
+     */
+    void cancelPreviews();
+
 private slots:
     /**
      * Generates previews for the items \a items asynchronously.
@@ -144,6 +152,12 @@ private:
     /** Kills all ongoing preview jobs. */
     void killPreviewJobs();
 
+    /**
+     * Returns true, if the item list \a items contains an item with the
+     * URL \a url. This is a helper method for IconManager::generatePreviews().
+     */
+    bool itemListContains(const KFileItemList& items, const KUrl& url) const;
+
 private:
     /** Remembers the pixmap for an item specified by an URL. */
     struct ItemInfo