Count the items inside directories in another thread

This prevents that the GUI freezes if there are many files inside the
directory, or if the access to the directory is slow for some other
reason.

BUG: 318518
REVIEW: 111920
FIXED-IN: 4.12.0

1 files changed, 90 insertions, 0 deletions

diff --git a/src/kitemviews/private/kdirectorycontentscounter.h b/src/kitemviews/private/kdirectorycontentscounter.h
new file mode 100644
index 000000000..425c3632a
--- /dev/null
+++ b/src/kitemviews/private/kdirectorycontentscounter.h
@@ -0,0 +1,90 @@
+/***************************************************************************
+ *   Copyright (C) 2011 by Peter Penz <[email protected]>             *
+ *   Copyright (C) 2013 by Frank Reininghaus <[email protected]>    *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
+ ***************************************************************************/
+
+#ifndef KDIRECTORYCONTENTSCOUNTER_H
+#define KDIRECTORYCONTENTSCOUNTER_H
+
+#include "kdirectorycontentscounterworker.h"
+
+#include <QSet>
+#include <QQueue>
+
+class KDirWatch;
+class KFileItemModel;
+class QString;
+
+class KDirectoryContentsCounter : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit KDirectoryContentsCounter(KFileItemModel* model, QObject* parent = 0);
+    ~KDirectoryContentsCounter();
+
+    /**
+     * Requests the number of items inside the directory \a path. The actual
+     * counting is done asynchronously, and the result is announced via the
+     * signal \a result.
+     *
+     * The directory \a path is watched for changes, and the signal is emitted
+     * again if a change occurs.
+     */
+    void addDirectory(const QString& path);
+
+    /**
+     * In contrast to \a addDirectory, this function counts the items inside
+     * the directory \a path synchronously and returns the result.
+     *
+     * The directory is watched for changes, and the signal \a result is
+     * emitted if a change occurs.
+     */
+    int countDirectoryContentsSynchronously(const QString& path);
+
+signals:
+    /**
+     * Signals that the directory \a path contains \a count items.
+     */
+    void result(const QString& path, int count);
+
+    void requestDirectoryContentsCount(const QString& path, KDirectoryContentsCounterWorker::Options options);
+
+private slots:
+    void slotResult(const QString& path, int count);
+    void slotDirWatchDirty(const QString& path);
+    void slotItemsRemoved();
+
+private:
+    void startWorker(const QString& path);
+
+private:
+    KFileItemModel* m_model;
+
+    QQueue<QString> m_queue;
+
+    QThread* m_workerThread;
+    KDirectoryContentsCounterWorker* m_worker;
+    bool m_workerIsBusy;
+
+    KDirWatch* m_dirWatcher;
+    QSet<QString> m_watchedDirs;    // Required as sadly KDirWatch does not offer a getter method
+                                    // to get all watched directories.
+};
+
+#endif
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