Persist size and treeview header state in preview dialog

- renamed variable m_headerState
 - renamed PreviewSelect class to PreviewSelectDialog
 - renamed previewselect files to previewselectdialog

src/gui/previewselectdialog.h

@@ -0,0 +1,84 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2011  Christophe Dumez <chris@qbittorrent.org>
+ *
+ * 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.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#ifndef PREVIEWSELECTDIALOG_H
+#define PREVIEWSELECTDIALOG_H
+
+#include <QDialog>
+#include <QList>
+
+#include "base/bittorrent/torrenthandle.h"
+#include "base/settingvalue.h"
+#include "ui_previewselectdialog.h"
+
+class QStandardItemModel;
+
+class PreviewListDelegate;
+
+class PreviewSelectDialog : public QDialog, private Ui::preview
+{
+    Q_OBJECT
+
+public:
+    enum PreviewColumn
+    {
+        NAME,
+        SIZE,
+        PROGRESS,
+        FILE_INDEX,
+
+        NB_COLUMNS
+    };
+
+    PreviewSelectDialog(QWidget *parent, BitTorrent::TorrentHandle *const torrent);
+    ~PreviewSelectDialog();
+
+signals:
+    void readyToPreviewFile(QString) const;
+
+protected:
+    void showEvent(QShowEvent *event) override;
+
+private slots:
+    void previewButtonClicked();
+
+private:
+    void loadWindowState();
+    void saveWindowState();
+
+    QStandardItemModel *m_previewListModel;
+    PreviewListDelegate *m_listDelegate;
+    BitTorrent::TorrentHandle *const m_torrent;
+    bool m_headerStateInitialized = false;
+
+    // Settings
+    CachedSettingValue<QSize> m_storeDialogSize;
+    CachedSettingValue<QByteArray> m_storeTreeHeaderState;
+};
+
+#endif // PREVIEWSELECTDIALOG_H