reworks text viewer plugin. (FS#11209)

new text viewer plugin: text_viewer.rock.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26571 a1c6a512-1295-4272-9138-f99709370657

apps/plugins/text_viewer/tv_pager.h

@@ -0,0 +1,104 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 Gilles Roux
+ *               2003 Garrett Derner
+ *               2010 Yoshihisa Uchida
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef PLUGIN_TEXT_VIEWER_PAGER_H
+#define PLUGIN_TEXT_VIEWER_PAGER_H
+
+#include "tv_screen_pos.h"
+
+/* stuff for the paging */
+
+/*
+ * initialize the pager module
+ *
+ * [In] buf
+ *          the start pointer of the buffer
+ *
+ * [In] size
+ *          enabled buffer size
+ *
+ * [Out] used_size
+ *          the size of the buffer which the pager uses
+ *
+ * return
+ *     true  initialize success
+ *     false initialize failure
+ */
+bool tv_init_pager(unsigned char *buf, size_t bufsize, size_t *used_size);
+
+/* finalize the pager module */
+void tv_finalize_pager(void);
+
+/* reset the stored line positions */
+void tv_reset_line_positions(void);
+
+/*
+ * move to the next line
+ *
+ * [In] size
+ *         the current line size
+ */
+void tv_move_next_line(int size);
+
+/*
+ * return the distance from the top of the current page
+ *
+ * [In] offset
+ *         the difference between the current line
+ *
+ * return
+ *        difference between the current line + offset from the top of the current page
+ */
+int tv_get_line_positions(int offset);
+
+/* change the new page */
+void tv_new_page(void);
+
+/*
+ * convert the given file position to the nearest the position (page, line)
+ *
+ * [In] fpos
+ *         the file position which want to convert
+ *
+ * [Out] pos
+ *         result
+ */
+void tv_convert_fpos(off_t fpos, struct tv_screen_pos *pos);
+
+/*
+ * move to the given page and line
+ *
+ * [In] page_offset
+ *          page offset
+ *
+ * [In] line_offset
+ *          line offset
+ *
+ * [In] whence
+ *          SEEK_CUR  seek to the current page + offset page, the current line + offset line.
+ *          SEEK_SET  seek to the offset page, offset line.
+ *          SEEK_END  seek to the reading last page + offset page,
+ *                            the last line of the reading last page + offset line.
+ */
+void tv_move_screen(int page_offset, int line_offset, int whence);
+
+#endif