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

1 files changed, 191 insertions, 0 deletions

diff --git a/apps/plugins/text_viewer/tv_reader.c b/apps/plugins/text_viewer/tv_reader.c
new file mode 100644
index 0000000..6dc66ef
--- /dev/null
+++ b/apps/plugins/text_viewer/tv_reader.c
@@ -0,0 +1,191 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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.
+ *
+ ****************************************************************************/
+#include "plugin.h"
+#include "tv_preferences.h"
+#include "tv_reader.h"
+
+#if PLUGIN_BUFFER_SIZE < 0x10000
+#define TV_MIN_BLOCK_SIZE 0x800
+#else
+#define TV_MIN_BLOCK_SIZE 0x1000
+#endif
+
+/* UTF-8 BOM */
+#define BOM "\xef\xbb\xbf"
+#define BOM_SIZE 3
+
+static int fd = -1;
+
+static off_t file_pos;
+static off_t start_file_pos;
+
+static off_t file_size;
+
+static unsigned char *reader_buffer;
+static ssize_t buffer_size;
+static ssize_t block_size;
+
+static ssize_t buf_pos;
+static ssize_t read_size;
+
+off_t tv_get_file_size(void)
+{
+    return file_size;
+}
+
+bool tv_is_eof(void)
+{
+    return (file_pos + buf_pos >= file_size);
+}
+
+off_t tv_get_current_file_pos(void)
+{
+    return file_pos + buf_pos;
+}
+
+const unsigned char *tv_get_buffer(ssize_t *bufsize)
+{
+    *bufsize = read_size - buf_pos;
+    return reader_buffer + buf_pos;
+}
+
+static ssize_t tv_read(unsigned char *buf, ssize_t reqsize)
+{
+    if (buf - reader_buffer + reqsize > buffer_size)
+        reqsize = buffer_size - (buf - reader_buffer);
+
+    return rb->read(fd, buf, reqsize);
+}
+
+void tv_seek(off_t offset, int whence)
+{
+    ssize_t size;
+
+    switch (whence)
+    {
+        case SEEK_SET:
+            if (offset >= file_pos && offset < file_pos + read_size)
+            {
+                buf_pos = offset - file_pos;
+                return;
+            }
+            file_pos = offset;
+            break;
+
+        case SEEK_CUR:
+            buf_pos += offset;
+            if (buf_pos >= 0 && buf_pos < read_size)
+            {
+                if (buf_pos > block_size)
+                {
+                    buf_pos  -= block_size;
+                    file_pos += block_size;
+                    size = read_size - block_size;
+                    rb->memcpy(reader_buffer, reader_buffer + block_size, size);
+                    read_size = tv_read(reader_buffer + block_size, block_size);
+                    if (read_size < 0)
+                        read_size = 0;
+
+                    read_size += size;
+                }
+                return;
+            }
+            file_pos += buf_pos;
+            whence = SEEK_SET;
+            break;
+
+        default:
+            return;
+            break;
+    }
+
+    if (whence == SEEK_SET)
+    {
+        if (file_pos < 0)
+            file_pos = 0;
+        else if (file_pos > file_size)
+            file_pos = file_size;
+
+        rb->lseek(fd, file_pos + start_file_pos, SEEK_SET);
+        buf_pos = 0;
+        read_size = tv_read(reader_buffer, buffer_size);
+    }
+}
+
+static void tv_change_preferences(const struct tv_preferences *oldp)
+{
+    unsigned char bom[BOM_SIZE];
+    const struct tv_preferences *prefs = tv_get_preferences();
+    int cur_start_file_pos = start_file_pos;
+    off_t cur_file_pos     = file_pos + buf_pos;
+
+    file_pos  = 0;
+    buf_pos   = 0;
+    read_size = 0;
+    start_file_pos = 0;
+
+    /* open the new file */
+    if (oldp == NULL || rb->strcmp(oldp->file_name, prefs->file_name))
+    {
+        if (fd >= 0)
+            rb->close(fd);
+
+        fd = rb->open(prefs->file_name, O_RDONLY);
+        if (fd < 0)
+            return;
+    }
+
+    /*
+     * When a file is UTF-8 file with BOM, if prefs.encoding is UTF-8,
+     * then file size decreases only BOM_SIZE.
+     */
+    if (prefs->encoding == UTF_8)
+    {
+        rb->lseek(fd, 0, SEEK_SET);
+        rb->read(fd, bom, BOM_SIZE);
+        if (rb->memcmp(bom, BOM, BOM_SIZE) == 0)
+            start_file_pos = BOM_SIZE;
+    }
+
+    file_size = rb->filesize(fd) - start_file_pos;
+    tv_seek(cur_file_pos + cur_start_file_pos - start_file_pos, SEEK_SET);
+}
+
+bool tv_init_reader(unsigned char *buf, size_t bufsize, size_t *used_size)
+{
+    if (bufsize < 2 * TV_MIN_BLOCK_SIZE)
+        return false;
+
+    reader_buffer = buf;
+    block_size    = bufsize / 2;
+    buffer_size   = 2 * block_size;
+    *used_size    = buffer_size;
+    tv_add_preferences_change_listner(tv_change_preferences);
+    return true;
+}
+
+void tv_finalize_reader(void)
+{
+    if (fd >= 0)
+        rb->close(fd);
+}