Gilles Roux's text viewer

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2452 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 342 insertions, 0 deletions

diff --git a/apps/viewer.c b/apps/viewer.c
new file mode 100644
index 0000000000..d986ce2dcf
--- /dev/null
+++ b/apps/viewer.c
@@ -0,0 +1,342 @@
+/***************************************************************************
+ *
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 Gilles Roux
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "file.h"
+#include "lcd.h"
+#include "button.h"
+#include "kernel.h"
+#include "font.h"
+#include "settings.h"
+#include "icons.h"
+#include "screens.h"
+
+#define BUFFER_SIZE 1024
+
+#define OUTSIDE_BUFFER -10
+#define OUTSIDE_FILE   -11
+
+static int fd;
+static int file_size;
+
+static char buffer[BUFFER_SIZE+1];
+static int buffer_pos; /* Position of the buffer in the file */
+
+static int begin_line; /* Index of the first line displayed on the lcd */
+static int end_line;   /* Index of the last line displayed on the lcd */
+static int begin_line_pos; /* Position of the first_line in the bufffer */
+static int end_line_pos; /* Position of the last_line in the buffer */
+
+/*
+ * Known issue: The caching algorithm will fail (display incoherent data) if
+ * the total space of the lines that are displayed on the screen exceeds the
+ * buffer size (only happens with very long lines).
+ */
+
+static int display_line_count(void)
+{
+#ifdef HAVE_LCD_BITMAP
+    int fh;
+    fh = font_get(FONT_UI)->height;
+    if (global_settings.statusbar)
+        return (LCD_HEIGHT - STATUSBAR_HEIGHT) / fh;
+    else
+        return LCD_HEIGHT/fh;
+#else
+    return 2;
+#endif
+}
+
+static int find_next_line(int pos)
+{
+    int i;
+
+    if (pos==OUTSIDE_BUFFER || pos==OUTSIDE_FILE)
+        return pos;
+
+    i = pos;
+    if (buffer_pos+i>=file_size) {
+        return OUTSIDE_FILE;
+    }
+    while (1) {
+        i++;
+        if (buffer_pos+i==file_size) {
+            return i;
+        }
+        if (i>=BUFFER_SIZE) {
+            return OUTSIDE_BUFFER;
+        }
+        if (buffer[i]==0) {
+            return i;
+        }
+    }
+}
+
+static int find_prev_line(int pos)
+{
+    int i;
+
+    if (pos==OUTSIDE_BUFFER || pos==OUTSIDE_FILE)
+        return pos;
+
+    i = pos;
+    if (buffer_pos+i<0) {
+        return OUTSIDE_FILE;
+    }
+    while (1) {
+        i--;
+        if (buffer_pos+i<0) {
+            return i;
+        }
+        if (i<0) {
+            return OUTSIDE_BUFFER;
+        }
+        if (buffer[i]==0) {
+            return i;
+        }
+    }
+}
+
+static void viewer_draw(int col)
+{
+    int i, j;
+    char* str;
+    int line_pos;
+
+    lcd_clear_display();
+
+    line_pos = begin_line_pos;
+
+    for (i=0;
+         i<=end_line-begin_line &&
+         line_pos!=OUTSIDE_BUFFER &&
+         line_pos!=OUTSIDE_FILE;
+         i++) {
+        str = buffer + line_pos + 1;
+        for (j=0; j<col && *str!=0; ++j)
+            str++;
+        lcd_puts(0, i, str);
+        line_pos = find_next_line(line_pos);
+    }
+
+    lcd_update();
+}
+
+static void fill_buffer(int pos)
+{
+    int i;
+    int numread;
+
+    if (pos>=file_size-BUFFER_SIZE)
+        pos = file_size-BUFFER_SIZE;
+    if (pos<0)
+        pos = 0;
+
+    lseek(fd, pos, SEEK_SET);
+    numread = read(fd, buffer, BUFFER_SIZE);
+
+    begin_line_pos -= pos - buffer_pos;
+    end_line_pos -= pos - buffer_pos;
+    buffer_pos = pos;
+
+    buffer[numread] = 0;
+    for(i=0;i<numread;i++) {
+        switch(buffer[i]) {
+            case '\r':
+                buffer[i] = ' ';
+                break;
+            case '\n':
+                buffer[i] = 0;
+                break;
+            default:
+                break;
+        }
+    }
+}
+
+static bool viewer_init(char* file)
+{
+    int i;
+    int ret;
+    int disp_lines;
+
+    fd = open(file, O_RDONLY);
+    if (fd==-1)
+        return false;
+
+    file_size = lseek(fd, 0, SEEK_END);
+
+    buffer_pos = 0;
+    begin_line = 0;
+    begin_line_pos = -1;
+    end_line = -1;
+    end_line_pos = -1;
+    fill_buffer(0);
+    disp_lines = display_line_count();
+    for (i=0; i<disp_lines; ++i) {
+        ret = find_next_line(end_line_pos);
+        if (ret!=OUTSIDE_FILE && ret!=OUTSIDE_BUFFER) {
+            end_line_pos = ret;
+            end_line++;
+        }
+    }
+
+    return true;
+}
+
+static void viewer_exit(void)
+{
+    close(fd);
+}
+
+static void viewer_scroll_down(void)
+{
+    int ret;
+
+    ret = find_next_line(end_line_pos);
+    if (ret==OUTSIDE_BUFFER) {
+        begin_line_pos = find_next_line(begin_line_pos);
+        fill_buffer(begin_line_pos+buffer_pos);
+        end_line_pos = find_next_line(end_line_pos);
+    } else if (ret==OUTSIDE_FILE) {
+        return;
+    } else {
+        begin_line_pos = find_next_line(begin_line_pos);
+        end_line_pos = ret;
+    }
+    begin_line++;
+    end_line++;
+}
+
+static void viewer_scroll_up(void)
+{
+    int ret;
+
+    ret = find_prev_line(begin_line_pos);
+    if (ret==OUTSIDE_BUFFER) {
+        end_line_pos = find_prev_line(end_line_pos);
+        fill_buffer(buffer_pos+end_line_pos-BUFFER_SIZE);
+        begin_line_pos = find_prev_line(begin_line_pos);
+    } else if (ret==OUTSIDE_FILE) {
+        return;
+    } else {
+        end_line_pos = find_prev_line(end_line_pos);
+        begin_line_pos = ret;
+    }
+    begin_line--;
+    end_line--;
+}
+
+bool viewer_run(char* file)
+{
+    int button;
+    int col = 0;
+    int ok;
+
+#ifdef HAVE_LCD_BITMAP
+    /* no margins */
+    lcd_setmargins(0, 0);
+#endif
+
+    ok = viewer_init(file);
+    if (!ok) {
+        lcd_clear_display();
+        lcd_puts(0, 0, "Error");
+        lcd_update();
+        sleep(HZ);
+        viewer_exit();
+        return false;
+    }
+
+    viewer_draw(col);
+    while(1) {
+        button = button_get(true);
+
+        switch ( button ) {
+
+#ifdef HAVE_RECORDER_KEYPAD
+            case BUTTON_F1:
+            case BUTTON_ON:
+#else
+            case BUTTON_STOP:
+            case BUTTON_ON:
+#endif
+                viewer_exit();
+                return true;
+                break;
+
+#ifdef HAVE_RECORDER_KEYPAD
+            case BUTTON_UP:
+            case BUTTON_UP | BUTTON_REPEAT:
+#else
+            case BUTTON_LEFT:
+            case BUTTON_LEFT | BUTTON_REPEAT:
+#endif
+                viewer_scroll_up();
+                viewer_draw(col);
+                break;
+
+#ifdef HAVE_RECORDER_KEYPAD
+            case BUTTON_DOWN:
+            case BUTTON_DOWN | BUTTON_REPEAT:
+#else
+            case BUTTON_RIGHT:
+            case BUTTON_RIGHT | BUTTON_REPEAT:
+#endif
+                viewer_scroll_down();
+                viewer_draw(col);
+                break;
+
+#ifdef HAVE_RECORDER_KEYPAD
+            case BUTTON_LEFT:
+            case BUTTON_LEFT | BUTTON_REPEAT:
+#else
+            case BUTTON_MENU | BUTTON_LEFT:
+            case BUTTON_MENU | BUTTON_LEFT | BUTTON_REPEAT:
+#endif
+                col--;
+                viewer_draw(col);
+                break;
+
+#ifdef HAVE_RECORDER_KEYPAD
+            case BUTTON_RIGHT:
+            case BUTTON_RIGHT | BUTTON_REPEAT:
+#else
+            case BUTTON_MENU | BUTTON_RIGHT:
+            case BUTTON_MENU | BUTTON_RIGHT | BUTTON_REPEAT:
+#endif
+                col++;
+                viewer_draw(col);
+                break;
+
+            case SYS_USB_CONNECTED:
+                usb_screen();
+#ifdef HAVE_LCD_CHARCELLS
+                lcd_icon(ICON_PARAM, false);
+#endif
+                viewer_exit();
+                return true;
+        }
+    }
+}
+