text viewer:

- if the file fits on one screen, there is no horizontal scrollbar.
- the callback function in tv_reader doesn't do useless processing when the preferences changes.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27212 a1c6a512-1295-4272-9138-f99709370657

apps/plugins/text_viewer/tv_display.c

@@ -100,6 +100,7 @@ static struct tv_rect bookmark;
 #endif
 static struct tv_rect drawarea;
 
+static bool show_horizontal_scrollbar;
 static bool show_vertical_scrollbar;
 
 static int display_columns;
@@ -138,7 +139,7 @@ static void tv_show_scrollbar(int window, int col, off_t cur_pos, int size)
     int min_shown;
     int max_shown;
 
-    if (preferences->horizontal_scrollbar)
+    if (show_horizontal_scrollbar)
     {
         items     = preferences->windows * display_columns;
         min_shown = window * display_columns + col;
@@ -168,7 +169,8 @@ static void tv_show_scrollbar(int window, int col, off_t cur_pos, int size)
 void tv_init_scrollbar(off_t total, bool show_scrollbar)
 {
     totalsize = total;
-    show_vertical_scrollbar = show_scrollbar;
+    show_horizontal_scrollbar = (show_scrollbar && preferences->horizontal_scrollbar);
+    show_vertical_scrollbar   = (show_scrollbar && preferences->vertical_scrollbar);
 }
 
 void tv_show_bookmarks(const int *rows, int count)
@@ -251,8 +253,10 @@ void tv_end_display(void)
 void tv_set_layout(bool show_scrollbar)
 {
 #ifdef HAVE_LCD_BITMAP
-    int scrollbar_width  = (show_scrollbar)?                    TV_SCROLLBAR_WIDTH  + 1 : 0;
+    int scrollbar_width  = (show_scrollbar && preferences->vertical_scrollbar)?
-    int scrollbar_height = (preferences->horizontal_scrollbar)? TV_SCROLLBAR_HEIGHT + 1 : 0;
+                           TV_SCROLLBAR_WIDTH  + 1 : 0;
+    int scrollbar_height = (show_scrollbar && preferences->horizontal_scrollbar)?
+                           TV_SCROLLBAR_HEIGHT + 1 : 0;
 
     row_height = preferences->font->height;
 

apps/plugins/text_viewer/tv_reader.c

@@ -134,14 +134,7 @@ void tv_seek(off_t offset, int whence)
 
 static int tv_change_preferences(const struct tv_preferences *oldp)
 {
-    unsigned char bom[BOM_SIZE];
+    bool change_file = false;
-    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, preferences->file_name))
@@ -152,22 +145,41 @@ static int tv_change_preferences(const struct tv_preferences *oldp)
         fd = rb->open(preferences->file_name, O_RDONLY);
         if (fd < 0)
             return TV_CALLBACK_ERROR;
+
+        file_size = rb->filesize(fd);
+        change_file = true;
     }
 
     /*
      * When a file is UTF-8 file with BOM, if encoding is UTF-8,
      * then file size decreases only BOM_SIZE.
      */
-    if (preferences->encoding == UTF_8)
+    if (change_file || oldp->encoding != preferences->encoding)
     {
-        rb->lseek(fd, 0, SEEK_SET);
+        int old_start_file_pos = start_file_pos;
-        rb->read(fd, bom, BOM_SIZE);
+        int delta_start_file_pos;
-        if (rb->memcmp(bom, BOM, BOM_SIZE) == 0)
+        off_t cur_file_pos = file_pos + buf_pos;
-            start_file_pos = BOM_SIZE;
+
+        file_pos  = 0;
+        buf_pos   = 0;
+        read_size = 0;
+        start_file_pos = 0;
+
+        if (preferences->encoding == UTF_8)
+        {
+            unsigned char bom[BOM_SIZE];
+
+            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;
+        }
+
+        delta_start_file_pos = old_start_file_pos - start_file_pos;
+        file_size += delta_start_file_pos;
+        tv_seek(cur_file_pos + delta_start_file_pos, SEEK_SET);
     }
 
-    file_size = rb->filesize(fd) - start_file_pos;
-    tv_seek(cur_file_pos + cur_start_file_pos - start_file_pos, SEEK_SET);
     return TV_CALLBACK_OK;
 }
 

apps/plugins/text_viewer/tv_window.c

@@ -104,25 +104,26 @@ bool tv_traverse_lines(void)
 
 static int tv_change_preferences(const struct tv_preferences *oldp)
 {
-    bool need_vertical_scrollbar = false;
+    bool need_scrollbar = false;
 
     (void)oldp;
 
-    tv_set_layout(need_vertical_scrollbar);
+    tv_set_layout(need_scrollbar);
     tv_get_drawarea_info(&window_width, &window_columns, &display_lines);
 
     if (tv_exist_scrollbar())
     {
         tv_seek_top();
         tv_set_read_conditions(preferences->windows, window_width);
-        if (tv_traverse_lines() && preferences->vertical_scrollbar)
+        if (tv_traverse_lines() &&
+            (preferences->vertical_scrollbar || preferences->horizontal_scrollbar))
         {
-            need_vertical_scrollbar = true;
+            need_scrollbar = true;
-            tv_set_layout(need_vertical_scrollbar);
+            tv_set_layout(need_scrollbar);
             tv_get_drawarea_info(&window_width, &window_columns, &display_lines);
         }
         tv_seek_top();
-        tv_init_scrollbar(tv_get_total_text_size(), need_vertical_scrollbar);
+        tv_init_scrollbar(tv_get_total_text_size(), need_scrollbar);
     }
 
     if (cur_window >= preferences->windows)