As draw_textarea_utf8 loops over each character of the textarea content, it
checks whether the character is on the screen; draws it if so; increments
the screen co-ordinate; and updates the position in the textarea text.
The last step was being skipped when the character was not on the line,
so a line would be drawn from the beginning, even if the left edge of the
textarea is off the screen.
Closes: Bug 835 - Text in textarea is unaffected by horizontal scrolling of
document in UTF-8 mode
If utf8_char2cells isn't told where the string that contains
the given UTF-8 character ends, it computes that itself. Two users
of utf8_char2cells, format_textutf8 and split_line, were calling
utf8_char2cells in a loop without providing the end of the string,
resulting in numerous calls by utf8_char2cells to strlen.
With this patch, format_textutf8 and split_line each find the end
of the string once and provide it to utf8_char2cells.
This particularly improves performance with textareas, since
format_textutf8 is called multiple times each time the user interacts
with the textarea and when it must be redrawn.
Closes: Bug 823 - Big textarea is too slow with CONFIG_UTF8
The configure script no longer recognizes "CONFIG_UTF_8=yes" lines
in custom features.conf files. They will have to be changed to
"CONFIG_UTF8=yes". This incompatibility was deemed acceptable
because no released version of ELinks supports CONFIG_UTF_8.
The --enable-utf-8 option was not renamed.
Suggested by Miciah on #elinks.
What was renamed:
add_utf_8 => add_utf8
cp2utf_8 => cp2utf8
encode_utf_8 => encode_utf8
get_translation_table_to_utf_8 => get_translation_table_to_utf8
goto invalid_utf_8_start_byte => goto invalid_utf8_start_byte
goto utf_8 => goto utf8
goto utf_8_select => goto utf8_select
terminal_interlink.utf_8 => terminal_interlink.utf8
utf_8_to_unicode => utf8_to_unicode
What was not renamed:
terminal._template_.utf_8_io option, TERM_OPT_UTF_8_IO
Compatibility with existing elinks.conf files would require an alias.
--enable-utf-8
Because the name of the charset is UTF-8, --enable-utf-8 looks better
than --enable-utf8.
CONFIG_UTF_8
Will be renamed in a later commit.
Unicode/utf_8.cp, table_utf_8, aliases_utf_8
Will be renamed in a later commit.
Including double-width glyph support.
Note: textarea is now drawn with blank collumn at end of lines. It seems
that this is more intuitive for users. It behaves similar as textareas in
graphical interfaces. I hope it will hold your interest.
+----+ +----+ +----+
|aaA | [right] |aaa_| [right] |aaa |
|aaa | |aaa | |Aaa |
|bb | |bb | |bb |
+----+ +----+ +----+
+----+ +----+ +----+
|Aaa | [end] |aaa_| [c] |aaa |
|aaa | |aaa | |Caa |
|bb | |bb | |abb |
+----+ +----+ +----+
A, _, C - cursor positions.
[right] - right arrow
[end] - ACT_END (End button)
[c] - Letter c.
Now this code:
<textarea rows="3" cols="3">aaaaaabb</textarea>
represents textarea with 3x3 positions for chars.
Before this texteare behaved some kind of weirdly. That code above was
rendered like this:
+----+
|aaaa|
|aabb|
|_ |
+----+
maximum length, do not simply drop the changes, but instead truncate them,
warn the user, and provide the user with the path to the temporary file
from which the full changes can be recovered.
