Use unicode_width instead of len, improve in_box.

voussoirkit/niceprints.py

@@ -12,6 +12,7 @@ these functions.
 import shutil
 
 from voussoirkit import dotdict
+from voussoirkit import stringtools
 
 SINGLE_BOX = dotdict.DotDict(
     upper_left='┌',
@@ -36,7 +37,7 @@ def equals_header(text):
     Sample text
     ===========
     '''
-    return text + '\n' + ('=' * len(text))
+    return text + '\n' + ('=' * stringtools.unicode_width(text))
 
 def in_box(text, *, boxchars=SINGLE_BOX, title=''):
     '''
@@ -50,16 +51,27 @@ def in_box(text, *, boxchars=SINGLE_BOX, title=''):
     │There is breaking news about an urgent topic│
     │and you'll never guess what it is           │
     └────────────────────────────────────────────┘
+
+    This function does not perform text wrapping. Wrap your text before putting
+    it in the box.
     '''
     lines = text.splitlines()
-    longest_line = max(max(len(line) for line in lines), len(title))
-    top = title + boxchars.top * (longest_line - len(title))
-    bottom = boxchars.top * longest_line
+    widths = {line: stringtools.unicode_width(line) for line in lines}
+    if len(widths) == 0:
+        longest_line = 0
+    else:
+        longest_line = max(widths.values())
+
+    box_width = max(longest_line, stringtools.unicode_width(title))
+    top = title + boxchars.top * (box_width - stringtools.unicode_width(title))
+    bottom = boxchars.top * box_width
 
     new_lines = []
     new_lines.append(boxchars.upper_left + top + boxchars.upper_right)
     for line in lines:
-        new_lines.append(boxchars.side + line.ljust(longest_line, ' ') + boxchars.side)
+        space_needed = box_width - widths[line]
+        space = ' ' * space_needed
+        new_lines.append(f'{boxchars.side}{line}{space}{boxchars.side}')
     new_lines.append(boxchars.lower_left + bottom + boxchars.lower_right)
     return '\n'.join(new_lines)
 
@@ -69,6 +81,6 @@ def solid_hash_header(text):
     '''
     cli_width = shutil.get_terminal_size()[0]
     # One left hash, space, and space after text.
-    right_count = cli_width - (len(text) + 3)
+    right_count = cli_width - (stringtools.unicode_width(text) + 3)
     right_hashes = '#' * right_count
     return f'# {text} {right_hashes}'