filters/cmd-wrap: new filter (promoting command format)

Signed-off-by: Jan Pokorný <jpokorny@redhat.com>

2 files changed, 60 insertions, 0 deletions

diff --git a/filters/cmd_wrap.py b/filters/cmd_wrap.py
new file mode 100644
index 0000000..4ac5d21
--- /dev/null
+++ b/filters/cmd_wrap.py
@@ -0,0 +1,60 @@
+# -*- coding: UTF-8 -*-
+# Copyright 2015 Red Hat, Inc.
+# Part of clufter project
+# Licensed under GPLv2+ (a copy included | http://gnu.org/licenses/gpl-2.0.txt)
+"""cmd-wrap filter"""
+__author__ = "Jan Pokorný <jpokorny @at@ Red Hat .dot. com>"
+
+from ..filter import Filter
+from ..formats.command import command
+
+from os import getenv
+from textwrap import TextWrapper
+
+
+@Filter.deco('string-iter', 'string-iter')
+def cmd_wrap(flt_ctxt, in_obj):
+    """Try to apply a bit smarter wrapping on lines carrying shell commands
+
+    Smarter means:
+    - do not delimit option from its argument
+    - when line is broken vertically, append backslash for the continuation
+      and indent subsequent lines for visual clarity
+    - and as a side-effect: normalize whitespace occurrences
+    """
+    try:
+        tw_system = int(getenv('COLUMNS'))
+    except TypeError:
+        tw_system = 0
+    try:
+        tw = int(flt_ctxt.get('text_width'))
+        if not tw:
+            raise TypeError
+        elif tw < 0:
+            tw = -tw
+            tw = tw if not tw_system or tw < tw_system else tw_system
+    except TypeError:
+        tw = tw_system
+    if not tw:
+        tw = 72
+    cw = TextWrapper(width=tw, subsequent_indent='# ')  # wrapper for comments
+
+    ret = []
+    for line in in_obj('stringiter', protect_safe=True):
+        if line.lstrip().startswith('#'):
+            ret.append(cw.wrap(line))
+            continue
+        linecnt, rline, remains = 0, [], tw - 2  # ' \'
+        for itemgroup in command('bytestring', line)('separated'):
+            item = ' '.join(itemgroup)
+            fills = len(item) + (1 if rline else 0)
+            # also deal with text width overflow on the first line
+            if (remains - fills >= 0 or not rline):
+                rline.append(item)
+                remains -= fills
+            else:
+                ret.append(('  ' if linecnt else '') + ' '.join(rline) + ' \\')
+                linecnt += 1
+                rline, remains = [item], tw - len(item) - 4  # ' \' & ident
+        ret.append(('  ' if linecnt else '') + ' '.join(rline))
+    return ('stringiter', ret)
diff --git a/ext-plugins/lib-general/formats/command.py b/formats/command.py
index 04a49ad..04a49ad 100644
--- a/ext-plugins/lib-general/formats/command.py
+++ b/formats/command.py