Support single quotes for strings as in CSS

doc/rofi-theme.5

@@ -565,13 +565,13 @@ Some of these types are a combination of other types.
 .SS String
 .RS
 .IP \(bu 2
-Format:  \fB\fC"[:print:]+"\fR
+Format:  \fB\fC(["'])[:print:]+\\1\fR
 
 .RE
 
 .PP
-A string is always surrounded by double quotes (\fB\fC"\fR). Between the quotes there
+Strings are always surrounded by double (\fB\fC"\fR) or single (\fB\fC\&'\fR, apostrophe) quotes. Between
-can be any printable character.
+the quotes there can be any printable character.
 
 .PP
 For example:
@@ -592,15 +592,16 @@ The string must be valid UTF-8, special characters can be escaped:
 .RS
 
 .nf
-text {
+text { content: "Line one\\n\\tIndented line two 'Quoted text'"; }
-    content: "Line one\\n\\tIndented line two";
+text { content: 'Line one\\n\\tIndented line two "Quoted text"'; }
-}
+text { content: "Line one\\n\\tIndented line two \\"Quoted text\\""; }
 
 .fi
 .RE
 
 .PP
-The following special characters can be escaped: \fB\fC\\b\fR, \fB\fC\\f\fR, \fB\fC\\n\fR, \fB\fC\\r\fR, \fB\fC\\t\fR, \fB\fC\\v\fR, \fB\fC\\\fR and \fB\fC"\fR\&.
+The following special characters can be escaped: \fB\fC\\b\fR, \fB\fC\\f\fR, \fB\fC\\n\fR, \fB\fC\\r\fR, \fB\fC\\t\fR, \fB\fC\\v\fR, \fB\fC\\\fR,
+\fB\fC"\fR and \fB\fC\&'\fR (double quotes inside single-quotes or in reverse don't need escape).
 
 .SS Integer
 .RS

doc/rofi-theme.5.markdown

@@ -379,10 +379,10 @@ Some of these types are a combination of other types.
 
 ### String
 
-- Format:  `"[:print:]+"`
+- Format:  `(["'])[:print:]+\1`
 
-A string is always surrounded by double quotes (`"`). Between the quotes there
+Strings are always surrounded by double (`"`) or single (`'`, apostrophe) quotes. Between
-can be any printable character.
+the quotes there can be any printable character.
 
 For example:
 
@@ -393,12 +393,13 @@ font: "Awasome 12";
 The string must be valid UTF-8, special characters can be escaped:
 
 ```css
-text {
+text { content: "Line one\n\tIndented line two 'Quoted text'"; }
-    content: "Line one\n\tIndented line two";
+text { content: 'Line one\n\tIndented line two "Quoted text"'; }
-}
+text { content: "Line one\n\tIndented line two \"Quoted text\""; }
 ```
 
-The following special characters can be escaped: `\b`, `\f`, `\n`, `\r`, `\t`, `\v`, `\` and `"`.
+The following special characters can be escaped: `\b`, `\f`, `\n`, `\r`, `\t`, `\v`, `\`,
+`"` and `'` (double quotes inside single-quotes or in reverse don't need escape).
 
 ### Integer
 

lexer/theme-lexer.l

@@ -163,17 +163,19 @@ static double rofi_theme_parse_convert_hex ( char high, char low)
 
 ASC     [\x00-\x7f]
 ASCN    [\x00-\t\v-\x7f]
-ASCNP   [\x00-\t\v-\x21\x23-\x7f]
+ASCNP1  [\x00-\t\v-\x21\x23-\x7f]
+ASCNP2  [\x00-\t\v-\x26\x28-\x7f]
 U       [\x80-\xbf]
 U2      [\xc2-\xdf]
 U3      [\xe0-\xef]
 U4      [\xf0-\xf4]
 
- // UANY    {ASC}|{U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
+UONLY   {U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
-UANYN   {ASCN}|{U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
+ // UANY    {ASC}|{UONLY}
- // UONLY   {U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
+UANYN   {ASCN}|{UONLY}
 
-UANYNP   {ASCNP}|{U2}{U}|{U3}{U}{U}|{U4}{U}{U}{U}
+UANYNP1   {ASCNP1}|{UONLY}
+UANYNP2   {ASCNP2}|{UONLY}
 
 WHITESPACE [[:blank:]]
 WSO        [[:blank:]]*
@@ -181,8 +183,8 @@ WORD       [[:alnum:]-]+
 WORD_ELEMENT [[:alpha:]][[:alnum:]-]*
 WORD_ENV   [[:alpha:]_][[:alnum:]_]*
 COLOR_NAME [[:alpha:]]+
-STRING     \"{UANYN}*\"
+STRING     \"{UANYN}*\"|\'{UANYN}*\'
-STRING_LIST \"{UANYNP}*\"
+STRING_LIST \"{UANYNP1}*\"|\'{UANYNP2}*\'
 CHAR       \'({ASCN}|\\\\|\\\'|\\0)\'
 HEX        [[:xdigit:]]
 NUMBER     [[:digit:]]+