console: Offer a more reliable API.

The old API is error-prone when combining two character attributes.

Signed-off-by: Jean-Christophe Beaupré <jcbrinfo@users.noreply.github.com>

diff --git a/lib/console.nit b/lib/console.nit
index e6a129f..d032886 100644 (file)
--- a/lib/console.nit
+++ b/lib/console.nit
@@ -12,25 +12,185 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Simple numerical statistical analysis and presentation
+# Defines some ANSI Terminal Control Escape Sequences.
 module console
 
-# Redef String class to add a function to color the string
-redef class String
-       private fun add_escape_char(escapechar: String): String do
-               return "{escapechar}{self}{esc}[0m"
+# A ANSI/VT100 escape sequence.
+abstract class TermEscape
+       # The US-ASCII ESC character.
+       protected fun esc: Char do return 27.ascii
+end
+
+# ANSI/VT100 code to switch character attributes (SGR).
+#
+# By default, resets everything to the terminal’s defaults.
+#
+# Note:
+#
+# The escape sequence inserted at the end of the string by terminal-related
+# methods of `String` resets all character attributes to the terminal’s
+# defaults. So, when combining format `a` and `b`, something like
+# `("foo".a + " bar").b` will not work as expected, but `"foo".a.b + " bar".b`
+# will. You may also use `TermCharFormat` (this class).
+#
+# Usage example:
+#
+#     print "{(new TermCharFormat).yellow_fg.bold}a{(new TermCharFormat).yellow_fg}b{new TermCharFormat}"
+class TermCharFormat
+       super TermEscape
+
+       private var attributes: Array[String] = new Array[String]
+
+       # Copies the attributes from the specified format.
+       init from(format: TermCharFormat) do
+               attributes.add_all(format.attributes)
        end
 
-       private fun esc: Char do return 27.ascii
-       fun gray: String do return add_escape_char("{esc}[30m")
-       fun red: String do return add_escape_char("{esc}[31m")
-       fun green: String do return add_escape_char("{esc}[32m")
-       fun yellow: String do return add_escape_char("{esc}[33m")
-       fun blue: String do return add_escape_char("{esc}[34m")
-       fun purple: String do return add_escape_char("{esc}[35m")
-       fun cyan: String do return add_escape_char("{esc}[36m")
-       fun light_gray: String do return add_escape_char("{esc}[37m")
-       fun bold: String do return add_escape_char("{esc}[1m")
-       fun underline: String do return add_escape_char("{esc}[4m")
+       redef fun to_s: String do return "{esc}[{attributes.join(";")}m"
+
+       # Apply the specified SGR and return `self`.
+       private fun apply(sgr: String): TermCharFormat do
+               attributes.add(sgr)
+               return self
+       end
+
+       # Apply normal (default) format and return `self`.
+       fun default: TermCharFormat do return apply("0")
+
+       # Apply bold weight and return `self`.
+       fun bold: TermCharFormat do return apply("1")
+
+       # Apply underlining and return `self`.
+       fun underline: TermCharFormat do return apply("4")
+
+       # Apply blinking or bold weight and return `self`.
+       fun blink: TermCharFormat do return apply("5")
+
+       # Apply reverse video and return `self`.
+       fun inverse: TermCharFormat do return apply("7")
+
+       # Apply normal weight and return `self`.
+       fun normalWeight: TermCharFormat do return apply("22")
+
+       # Add the attribute that disable inderlining and return `self`.
+       fun not_underlined: TermCharFormat do return apply("24")
+
+       # Add the attribute that disable blinking and return `self`.
+       fun steady: TermCharFormat do return apply("25")
+
+       # Add the attribute that disable reverse video and return `self`.
+       fun positive: TermCharFormat do return apply("27")
+
+       # Apply a black foreground and return `self`.
+       fun black_fg: TermCharFormat do return apply("30")
+
+       # Apply a red foreground and return `self`.
+       fun red_fg: TermCharFormat do return apply("31")
+
+       # Apply a green foreground and return `self`.
+       fun green_fg: TermCharFormat do return apply("32")
+
+       # Apply a yellow foreground and return `self`.
+       fun yellow_fg: TermCharFormat do return apply("33")
+
+       # Apply a blue foreground and return `self`.
+       fun blue_fg: TermCharFormat do return apply("34")
+
+       # Apply a mangenta foreground and return `self`.
+       fun magenta_fg: TermCharFormat do return apply("35")
+
+       # Apply a cyan foreground and return `self`.
+       fun cyan_fg: TermCharFormat do return apply("36")
+
+       # Apply a white foreground and return `self`.
+       fun white_fg: TermCharFormat do return apply("37")
+
+       # Apply the default foreground and return `self`.
+       fun default_fg: TermCharFormat do return apply("39")
+
+       # Apply a black backgroud and return `self`.
+       fun black_bg: TermCharFormat do return apply("40")
+
+       # Apply a red backgroud and return `self`.
+       fun red_bg: TermCharFormat do return apply("41")
+
+       # Apply a green backgroud and return `self`.
+       fun green_bg: TermCharFormat do return apply("42")
+
+       # Apply a yellow backgroud and return `self`.
+       fun yellow_bg: TermCharFormat do return apply("43")
+
+       # Apply a blue backgroud and return `self`.
+       fun blue_bg: TermCharFormat do return apply("44")
+
+       # Apply a mangenta backgroud and return `self`.
+       fun magenta_bg: TermCharFormat do return apply("45")
+
+       # Apply a cyan backgroud and return `self`.
+       fun cyan_bg: TermCharFormat do return apply("46")
+
+       # Apply a white backgroud and return `self`.
+       fun white_bg: TermCharFormat do return apply("47")
+
+       # Apply the default backgroud and return `self`.
+       fun default_bg: TermCharFormat do return apply("49")
 end
 
+# Redefine the `String` class to add functions to color the string.
+redef class String
+       private fun apply_format(f: TermCharFormat): String do
+               return "{f}{self}{normal}"
+       end
+
+       private fun normal: TermCharFormat do return new TermCharFormat
+
+       # Make the text appear in dark gray (or black) in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun gray: String do return apply_format(normal.black_fg)
+
+       # Make the text appear in red in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun red: String do return apply_format(normal.red_fg)
+
+       # Make the text appear in green in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun green: String do return apply_format(normal.green_fg)
+
+       # Make the text appear in yellow in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun yellow: String do return apply_format(normal.yellow_fg)
+
+       # Make the text appear in blue in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun blue: String do return apply_format(normal.blue_fg)
+
+       # Make the text appear in mangenta in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun purple: String do return apply_format(normal.magenta_fg)
+
+       # Make the text appear in cyan in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun cyan: String do return apply_format(normal.cyan_fg)
+
+       # Make the text appear in light gray (or white) in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun light_gray: String do return apply_format(normal.white_fg)
+
+       # Make the text appear in bold in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun bold: String do return apply_format(normal.bold)
+
+       # Make the text underlined in a ANSI/VT100 terminal.
+       #
+       # WARNING: SEE: `TermCharFormat`
+       fun underline: String do return apply_format(normal.underline)
+end