console: Add sequences for cursor moving and erasing.

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

diff --git a/lib/console.nit b/lib/console.nit
index 04dcb6e..e922a84 100644 (file)
--- a/lib/console.nit
+++ b/lib/console.nit
@@ -19,9 +19,162 @@ module console
 abstract class TermEscape
        # The US-ASCII ESC character.
        protected fun esc: Char do return 27.ascii
+
+       # The Control Sequence Introducer (CSI).
+       protected fun csi: String do return "{esc}["
+end
+
+# Abstract class of the ANSI/VT100 escape sequences for directional moves.
+abstract class TermDirectionalMove
+       super TermEscape
+
+       # The length of the move.
+       var magnitude: Int = 1 is protected writable
+
+       redef fun to_s do
+               if magnitude == 1 then return "{csi}{code}"
+               return "{csi}{magnitude}{code}"
+       end
+
+       # The code of the command.
+       protected fun code: String is abstract
+end
+
+# ANSI/VT100 code to move the cursor up by `magnitude` rows (CUU).
+class TermMoveUp
+       super TermDirectionalMove
+
+       init do end
+
+       # Move by the specified number of cells.
+       init by(magnitude: Int) do self.magnitude = magnitude
+
+       redef fun code do return "A"
+end
+
+# ANSI/VT100 code to move the cursor down by `magnitude` rows (CUD).
+class TermMoveDown
+       super TermDirectionalMove
+
+       init do end
+
+       # Move by the specified number of cells.
+       init by(magnitude: Int) do self.magnitude = magnitude
+
+       redef fun code do return "B"
+end
+
+# ANSI/VT100 code to move the cursor foward by `magnitude` columns (CUF).
+class TermMoveFoward
+       super TermDirectionalMove
+
+       init do end
+
+       # Move by the specified number of cells.
+       init by(magnitude: Int) do self.magnitude = magnitude
+
+       redef fun code do return "C"
+end
+
+# ANSI/VT100 code to move the cursor backward by `magnitude` columns (CUB).
+class TermMoveBackward
+       super TermDirectionalMove
+
+       init do end
+
+       # Move by the specified number of cells.
+       init by(magnitude: Int) do self.magnitude = magnitude
+
+       redef fun code do return "D"
+end
+
+# ANSI/VT100 code to move the cursor at the specified position (CUP).
+class TermMove
+       super TermEscape
+
+       # Vertical position.
+       #
+       # 1 is the top.
+       var row: Int = 1
+
+       # Horizontal position.
+       #
+       # 1 is the left.
+       var column: Int = 1
+
+       init do end
+
+       # Move at the specified position.
+       #
+       # (1, 1) is the top-left corner of the display.
+       init at(row: Int, column: Int) do
+               self.row = row
+               self.column = column
+       end
+
+       redef fun to_s do
+               if row == 1 then
+                       if column == 1 then return "{csi}H"
+                       return "{csi};{column}H"
+               else
+                       if column == 1 then return "{csi}{row}H"
+                       return "{csi}{row};{column}H"
+               end
+       end
+end
+
+# ANSI/VT100 code to clear from the cursor to the end of the screen (ED 0).
+class TermEraseDisplayDown
+       super TermEscape
+       redef fun to_s do return "{csi}J"
+end
+
+# ANSI/VT100 code to clear from the cursor to the beginning of the screen (ED 1).
+class TermEraseDisplayUp
+       super TermEscape
+       redef fun to_s do return "{csi}1J"
+end
+
+# ANSI/VT100 code to clear the entire display and move the cursor to the top left of screen (ED 2).
+#
+# Note: Some terminals always move the cursor when the screen is cleared. So we
+# force this behaviour to ensure interoperability of the code.
+class TermClearDisplay
+       super TermEscape
+       redef fun to_s do return "{csi}2J{csi}H"
+end
+
+# ANSI/VT100 code to erase anything after the cursor in the line (EL 0).
+class TermEraseLineFoward
+       super TermEscape
+       redef fun to_s do return "{csi}K"
+end
+
+# ANSI/VT100 code to erase anything before the cursor in the line (EL 1).
+class TermEraseLineBackward
+       super TermEscape
+       redef fun to_s do return "{csi}1K"
+end
+
+# ANSI/VT100 code to clear everything in the current line (EL 2).
+class TermClearLine
+       super TermEscape
+       redef fun to_s do return "{csi}2K"
+end
+
+# ANSI/VT100 code to save the current cursor position (SCP).
+class TermSaveCursor
+       super TermEscape
+       redef fun to_s do return "{csi}s"
+end
+
+# ANSI/VT100 code to restore the current cursor position (RCP).
+class TermRestoreCursor
+       super TermEscape
+       redef fun to_s do return "{csi}u"
 end
 
-# ANSI/VT100 code to switch character attributes (SGR).
+# ANSI/VT100 code to change character look (SGR).
 #
 # By default, resets everything to the terminal’s defaults.
 #
@@ -46,7 +199,7 @@ class TermCharFormat
                attributes.add_all(format.attributes)
        end
 
-       redef fun to_s: String do return "{esc}[{attributes.join(";")}m"
+       redef fun to_s: String do return "{csi}{attributes.join(";")}m"
 
        # Apply the specified SGR and return `self`.
        private fun apply(sgr: String): TermCharFormat do