Add pexpect-2.3 to third_party

third_party/pexpect/screen.py

+"""This implements a virtual screen. This is used to support ANSI terminal
+emulation. The screen representation and state is implemented in this class.
+Most of the methods are inspired by ANSI screen control codes. The ANSI class
+extends this class to add parsing of ANSI escape codes.
+
+$Id: screen.py 486 2007-07-13 01:04:16Z noah $
+"""
+
+import copy
+
+NUL = 0    # Fill character; ignored on input.
+ENQ = 5    # Transmit answerback message.
+BEL = 7    # Ring the bell.
+BS  = 8    # Move cursor left.
+HT  = 9    # Move cursor to next tab stop.
+LF = 10    # Line feed.
+VT = 11    # Same as LF.
+FF = 12    # Same as LF.
+CR = 13    # Move cursor to left margin or newline.
+SO = 14    # Invoke G1 character set.
+SI = 15    # Invoke G0 character set.
+XON = 17   # Resume transmission.
+XOFF = 19  # Halt transmission.
+CAN = 24   # Cancel escape sequence.
+SUB = 26   # Same as CAN.
+ESC = 27   # Introduce a control sequence.
+DEL = 127  # Fill character; ignored on input.
+SPACE = chr(32) # Space or blank character.
+
+def constrain (n, min, max):
+
+    """This returns a number, n constrained to the min and max bounds. """
+
+    if n < min:
+        return min
+    if n > max:
+        return max
+    return n
+
+class screen:
+
+    """This object maintains the state of a virtual text screen as a
+    rectangluar array. This maintains a virtual cursor position and handles
+    scrolling as characters are added. This supports most of the methods needed
+    by an ANSI text screen. Row and column indexes are 1-based (not zero-based,
+    like arrays). """
+
+    def __init__ (self, r=24,c=80):
+
+        """This initializes a blank scree of the given dimentions."""
+
+        self.rows = r
+        self.cols = c
+        self.cur_r = 1
+        self.cur_c = 1
+        self.cur_saved_r = 1
+        self.cur_saved_c = 1
+        self.scroll_row_start = 1
+        self.scroll_row_end = self.rows
+        self.w = [ [SPACE] * self.cols for c in range(self.rows)]
+
+    def __str__ (self):
+
+        """This returns a printable representation of the screen. The end of
+        each screen line is terminated by a newline. """
+
+        return '\n'.join ([ ''.join(c) for c in self.w ])
+
+    def dump (self):
+
+        """This returns a copy of the screen as a string. This is similar to
+        __str__ except that lines are not terminated with line feeds. """
+
+        return ''.join ([ ''.join(c) for c in self.w ])
+
+    def pretty (self):
+
+        """This returns a copy of the screen as a string with an ASCII text box
+        around the screen border. This is similar to __str__ except that it
+        adds a box. """
+
+        top_bot = '+' + '-'*self.cols + '+\n'
+        return top_bot + '\n'.join(['|'+line+'|' for line in str(self).split('\n')]) + '\n' + top_bot
+
+    def fill (self, ch=SPACE):
+
+        self.fill_region (1,1,self.rows,self.cols, ch)
+
+    def fill_region (self, rs,cs, re,ce, ch=SPACE):
+
+        rs = constrain (rs, 1, self.rows)
+        re = constrain (re, 1, self.rows)
+        cs = constrain (cs, 1, self.cols)
+        ce = constrain (ce, 1, self.cols)
+        if rs > re:
+            rs, re = re, rs
+        if cs > ce:
+            cs, ce = ce, cs
+        for r in range (rs, re+1):
+            for c in range (cs, ce + 1):
+                self.put_abs (r,c,ch)
+
+    def cr (self):
+
+        """This moves the cursor to the beginning (col 1) of the current row.
+        """
+
+        self.cursor_home (self.cur_r, 1)
+
+    def lf (self):
+
+        """This moves the cursor down with scrolling.
+        """
+
+        old_r = self.cur_r
+        self.cursor_down()
+        if old_r == self.cur_r:
+            self.scroll_up ()
+            self.erase_line()
+
+    def crlf (self):
+
+        """This advances the cursor with CRLF properties.
+        The cursor will line wrap and the screen may scroll.
+        """
+
+        self.cr ()
+        self.lf ()
+
+    def newline (self):
+
+        """This is an alias for crlf().
+        """
+
+        self.crlf()
+
+    def put_abs (self, r, c, ch):
+
+        """Screen array starts at 1 index."""
+
+        r = constrain (r, 1, self.rows)
+        c = constrain (c, 1, self.cols)
+        ch = str(ch)[0]
+        self.w[r-1][c-1] = ch
+
+    def put (self, ch):
+
+        """This puts a characters at the current cursor position.
+        """
+
+        self.put_abs (self.cur_r, self.cur_c, ch)
+
+    def insert_abs (self, r, c, ch):
+
+        """This inserts a character at (r,c). Everything under
+        and to the right is shifted right one character.
+        The last character of the line is lost.
+        """
+
+        r = constrain (r, 1, self.rows)
+        c = constrain (c, 1, self.cols)
+        for ci in range (self.cols, c, -1): 
+            self.put_abs (r,ci, self.get_abs(r,ci-1))
+        self.put_abs (r,c,ch)
+
+    def insert (self, ch):
+
+        self.insert_abs (self.cur_r, self.cur_c, ch)
+
+    def get_abs (self, r, c):
+    
+        r = constrain (r, 1, self.rows)
+        c = constrain (c, 1, self.cols)
+        return self.w[r-1][c-1]
+
+    def get (self):
+
+        self.get_abs (self.cur_r, self.cur_c)
+
+    def get_region (self, rs,cs, re,ce):
+
+        """This returns a list of lines representing the region.
+        """
+
+        rs = constrain (rs, 1, self.rows)
+        re = constrain (re, 1, self.rows)
+        cs = constrain (cs, 1, self.cols)
+        ce = constrain (ce, 1, self.cols)
+        if rs > re:
+            rs, re = re, rs
+        if cs > ce:
+            cs, ce = ce, cs
+        sc = []
+        for r in range (rs, re+1):
+            line = ''
+            for c in range (cs, ce + 1):
+                ch = self.get_abs (r,c)
+                line = line + ch
+            sc.append (line)
+        return sc
+
+    def cursor_constrain (self):
+
+        """This keeps the cursor within the screen area.
+        """
+
+        self.cur_r = constrain (self.cur_r, 1, self.rows)
+        self.cur_c = constrain (self.cur_c, 1, self.cols)
+
+    def cursor_home (self, r=1, c=1): # <ESC>[{ROW};{COLUMN}H
+
+        self.cur_r = r
+        self.cur_c = c
+        self.cursor_constrain ()
+
+    def cursor_back (self,count=1): # <ESC>[{COUNT}D (not confused with down)
+
+        self.cur_c = self.cur_c - count
+        self.cursor_constrain ()
+
+    def cursor_down (self,count=1): # <ESC>[{COUNT}B (not confused with back)
+
+        self.cur_r = self.cur_r + count
+        self.cursor_constrain ()
+
+    def cursor_forward (self,count=1): # <ESC>[{COUNT}C
+
+        self.cur_c = self.cur_c + count
+        self.cursor_constrain ()
+
+    def cursor_up (self,count=1): # <ESC>[{COUNT}A
+
+        self.cur_r = self.cur_r - count
+        self.cursor_constrain ()
+
+    def cursor_up_reverse (self): # <ESC> M   (called RI -- Reverse Index)
+
+        old_r = self.cur_r
+        self.cursor_up()
+        if old_r == self.cur_r:
+            self.scroll_up()
+
+    def cursor_force_position (self, r, c): # <ESC>[{ROW};{COLUMN}f
+
+        """Identical to Cursor Home."""
+
+        self.cursor_home (r, c)
+
+    def cursor_save (self): # <ESC>[s
+
+        """Save current cursor position."""
+
+        self.cursor_save_attrs()
+
+    def cursor_unsave (self): # <ESC>[u
+
+        """Restores cursor position after a Save Cursor."""
+
+        self.cursor_restore_attrs()
+
+    def cursor_save_attrs (self): # <ESC>7
+
+        """Save current cursor position."""
+
+        self.cur_saved_r = self.cur_r
+        self.cur_saved_c = self.cur_c
+
+    def cursor_restore_attrs (self): # <ESC>8
+
+        """Restores cursor position after a Save Cursor."""
+
+        self.cursor_home (self.cur_saved_r, self.cur_saved_c)
+
+    def scroll_constrain (self):
+
+        """This keeps the scroll region within the screen region."""
+
+        if self.scroll_row_start <= 0:
+            self.scroll_row_start = 1
+        if self.scroll_row_end > self.rows:
+            self.scroll_row_end = self.rows
+
+    def scroll_screen (self): # <ESC>[r
+
+        """Enable scrolling for entire display."""
+
+        self.scroll_row_start = 1
+        self.scroll_row_end = self.rows
+
+    def scroll_screen_rows (self, rs, re): # <ESC>[{start};{end}r
+
+        """Enable scrolling from row {start} to row {end}."""
+
+        self.scroll_row_start = rs
+        self.scroll_row_end = re
+        self.scroll_constrain()
+
+    def scroll_down (self): # <ESC>D
+
+        """Scroll display down one line."""
+
+        # Screen is indexed from 1, but arrays are indexed from 0.
+        s = self.scroll_row_start - 1
+        e = self.scroll_row_end - 1
+        self.w[s+1:e+1] = copy.deepcopy(self.w[s:e])
+
+    def scroll_up (self): # <ESC>M
+
+        """Scroll display up one line."""
+
+        # Screen is indexed from 1, but arrays are indexed from 0.
+        s = self.scroll_row_start - 1
+        e = self.scroll_row_end - 1
+        self.w[s:e] = copy.deepcopy(self.w[s+1:e+1])
+
+    def erase_end_of_line (self): # <ESC>[0K -or- <ESC>[K
+
+        """Erases from the current cursor position to the end of the current
+        line."""
+
+        self.fill_region (self.cur_r, self.cur_c, self.cur_r, self.cols)
+
+    def erase_start_of_line (self): # <ESC>[1K
+
+        """Erases from the current cursor position to the start of the current
+        line."""
+
+        self.fill_region (self.cur_r, 1, self.cur_r, self.cur_c)
+
+    def erase_line (self): # <ESC>[2K
+
+        """Erases the entire current line."""
+
+        self.fill_region (self.cur_r, 1, self.cur_r, self.cols)
+
+    def erase_down (self): # <ESC>[0J -or- <ESC>[J
+
+        """Erases the screen from the current line down to the bottom of the
+        screen."""
+
+        self.erase_end_of_line ()
+        self.fill_region (self.cur_r + 1, 1, self.rows, self.cols)
+
+    def erase_up (self): # <ESC>[1J
+
+        """Erases the screen from the current line up to the top of the
+        screen."""
+
+        self.erase_start_of_line ()
+        self.fill_region (self.cur_r-1, 1, 1, self.cols)
+
+    def erase_screen (self): # <ESC>[2J
+
+        """Erases the screen with the background color."""
+
+        self.fill ()
+
+    def set_tab (self): # <ESC>H
+
+        """Sets a tab at the current position."""
+
+        pass
+
+    def clear_tab (self): # <ESC>[g
+
+        """Clears tab at the current position."""
+
+        pass
+
+    def clear_all_tabs (self): # <ESC>[3g
+
+        """Clears all tabs."""
+
+        pass
+
+#        Insert line             Esc [ Pn L
+#        Delete line             Esc [ Pn M
+#        Delete character        Esc [ Pn P
+#        Scrolling region        Esc [ Pn(top);Pn(bot) r
+