Add third_party/pexpect

third_party/pexpect/pexpect/screen.py

Index: third_party/pexpect/pexpect/screen.py
diff --git a/third_party/pexpect/pexpect/screen.py b/third_party/pexpect/pexpect/screen.py
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+'''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
+:class:`~pexpect.ANSI.ANSI` class extends this class to add parsing of ANSI
+escape codes.
+
+PEXPECT LICENSE
+
+    This license is approved by the OSI and FSF as GPL-compatible.
+        http://opensource.org/licenses/isc-license.txt
+
+    Copyright (c) 2012, Noah Spurrier <noah@noah.org>
+    PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY
+    PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE
+    COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES.
+    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+'''
+
+import codecs
+import copy
+import sys
+
+import warnings
+
+warnings.warn(("pexpect.screen and pexpect.ANSI are deprecated. "
+               "We recommend using pyte to emulate a terminal screen: "
+               "https://pypi.python.org/pypi/pyte"),
+               stacklevel=2)
+
+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 = u' ' # Space or blank character.
+
+PY3 = (sys.version_info[0] >= 3)
+if PY3:
+    unicode = str
+
+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).
+
+    Characters are represented internally using unicode. Methods that accept
+    input characters, when passed 'bytes' (which in Python 2 is equivalent to
+    'str'), convert them from the encoding specified in the 'encoding'
+    parameter to the constructor. Methods that return screen contents return
+    unicode strings, with the exception of __str__() under Python 2. Passing
+    ``encoding=None`` limits the API to only accept unicode input, so passing
+    bytes in will raise :exc:`TypeError`.
+    '''
+    def __init__(self, r=24, c=80, encoding='latin-1', encoding_errors='replace'):
+        '''This initializes a blank screen of the given dimensions.'''
+
+        self.rows = r
+        self.cols = c
+        self.encoding = encoding
+        self.encoding_errors = encoding_errors
+        if encoding is not None:
+            self.decoder = codecs.getincrementaldecoder(encoding)(encoding_errors)            
+        else:
+            self.decoder = None
+        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 _ in range(self.rows)]
+
+    def _decode(self, s):
+        '''This converts from the external coding system (as passed to
+        the constructor) to the internal one (unicode). '''
+        if self.decoder is not None:
+            return self.decoder.decode(s)
+        else:
+            raise TypeError("This screen was constructed with encoding=None, "
+                            "so it does not handle bytes.")
+
+    def _unicode(self):
+        '''This returns a printable representation of the screen as a unicode
+        string (which, under Python 3.x, is the same as 'str'). The end of each
+        screen line is terminated by a newline.'''
+
+        return u'\n'.join ([ u''.join(c) for c in self.w ])
+
+    if PY3:
+        __str__ = _unicode
+    else:
+        __unicode__ = _unicode
+
+        def __str__(self):
+            '''This returns a printable representation of the screen. The end of
+            each screen line is terminated by a newline. '''
+            encoding = self.encoding or 'ascii'
+            return self._unicode().encode(encoding, 'replace')
+
+    def dump (self):
+        '''This returns a copy of the screen as a unicode string. This is similar to
+        __str__/__unicode__ except that lines are not terminated with line
+        feeds.'''
+
+        return u''.join ([ u''.join(c) for c in self.w ])
+
+    def pretty (self):
+        '''This returns a copy of the screen as a unicode string with an ASCII
+        text box around the screen border. This is similar to
+        __str__/__unicode__ except that it adds a box.'''
+
+        top_bot = u'+' + u'-'*self.cols + u'+\n'
+        return top_bot + u'\n'.join([u'|'+line+u'|' for line in unicode(self).split(u'\n')]) + u'\n' + top_bot
+
+    def fill (self, ch=SPACE):
+
+        if isinstance(ch, bytes):
+            ch = self._decode(ch)
+
+        self.fill_region (1,1,self.rows,self.cols, ch)
+
+    def fill_region (self, rs,cs, re,ce, ch=SPACE):
+
+        if isinstance(ch, bytes):
+            ch = self._decode(ch)
+
+        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)
+        if isinstance(ch, bytes):
+            ch = self._decode(ch)[0]
+        else:
+            ch = ch[0]
+        self.w[r-1][c-1] = ch
+
+    def put (self, ch):
+        '''This puts a characters at the current cursor position.
+        '''
+
+        if isinstance(ch, bytes):
+            ch = self._decode(ch)
+
+        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.
+        '''
+
+        if isinstance(ch, bytes):
+            ch = self._decode(ch)
+
+        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):
+
+        if isinstance(ch, bytes):
+            ch = self._decode(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 = u''
+            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
+