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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
- rectangular 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
-
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