Import m_lib/pbar

[m_lib.git] / m_lib / pbar / tty_pbar.py

diff --git a/m_lib/pbar/tty_pbar.py b/m_lib/pbar/tty_pbar.py
new file mode 100644 (file)
index 0000000..3903d1f
--- /dev/null
+++ b/m_lib/pbar/tty_pbar.py
@@ -0,0 +1,113 @@
+"""
+   Progress bar (TTY version)
+
+   Written by Broytman, Jan 1997 - Sep 2003. Copyright (C) 1997-2003 PhiloSoft Design
+"""
+
+
+import sys, os
+
+
+class ttyProgressBar:
+   """
+      Simple progress indicator - displays bar "graph" using standard tty
+      commands - space, backspace, etc. This method is compatible with
+      (almost) all UNIX consoles and DOS boxes.
+
+      Example:
+
+         ====------  42%
+
+      This is a "bar" (width 10 chars) for 42%
+
+      Certainly, to use it nicely, do not write anything on screen
+      (to stdout or stderr), while using it (or use erase()/redraw() methods).
+      Erase or delete it after using.
+   """
+
+   left_c = '#'     # Chars for "graphics"
+   right_c = '_'
+   space_c = ' '    # a space
+   back_c = chr(8)  # a backspace
+
+   if os.name == 'dos' or os.name == 'nt' : # Use nice chars on DOS screen
+      left_c = chr(178)
+      right_c = chr(176)
+
+
+   def __init__(self, min, max, out = sys.stderr, width1 = 10,
+         width2 = 1+3+1): # 1 space + 3 chars for "100" + 1 for "%"
+      self.min = min
+      self.current = min
+      self.max = max - min
+
+      self.width1 = width1
+      self.width2 = width2
+      self.out = out
+
+      self.redraw()
+
+
+   def __del__(self):
+      self.erase()
+
+
+   def display(self, current):
+      """
+         Draw current value on indicator.
+         Optimized to draw as little as possible.
+      """
+
+      self.current = current
+      current -= self.min
+      lng = (current * self.width1) / self.max
+
+      if current >= self.max:
+         percent = 100
+      else:
+         percent = (current * 100) / self.max
+
+      flush = False
+
+      if self.lng <> lng:
+         self.lng =  lng
+         self.out.write(ttyProgressBar.back_c*(self.width1+self.width2))
+         self.out.write(ttyProgressBar.left_c*lng)
+         self.out.write(ttyProgressBar.right_c*(self.width1-lng) + ttyProgressBar.space_c)
+         self.percent = -1 # force to redraw percentage; the bug was fixed by William McVey
+         flush = True
+
+      elif self.percent <> percent:
+         self.out.write(ttyProgressBar.back_c * (self.width2-1))
+         flush = True
+
+
+      if self.percent <> percent:
+         self.percent =  percent
+         self.out.write(str(percent).rjust(3) + '%')
+         flush = True
+
+
+      if flush:
+         self.out.flush()
+
+      self.visible = True
+
+
+   def erase(self):
+      if self.visible: # Prevent erase() to be called twice - explicitly and from __del__()
+         self.out.write(ttyProgressBar.back_c*(self.width1+self.width2))
+         self.out.write(ttyProgressBar.space_c*(self.width1+self.width2))
+         self.out.write(ttyProgressBar.back_c*(self.width1+self.width2))
+         self.out.flush()
+         self.visible = False
+
+
+   def redraw(self):
+      self.lng = -1 # force to draw bar on the first call
+      self.percent = -1
+
+      # Clear space - just in case there was some cruft left
+      self.out.write(ttyProgressBar.space_c*(self.width1+self.width2))
+      # redraw everything
+      self.display(self.current)