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Minor edits to the curses HOWTO

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Andrew M. Kuchling 2007-01-29 20:21:43 +00:00
parent e05e6b0032
commit 85acbca511
2 changed files with 29 additions and 28 deletions
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2
Doc/howto/TODO
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@ -1,7 +1,7 @@
Short-term tasks:
Quick revision pass to make HOWTOs match the current state of Python:
curses doanddont regex sockets sorting
doanddont regex sockets sorting
Medium-term tasks:
Revisit the regex howto.

55
Doc/howto/curses.tex
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@ -2,7 +2,7 @@
\title{Curses Programming with Python}
\release{2.01}
\release{2.02}
\author{A.M. Kuchling, Eric S. Raymond}
\authoraddress{\email{amk@amk.ca}, \email{esr@thyrsus.com}}
@ -147,10 +147,10 @@ makes using the shell difficult.
In Python you can avoid these complications and make debugging much
easier by importing the module \module{curses.wrapper}. It supplies a
function \function{wrapper} that takes a hook argument. It does the
\function{wrapper()} function that takes a callable. It does the
initializations described above, and also initializes colors if color
support is present. It then runs your hook, and then finally
deinitializes appropriately. The hook is called inside a try-catch
support is present. It then runs your provided callable and finally
deinitializes appropriately. The callable is called inside a try-catch
clause which catches exceptions, performs curses deinitialization, and
then passes the exception upwards. Thus, your terminal won't be left
in a funny state on exception.
@ -159,7 +159,7 @@ in a funny state on exception.
Windows are the basic abstraction in curses. A window object
represents a rectangular area of the screen, and supports various
methods to display text, erase it, allow the user to input strings,
methods to display text, erase it, allow the user to input strings,
and so forth.
The \code{stdscr} object returned by the \function{initscr()} function
@ -223,14 +223,14 @@ pad.refresh( 0,0, 5,5, 20,75)
The \function{refresh()} call displays a section of the pad in the
rectangle extending from coordinate (5,5) to coordinate (20,75) on the
screen;the upper left corner of the displayed section is coordinate
screen; the upper left corner of the displayed section is coordinate
(0,0) on the pad. Beyond that difference, pads are exactly like
ordinary windows and support the same methods.
If you have multiple windows and pads on screen there is a more
efficient way to go, which will prevent annoying screen flicker at
refresh time. Use the methods \method{noutrefresh()} and/or
\method{noutrefresh()} of each window to update the data structure
refresh time. Use the \method{noutrefresh()} method
of each window to update the data structure
representing the desired state of the screen; then change the physical
screen to match the desired state in one go with the function
\function{doupdate()}. The normal \method{refresh()} method calls
@ -254,9 +254,9 @@ four different forms.
\begin{tableii}{|c|l|}{textrm}{Form}{Description}
\lineii{\var{str} or \var{ch}}{Display the string \var{str} or
character \var{ch}}
character \var{ch} at the current position}
\lineii{\var{str} or \var{ch}, \var{attr}}{Display the string \var{str} or
character \var{ch}, using attribute \var{attr}}
character \var{ch}, using attribute \var{attr} at the current position}
\lineii{\var{y}, \var{x}, \var{str} or \var{ch}}
{Move to position \var{y,x} within the window, and display \var{str}
or \var{ch}}
@ -271,7 +271,7 @@ in more detail in the next subsection.
The \function{addstr()} function takes a Python string as the value to
be displayed, while the \function{addch()} functions take a character,
which can be either a Python string of length 1, or an integer. If
which can be either a Python string of length 1 or an integer. If
it's a string, you're limited to displaying characters between 0 and
255. SVr4 curses provides constants for extension characters; these
constants are integers greater than 255. For example,
@ -331,15 +331,15 @@ The curses library also supports color on those terminals that
provide it, The most common such terminal is probably the Linux
console, followed by color xterms.
To use color, you must call the \function{start_color()} function
soon after calling \function{initscr()}, to initialize the default
color set (the \function{curses.wrapper.wrapper()} function does this
To use color, you must call the \function{start_color()} function soon
after calling \function{initscr()}, to initialize the default color
set (the \function{curses.wrapper.wrapper()} function does this
automatically). Once that's done, the \function{has_colors()}
function returns TRUE if the terminal in use can actually display
color. (Note from AMK: curses uses the American spelling
'color', instead of the Canadian/British spelling 'colour'. If you're
like me, you'll have to resign yourself to misspelling it for the sake
of these functions.)
color. (Note: curses uses the American spelling 'color', instead of
the Canadian/British spelling 'colour'. If you're used to the British
spelling, you'll have to resign yourself to misspelling it for the
sake of these functions.)
The curses library maintains a finite number of color pairs,
containing a foreground (or text) color and a background color. You
@ -400,18 +400,19 @@ Python's support adds a text-input widget that makes up some of the
lack.
The most common way to get input to a window is to use its
\method{getch()} method. that pauses, and waits for the user to hit
a key, displaying it if \function{echo()} has been called earlier.
You can optionally specify a coordinate to which the cursor should be
moved before pausing.
\method{getch()} method. \method{getch()} pauses and waits for the
user to hit a key, displaying it if \function{echo()} has been called
earlier. You can optionally specify a coordinate to which the cursor
should be moved before pausing.
It's possible to change this behavior with the method
\method{nodelay()}. After \method{nodelay(1)}, \method{getch()} for
the window becomes non-blocking and returns ERR (-1) when no input is
ready. There's also a \function{halfdelay()} function, which can be
used to (in effect) set a timer on each \method{getch()}; if no input
becomes available within the number of milliseconds specified as the
argument to \function{halfdelay()}, curses throws an exception.
the window becomes non-blocking and returns \code{curses.ERR} (a value
of -1) when no input is ready. There's also a \function{halfdelay()}
function, which can be used to (in effect) set a timer on each
\method{getch()}; if no input becomes available within the number of
milliseconds specified as the argument to \function{halfdelay()},
curses raises an exception.
The \method{getch()} method returns an integer; if it's between 0 and
255, it represents the ASCII code of the key pressed. Values greater