libcurses

Framework and tools for multi-threaded, curses(3)-based, terminal applications.

• Write to screen from multiple threads.

  • Use libcurses.wrapper instead of curses.wrapper.
  • Use libcurses.getkey instead of curses.getch.
  • Use libcurses.getline instead of curses.getstr.
  • Preserve the cursor with context manager libcurses.preserve_cursor.

• Register callbacks with register_fkey to handle function-keys pressed during getkey and getline processing.

• Register callbacks with add_mouse_handler to handle mouse events during getkey and getline processing.

• Manage a logger destination, LogSink, to write to a curses window.

• A Grid framework.

class Grid

Grid of windows.

A rectangular collection of windows with shared (collapsed) borders that resize the windows to either side (syncronized shrink/expand) when moused upon.

    +-------+---+------+    example `Grid`, 9 windows.
    |       |   |      |
    +-------+---+------+
    |           |      |
    +------+----+------+
    |      |           |
    +------+--+--------+
    |         |        |
    +---------+--------+

Drag and drop an interior border to resize the windows on either side.

Double-click an interior border to enter Resize Mode: * scroll-wheel and arrow-keys move the border, and * click anywhere, Enter and Esc to exit Resize Mode.

Grids also provide a wrapper around curses.newwin that takes positioning parameters that describe the spatial-relationship to other windows on the screen, instead of (y,x) coordinates:

      +--------+                 +--------+
      |        |                 |  ^     |
      |        |<------ left2r --|  |     |
      |        |                 |  |     |
      |<---------------- left ---|  |     |
      |        |                 |  |     |
      +--------+                 +--|-----+
         |  |                       |  ^
bottom2t |  | bottom            top |  | top2b
         v  |                       |  |
      +-----|--+                 +--------+
      |     |  |                 |        |
      |     |  |-- right ---------------->|
      |     |  |                 |        |
      |     |  |-- right2l ----->|        |
      |     v  |                 |        |
      +--------+                 +--------+

For example, this 3x13 grid with three 3x5 boxes may be described at least three different ways:

        +---+---+---+
        | a | b | c |
        +---+---+---+

grid = Grid(curses.newwin(3, 13))

1)  a = grid.box('a', 3, 5)
    b = grid.box('b', 3, 5, left2r=a)
    c = grid.box('c', 3, 5, left2r=b)

2)  c = grid.box('c', 3, 5, right=grid)
    b = grid.box('b', 3, 5, right=c)
    a = grid.box('a', 3, 5, right=b)

3)  a = grid.box('a', 3, 5, left=grid)
    c = grid.box('c', 3, 5, right=grid)
    b = grid.box('b', 3, 0, left2r=a, right=c)

If two endpoints are given (such as 3b), the length will be calculated to fill the gap between the endpoints.

class LogSink

Logger sink to curses window.

The LogSink class provides a logger destination that writes log messages to a curses window, and methods that control various logging features.

class MouseEvent

Wrap curses.getmouse with additional, convenience-properties.

MouseEvent encapsulates the results of curses.getmouse,

x               x-coordinate.
y               y-coordinate.
bstate          bitmask describing the type of event.

and provides these additional properties:

button          button number (1-5).
nclicks         number of clicks (1-3).
is_pressed      True if button is pressed.
is_released     True if button was just released.
is_alt          True if Alt key is held.
is_ctrl         True if Ctrl key is held.
is_shift        True if Shift key is held.
is_moving       True if mouse is moving.

method add_mouse_handler

Call func with args when mouse event happens at (y, x).

method clear_mouse_handlers

Remove all mouse handlers.

function get_colormap

Return map of loguru-level-name to curses-color/attr.

Call after creating all custom levels with logger.level(). Map is build once and cached; repeated calls return same map.

function getkey

Read and return a character from window.

Args: win: curses window to read from. no_mouse: ignore mouse events (for internal use).

Return: -1 when no-input in no-delay mode, or None on end of file, or >=0 int character read.

function getline

Read and return a line of input from window.

A line is terminated with CR, LF or KEY_ENTER. Backspace deletes the previous character. NAK (ctrl-U) kills the line. Mouse events are handled.

function preserve_cursor

Context manager to save and restore the cursor.

function register_fkey

Register func to be called when key is pressed.

Args: func: callable, to be called on receipt of key. key: the key to be captured, e.g., curses.KEY_F1, or zero (0) for all keys.

func is appended to a list for the key; pass func=None to remove list of funcs for key from registry.

function wrapper

Use instead of curses.wrapper.