Class: Umbra::Window

Inherits:
Object
  • Object
show all
Defined in:
lib/umbra/window.rb

Overview

Window class 

Creates and manages the underlying window in which we write or place a form and fields.
The two important methods here are the constructor, and +destroy()+.
+pointer+ is important for making further direct calls to FFI::NCurses.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(h = 0, w = 0, top = 0, left = 0) ⇒ Window

creates a window with given height, width, top and left. If no args given, creates a root window (i.e. full size).

Parameters:

  • height (Integer)
  • width (Integer)
  • top (Integer) (defaults to: 0)
  • left (Integer) (defaults to: 0) 


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# File 'lib/umbra/window.rb', line 129

def initialize h=0, w=0, top=0, left=0
  @height, @width, @top, @left = h, w, top, left

  @height = FFI::NCurses.LINES if @height == 0   # 2011-11-14 added since tired of checking for zero
  @width = FFI::NCurses.COLS   if @width == 0
  @pointer = FFI::NCurses.newwin(@height, @width, @top, @left) # added FFI 2011-09-6 

  @panel = FFI::NCurses.new_panel(@pointer)
  FFI::NCurses.keypad(@pointer, true)
  return @pointer
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object

route other methods to ffi. {{{ This should preferable NOT be used. Better to use the direct call itself. It attempts to route other calls to FFI::NCurses by trying to add w to the name and passing the pointer. I would like to remove this at some time.



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# File 'lib/umbra/window.rb', line 271

def method_missing(name, *args)
  name = name.to_s
  if (name[0,2] == "mv")
    test_name = name.dup
    test_name[2,0] = "w" # insert "w" after"mv"
    if (FFI::NCurses.respond_to?(test_name))
      return FFI::NCurses.send(test_name, @pointer, *args)
    end
  end
  test_name = "w" + name
  if (FFI::NCurses.respond_to?(test_name))
    return FFI::NCurses.send(test_name, @pointer, *args)
  end
  FFI::NCurses.send(name, @pointer, *args)
end

Instance Attribute Details

#height ⇒ Object (readonly)

Returns the value of attribute height.



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# File 'lib/umbra/window.rb', line 121

def height
  @height
end

#left ⇒ Object (readonly)

Returns the value of attribute left.



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# File 'lib/umbra/window.rb', line 121

def left
  @left
end

#panel ⇒ Object (readonly)

panel associated with window



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# File 'lib/umbra/window.rb', line 120

def panel
  @panel
end

#pointer ⇒ Object (readonly)

pointer to FFI routines, use when calling FFI directly.



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# File 'lib/umbra/window.rb', line 119

def pointer
  @pointer
end

#top ⇒ Object (readonly)

Returns the value of attribute top.



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# File 'lib/umbra/window.rb', line 121

def top
  @top
end

#width ⇒ Object (readonly)

Returns the value of attribute width.



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# File 'lib/umbra/window.rb', line 121

def width
  @width
end

Class Method Details

.create(h = 0, w = 0, top = 0, left = 0) ⇒ Object

create a window and return window, or yield window to block



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# File 'lib/umbra/window.rb', line 142

def self.create h=0, w=0, top=0, left=0
  win = Window.new h, w, top, left
  return win unless block_given?

  begin
    yield win
  ensure
    win.destroy
  end

end

Instance Method Details

#box ⇒ Object

make a box around the window. Just a wrapper



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# File 'lib/umbra/window.rb', line 287

def box
  @box = true
  FFI::NCurses.box(@pointer, 0, 0)
end

#destroy ⇒ Object

destroy the window and the panel. This is important. It should be placed in the ensure block of caller application, so it happens.



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# File 'lib/umbra/window.rb', line 262

def destroy
  FFI::NCurses.del_panel(@panel) if @panel
  FFI::NCurses.delwin(@pointer)   if @pointer
  @panel = @pointer = nil # prevent call twice
end

#getch ⇒ Integer Also known as: getkey

Get a key from the standard input.

This will get control keys and function keys but not Alt keys. This is usually called in a loop by the main program. It returns the ascii code (integer). 1 is Ctrl-a .… 27 is Esc FFI already has constants declared for function keys and control keys for checkin against. Can return a 3 or -1 if user pressed Control-C.

NOTE: For ALT keys we need to check for 27/Esc and if so, then do another read with a timeout. If we get a key, then resolve. Otherwise, it is just ESC NOTE: this was working fine with nodelay. However, that would not allow an app to continuously

update the screen, as the getch was blocked. wtimeout allows screen to update without a key
being pressed. 2018-04-07

Returns:

  • (Integer) —

    ascii code of key. For undefined keys, returns a String representation.



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# File 'lib/umbra/window.rb', line 197

def getch
  FFI::NCurses.wtimeout(@pointer, $ncurses_timeout || 1000)
  c = FFI::NCurses.wgetch(@pointer)
  if c == 27    ## {{{

    # don't wait for another key
    FFI::NCurses.nodelay(@pointer, true)
    k = FFI::NCurses.wgetch(@pointer)
    if k == -1
      # wait for key
      #FFI::NCurses.nodelay(@pointer, false)
      return 27
    else
      buf = ""
      loop do
        n = FFI::NCurses.wgetch(@pointer)
        break if n == -1
        buf += n.chr
      end
      # wait for next key
      #FFI::NCurses.nodelay(@pointer, false)

      # this works for all alt-keys but it messes with shift-function keys
      # shift-function keys start with M-[ (91) and then have more keys
      if buf == ""
        return k + 128
      end
      #$log.debug "  getch buf is #{k.chr}#{buf} "
      # returning a string key here which is for Shift-Function keys or other undefined keys.
      key = 27.chr + k.chr + buf
      return key

    end
  end   ## }}}
  #FFI::NCurses.nodelay(@pointer, false) # this works but trying out for continueous updates
  c
rescue SystemExit, Interrupt 
  3      # is C-c
rescue StandardError
  -1     # is C-c
end

#getchar ⇒ Object

Convenience method for a waiting getch



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# File 'lib/umbra/window.rb', line 240

def getchar
  $ncurses_timeout = -1
  return self.getch
end

#OLDgetch ⇒ Object

this works fine for basic, control and function keys



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# File 'lib/umbra/window.rb', line 246

def OLDgetch
  c = FFI::NCurses.wgetch(@pointer)
rescue SystemExit, Interrupt 
  3      # is C-c
rescue StandardError
  -1     # is C-c
end

#printstr(str, x = 0, y = 0) ⇒ Object

Deprecated.

print string at x, y coordinates. replace this with the original one below



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# File 'lib/umbra/window.rb', line 156

def printstr(str, x=0,y=0)
  win = @pointer
  FFI::NCurses.wmove(win, x, y)
  FFI::NCurses.waddstr win, str
end

#printstring(r, c, string, color = 0, att = FFI::NCurses::A_NORMAL) ⇒ Object

2018-03-08 - taken from canis reduced print given string at row, col with given color and attributes

Parameters:

  • row (Integer) —

    row to print on

  • col (Integer) —

    column to print on

  • color (Integer) (defaults to: 0) —

    color_pair created earlier

  • attr (Integer) —

    any of the four FFI attributes, e.g. A_BOLD, A_REVERSE



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# File 'lib/umbra/window.rb', line 168

def printstring(r,c,string, color=0, att = FFI::NCurses::A_NORMAL)

  #$log.debug "printstring recvd nil row #{r} or col #{c}, color:#{color},att:#{att}."  if $log
  raise "printstring recvd nil row #{r} or col #{c}, color:#{color},att:#{att} " if r.nil? || c.nil?
  att ||= FFI::NCurses::A_NORMAL
  color ||= 0
  raise "color is nil " unless color
  raise "att is nil " unless att

  FFI::NCurses.wattron(@pointer, FFI::NCurses.COLOR_PAIR(color) | att)
  FFI::NCurses.mvwprintw(@pointer, r, c, "%s", :string, string);
  FFI::NCurses.wattroff(@pointer, FFI::NCurses.COLOR_PAIR(color) | att)
end

#repaint ⇒ Object

repaints windows objects like title and box. To be called from form on pressing redraw, and SIGWINCH



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# File 'lib/umbra/window.rb', line 307

def repaint
  curses.wclear(@pointer)
  if @box
    self.box
  end
  if @title_data
    str, color, att = @title_data
    self.title str, color, att
  end
end

#title(str, color = 0, att = BOLD) ⇒ Object

Print a centered title on top of window. NOTE : the string is not stored, so it can be overwritten. This should be called after box, or else box will erase the title

Parameters:

  • str (String) —

    title to print

  • color (Integer) (defaults to: 0) —

    color_pair

  • att (Integer) (defaults to: BOLD) —

    attribute constant



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# File 'lib/umbra/window.rb', line 297

def title str, color=0, att=BOLD
  ## save so we can repaint if required
  @title_data = [str, color, att]
  strl = str.length
  col = (@width - strl)/2
  printstring(0,col, str, color, att)
end

#wrefresh ⇒ Object

refresh the window (wrapper) To be called after printing on a window.



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# File 'lib/umbra/window.rb', line 257

def wrefresh
  FFI::NCurses.wrefresh(@pointer)
end