Class: Canis::ListRenderer

Inherits:
AbstractTextPadRenderer show all
Defined in:
lib/canis/core/widgets/listbox.rb

Overview

Takes care of rendering the list. In the case of a List we take care of selected indices. Also, focussed row is shown in bold, although we can make that optional and configurable A user wanting a different rendering of listboxes may either extend this class or completely replace it and set it as the renderer.

Since:

  • 1.2.0

Instance Attribute Summary collapse

Attributes inherited from AbstractTextPadRenderer

#attr, #color_pair, #content_cols, #cp, #list, #source

Instance Method Summary collapse

Methods inherited from AbstractTextPadRenderer

#render_all

Constructor Details

#initialize(source) ⇒ ListRenderer

Returns a new instance of ListRenderer.

Since:

  • 1.2.0



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# File 'lib/canis/core/widgets/listbox.rb', line 225

def initialize source
  @source = source
  # internal width based on both borders - earlier internal_width which we need
  @int_w = 3 
  # 3 leaves a blank black in popuplists as in testlistbox.rb F4
  # setting it as 2 means that in some cases, the next line first character
  #   gets overwritten with traversal
  #@int_w = 2 
end

Instance Attribute Details

#left_margin_text ⇒ Object

text to be placed in the left margin. This requires that a left margin be set in the source object.

Since:

  • 1.2.0



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# File 'lib/canis/core/widgets/listbox.rb', line 222

def left_margin_text
  @left_margin_text
end

#row_focussed_attr ⇒ Object

Since:

  • 1.2.0



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# File 'lib/canis/core/widgets/listbox.rb', line 223

def row_focussed_attr
  @row_focussed_attr
end

Instance Method Details

#_clear_row(pad, lineno) ⇒ Object

clear row before writing so previous contents are erased and don’t show through I could do this everytime i write but trying to make it faster and only call this if fire_row_changed is called. NOTE: in clear_row one is supposed to clear to the width of the pad, not window

otherwise on scrolling you might get black bg if you have some other color bg.
This is mostly important if you have a bgcolor that is different from the terminal
bgcolor.

Parameters:

  • - —

    pad

  • - —

    line number (index of row to clear)

Since:

  • 1.2.0



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# File 'lib/canis/core/widgets/listbox.rb', line 313

def _clear_row pad, lineno
  raise "unused"
  @color_pair ||= get_color($datacolor, @source.color, @source.bgcolor)
  cp = @color_pair
  att = NORMAL
  @_clearstring ||= " " * (@source.width - @left_margin - @int_w)
  # with int_w = 3 we get that one space in popuplist
  # added attr on 2014-05-02 - 00:16 otherwise a list inside a white bg messagebox shows
  # empty rows in black bg.
  FFI::NCurses.wattron(pad,FFI::NCurses.COLOR_PAIR(cp) | att)
  FFI::NCurses.mvwaddstr(pad,lineno, @left_margin, @_clearstring) 
  FFI::NCurses.wattroff(pad,FFI::NCurses.COLOR_PAIR(cp) | att)
end

#pre_render ⇒ Object

This is called prior to render_all, and may not be called when a single row is rendered

as in fire_row_changed

Since:

  • 1.2.0



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# File 'lib/canis/core/widgets/listbox.rb', line 236

def pre_render
  super
  @selected_indices = @source.selected_indices
  @left_margin = @source.left_margin
  @bg = @source.bgcolor
  @fg = @source.color
  @attr = NORMAL
  @row_focussed_attr ||= $row_focussed_attr
end

#render(pad, lineno, text) ⇒ Object

– NOTE: in some cases like testlistbox.rb if a line is updated then the newly printed value may not overwrite the entire line, addstr seems to only write the text no more Fixed with clear_row ++

Parameters:

  • pad —

    for calling print methods on

  • lineno —

    the line number on the pad to print on

  • text —

    data to print

Since:

  • 1.2.0



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# File 'lib/canis/core/widgets/listbox.rb', line 255

def render pad, lineno, text
  sele = false
=begin
  bg = @source.bgcolor
  fg = @source.color
  att = NORMAL
  cp = get_color($datacolor, fg, bg)
=end
  bg = @bg || @source.bgcolor
  fg = @fg || @source.color
  att = @attr || NORMAL
  cp = get_color($datacolor, fg, bg)

  if @selected_indices.include? lineno
    # print selected row in reverse
    sele = true
    fg = @source.selected_color || fg
    bg = @source.selected_bgcolor || bg
    att = @source.selected_attr || REVERSE
    cp = get_color($datacolor, fg, bg)

  elsif lineno == @source.current_index 
    # print focussed row in different attrib
    if @source.should_show_focus
      # bold was supposed to be if the object loses focus, but although render is called
      #  however, padrefresh is not happening since we do not paint on exiting a widget
      att = BOLD
      if @source.focussed
        att = @row_focussed_attr 
      end
    end
    # take current index into account as BOLD
    # and oldindex as normal
  end
  FFI::NCurses.wattron(pad,FFI::NCurses.COLOR_PAIR(cp) | att)
  FFI::NCurses.mvwaddstr(pad, lineno, 0, @left_margin_text) if @left_margin_text
  FFI::NCurses.mvwaddstr(pad, lineno, @left_margin, text)
  FFI::NCurses.wattroff(pad,FFI::NCurses.COLOR_PAIR(cp) | att)

  # the above only sets the attrib under the text not the whole line, we 
  # need the whole line to be REVERSE
  # Strangely in testlistbox1 unselecting removes the entire lines REVERSE
  # but in testlistbox.rb the previous selected lines REV only partially goes
  # so we have to make the entire line in current attrib
  sele = true
  if sele
    FFI::NCurses.mvwchgat(pad, y=lineno, x=@left_margin, @source.width - @left_margin - @int_w, att, cp, nil)
  end
end