Class: RNDK::Scroller

Inherits:
Widget
  • Object
show all
Defined in:
lib/rndk/scroller.rb

Overview

Note:

Do not instantiate this class! Use it's subclasses.

Common actions and functionality between scrolling Widgets.

Direct Known Subclasses

Radio, Scroll

Instance Attribute Summary

Attributes inherited from Widget

#BXAttr, #HZChar, #LLChar, #LRChar, #ULChar, #URChar, #VTChar, #accepts_focus, #binding_list, #border_size, #box, #exit_type, #has_focus, #is_visible, #screen, #screen_index, #supported_signals, #widget_type

Instance Method Summary collapse

Methods inherited from Widget

#Screen_XPOS, #Screen_YPOS, #after_processing, #before_processing, #bind_key, #bind_signal, #bindable_widget, #clean_bindings, #clean_title, #destroy, #draw, #draw_title, #erase, #focus, #get_box, #getch, #inject, #is_bound?, #move, #position, #refresh_data, #run_key_binding, #run_signal_binding, #save_data, #setBXattr, #setHZchar, #setLLchar, #setLRchar, #setULchar, #setURchar, #setVTchar, #set_bg_color, #set_box, #set_exit_type, #set_title, #unbind_key, #unfocus, #valid?, #valid_type?

Constructor Details

#initialize ⇒ Scroller

Returns a new instance of Scroller.



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# File 'lib/rndk/scroller.rb', line 12

def initialize
  super()
end

Instance Method Details

#get_current_item ⇒ Object

Get/Set the current item number of the scroller.



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# File 'lib/rndk/scroller.rb', line 183

def get_current_item
  @current_item
end

#max_view_size ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 137

def max_view_size
  return @box_height - (2 * @border_size + @title_lines)
end

#scroll_begin ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 120

def scroll_begin
  @current_top = 0
  @current_item = 0
  @current_high = 0
end

#scroll_down ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 38

def scroll_down
  if @list_size > 0
    if @current_item < @list_size - 1
      if @current_high == @view_size - 1
        if @current_top < @max_top_item
          @current_top += 1
          @current_item += 1
        else
          RNDK.beep
        end
      else
        @current_item += 1
        @current_high += 1
      end
    else
      RNDK.beep
    end
  else
    RNDK.beep
  end
end

#scroll_end ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 126

def scroll_end
  if @max_top_item == -1
    @current_top = 0
    @current_item = @last_item - 1
  else
    @current_top = @max_top_item
    @current_item = @last_item
  end
  @current_high = @view_size - 1
end

#scroll_left ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 60

def scroll_left
  if @list_size > 0
    if @left_char == 0
      RNDK.beep
    else
      @left_char -= 1
    end
  else
    RNDK.beep
  end
end

#scroll_page_down ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 101

def scroll_page_down
  if @list_size > 0
    if @current_top < @max_top_item
      if @current_top + @view_size - 1 <= @max_top_item
        @current_top += @view_size - 1
        @current_item += @view_size - 1
      else
        @current_top = @max_top_item
        @current_item = @last_item
        @current_high = @view_size - 1
      end
    else
      RNDK.beep
    end
  else
    RNDK.beep
  end
end

#scroll_page_up ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 84

def scroll_page_up
  if @list_size > 0
    if @current_top > 0
      if @current_top >= @view_size - 1
        @current_top -= @view_size - 1
        @current_item -= @view_size - 1
      else
        self.scroll_begin
      end
    else
      RNDK.beep
    end
  else
    RNDK.beep
  end
end

#scroll_right ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 72

def scroll_right
  if @list_size > 0
    if @left_char >= @max_left_char
      RNDK.beep
    else
      @left_char += 1
    end
  else
    RNDK.beep
  end
end

#scroll_up ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 16

def scroll_up
  if @list_size > 0
    if @current_item > 0
      if @current_high == 0
        if @current_top != 0
          @current_top -= 1
          @current_item -= 1
        else
          RNDK.beep
        end
      else
        @current_item -= 1
        @current_high -= 1
      end
    else
      RNDK.beep
    end
  else
    RNDK.beep
  end
end

#set_current_item(item) ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 187

def set_current_item(item)
  self.set_position(item);
end

#set_position(item) ⇒ Object 



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# File 'lib/rndk/scroller.rb', line 165

def set_position(item)
  if item <= 0
    self.scroll_begin
  elsif item > @list_size - 1
    @current_top = @max_top_item
    @current_item = @list_size - 1
    @current_high = @view_size - 1
  elsif item >= @current_top && item < @current_top + @view_size
    @current_item = item
    @current_high = item - @current_top
  else
    @current_top = item - (@view_size - 1)
    @current_item = item
    @current_high = @view_size - 1
  end
end

#set_view_size(list_size) ⇒ Object

Set variables that depend upon the list_size



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# File 'lib/rndk/scroller.rb', line 142

def set_view_size(list_size)
  @view_size = self.max_view_size
  @list_size = list_size
  @last_item = list_size - 1
  @max_top_item = list_size - @view_size

  if list_size < @view_size
    @view_size = list_size
    @max_top_item = 0
  end

  if @list_size > 0 && self.max_view_size > 0
    @step = 1.0 * self.max_view_size / @list_size
    @toggle_size = if @list_size > self.max_view_size
                   then 1
                   else @step.ceil
                   end
  else
    @step = 1
    @toggle_size = 1
  end
end