Class: Scryglass::TreePanel

Inherits:
ViewPanel show all
Defined in:
lib/scryglass/tree_panel.rb

Instance Attribute Summary

Attributes inherited from ViewPanel

#current_view_coords, #scry_session, #x_boundaries, #y_boundaries

Instance Method Summary collapse

Methods inherited from ViewPanel

#ensure_correct_view_coords, #initialize, #move_view_down, #move_view_left, #move_view_right, #move_view_up, #recalculate_boundaries, #screen_string, #visible_body_string, #visible_header_string

Constructor Details

This class inherits a constructor from Scryglass::ViewPanel

Instance Method Details

#slide_view_to_cursor ⇒ Object 



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# File 'lib/scryglass/tree_panel.rb', line 9

def slide_view_to_cursor
  cursor_tracking = Scryglass.config.cursor_tracking

  current_ro = scry_session.current_ro

  ## Here we calculate the ro_in_center_of_view:
  visible_ros_from_center = (body_screen_height / 2)
  scanning_ro = top_visible_ro_of_tree_view
  visible_ros_from_center.times do
    next_visible_ro = scanning_ro.next_visible_ro_down
    scanning_ro = next_visible_ro if next_visible_ro
  end
  ro_in_center_of_view = scanning_ro

  ## We don't need to do anything if current_ro is already in the center:
  relative_index = current_ro.index - ro_in_center_of_view.index
  return if relative_index.zero?

  ## Establish the number of visible ros between current_ro and center point
  index_span = [ro_in_center_of_view.index, current_ro.index]
  ros_between_them = scry_session.all_ros[index_span.min...index_span.max]
  visible_count_between_them = ros_between_them.count(&:visible?)

  direction = :up   if relative_index.negative?
  direction = :down if relative_index.positive?

  ## If view movement is needed, and how far, depends on the tracking config
  case cursor_tracking
  when :flexible_range
    flex_range = body_screen_height / 3
    if visible_count_between_them >= flex_range
      distance_to_flex_range = visible_count_between_them - flex_range
      move_view_up(distance_to_flex_range)   if direction == :up
      move_view_down(distance_to_flex_range) if direction == :down
    end
  when :dead_center
    move_view_up(visible_count_between_them)   if direction == :up
    move_view_down(visible_count_between_them) if direction == :down
  end
end