Class: Shoes::Line

Inherits:
Common::ArtElement show all
Defined in:
shoes-core/lib/shoes/line.rb

Constant Summary collapse

STYLES = 
{ fill: Shoes::COLORS[:black] }.freeze
REDRAW_OFFSET_FACTOR =

Redrawing needs a bit of extra room. We offset by this factor, then extend our size by twice that to evenly surround the whole thing.

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REDRAW_SIZING_FACTOR = 
REDRAW_OFFSET_FACTOR * 2

Constants included from Common::Style

Common::Style::DEFAULT_STYLES, Common::Style::STYLE_GROUPS

Instance Attribute Summary collapse

Attributes included from Common::Clickable

#pass_coordinates

Attributes inherited from Common::UIElement

#app, #dimensions, #gui, #parent

Instance Method Summary collapse

Methods inherited from Common::ArtElement

#painted?

Methods included from Common::Translate

#clear_translate, #translate_left, #translate_top

Methods included from Common::Stroke

#update_stroke

Methods included from Common::Rotate

#needs_rotate?

Methods included from Common::Fill

#update_fill

Methods included from Common::Clickable

#click, #pass_coordinates?, #register_click, #release

Methods inherited from Common::UIElement

#add_to_parent, #after_initialize, #before_initialize, #create_backend, #handle_block, #initialize, #needs_rotate?, #painted?, #update_fill, #update_stroke

Methods included from Common::Style

#applicable_app_styles, #create_style_hash, included, #style, #style_init

Methods included from Common::SafelyEvaluate

#safely_evaluate

Methods included from Common::Remove

#remove

Methods included from Common::Positioning

#_position, #displace

Methods included from Common::Visibility

#hidden?, #hidden_from_view?, #hide, #outside_parent_view?, #show, #toggle, #visible?

Methods included from Common::Inspect

#inspect, #to_s

Methods included from Common::Attachable

#attached_to

Constructor Details

This class inherits a constructor from Shoes::Common::UIElement

Instance Attribute Details

#point_a ⇒ Object (readonly)

Returns the value of attribute point_a.



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# File 'shoes-core/lib/shoes/line.rb', line 7

def point_a
  @point_a
end

#point_b ⇒ Object (readonly)

Returns the value of attribute point_b.



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# File 'shoes-core/lib/shoes/line.rb', line 7

def point_b
  @point_b
end

Instance Method Details

#bottom=(val) ⇒ Object Also known as: y2= 



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# File 'shoes-core/lib/shoes/line.rb', line 78

def bottom=(val)
  set_point_b(:y, val)
end

#create_dimensions(x1, y1, x2, y2) ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 12

def create_dimensions(x1, y1, x2, y2)
  x1, y1, x2, y2 = default_coordinates(x1, y1, x2, y2)

  @point_a = Shoes::Point.new(x1, y1)
  @point_b = Shoes::Point.new(x2, y2)

  enclosing_box_of_line

  style[:x2] = @point_b.x
  style[:y2] = @point_b.y
end

#default_coordinates(x1, y1, x2, y2) ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 24

def default_coordinates(x1, y1, x2, y2)
  x1 ||= @style[:left] || 0
  y1 ||= @style[:top]  || 0

  x2 ||= @style[:right]
  if x2
    # With 3 arguments, draws horizontal line, so fallback to y1
    y2 ||= @style[:bottom] || y1
  else
    # If didn't get needed arguments, set start to end which draws nothing
    x2 = x1
    y2 = y1
  end

  [x1, y1, x2, y2]
end

#in_bounds?(x, y) ⇒ Boolean

Check out math.stackexchange.com/questions/60070/checking-whether-a-point-lies-on-a-wide-line-segment for explanations how the algorithm works

Returns:

  • (Boolean) 


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# File 'shoes-core/lib/shoes/line.rb', line 43

def in_bounds?(x, y)
  # c is (x, y)
  left_most, right_most = point_a.x < point_b.x ? [point_a, point_b] : [point_b, point_a]
  left_c = Vector.elements((left_most - [x, y]).to_a, false)
  left_right = Vector.elements((left_most - right_most).to_a, false)

  boldness = style[:strokewidth].to_i / 2
  left_c_dot_left_right = left_c.inner_product(left_right)
  left_right_dot_left_right = left_right.inner_product(left_right)

  if left_c_dot_left_right.between?(0, left_right_dot_left_right)
    left_c_dot_left_c = left_c.inner_product(left_c)
    left_right_dot_left_right * left_c_dot_left_c <= boldness**2 * left_right_dot_left_right + left_c_dot_left_right**2
  else
    false
  end
end

#left=(val) ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 66

def left=(val)
  set_point_a(:x, val)
end

#move(x, y, x2 = nil, y2 = nil) ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 106

def move(x, y, x2 = nil, y2 = nil)
  @point_a.x = x
  @point_a.y = y
  @point_b.x = x2 if x2
  @point_b.y = y2 if y2
  enclosing_box_of_line
  self
end

#redraw_height ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 102

def redraw_height
  (@point_a.y - @point_b.y).abs + strokewidth.ceil * REDRAW_SIZING_FACTOR
end

#redraw_left ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 90

def redraw_left
  [@point_a.x, @point_b.x].min - strokewidth.ceil * REDRAW_OFFSET_FACTOR
end

#redraw_top ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 94

def redraw_top
  [@point_a.y, @point_b.y].min - strokewidth.ceil * REDRAW_OFFSET_FACTOR
end

#redraw_width ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 98

def redraw_width
  (@point_a.x - @point_b.x).abs + strokewidth.ceil * REDRAW_SIZING_FACTOR
end

#right=(val) ⇒ Object Also known as: x2= 



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# File 'shoes-core/lib/shoes/line.rb', line 70

def right=(val)
  set_point_b(:x, val)
end

#top=(val) ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 74

def top=(val)
  set_point_a(:y, val)
end

#update_style(new_styles) ⇒ Object 



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# File 'shoes-core/lib/shoes/line.rb', line 61

def update_style(new_styles)
  super
  enclosing_box_of_line
end