Class: Hokusai::Blocks::Scrollbar

Inherits:
Hokusai::Block show all
Defined in:
ui/src/hokusai/blocks/scrollbar.rb

Instance Attribute Summary collapse

Attributes inherited from Hokusai::Block

#node, #provides, #publisher

Instance Method Summary collapse

Methods inherited from Hokusai::Block

#children, #children?, compile, computed, computed!, #draw, #draw_with, #dump, #emit, inject, inject!, #method_missing, mount, #on_resize, provide, provides, style, styles_get, template, template_from_file, template_get, #update, use, uses

Constructor Details

#initialize(**args) ⇒ Scrollbar

Returns a new instance of Scrollbar.



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 88

def initialize(**args)
  @scroll_y = 0.0
  @scrolling = false
  @height = 0.0
  @offset = 0.0

  super(**args)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Hokusai::Block

Instance Attribute Details

#height ⇒ Object

Returns the value of attribute height.



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 38

def height
  @height
end

#offset ⇒ Object

Returns the value of attribute offset.



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 38

def offset
  @offset
end

#scroll_y ⇒ Object

Returns the value of attribute scroll_y.



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 38

def scroll_y
  @scroll_y
end

#scrolling ⇒ Object

Returns the value of attribute scrolling.



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 38

def scrolling
  @scrolling
end

Instance Method Details

#after_updated ⇒ Object 



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 72

def after_updated
  do_goto(goto) unless goto.nil?
end

#do_goto(value) ⇒ Object 



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 82

def do_goto(value)
  self.scroll_y = value.to_f

  emit("scroll", scroll_y, percent: percent_scrolled)
end

#percent_scrolled ⇒ Object 



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 76

def percent_scrolled
  return 0 if scroll_top_height === 0

  scroll_top_height / (height - control_height)
end

#render(canvas) {|canvas| ... } ⇒ Object

Yields:

  • (canvas) 


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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 97

def render(canvas)
  self.offset = canvas.y
  self.height = canvas.height

  yield(canvas)
end

#scroll_handle(event) ⇒ Object 



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 47

def scroll_handle(event)
  if event.left.down && scrolling
    do_goto(event.pos.y)
  else
    self.scrolling = false
  end

  # event.stop
end

#scroll_start(event) ⇒ Object 



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 40

def scroll_start(event)
  self.scrolling = true
  do_goto(event.pos.y)

  event.stop
end

#scroll_top_height ⇒ Object 



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# File 'ui/src/hokusai/blocks/scrollbar.rb', line 57

def scroll_top_height
  start = scroll_y
  control_middle = (control_height / 2)

  if start <= offset + control_middle
    return 0.0
  elsif start >= offset + height - control_middle
    return height - control_height
  else
    return scroll_y - offset - control_middle
  end

  0.0
end