Class: Chamomile::Viewport

Inherits:
Object
  • Object
show all
Defined in:
lib/chamomile/components/viewport.rb,
lib/chamomile/components/viewport/key_map.rb

Overview

Scrollable content pane with key binding and mouse wheel support.

Constant Summary collapse

DEFAULT_KEY_MAP = 
KeyBinding.normalize({
  up: [[:up, []], ["k", []]],
  down: [[:down, []], ["j", []]],
  page_up: [[:page_up, []], ["b", []]],
  page_down: [[:page_down, []], ["f", []], [" ", []]],
  half_page_up: [["u", [:ctrl]]],
  half_page_down: [["d", [:ctrl]]],
  goto_top: [["g", []]],
  goto_bottom: [["G", [:shift]]],
  left: [[:left, []], ["h", [:alt]]],
  right: [[:right, []], ["l", [:alt]]],
})

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(width: 80, height: 24, key_map: DEFAULT_KEY_MAP) ⇒ Viewport

Returns a new instance of Viewport.



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# File 'lib/chamomile/components/viewport.rb', line 9

def initialize(width: 80, height: 24, key_map: DEFAULT_KEY_MAP)
  @width = width
  @height = height
  @key_map = key_map
  @lines = []
  @y_offset = 0
  @x_offset = 0
  @mouse_wheel_enabled = true
  @mouse_wheel_delta = 3
  @soft_wrap = false
end

Instance Attribute Details

#height ⇒ Object

Returns the value of attribute height.



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# File 'lib/chamomile/components/viewport.rb', line 6

def height
  @height
end

#key_map ⇒ Object

Returns the value of attribute key_map.



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# File 'lib/chamomile/components/viewport.rb', line 7

def key_map
  @key_map
end

#mouse_wheel_delta ⇒ Object

Returns the value of attribute mouse_wheel_delta.



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# File 'lib/chamomile/components/viewport.rb', line 7

def mouse_wheel_delta
  @mouse_wheel_delta
end

#mouse_wheel_enabled ⇒ Object

Returns the value of attribute mouse_wheel_enabled.



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# File 'lib/chamomile/components/viewport.rb', line 7

def mouse_wheel_enabled
  @mouse_wheel_enabled
end

#soft_wrap ⇒ Object

Returns the value of attribute soft_wrap.



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# File 'lib/chamomile/components/viewport.rb', line 7

def soft_wrap
  @soft_wrap
end

#width ⇒ Object

Returns the value of attribute width.



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# File 'lib/chamomile/components/viewport.rb', line 6

def width
  @width
end

#x_offset ⇒ Object

Returns the value of attribute x_offset.



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# File 'lib/chamomile/components/viewport.rb', line 6

def x_offset
  @x_offset
end

#y_offset ⇒ Object

Returns the value of attribute y_offset.



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# File 'lib/chamomile/components/viewport.rb', line 6

def y_offset
  @y_offset
end

Instance Method Details

#at_bottom? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chamomile/components/viewport.rb', line 133

def at_bottom?
  @y_offset >= max_scroll
end

#at_top? ⇒ Boolean

Queries

Returns:

  • (Boolean) 


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# File 'lib/chamomile/components/viewport.rb', line 129

def at_top?
  @y_offset <= 0
end

#content ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 50

def content
  @lines.join("\n")
end

#content=(s) ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 38

def content=(s)
  @lines = s.to_s.split("\n", -1)
  clamp_offset
  @x_offset = @x_offset.clamp(0, [max_horizontal_scroll, 0].max) unless @soft_wrap
end

#ensure_visible(line) ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 143

def ensure_visible(line)
  if line < @y_offset
    self.y_offset = line
  elsif line >= @y_offset + @height
    self.y_offset = line - @height + 1
  end
  self
end

#goto_bottom ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 92

def goto_bottom
  self.y_offset = max_scroll
end

#goto_top ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 88

def goto_top
  self.y_offset = 0
end

#half_page_down ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 84

def half_page_down
  scroll_down(@height / 2)
end

#half_page_up ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 80

def half_page_up
  scroll_up(@height / 2)
end

#handle(msg) ⇒ Object Also known as: update

Handle an incoming event.



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# File 'lib/chamomile/components/viewport.rb', line 153

def handle(msg)
  case msg
  when Chamomile::KeyEvent
    handle_key(msg)
  when Chamomile::MouseEvent
    handle_mouse(msg)
  end

  nil
end

#max_horizontal_scroll ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 120

def max_horizontal_scroll
  return 0 if @lines.empty?

  longest = @lines.map(&:length).max || 0
  [longest - @width, 0].max
end

#page_down ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 76

def page_down
  scroll_down(@height)
end

#page_up ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 72

def page_up
  scroll_up(@height)
end

#scroll_down(n = 1) ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 68

def scroll_down(n = 1)
  self.y_offset = @y_offset + n
end

#scroll_left(n = 1) ⇒ Object

Horizontal scrolling



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# File 'lib/chamomile/components/viewport.rb', line 102

def scroll_left(n = 1)
  return if @soft_wrap

  self.x_offset = @x_offset - n
end

#scroll_percent ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 137

def scroll_percent
  return 1.0 if max_scroll <= 0

  @y_offset.to_f / max_scroll
end

#scroll_right(n = 1) ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 108

def scroll_right(n = 1)
  return if @soft_wrap

  self.x_offset = @x_offset + n
end

#scroll_up(n = 1) ⇒ Object

Vertical scrolling



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# File 'lib/chamomile/components/viewport.rb', line 64

def scroll_up(n = 1)
  self.y_offset = @y_offset - n
end

#set_content(s) ⇒ Object

Backward compat — preserves the return-self convention



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# File 'lib/chamomile/components/viewport.rb', line 45

def set_content(s)
  self.content = s
  self
end

#total_line_count ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 54

def total_line_count
  @soft_wrap ? wrapped_lines.length : @lines.length
end

#view ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 167

def view
  if @soft_wrap
    render_soft_wrap
  else
    render_normal
  end
end

#visible_line_count ⇒ Object 



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# File 'lib/chamomile/components/viewport.rb', line 58

def visible_line_count
  [total_line_count, @height].min
end