Module: Vedeu::Terminal::Buffer

Extended by:
Buffer
Included in:
Buffer
Defined in:
lib/vedeu/terminal/buffer.rb

Overview

All output will be written to this singleton, and #render will be called at the end of each run of MainLoop; effectively rendering this buffer to each registered renderer. This buffer is not cleared after this action though, as subsequent actions will modify the contents. This means that individual parts of Vedeu can write content here at various points and only at the end of each run of MainLoop will it be actually output ‘somewhere’.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.buffer ⇒ Array<Array<Vedeu::Models::Cell>> Also known as: cells

Return a grid of Models::Cell objects defined by the height and width of this virtual terminal.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 21

def buffer
  @output ||= empty_buffer.dup
end

.empty_buffer ⇒ Array<Array<Vedeu::Models::Cell>>

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 27

def empty_buffer
  Array.new(Vedeu.height) do |y|
    Array.new(Vedeu.width) do |x|
      Vedeu::Models::Cell.new(position: [y + 1, x + 1])
    end
  end
end

.fetch(from, which) ⇒ Array<Vedeu::Views::Char>|Array (private)

Parameters:

  • from (Array) —

    An Array of rows, or an Array of cells.

  • which (Fixnum) —

    A Fixnum representing the index; the row number or the cell number for a row.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 95

def fetch(from, which)
  from[which] || []
end

.output ⇒ Vedeu::Models::Page

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 36

def output
  Vedeu::Models::Page.coerce(buffer)
end

.position?(value) ⇒ Boolean (private)

Returns a boolean indicating the value has a position attribute.

Parameters:

  • value (void)

Returns:

  • (Boolean) 


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# File 'lib/vedeu/terminal/buffer.rb', line 104

def position?(value)
  value.respond_to?(:position) &&
    value.position.is_a?(Vedeu::Geometry::Position)
end

.read(y, x) ⇒ Vedeu::Views::Char

Note:

Given two actual coordinates (y, x) e.g. (1, 1) Convert to coordinate indices (cy, cx) e.g. (0, 0) Fetch the row at cy and return the cell from cx

Read a single cell from the virtual terminal.

Parameters:

  • y (Fixnum) —

    The row/line coordinate.

  • x (Fixnum) —

    The column/character coordinate.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 50

def read(y, x)
  cy, cx = Vedeu::Geometry::Position[y, x].as_indices

  row  = fetch(cells, cy)
  cell = fetch(row, cx)

  cell
end

.render ⇒ String|void

Send the cells to the renderer and return the rendered result.

Returns:

  • (String|void) —

    Most likely to be a String.



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# File 'lib/vedeu/terminal/buffer.rb', line 62

def render
  Vedeu.renderers.render(output) if Vedeu.ready?
end

.reset ⇒ Array<Array<Vedeu::Models::Cell>> Also known as: clear

Removes all content from the virtual terminal; effectively clearing it.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 70

def reset
  @output = empty_buffer
end

.valid_position?(value) ⇒ Boolean (private)

Returns a boolean indicating the value has a position attribute and is within the terminal boundary.

Parameters:

  • value (void)

Returns:

  • (Boolean) 


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# File 'lib/vedeu/terminal/buffer.rb', line 114

def valid_position?(value)
  position?(value) && within_terminal_boundary?(value)
end

.within_terminal_boundary?(value) ⇒ Boolean (private)

Returns a boolean indicating the position of the value object is valid for this terminal.

Parameters:

  • value (void)

Returns:

  • (Boolean) 


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# File 'lib/vedeu/terminal/buffer.rb', line 123

def within_terminal_boundary?(value)
  value.position.y > 0 && value.position.y <= Vedeu.height &&
    value.position.x > 0 && value.position.x <= Vedeu.width
end

.write(value) ⇒ Array<Array<Vedeu::Views::Char>>

Write a collection of cells to the virtual terminal.

Parameters:

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 79

def write(value)
  values = Array(value).flatten

  values.each do |v|
    buffer[v.position.y][v.position.x] = v if valid_position?(v)
  end

  self
end

Instance Method Details

#buffer ⇒ Array<Array<Vedeu::Models::Cell>> Also known as: cells

Return a grid of Models::Cell objects defined by the height and width of this virtual terminal.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 21

def buffer
  @output ||= empty_buffer.dup
end

#empty_buffer ⇒ Array<Array<Vedeu::Models::Cell>>

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 27

def empty_buffer
  Array.new(Vedeu.height) do |y|
    Array.new(Vedeu.width) do |x|
      Vedeu::Models::Cell.new(position: [y + 1, x + 1])
    end
  end
end

#fetch(from, which) ⇒ Array<Vedeu::Views::Char>|Array (private)

Parameters:

  • from (Array) —

    An Array of rows, or an Array of cells.

  • which (Fixnum) —

    A Fixnum representing the index; the row number or the cell number for a row.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 95

def fetch(from, which)
  from[which] || []
end

#output ⇒ Vedeu::Models::Page

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 36

def output
  Vedeu::Models::Page.coerce(buffer)
end

#position?(value) ⇒ Boolean (private)

Returns a boolean indicating the value has a position attribute.

Parameters:

  • value (void)

Returns:

  • (Boolean) 


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# File 'lib/vedeu/terminal/buffer.rb', line 104

def position?(value)
  value.respond_to?(:position) &&
    value.position.is_a?(Vedeu::Geometry::Position)
end

#read(y, x) ⇒ Vedeu::Views::Char

Note:

Given two actual coordinates (y, x) e.g. (1, 1) Convert to coordinate indices (cy, cx) e.g. (0, 0) Fetch the row at cy and return the cell from cx

Read a single cell from the virtual terminal.

Parameters:

  • y (Fixnum) —

    The row/line coordinate.

  • x (Fixnum) —

    The column/character coordinate.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 50

def read(y, x)
  cy, cx = Vedeu::Geometry::Position[y, x].as_indices

  row  = fetch(cells, cy)
  cell = fetch(row, cx)

  cell
end

#render ⇒ String|void

Send the cells to the renderer and return the rendered result.

Returns:

  • (String|void) —

    Most likely to be a String.



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# File 'lib/vedeu/terminal/buffer.rb', line 62

def render
  Vedeu.renderers.render(output) if Vedeu.ready?
end

#reset ⇒ Array<Array<Vedeu::Models::Cell>> Also known as: clear

Removes all content from the virtual terminal; effectively clearing it.

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 70

def reset
  @output = empty_buffer
end

#valid_position?(value) ⇒ Boolean (private)

Returns a boolean indicating the value has a position attribute and is within the terminal boundary.

Parameters:

  • value (void)

Returns:

  • (Boolean) 


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# File 'lib/vedeu/terminal/buffer.rb', line 114

def valid_position?(value)
  position?(value) && within_terminal_boundary?(value)
end

#within_terminal_boundary?(value) ⇒ Boolean (private)

Returns a boolean indicating the position of the value object is valid for this terminal.

Parameters:

  • value (void)

Returns:

  • (Boolean) 


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# File 'lib/vedeu/terminal/buffer.rb', line 123

def within_terminal_boundary?(value)
  value.position.y > 0 && value.position.y <= Vedeu.height &&
    value.position.x > 0 && value.position.x <= Vedeu.width
end

#write(value) ⇒ Array<Array<Vedeu::Views::Char>>

Write a collection of cells to the virtual terminal.

Parameters:

Returns:



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# File 'lib/vedeu/terminal/buffer.rb', line 79

def write(value)
  values = Array(value).flatten

  values.each do |v|
    buffer[v.position.y][v.position.x] = v if valid_position?(v)
  end

  self
end