Module: RatatuiRuby::Buffer

Defined in:
lib/ratatui_ruby/buffer.rb,
lib/ratatui_ruby/buffer/cell.rb

Overview

Buffer primitives for terminal cell inspection.

Widgets render to an intermediate buffer, not directly to the terminal. Testing and debugging require access to buffer state.

This module mirrors ratatui::buffer and provides query methods for inspecting buffer contents, converting between coordinates and indices, and retrieving individual cells.

Use it in tests to verify rendered output or in debugging to inspect state.

Defined Under Namespace

Classes: Cell

Class Method Summary collapse

Class Method Details

.content ⇒ Object

Returns all cells in the buffer as a flat array.

Snapshot testing compares entire buffer states. Manually iterating coordinates is verbose and error-prone.

This method returns every cell, ordered row by row (top to bottom, left to right).

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

cells = Buffer.content
cells.each { |cell| puts cell.char }

– SPDX-SnippetEnd ++

Returns an Array of Buffer::Cell objects.



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# File 'lib/ratatui_ruby/buffer.rb', line 130

def content
  area = RatatuiRuby._get_terminal_area
  width = area["width"]
  height = area["height"]
  cells = [] #: Array[Buffer::Cell]
  (0...height).each do |y|
    (0...width).each do |x|
      cells << RatatuiRuby.get_cell_at(x, y)
    end
  end
  cells
end

.get(x, y) ⇒ Object Also known as: []

Returns the Cell at the specified position.

Tests assert on cell contents. This method provides direct access without iterating the entire buffer.

Delegates to RatatuiRuby.get_cell_at.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

cell = Buffer.get(0, 0)
assert_equal "H", cell.char

– SPDX-SnippetEnd ++

x

Column (0-indexed from left).

y

Row (0-indexed from top).

Returns a Buffer::Cell containing the character and style at that position.



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# File 'lib/ratatui_ruby/buffer.rb', line 104

def get(x, y)
  RatatuiRuby.get_cell_at(x, y)
end

.index_of(x, y) ⇒ Object

Converts a position to a linear buffer index.

Buffers store cells in a flat array, row by row. Widget code works with (x, y) coordinates. Bridging these representations requires index translation.

The index is calculated as y * width + x.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

# In a 10-wide buffer, position (3, 2) maps to index 23
Buffer.index_of(3, 2) # => 23

– SPDX-SnippetEnd ++

x

Column (0-indexed from left).

y

Row (0-indexed from top).

Returns the linear index (Integer).



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# File 'lib/ratatui_ruby/buffer.rb', line 46

def index_of(x, y)
  area = RatatuiRuby._get_terminal_area
  (y * area["width"]) + x
end

.pos_of(index) ⇒ Object

Converts a linear buffer index to position coordinates.

Inverse of index_of. When iterating over buffer content by index, use this to recover the original coordinates.

Example

– SPDX-SnippetBegin SPDX-FileCopyrightText: 2026 Kerrick Long SPDX-License-Identifier: MIT-0 ++

# In a 10-wide buffer, index 23 maps to position (3, 2)
Buffer.pos_of(23) # => [3, 2]

– SPDX-SnippetEnd ++

index

Linear buffer index (Integer).

Returns [x, y] coordinates.



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# File 'lib/ratatui_ruby/buffer.rb', line 72

def pos_of(index)
  area = RatatuiRuby._get_terminal_area
  width = area["width"]
  x = index % width
  y = index / width
  [x, y]
end