MingaEditor.Layout (Minga v0.1.0)

Single source of truth for all screen rectangles.

Layout.compute/1 takes editor state and produces a struct of named rectangles for every UI element. The renderer never computes its own coordinates; it receives pre-computed rectangles and draws into them.

Rectangle format

All rectangles are {row, col, width, height} tuples matching the existing WindowTree.rect() type. The origin is the top-left corner of the allocated area.

Regions vs Overlays

Regions are non-overlapping areas that tile the screen: file tree, editor area, agent panel, modeline, minibuffer. They participate in the non-overlap invariant.

Overlays float over regions: picker, which-key popup, completion menu. They have positioning rects but don't participate in the tiling constraint.

Summary

Types

horizontal_separator()

A horizontal separator between split panes: {row, col, width, filename}.

rect()

A screen rectangle: {row, col, width, height}.

t()

Complete layout for one frame.

window_layout()

Layout for a single editor window, with sub-rects for each chrome element.

Functions

active_content_height(layout, state)

Returns the content height (visible rows) for the active window.

active_content_width(layout, state)

Returns the content width for the active window.

active_window_layout(layout, state)

Returns the window layout for the active window, or nil.

add_sidebar(layout)

Splits a window layout's content rect to carve out a sidebar.

compute(state)

Computes the complete layout for the current frame.

compute_window_layouts_with_separators(tree, editor_area, window_map)

Computes window layouts and horizontal separator positions simultaneously.

get(state)

Returns the cached layout from state, or computes it fresh.

invalidate(state)

Invalidates the cached layout. Call when layout-affecting state changes (viewport resize, file tree toggle, agent panel toggle, window split/close).

put(state)

Computes the layout and stores it in state for reuse within the same frame.

Types

horizontal_separator()

@type horizontal_separator() ::
  {non_neg_integer(), non_neg_integer(), pos_integer(), String.t()}

A horizontal separator between split panes: {row, col, width, filename}.

rect()

@type rect() :: {non_neg_integer(), non_neg_integer(), pos_integer(), pos_integer()}

A screen rectangle: {row, col, width, height}.

t()

@type t() :: %MingaEditor.Layout{
  agent_panel: rect() | nil,
  editor_area: rect(),
  file_tree: rect() | nil,
  horizontal_separators: [horizontal_separator()],
  minibuffer: rect(),
  status_bar: rect() | nil,
  tab_bar: rect() | nil,
  terminal: rect(),
  window_layouts: %{required(MingaEditor.Window.id()) => window_layout()}
}

Complete layout for one frame.

window_layout()

@type window_layout() :: %{
  total: rect(),
  content: rect(),
  modeline: {non_neg_integer(), non_neg_integer(), pos_integer(), 0},
  sidebar: rect() | nil
}

Layout for a single editor window, with sub-rects for each chrome element.

total — the full window rect (from WindowTree.layout)
content — the text area within the window (full window; no per-window modeline)
modeline — always zero-height; kept for backward compatibility. The global status bar at Layout.t().status_bar replaces per-window modelines.
sidebar — optional info panel (agent chat dashboard)

Functions

active_content_height(layout, state)

@spec active_content_height(t(), MingaEditor.State.t()) :: pos_integer()

Returns the content height (visible rows) for the active window.

active_content_width(layout, state)

@spec active_content_width(t(), MingaEditor.State.t()) :: pos_integer()

Returns the content width for the active window.

This is useful for computing gutter width and wrap maps before rendering.

active_window_layout(layout, state)

@spec active_window_layout(t(), MingaEditor.State.t()) :: window_layout() | nil

Returns the window layout for the active window, or nil.

add_sidebar(layout)

@spec add_sidebar(window_layout()) :: window_layout()

Splits a window layout's content rect to carve out a sidebar.

Returns the layout with content narrowed and sidebar set to the right-hand info panel rect. Only applied when the content width exceeds @sidebar_threshold.

compute(state)

@spec compute(MingaEditor.State.t() | map()) :: t()

Computes the complete layout for the current frame.

Delegates to the shell's compute_layout callback, which dispatches to the appropriate TUI or GUI layout module.

compute_window_layouts_with_separators(tree, editor_area, window_map)

@spec compute_window_layouts_with_separators(
  MingaEditor.WindowTree.t(),
  rect(),
  map()
) ::
  {%{required(MingaEditor.Window.id()) => window_layout()},
   [horizontal_separator()]}

Computes window layouts and horizontal separator positions simultaneously.

Horizontal splits steal 1 row from the top window for a separator bar. The separator shows the lower window's buffer filename.

Returns {window_layouts_map, horizontal_separators_list}.

get(state)

@spec get(MingaEditor.State.t() | map()) :: t()

Returns the cached layout from state, or computes it fresh.

Prefer this over compute/1 when you have a state that might already have a cached layout. The cache is invalidated on resize, file tree toggle, and agent panel toggle.

invalidate(state)

@spec invalidate(MingaEditor.State.t()) :: MingaEditor.State.t()

Invalidates the cached layout. Call when layout-affecting state changes (viewport resize, file tree toggle, agent panel toggle, window split/close).

put(state)

@spec put(MingaEditor.State.t() | map()) :: map()

Computes the layout and stores it in state for reuse within the same frame.

Call this once at the start of a render cycle or event handler, then read state.layout downstream.