feat: layout actions (#1383)

Co-authored-by: johnybx <johnybx@users.noreply.github.com>

1 files changed, 140 insertions, 0 deletions

diff --git a/lua/telescope/actions/layout.lua b/lua/telescope/actions/layout.lua
new file mode 100644
index 0000000..f40151f
--- /dev/null
+++ b/lua/telescope/actions/layout.lua
@@ -0,0 +1,140 @@
+---@tag telescope.actions.layout
+
+---@brief [[
+--- The layout actions are actions to be used to change the layout of a picker.
+---@brief ]]
+
+local action_state = require "telescope.actions.state"
+local state = require "telescope.state"
+local layout_strats = require "telescope.pickers.layout_strategies"
+
+local action_layout = {}
+
+--- Toggle preview window.
+--- - Note: preview window can be toggled even if preview is set to false.
+---
+--- This action is not mapped by default.
+---@param prompt_bufnr number: The prompt bufnr
+action_layout.toggle_preview = function(prompt_bufnr)
+  local picker = action_state.get_current_picker(prompt_bufnr)
+  local status = state.get_status(picker.prompt_bufnr)
+
+  if picker.previewer and status.preview_win then
+    picker.hidden_previewer = picker.previewer
+    picker.previewer = nil
+  elseif picker.hidden_previewer and not status.preview_win then
+    picker.previewer = picker.hidden_previewer
+    picker.hidden_previewer = nil
+  else
+    return
+  end
+  picker:full_layout_update()
+end
+
+-- TODO IMPLEMENT (mentored project available, contact @l-kershaw)
+action_layout.toggle_padding = function(prompt_bufnr)
+  local picker = action_state.get_current_picker(prompt_bufnr)
+  -- if padding ~= 0
+  --    1. Save `height` and `width` of picker
+  --    2. Set both to `{padding = 0}`
+  -- else
+  --    1. Lookup previous `height` and `width` of picker
+  --    2. Set both to previous values
+  picker:full_layout_update()
+end
+
+--- Toggles the `prompt_position` option between "top" and "bottom".
+--- Checks if `prompt_position` is an option for the current layout.
+---
+--- This action is not mapped by default.
+---@param prompt_bufnr number: The prompt bufnr
+action_layout.toggle_prompt_position = function(prompt_bufnr)
+  local picker = action_state.get_current_picker(prompt_bufnr)
+  picker.layout_config = picker.layout_config or {}
+  picker.layout_config[picker.layout_strategy] = picker.layout_config[picker.layout_strategy] or {}
+  -- flex layout is weird and needs handling separately
+  if picker.layout_strategy == "flex" then
+    picker.layout_config.flex.horizontal = picker.layout_config.flex.horizontal or {}
+    picker.layout_config.flex.vertical = picker.layout_config.flex.vertical or {}
+    local old_pos = picker.layout_config.flex[picker.__flex_strategy].prompt_position
+    local new_pos = old_pos == "top" and "bottom" or "top"
+    picker.layout_config[picker.__flex_strategy].prompt_position = new_pos
+    picker.layout_config.flex[picker.__flex_strategy].prompt_position = new_pos
+    picker:full_layout_update()
+  elseif layout_strats._configurations[picker.layout_strategy].prompt_position then
+    if picker.layout_config.prompt_position == "top" then
+      picker.layout_config.prompt_position = "bottom"
+      picker.layout_config[picker.layout_strategy].prompt_position = "bottom"
+    else
+      picker.layout_config.prompt_position = "top"
+      picker.layout_config[picker.layout_strategy].prompt_position = "top"
+    end
+    picker:full_layout_update()
+  end
+end
+
+--- Toggles the `mirror` option between `true` and `false`.
+--- Checks if `mirror` is an option for the current layout.
+---
+--- This action is not mapped by default.
+---@param prompt_bufnr number: The prompt bufnr
+action_layout.toggle_mirror = function(prompt_bufnr)
+  local picker = action_state.get_current_picker(prompt_bufnr)
+  -- flex layout is weird and needs handling separately
+  if picker.layout_strategy == "flex" then
+    picker.layout_config.flex.horizontal = picker.layout_config.flex.horizontal or {}
+    picker.layout_config.flex.vertical = picker.layout_config.flex.vertical or {}
+    local new_mirror = not picker.layout_config.flex[picker.__flex_strategy].mirror
+    picker.layout_config[picker.__flex_strategy].mirror = new_mirror
+    picker.layout_config.flex[picker.__flex_strategy].mirror = new_mirror
+    picker:full_layout_update()
+  elseif layout_strats._configurations[picker.layout_strategy].mirror then
+    picker.layout_config = picker.layout_config or {}
+    local new_mirror = not picker.layout_config.mirror
+    picker.layout_config.mirror = new_mirror
+    picker.layout_config[picker.layout_strategy] = picker.layout_config[picker.layout_strategy] or {}
+    picker.layout_config[picker.layout_strategy].mirror = new_mirror
+    picker:full_layout_update()
+  end
+end
+
+-- Helper function for `cycle_layout_next` and `cycle_layout_prev`.
+local get_cycle_layout = function(dir)
+  return function(prompt_bufnr)
+    local picker = action_state.get_current_picker(prompt_bufnr)
+    if picker.__layout_index then
+      picker.__layout_index = ((picker.__layout_index + dir - 1) % #picker.__cycle_layout_list) + 1
+    else
+      picker.__layout_index = 1
+    end
+    local new_layout = picker.__cycle_layout_list[picker.__layout_index]
+    if type(new_layout) == "string" then
+      picker.layout_strategy = new_layout
+      picker.layout_config = nil
+      picker.previewer = picker.all_previewers and picker.all_previewers[1] or nil
+    elseif type(new_layout) == "table" then
+      picker.layout_strategy = new_layout.layout_strategy
+      picker.layout_config = new_layout.layout_config
+      picker.previewer = (new_layout.previewer == nil and picker.all_previewers[picker.current_previewer_index])
+        or new_layout.previewer
+    else
+      error("Not a valid layout setup: " .. vim.inspect(new_layout) .. "\nShould be a string or a table")
+    end
+
+    picker:full_layout_update()
+  end
+end
+
+--- Cycles to the next layout in `cycle_layout_list`.
+---
+--- This action is not mapped by default.
+---@param prompt_bufnr number: The prompt bufnr
+action_layout.cycle_layout_next = get_cycle_layout(1)
+
+--- Cycles to the previous layout in `cycle_layout_list`.
+---
+--- This action is not mapped by default.
+---@param prompt_bufnr number: The prompt bufnr
+action_layout.cycle_layout_prev = get_cycle_layout(-1)
+
+return action_layout