feat: add greenhouse pager

nature/commands/greenhouse.lua

@@ -0,0 +1,67 @@
+local ansikit = require 'ansikit'
+local bait = require 'bait'
+local commander = require 'commander'
+local hilbish = require 'hilbish'
+local terminal = require 'terminal'
+local Greenhouse = require 'nature.greenhouse'
+
+commander.register('greenhouse', function(args, sinks)
+	local fname = args[1]
+	local done = false
+	local f <close> = io.open(fname, 'r')
+	if not f then
+		sinks.err:writeln(string.format('could not open file %s', fname))
+	end
+
+	bait.catch('signal.sigint', function()
+		done = true
+	end)
+
+	local gh = Greenhouse(sinks.out)
+	gh:setText(f:read '*a')
+
+	ansikit.screenAlt()
+	ansikit.clear(true)
+	gh:draw()
+
+	hilbish.goro(function()
+		while not done do
+			local c = read()
+			if c == 3 then
+				done = true
+			end
+
+			if c == 27 then
+				local c1 = read()
+				if c1 == 91 then
+					local c2 = read()
+					if c2 == 66 then -- arrow down
+						gh:scroll 'down'
+					elseif c2 == 65 then -- arrow up
+						gh:scroll 'up'
+					end
+				end
+				goto continue
+			end
+			print('\nchar:')
+			print(c)
+
+			::continue::
+		end
+	end)
+
+	while not done do
+		--
+	end
+	ansikit.clear()
+	ansikit.screenMain()
+end)
+
+function read()
+	terminal.saveState()
+	terminal.setRaw()
+	local c = io.read(1)
+
+	terminal.restoreState()
+	return c:byte()
+end

nature/greenhouse.lua

@@ -0,0 +1,47 @@
+-- Greenhouse is a simple text scrolling handler for terminal program.
+-- The idea is that it can be set a region to do its scrolling and paging
+-- job and then the user can draw whatever outside it.
+-- This reduces code duplication for the message viewer
+-- and flowerbook.
+
+local ansikit = require 'ansikit'
+local terminal = require 'terminal'
+local Object = require 'nature.object'
+
+local Greenhouse = Object:extend()
+
+function Greenhouse:new(sink)
+	local size = terminal.size()
+	self.region = size
+	self.start = 1
+	self.offset = 0
+	self.sink = sink
+
+	return self
+end
+
+function Greenhouse:setText(text)
+	self.lines = string.split(text, '\n')
+end
+
+function Greenhouse:draw()
+	self.sink:write(ansikit.getCSI(self.start .. ';1', 'H'))
+
+	for i = 1, #self.lines do
+		if i > self.region.height - 1 then break end
+		if not self.lines[i + self.offset] then break end
+
+		self.sink:writeln(self.lines[i + self.offset]:gsub('\t', '        '):sub(0, self.region.width - 2))
+	end
+end
+
+function Greenhouse:scroll(direction)
+	if direction == 'down' then
+		self.offset = self.offset + 1
+	elseif direction == 'up' then
+		self.offset = self.offset - 1
+	end
+	self:draw()
+end
+
+return Greenhouse

nature/object.lua

@@ -0,0 +1,59 @@
+---@class nature.object
+---@field super nature.object
+local Object = {}
+Object.__index = Object
+
+---Can be overrided by child objects to implement a constructor.
+function Object:new() end
+
+---@return nature.object
+function Object:extend()
+  local cls = {}
+  for k, v in pairs(self) do
+    if k:find("__") == 1 then
+      cls[k] = v
+    end
+  end
+  cls.__index = cls
+  cls.super = self
+  setmetatable(cls, self)
+  return cls
+end
+
+---Check if the object is strictly of the given type.
+---@param T any
+---@return boolean
+function Object:is(T)
+  return getmetatable(self) == T
+end
+
+---Check if the object inherits from the given type.
+---@param T any
+---@return boolean
+function Object:extends(T)
+  local mt = getmetatable(self)
+  while mt do
+    if mt == T then
+      return true
+    end
+    mt = getmetatable(mt)
+  end
+  return false
+end
+
+---Metamethod to get a string representation of an object.
+---@return string
+function Object:__tostring()
+  return "Object"
+end
+
+---Methamethod to allow using the object call as a constructor.
+---@return nature.object
+function Object:__call(...)
+  local obj = setmetatable({}, self)
+  obj:new(...)
+  return obj
+end
+
+
+return Object