CC-Tweaked/src/main/resources/data/computercraft/lua/rom/programs/help.lua

132 lines
3.4 KiB
Lua

local tArgs = { ... }
local sTopic
if #tArgs > 0 then
sTopic = tArgs[1]
else
sTopic = "intro"
end
if sTopic == "index" then
print("Help topics available:")
local tTopics = help.topics()
textutils.pagedTabulate(tTopics)
return
end
local strings = require "cc.strings"
local function word_wrap(text, width)
local lines = strings.wrap(text, width)
-- Normalise the strings suitable for use with blit. We could skip this and
-- just use term.write, but saves us a clearLine call.
for k, line in pairs(lines) do
lines[k] = strings.ensure_width(line, width)
end
return lines
end
local sFile = help.lookup(sTopic)
local file = sFile ~= nil and io.open(sFile) or nil
if not file then
printError("No help available")
return
end
local contents = file:read("*a"):gsub("(\n *)[-*]( +)", "%1\7%2")
file:close()
local width, height = term.getSize()
local lines = word_wrap(contents, width)
local print_height = #lines
-- If we fit within the screen, just display without pagination.
if print_height <= height then
print(contents)
return
end
local offset = 0
local function draw()
local fg, bg = ("0"):rep(width), ("f"):rep(width)
for y = 1, height - 1 do
term.setCursorPos(1, y)
if y + offset > print_height then
-- Should only happen if we resize the terminal to a larger one
-- than actually needed for the current text.
term.clearLine()
else
term.blit(lines[y + offset], fg, bg)
end
end
end
local function draw_menu()
term.setTextColor(colors.yellow)
term.setCursorPos(1, height)
term.clearLine()
local tag = "Help: " .. sTopic
term.write("Help: " .. sTopic)
if width >= #tag + 16 then
term.setCursorPos(width - 14, height)
term.write("Press Q to exit")
end
end
draw()
draw_menu()
while true do
local event, param = os.pullEvent()
if event == "key" then
if param == keys.up and offset > 0 then
offset = offset - 1
draw()
elseif param == keys.down and offset < print_height - height then
offset = offset + 1
draw()
elseif param == keys.pageUp and offset > 0 then
offset = math.max(offset - height + 2, 0)
draw()
elseif param == keys.pageDown and offset < print_height - height then
offset = math.min(offset + height - 2, print_height - height)
draw()
elseif param == keys.home then
offset = 0
draw()
elseif param == keys["end"] then
offset = print_height - height
draw()
elseif param == keys.q then
sleep(0) -- Super janky, but consumes stray "char" events.
break
end
elseif event == "mouse_scroll" then
if param < 0 and offset > 0 then
offset = offset - 1
draw()
elseif param > 0 and offset < print_height - height then
offset = offset + 1
draw()
end
elseif event == "term_resize" then
local new_width, new_height = term.getSize()
if new_width ~= width then
lines = word_wrap(contents, new_width)
print_height = #lines
end
width, height = new_width, new_height
offset = math.max(math.min(offset, print_height - height), 0)
draw()
draw_menu()
end
end
term.setCursorPos(1, 1)
term.clear()