sys.Pipe:read() in GUI

Idol1111222

Lets say i have a program named a.exe and i want to make an GUI for it using LuaRT, my program should not only write but also receive info from a.exe. I know that there is sys.Pipe, but if i use pipe:read() - lua freezes until the task is finished and the interface are not updating, which will lead to the fact that the user will not be able to press the buttons at this time.

Samir

Are you using LuaRT 1.8.0 ?
sys.Pipe methods are now non blocking and return a Task object

You should use the ui.run() function to update the GUi asynchronously too

Idol1111222

I dont understand how the pipe:read() method works, since the examples also had pipe:read(100) and i dont understand what it could be. The method description doesnt say what the arguments are.

Samir

Pipe:read() don't take any parameter now. Some examples in the documentation have not been updated, sorry for that.

I will update this examples today to better understand how it works

Samir

Update : examples have been updated in the documentation.
You should look at this one for GUI and Pipe usage : [Login to see the link]

Idol1111222

Thanks, but i still cant get it to work. the GUI still freezes after the first output from the a.exe program. here is the code:
`local ui = require "ui"
local sys = require "sys"

local Window = ui.Window("test", "fixed",0,0)
Window.bgcolor = "15790320"
Window.font = 'Segoe UI'
Window.fontsize = "9"
Window:center()
Window.x = Window.x - 256
Window.y = Window.y - 256
Window.width = 512
Window.height = 512
Window:show()

local console_output = ui.Edit(Window,"",5,25,507,364)
local console_input = ui.Entry(Window,"",5,394,412,25)
local console_input_send = ui.Button(Window,"SEND",422,393,85,27)
local start_button = ui.Button(Window,"Start",5,424,90,30)
local shutdown_button = ui.Button(Window,"Shutdown",100,424,90,30)

local mainpipe = nil

local function print_str(str)
console_output.text = console_output.text .. str
end

local main_printout_can = true
local function main_printout()
if mainpipe then
main_printout_can = false
async(function()
local output = mainpipe:read():wait()
print_str(tostring(output))
main_printout_can = true
end)
end
end
local function main_sendcmd(cmd)
print_str(cmd .. "\n")
if mainpipe then
mainpipe:write(cmd .. "\n")
end
end
console_input_send.onClick = function()
main_sendcmd(console_input.text)
console_input.text = ""
end
local function main_start()
if mainpipe then
print_str("[ERR] a.exe is already started!\n")
return false
end
mainpipe = sys.Pipe("a.exe")
if mainpipe then
print_str("a.exe is started!\n")
main_printout()
return true
end
print_str("[ERR] Can't start a.exe\n")
return false
end
local function main_shutdown()
if mainpipe then
print_str("Closing a.exe...\n")
mainpipe:close()
mainpipe = nil
return
end
print_str("[ERR] a.exe is already closed!\n")
end

start_button.onClick = main_start
shutdown_button.onClick = main_shutdown

async(function()
while Window.visible do
if main_printout_can then
main_printout()
end
ui.update()
end
end)`

Samir

You must use a sleep() call in your ui.update() loop, it should work

Idol1111222

Where exactly should i put it? I tried to put it before pipe:read(), after pipe:read()(before ui.update()) and after ui.update() and in any case the program interface is hidden after start

Samir

Have you called the win:show() method before your main ui loop ?

Idol1111222

Yes

Samir

I will try your example and see what's wrong

Idol1111222

Thank you, i will wait

Samir

Here is what you were waiting for :


local ui = require "ui"

local Window = ui.Window("test", "fixed", 512, 512)
Window:center()

local console_output = ui.Edit(Window,"",5,25,507,364)
local console_input = ui.Entry(Window,"",5,394,412,25)
local console_input_send = ui.Button(Window,"SEND",422,393,85,27)
local start_button = ui.Button(Window,"Start",5,424,90,30)
local shutdown_button = ui.Button(Window,"Shutdown",100,424,90,30)

local mainpipe = nil
local maintask = nil

local function print_str(str)
    if str then
        console_output:append(str)
    end
end

local function main_printout()
    while Window.visible do
        if mainpipe ~= nil then
            local output = mainpipe:read():wait()
            print_str(output)
        end
        sleep()
    end
end

local function main_sendcmd(cmd)
    if mainpipe then
        mainpipe:write(cmd .. "\n")
    end
end

function console_input_send:onClick()
    main_sendcmd(console_input.text)
    console_input.text = ""
end

function start_button:onClick()
    if mainpipe then
        print_str("[ERR] a.exe is already started!\n")
        return false
    else
        mainpipe = sys.Pipe("cmd.exe")
        if mainpipe then
            print_str("a.exe is started!\n")
            maintask = async(main_printout)
        else
            error("[ERR] Can't start a.exe\n")
        end
    end
end

function shutdown_button:onClick()
    if mainpipe then
        print_str("Closing a.exe...\n")
        maintask:cancel()
        mainpipe:close()
        mainpipe = nil
    else
        print_str("[ERR] a.exe is already closed!\n")
    end
end

function Window:onClose()
    shutdown_button:onClick()
end

console_input.onSelect = console_input_send.onClick

ui.run(Window):wait()

All this allowed me to detect two bugs in the management of pipes. They will be corrected in next LuaRT release