_IsPressed in a loop + abnormal conditions?

[misrepresentative]

; ....

While 1

    Switch TrayGetMsg()
        Case $id_Exit
            Exit
        Case $id_Test
            _test()
    EndSwitch

    If _IsPressed("23", $USER32_DLL) Then
        _example()
    EndIf

WEnd

 

For example, it may not work as expected under abnormal conditions such as high CPU utilization. If you press End key ("23"), it's not guaranteed that key press is detected. Could you kindly recommend me a way to improve it?

(note: without using Hotkeyset, if possible.)

 

Many thanks in advance for you time.

Edited December 9, 2016 by misrepresentative
added another case (for better ilustration)

[water]

Welcome to AutoIt and the forum!

user32.dll is the default. To which value do you set variable $USER32_DLL?

[misrepresentative]

Thank you, water. Sorry if I'm misunderstanding but does it really matter?

 

Local $USER32_DLL = DllOpen("user32.dll")
If $USER32_DLL = -1 Then
    MsgBox($MB_ICONERROR + $MB_OK, "Error- DllOpen", "Unable to open user32.dll for use." & @CRLF & "Application will now exit.")
    Exit
EndIf

OnAutoItExitRegister("On_Exit")
Func On_Exit()
    DllClose($USER32_DLL)
EndFunc   ;==>On_Exit

; ...

 

 

[misrepresentative]

Sorry for kind of bumping it. Maybe the issue is triggered by TrayGetMsg() as it does not poll tray timely enough?

[spudw2k]

That's a pretty vague issue to solve.  Since _IsPressed is evaluating the state of the keyboard, it is necessarily going to execute at the whim of CPU scheduling.  A hotkey might be better as it should trigger an, "as on demand as possible" event...depending on what you are really looking to do.   Why isn't hotkey an option for you?

[misrepresentative]

I am launching applications in protected environment(s) for various testing purposes. Hotkeys are dangerous from a security point of view & not allowed to be set.

[SadBunny]

You're not allowed to write code that is executed on keypress, so to work around that you are writing code that is executed on keypress? 

[Bert]

Hotkeyset is dangerous if and ONLY if you have a blanket hotkeyset that is active as long as the script is running. The trick is have in your loop on the top level this:

• sleep (100
• if winactive then call a function that turns on the hotkeyset
• a sub loop after that in the function that will look for what you want AND if the window is still active or not.
• If the window you have the hotkeyset is no longer active - turn off the hotkeyset

This type of setup is very common in many applications that has keys set to do specific functions. For example pressing the F3 key in Firefox opens the text search function. 

[misrepresentative]

23 minutes ago, SadBunny said:

You're not allowed to write code that is executed on keypress, so to work around that you are writing code that is executed on keypress? 

Disclaimer: I'm not a programmer. I'm breaking stuff as a hobby. Volunteering if you want. Do note that I did not create the environment. (It's like a Sandbox if you're familiar with the concept.)

Hope it doesn't go really that off-topic. Sorry about it.

I might be wrong but here's an example : it's possible to block input by setting hotkeys. Now, is it possible to use _IsPressed to block input? Probably not. Another reason is that in such protected environments, you need compatibility as well. It affects compatibility of applications. (If you find a way to block it then another method should be found.)

To me it seems more risky to set hotkeys at first-sight.

 

Please correct me if I'm wrong.

[Jos]

1 minute ago, misrepresentative said:

To me it seems more risky to set hotkeys at first-sight.

Don't know what that means. You can set/disable the HotKeySet() at any time in the script so you are always in control.

Jos 

[misrepresentative]

Yes, Jos. You are right but unknown application run as well. There is a higher risk with unknown applications.

 

Thanks.

Edited December 9, 2016 by misrepresentative

[Jos]

Why? what is the difference?

Jos

[misrepresentative]

Unknown and possibly malicious applications run in the environment. Trusted applications do not.

[Jos]

I mean between the use of _IsPressed() and HotKeySet()? 
Well aware of security risks and keylogging, but then is this discussion in the amateur league, but are not going down that road here.

Jos 

[misrepresentative]

I think there is a misunderstanding. Sorry. English is not my native language.

It's simply not possible to use HotKeySet in my case. It is considered more risky with mentioned environment. I just can't use it-- it's blocked.

[misrepresentative]

47 minutes ago, Bert said:

Hotkeyset is dangerous if and ONLY if you have a blanket hotkeyset that is active as long as the script is running. The trick is have in your loop on the top level this:

• sleep (100
• if winactive then call a function that turns on the hotkeyset
• a sub loop after that in the function that will look for what you want AND if the window is still active or not.
• If the window you have the hotkeyset is no longer active - turn off the hotkeyset

This type of setup is very common in many applications that has keys set to do specific functions. For example pressing the F3 key in Firefox opens the text search function. 

What if the user intends to use the key at the same time? eg not working with active window

Thanks.

[Jos]

23 minutes ago, misrepresentative said:

It is considered more risky with mentioned environment.

So back to my original question: Why? What is the difference? 

Jos

[misrepresentative]

Because you can block keyboard input with it. That's one example.  eg make it do nothing on all keyboard keys

 

[Jos]

Ok, I am going to exit this conversation as it's not making much sense to me and there are way better ways to accomplish that but that isn't going to be discussed here as that can be used for malicious purposes.

Good luck with your scripting!

Jos

[BrewManNH]

@misrepresentative If you're script has a GUI, then you can use accelerator keys, they are only active when the GUI is active. If you're just monitoring for key presses using _IsPressed or _WinAPI_GetAsyncKetState then you're at the whim of the timing available to the script to read from the keyboard, this will be CPU dependent and also depends on whatever else might be running at the time.

BTW, you can block any/all keyboard input very easily without ever using HotKeys, so the prohibition you have against them is ludicrous.