Capturing the length of a key press

[danny770]

I'm currently writing a piece of code which captures a key press and determines the length of that press, and I'm having trouble deciding how precisely I should go about calculating the lenght of the press. Would a timer be the best idea?

My current setup has an "OnMessage" function which kicks-in whenever a message (key press, alarm activation etc.) is received by the system. I'm not sure if the functionality is such that a continued key press will result in multiples "key pressed" messages being sent to the system, in which case it may be simpler.

If a timer is required, what's the most simple/appropriate method of implementing it?

I'm looking to have say:

1 second press sets i value = 1
5 second press sets i value = 5
10 second press sets i value = 10

And so on...

I need something which regularly checks whether the key is still pressed, and increases the value accordingly.

Many thanks in advance. :-)

[olivthill]

You can avoid a timer, since Windows messages contain the time when they were posted.

Retrieve the message structure with GetMessage(). See http://msdn.microsoft.com/library/de...ctures/msg.asp.

[Roger Allen]

You may find that setting a hook using

// setup the keyboard hook
        m_keyboardHookHandle = ::SetWindowsHookEx(
                WH_KEYBOARD,
                KeyboardHookFunction,
                GetInstanceHandle(),
                GetCurrentThreadId());

// finish with the hook
    if (m_keyboardHookHandle != NULL)
    {
        ::UnhookWindowsHookEx(m_keyboardHookHandle);
        m_keyboardHookHandle = NULL;
    }


LRESULT CALLBACK KeyboardHookFunction(int code, WPARAM wParam, LPARAM lParam)
{
    if ((HIWORD(lParam) & KF_UP) == 0)
    {
        if ((HIWORD(lParam) & KF_REPEAT) == 0)
        {
            // its not a repeat key message
            // its a key down message
            // start a timer here for this key
        }
    }
    else
    {
        // its a key-up message, switch back to correct cursor
        // end correct timer here
    }
    return ::CallNextHookEx(m_keyboardHookHandle, code, wParam, lParam);
}

will allow you to get every key press/release in the hook function and determine times there