Layer based Keyboard using AutoHotKey: Change modifiers single press, hold, and double press behavior - autohotkey

Question

folks,
I want to create a layer based keyboard using AutoHotkey. Basicly, I want to achieve what shift already does: modify each key when a modifier is used.
I want to improve regular shift in the following:
press modifier once: only change layer for next character
hold modifier: change layer as long as modifier is down
press modifier twice: enter layer mode, like capslock. (end by another press)
Modifiers: LAlt, RAlt, LControl, RControl (CapsLock, Shift)
How cas I accomplish this?
what I found so far on stackoverflow:
This code allows for shift to be pressed and released for the next character
$*LShift::
SendInput, {LShift Down} ; press shift
Input, Key, L1 M V ; wait for input character
If GetKeyState("LShift", "P") ; if shift still pressed, wait for release
KeyWait, LShift
SendInput, {LShift Up} ; send input with shift down, the shift up
Return
this code turns a double shift press into CapsLock
LShift::
KeyWait, CapsLock ; wait to be released
KeyWait, CapsLock, D T0.2 ; and pressed again within 0.2 seconds
if ErrorLevel
return
else if (A_PriorKey = "CapsLock")
SetCapsLockState, % GetKeyState("CapsLock","T") ? "Off" : "On"
return
#If, GetKeyState("CapsLock", "P") ; hotkeys go below
a::b
#If
But I am not experienced enough with AHK to bring this together. My goal is to have something like
Modifier::
; code that makes the modifier behave like expected: single press, hold, double press
Return
#If, GetKeyState("Modifier", "P") ; List of key remaps in specific layer
#If
I hope this is specific enough and that you can help me out here.
thanks!

Answer 1

Assign the corresponding Booleam values (true or false) to the variables "Double_LAlt" and "Double_LAlt_holding" in order to create context-sensitive hotkeys depended on their values:
LAlt::
ToolTip,,,, 3
ToolTip,,,, 4
Double_LAlt := false
; Press twice or press twice and hold LAlt within 0,2 seconds
If (A_PriorHotKey = "~LAlt Up" AND A_TimeSincePriorHotkey < 200)
{
Sleep, 200
If GetKeyState("LAlt","P")
{
ToolTip,,,, 4
ToolTip, Double_LAlt_holding,,, 2
Double_LAlt_holding := true
}
else
{
ToolTip,,,, 4
ToolTip, Double_LAlt,,, 3
Double_LAlt := true
}
}
If !((Double_LAlt_holding) || (Double_LAlt)) ; "!" means "NOT" and "||" means "OR"
ToolTip, LAlt_holding,,, 1
return
~LAlt Up::
ToolTip,,,, 1
ToolTip,,,, 2
Double_LAlt_holding := false
Sleep, 100
If (A_TimeIdlePhysical > 100)
Tooltip, PriorHotKey = LAlt Up,,, 4
SetTimer, RemoveTooltip, 1000
return
#If (Double_LAlt_holding) ; If this variable has the value "true"
<!a:: MsgBox, a while Double_LAlt_holding ; "<!" means "LAlt"
<!1:: MsgBox, 1 while Double_LAlt_holding
#If (Double_LAlt)
a:: MsgBox, a after Double_LAlt
1:: MsgBox, 1 after Double_LAlt
; Press a key within 2 seconds after releasing LAlt:
#If (A_PriorHotKey = "~LAlt Up" AND A_TimeSincePriorHotkey < 2000)
a:: MsgBox, a after LAlt Up
1:: MsgBox, 1 after LAlt Up
#If GetKeyState("LAlt","P")
a:: MsgBox, a while LAlt_holding
1:: MsgBox, 1 while LAlt_holding
#If
RemoveTooltip:
If (A_TimeSincePriorHotkey > 2000) ; 2 seconds
ToolTip,,,, 4
return