I want to perform background tasks (Updates, Backups, Calculations, ...) at a time when nobody is using my application.
Therefore, I want to determine the time since the last keystroke and/or mouse move in my application. If there is no user activity for more than a specific time, the chance is high not to disturb a user. Multithreading is not an option for me.
I want to avoid touching every single OnMouseDown-/OnKeyPress-Event of every component in my application because this doesn't make any sense.
How can I get
a) The time since last input in Windows
b) The time since last input in my application
This solution works for problem
a) The time since last input in Windows
Every mouse move or keyboard input resets the time to zero.
function GetTimeSinceLastUserInputInWindows(): TTimeSpan;
var
lastInput: TLastInputInfo;
currentTickCount: DWORD;
millisecondsPassed: Double;
begin
lastInput := Default(TLastInputInfo);
lastInput.cbSize := SizeOf(TLastInputInfo);
Win32Check( GetLastInputInfo(lastInput) );
currentTickCount := GetTickCount();
if (lastInput.dwTime > currentTickCount) then begin // lastInput was before 49.7 days but by now, 49.7 days have passed
millisecondsPassed :=
(DWORD.MaxValue - lastInput.dwTime)
+ (currentTickCount * 1.0); // cast to float by multiplying to avoid DWORD overflow
Result := TTimeSpan.FromMilliseconds(millisecondsPassed);
end else begin
Result := TTimeSpan.FromMilliseconds(currentTickCount - lastInput.dwTime );
end;
end;