SetCursorPos malfunctions?

Question

I wanted to write a procedure in delphi to simulate a moving mouse pointer with a specific speed (similar to the AutoIT MouseMove function). Either my code is wrong or SetCursorPos malfunctions after it gets called too many times. Here is the function I have:

procedure MoveMouse ( X, Y, Speed : Integer);
var
  P     : TPoint;
  NewX  : Integer;
  NewY  : Integer;
begin
  if X < 0 then exit;
  if Y < 0 then exit;
  if X > Screen.Height then exit;
  if Y > Screen.Width then Exit;
  repeat
    GetCursorPos(P);
    NewX := P.X;
    NewY := P.Y;
    if P.X <> X then begin
      if P.X > X then begin
        NewX := P.X - 1;
      end else begin
        NewX := P.X + 1;
      end;
    end;
    if P.Y <> Y then begin
      if P.Y > Y then begin
        NewY := P.Y - 1;
      end else begin
        NewY := P.Y + 1;
      end;
    end;
    sleep (Speed);
    SetCursorPos(NewX, NewY);
  until (P.X = X) and (P.Y = Y);
end;

I use it like this:

procedure TForm1.btn1Click(Sender: TObject);
var
  X : Integer;
  Y : Integer;
begin
  for X := 0 to Screen.Width do begin
    for Y := 0 to Screen.Height do begin
      MouseClick (X, Y, 1);
    end;
  end;
end;

For some reason the mousepointer gets stuck at a certain X point and then jumps back to 0,0 but why is that?

Answer 1

You code is stuck , because in the repeat loop, the condition

until (P.X = X) and (P.Y = Y);

is never satisfied when you pass the values X=0 and Y=Screen.Height, so you must modify your loop to pass only valid screen coordinates values

  for X := 0 to Screen.Width-1 do
    for Y := 0 to Screen.Height-1 do
      MoveMouse (X, Y, 1); 

Also you can improve your method checking the result of the GetCursorPos and SetCursorPos functions.

procedure MoveMouse ( X, Y, Speed : Word);
var
  P     : TPoint;
  NewX  : Integer;
  NewY  : Integer;
begin
  if X > Screen.Width-1  then Exit;
  if Y > Screen.Height-1 then Exit;
  repeat
    if not GetCursorPos(P) then RaiseLastOSError;
    NewX := P.X;
    NewY := P.Y;
    if P.X <> X then
    begin
      if P.X > X then
        NewX := P.X - 1
      else
        NewX := P.X + 1;
    end;

    if P.Y <> Y then
    begin
      if P.Y > Y then
        NewY := P.Y - 1
      else
        NewY := P.Y + 1
    end;
    Sleep (Speed);
    if not SetCursorPos(NewX, NewY) then RaiseLastOSError;
  until (P.X = X) and (P.Y = Y);
end;