Stupidly simple image series viewer

program ImageVideoSeries;
(*
  Views an image series at specified FPS.
  Pauses with space.
  When paused you can rewind or skip forward using arrow-keys.
*)

const
  DISK_LOCATION = 'C:\Simba\Images\';
  PAUSE_BUTTON  = VK_SPACE;
  REWIND_FRAME  = VK_LEFT;
  FORWARD_FRAME = VK_RIGHT;
  FPS           = 5;

var
  bmp: TMufasaBitmap;
  i: Int32;
  frames: TStringArray;

procedure ShowFrame(i: Int32);
begin
  bmp.Init();
  bmp.LoadFromFile(DISK_LOCATION+frames[i]);
  ShowBitmap(bmp);
  bmp.Free();
end;

procedure HandleAll();
var
  t: Double;
  isPaused: Boolean;
begin
  t := GetTimeRunning() + 1000 div FPS;
  while GetTimeRunning() < t do
  begin
    isPaused := isKeyDown(PAUSE_BUTTON);
    while isKeyDown(PAUSE_BUTTON) do Sleep(1);

    if isPaused then
    begin
      while not isKeyDown(PAUSE_BUTTON) do
      begin
        //check for rewinding
        if isKeyDown(REWIND_FRAME) then
        begin
          WriteLn('<< [frame='+ToStr(i-1)+']');
          while isKeyDown(REWIND_FRAME) do Sleep(1);
          i := Max(0,i-1);
          ShowFrame(i);
        end;

        if isKeyDown(FORWARD_FRAME) then
        begin
          WriteLn('>> [frame='+ToStr(i+1)+']');
          while isKeyDown(FORWARD_FRAME) do Sleep(1);
          i := Min(i+1, High(frames));
          ShowFrame(i);
        end;
        Sleep(1);
      end;
      while isKeyDown(PAUSE_BUTTON) do Sleep(1);
    end;
    Sleep(1);
  end;
end;


begin
  frames := GetFiles(DISK_LOCATION,'png');

  for i:=0 to High(frames) do
  begin
    ShowFrame(i);
    HandleAll();
  end;
end.