unit Animation;

interface

uses
   System.SysUtils, System.Types, System.UITypes, System.Classes,
   System.Variants,
   FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.Ani,
   FMX.Objects, Rocket, System.Generics.Collections;

const
   ROCKET_AMNT = 10;

type
   TMainForm = class(TForm)
      Timer1: TTimer;
      imgBackground: TImage;
      procedure FormCreate(Sender: TObject);
      procedure Timer1Timer(Sender: TObject);
      procedure FormKeyUp(Sender: TObject; var Key: Word; var KeyChar: Char;
        Shift: TShiftState);
   private
      { Private declarations }
   public
      ArrayOfRockets: TObjectList<TRocket>;
      { Public declarations }
   end;

var
   MainForm: TMainForm;

implementation

{$R *.fmx}

procedure TMainForm.FormCreate(Sender: TObject);
var
   I: Integer;
begin
   Randomize;
   ArrayOfRockets := TObjectList<TRocket>.Create(False);
end;

procedure UpdateWorld(var F: TMainForm);
var
   I: Integer;
begin
   with F do
   begin
      I := 0;
      while I <> ArrayOfRockets.Count do
      begin
         if Assigned(ArrayOfRockets[I]) then
         begin
            if not ArrayOfRockets[I].Destroyed then
               ArrayOfRockets[I].Update
            else
            begin
               ArrayOfRockets[I].Destroy;
               ArrayOfRockets.Delete(I);
               Dec(I);
            end;
         end;
         Inc(I);
      end;
   end;
end;

procedure TMainForm.FormKeyUp(Sender: TObject; var Key: Word; var KeyChar: Char;
  Shift: TShiftState);
begin
   if Key = vkReturn then
      ArrayOfRockets.Add(TRocket.Create(200 + Random(300), 408,
        30 - Random(60), 2));
end;

procedure TMainForm.Timer1Timer(Sender: TObject);
begin
   UpdateWorld(Self);
end;

end.