Graceful shutdown with saves when using SDL window close button

SDLPORT.PAS

@@ -3,13 +3,15 @@ unit SDLPort;
 interface
 
   type TPalette = Array[0..255,0..2] of byte;
+  type TCloseCallback = procedure;
 
   function GetVersion : string;
 
   procedure Init;
   procedure DeinitGraphics;
   procedure Deinit;
 
+  procedure SetCloseCallback(callback : TCloseCallback);
   procedure SetPalette(input : TPalette);
   procedure Render(buffer : array of byte);
   procedure WaitRaster;
@@ -42,6 +44,7 @@ implementation
 
       timer: TSDL_TimerID;
       frameCount, lastFrameCount, subFrameCount, lastFrameTick: LongInt;
+      closeCallback: TCloseCallback;
 
 function TimerCallback(interval: UInt32; param: Pointer): UInt32; cdecl;
 var frameIntervalMs, nowMs : LongInt;
@@ -142,6 +145,8 @@ begin
   lastFrameTick := SDL_GetTicks();
 
   timer := SDL_AddTimer(1, TimerCallback, nil);
+
+  closeCallback := nil;
 end;
 
 procedure DeinitGraphics;
@@ -172,6 +177,11 @@ begin
   SDL_SetPaletteColors(originalSurface^.format^.palette, @palette, 0, 256);
 end;
 
+procedure SetCloseCallback(callback : TCloseCallback);
+begin
+  closeCallback:=callback;
+end;
+
 procedure Render(buffer : array of byte);
 var pixels : Pointer;
     pitch : LongInt;
@@ -233,7 +243,10 @@ begin
 
     if (event.type_= SDL_QUITEV) then
     begin
-      Halt;
+      if Assigned(closeCallback) then
+      begin
+        closeCallback;
+      end;
     end;
 
     if event.type_= SDL_KEYDOWN then

SJ3.PAS

@@ -5816,8 +5816,20 @@ begin
 
 end;
 
+procedure Close;
+begin
+  SDLPort.DeinitGraphics;
 
+  Loppu;
 
+  SDLPort.Deinit;
+end;
+
+procedure CloseAndHalt;
+begin
+  Close;
+  Halt;
+end;
 
 begin  { MAIN }
 
@@ -5852,6 +5864,7 @@ begin  { MAIN }
   regnumber:='1234A'; }
 
  SDLPort.Init;
+ SDLPort.SetCloseCallback(CloseAndHalt);
 
  alku;
 
@@ -5868,11 +5881,7 @@ begin  { MAIN }
 
 {  Valikko; }
 
-  SDLPort.DeinitGraphics;
-
-  Loppu;
-
-  SDLPort.Deinit;
+  Close;
 
 (*
   CloseFont;  { vapautetaan niiden k„ytt„m„ muisti }