C++ Close the J2Play community wrapper

From J2Play

Close the J2Play community wrapper

If you provide a EXIT button in your game except the standard window 'X' close button on topright, call the CloseGameCommunity() API in the button handler to close the playground.

 CGDKInstance* j2play = CGDKInstance::GetInstance();
 j2play->CloseGameCommunity();

Side effect

Because the game window has become a child window of the J2Play Community, the playground close process may have some side effects on game window.

Usually, the normal process of window game close is

MFC:

1) User clicks EXIT button (or similar opreation);
2) OnLButtonUp() handler (or other similar handler like CWnd::OnCommand(), CDialog::OnOK() and CDialog::OnCancel() ) (Cleanup code 1);
3) The handler function sends WM_CLOSE to the game main window (it is default action for CDialog::OnOK() and CDialog::OnCancel() );
4) OnClose() handler (Cleanup code 2);
5) Call DestroyWindow() to send WM_DESTROY explicitly (or let CWnd::OnClose() handle it by default)
6) OnDestroy() handler (Cleanup code 3);
7) Call PostQuitMessage() to send WM_QUIT explicitly (or let CWnd::OnDestroy() handle it by default)
8) WM_QUIT message terminates message loop;
9) CWinApp::ExitInstance() (Cleanup code 4).

WIN32:

1) User clicks EXIT button (or similar opreation);
2) WM_LBUTTONUP case of WndProc (or other similar user operation handler) (Cleanup code 1)
3) The operation handler sends WM_CLOSE to the game main window;
4) WM_CLOSE case of WndProc (Cleanup code 2);
5) Call DestroyWindow() explicitly, or call DefaultWndProc to handle WM_CLOSE, both sends WM_DESTROY;
6) WM_DESTROY case of WndProc (Cleanup code 3);
7) Call PostQuitMessage() explicitly, or call DefaultWndProc to handle WM_DESOTRY, both send WM_QUIT;
8) WM_QUIT terminates message loop;
9) Cleanup after message loop (Cleanup code 4).

You may not have all these steps, for example, if your game don't have anything in place of Cleanup code 1 & 2, you may call DestroyWindow() in your code directly when user clicks EXIT button.

However, close through CloseGameCommunity(), the process will becomes

1) User clicks EXIT button (or similar opreation);
2) Your button handler(Cleanup code 1)
3) The handler calls CloseGameCommunity();
4) CloseGameCommunity() sends WM_CLOSE to the game window;
5) OnClose() or other WM_CLOSE handler (Cleanup code 2);
6) CloseGameCommunity() sends WM_DESTROY to the game window;
7) OnDestry() or other WM_DESTROY handler (Cleanup code 3);
8) CloseGameCommunity() sends WM_QUIT to the message loop;
9) WM_QUIT message terminates message loop;
10) Cleanup after message loop (Cleanup code 4).

So, you need

• check all API calls relates to closing in your code, like SendMessage(WM_CLOSE,0,0), DestroyWindow(), PostQuitMessage(), OnOK() and OnCancel()
• replace the original call(s) with CloseGameCommunity()
• remove other unnecessary close message processing, rely on the CloseGameCommunity() to dispatch all window close messages

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