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ShowWindow
  show_window
    SetWindowPos
      USER_SetWindowPos
        set_window_pos

/***********************************************************************
 *              show_window
 *
 * Implementation of ShowWindow and ShowWindowAsync.
 */
static BOOL show_window( HWND hwnd, INT cmd )
{
    ...

    switch(cmd)
    {
        case SW_HIDE:
            ...
        case SW_RESTORE:
        /* fall through */
          case SW_SHOWNORMAL:  /* same as SW_NORMAL: */
          case SW_SHOWDEFAULT: /* FIXME: should have its own handler */
        ...
    }
  }

/***********************************************************************
 *           NC_HandleSysCommand
 *
 * Handle a WM_SYSCOMMAND message. Called from DefWindowProc().
 */
LRESULT NC_HandleSysCommand( HWND hwnd, WPARAM wParam, LPARAM lParam )
{
	...
  case SC_RESTORE:
      if (IsIconic(hwnd) && hwnd == GetActiveWindow())
          ShowOwnedPopups(hwnd,TRUE);
      ShowWindow( hwnd, SW_RESTORE );
      break;
    ...
  }

(gdb) bt
#0  ShowWindow (hwnd=0xb06f6, cmd=9) at winpos.c:1239
#1  0x7bc7b86e in relay_call () from /lib/wine/ntdll.dll.so
#2  0x7fa69f15 in __wine_spec_relay_entry_points ()
   from /lib/wine/user32.dll.so
#3  0x51072c9c in ?? ()
#4  0x51026296 in ?? ()
#5  0x7fb09dfa in WINPROC_wrapper () from /lib/wine/user32.dll.so
#6  0x7fb0a547 in call_window_proc (hwnd=0xb06f6, msg=274, wp=61728, lp=0,
    result=0x33f554, arg=0x960fef) at winproc.c:245
#7  0x7fb0aaa1 in WINPROC_CallProcWtoA (callback=<optimized out>,
    hwnd=<optimized out>, msg=274, wParam=61728, lParam=0, result=0x33f554,
    arg=0x960fef) at winproc.c:859
#8  0x7fb0cf37 in WINPROC_call_window (hwnd=0xb06f6, msg=274, wParam=61728,
    lParam=0, result=0x33f554, unicode=1, mapping=2130074987) at winproc.c:907
#9  0x7fac5f6a in call_window_proc (hwnd=0xb06f6, msg=274, wparam=61728,
    lparam=0, unicode=1, same_thread=1, mapping=2130074987) at message.c:2224
#10 0x7facdf3a in send_message (info=0x33f620, res_ptr=0x33f61c, unicode=1)
    at message.c:3279
#11 0x7face216 in SendMessageW (hwnd=0xb06f6, msg=274, wparam=61728, lparam=0)
    at message.c:3479
#12 0x7ef3d4d8 in handle_wm_state_notify (hwnd=0xb06f6, update_window=1,
    event=<optimized out>, event=<optimized out>) at event.c:1330
#13 0x7ef3d8ce in X11DRV_PropertyNotify (hwnd=0xb06f6, xev=0x33f75c)
#14 0x7ef3e707 in process_events (display=<optimized out>,
    arg=<optimized out>, filter=<optimized out>) at event.c:399
#15 0x7ef3ef97 in X11DRV_MsgWaitForMultipleObjectsEx (count=0, handles=0x0,
    timeout=0, mask=1279, flags=0) at event.c:494
#16 0x7bc7b86e in relay_call () from /lib/wine/ntdll.dll.so
#17 0x7ef2e9d5 in __wine_spec_relay_entry_points ()
   from /lib/wine/winex11.drv.so
#18 0x7fb0a880 in wait_message (count=0, handles=0x0, timeout=0, mask=1279,
    flags=0) at winproc.c:1136
#19 0x7facd0ae in PeekMessageW (msg_out=<optimized out>, hwnd=<optimized out>,
    first=<optimized out>, last=<optimized out>, flags=<optimized out>)
    at message.c:3788
#20 0x7facd31e in PeekMessageA (msg=0x33fa64, hwnd=0x0, first=0, last=0,
    flags=1) at message.c:3815
#21 0x7bc7b86e in relay_call () from /lib/wine/ntdll.dll.so
#22 0x7fa691ad in __wine_spec_relay_entry_points ()
   from /lib/wine/user32.dll.so
#23 0x510740e4 in ?? ()
#24 0x51172dbe in ?? ()
#25 0x510c4a94 in ?? ()
#26 0x510c4d71 in ?? ()
#27 0x51026296 in ?? ()
#28 0x7fb09dfa in WINPROC_wrapper () from /lib/wine/user32.dll.so
#29 0x7fb0a547 in call_window_proc (hwnd=0xe06cc, msg=45156, wp=0, lp=514,
    result=0x33fc68, arg=0x960f12) at winproc.c:245
#30 0x7fb0cecb in WINPROC_call_window (hwnd=0xe06cc, msg=45156, wParam=0,
    lParam=514, result=0x33fc68, unicode=0, mapping=WMCHAR_MAP_DISPATCHMESSAGE)
    at winproc.c:920
#31 0x7fac8184 in DispatchMessageA (msg=0x33fd9c) at message.c:3974
#32 0x7bc7b86e in relay_call () from /lib/wine/ntdll.dll.so
#33 0x7fa6728d in __wine_spec_relay_entry_points ()
   from /lib/wine/user32.dll.so
#34 0x51074154 in ?? ()
#35 0x511989b6 in ?? ()
#36 0x7b46af09 in call_process_entry () from /lib/wine/kernel32.dll.so

/***********************************************************************
 *           handle_wm_state_notify
 *
 * Handle a PropertyNotify for WM_STATE.
 */
static void handle_wm_state_notify( HWND hwnd, XPropertyEvent *event, BOOL update_window )
{
    ...
    style = GetWindowLongW( data->hwnd, GWL_STYLE );
    /*
     * 这里判断当前窗口是否是iconic状态(即最小化状态)，同时wm_state(即窗口管理器测对应的窗口状态)
     * 是否是NormalState。这里需要仔细理解下，data中的iconic表示的是X11的窗口状态，而wm_state
     * 则是窗口管理器侧的。同时满足这两个条件表明X11的窗口状态已经设置为了最小化状态，但是窗口管理器
     * 中的状态，还没有变成IconicState，这种情况本身应该是一种异常，按理状态应该一致才对，出现
     * 这种情况时，对窗口进行Restore操作，看似也是合理的。而对于EDiary，则刚好满足这种条件。
     */
    if (data->iconic && data->wm_state == NormalState)  /* restore window */
    {
        data->iconic = FALSE;
        read_net_wm_states( event->display, data );
        if ((style & WS_CAPTION) == WS_CAPTION && (data->net_wm_state & (1 << NET_WM_STATE_MAXIMIZED)))
        {
            if ((style & WS_MAXIMIZEBOX) && !(style & WS_DISABLED))
            {
                TRACE( "restoring to max %p/%lx\n", data->hwnd, data->whole_window );
                release_win_data( data );
                SendMessageW( hwnd, WM_SYSCOMMAND, SC_MAXIMIZE, 0 );
                return;
            }
            TRACE( "not restoring to max win %p/%lx style %08x\n", data->hwnd, data->whole_window, style );
        }
        else
        {
            // 这里开始，判断当前style，如果是最小化或者最大化状态，是的话，发送Restore对应的消息。
            if (style & (WS_MINIMIZE | WS_MAXIMIZE))
            {
                TRACE( "restoring win %p/%lx\n", data->hwnd, data->whole_window );
                release_win_data( data );
                SendMessageW( hwnd, WM_SYSCOMMAND, SC_RESTORE, 0 );
                return;
            }
            TRACE( "not restoring win %p/%lx style %08x\n", data->hwnd, data->whole_window, style );
        }
    }
	...
}