WIN unify deferred message handling

Moves the common code into ProcessOrDeferMessage.

All callers (try to) aquire the mutex before getting the
WinSalFrame pointer, except for ImplHandleDeferredPaintMsg.

This was probably an oversight, so this reverses the order in this
function, so the GetWindowPtr is now always protected by the Solar
mutex.

Change-Id: Icb8f34f7e8716f0faa90a95903b1681f7489aed2

vcl/win/window/salframe.cxx

@@ -3692,47 +3692,82 @@ long ImplHandleSalObjSysCharMsg( HWND hWnd, WPARAM wParam, LPARAM lParam )
     return nRet;
 }
 
-enum class PostPaint
+enum class DeferPolicy
 {
-    IsPosted,
-    IsInitial
+    Blocked,
+    Allowed
 };
 
-static bool ImplHandlePostPaintMsg( HWND hWnd, RECT* pRect,
-                                    PostPaint eProcessed = PostPaint::IsPosted )
+// Remember to release the solar mutex on success!
+static inline WinSalFrame* ProcessOrDeferMessage( HWND hWnd, INT nMsg, WPARAM pWParam = 0,
+                                                  DeferPolicy eCanDefer = DeferPolicy::Allowed )
 {
-    bool bGotMutex = false;
+    bool bFailedCondition = FALSE, bGotMutex = FALSE;
+    WinSalFrame* pFrame = nullptr;
 
-    WinSalFrame* pFrame = GetWindowPtr( hWnd );
-    if ( pFrame )
+    if ( DeferPolicy::Blocked == eCanDefer )
+        assert( (DeferPolicy::Blocked == eCanDefer) && (nMsg == 0) && (pWParam == 0) );
+    else
+        assert( (DeferPolicy::Allowed == eCanDefer) && (nMsg != 0) );
+
+    if ( DeferPolicy::Blocked == eCanDefer )
     {
-        if ( ImplSalYieldMutexTryToAcquire() )
-            bGotMutex = true;
+        ImplSalYieldMutexAcquireWithWait();
+        bGotMutex = TRUE;
+    }
+    else if ( !(bGotMutex = ImplSalYieldMutexTryToAcquire()) )
+        bFailedCondition = TRUE;
 
-        if ( bGotMutex )
+    if ( !bFailedCondition )
     {
-            SalPaintEvent aPEvt( pRect->left, pRect->top, pRect->right-pRect->left, pRect->bottom-pRect->top );
-            pFrame->CallCallback( SalEvent::Paint, &aPEvt );
-            ImplSalYieldMutexRelease();
-            if ( PostPaint::IsPosted == eProcessed )
-                delete pRect;
+        pFrame = GetWindowPtr( hWnd );
+        bFailedCondition = pFrame == nullptr;
     }
-        else
+
+    if ( bFailedCondition )
     {
+        if ( bGotMutex )
+            ImplSalYieldMutexRelease();
+        if ( DeferPolicy::Allowed == eCanDefer )
+        {
+            BOOL const ret = PostMessageW(hWnd, nMsg, pWParam, 0);
+            SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
+        }
+    }
+
+    return pFrame;
+}
+
+enum class PostedState
+{
+    IsPosted,
+    IsInitial
+};
+
+static bool ImplHandlePostPaintMsg( HWND hWnd, RECT* pRect,
+                                    PostedState eProcessed = PostedState::IsPosted )
+{
     RECT* pMsgRect;
-            if ( PostPaint::IsInitial == eProcessed )
+    if ( PostedState::IsInitial == eProcessed )
     {
         pMsgRect = new RECT;
         CopyRect( pMsgRect, pRect );
     }
     else
         pMsgRect = pRect;
-            BOOL const ret = PostMessageW(hWnd, SAL_MSG_POSTPAINT, reinterpret_cast<WPARAM>(pMsgRect), 0);
-            SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
-        }
+
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, SAL_MSG_POSTPAINT,
+                                                 reinterpret_cast<WPARAM>(pMsgRect) );
+    if ( pFrame )
+    {
+        SalPaintEvent aPEvt( pRect->left, pRect->top, pRect->right-pRect->left, pRect->bottom-pRect->top );
+        pFrame->CallCallback( SalEvent::Paint, &aPEvt );
+        ImplSalYieldMutexRelease();
+        if ( PostedState::IsPosted == eProcessed )
+            delete pRect;
     }
 
-    return bGotMutex;
+    return (pFrame != nullptr);
 }
 
 static bool ImplHandlePaintMsg( HWND hWnd )
@@ -3773,8 +3808,8 @@ static bool ImplHandlePaintMsg( HWND hWnd )
         // try painting
         if ( bHasPaintRegion )
         {
-            bPaintSuccessful = ImplHandlePostPaintMsg( hWnd, &aUpdateRect,
-                                                       PostPaint::IsInitial );
+            bPaintSuccessful = ImplHandlePostPaintMsg(
+                hWnd, &aUpdateRect, PostedState::IsInitial );
             EndPaint( hWnd, &aPs );
         }
         else // if there is nothing to paint, the paint is successful
@@ -3891,9 +3926,7 @@ static void ImplCallClosePopupsHdl( HWND hWnd )
 
 static void ImplHandleMoveMsg( HWND hWnd )
 {
-    if ( ImplSalYieldMutexTryToAcquire() )
-    {
-        WinSalFrame* pFrame = GetWindowPtr( hWnd );
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, SAL_MSG_POSTMOVE );
         if ( pFrame )
         {
             UpdateFrameGeometry( hWnd, pFrame );
@@ -3918,39 +3951,24 @@ static void ImplHandleMoveMsg( HWND hWnd )
             //#93851 if we call this handler, VCL floating windows are not updated correctly
             ImplCallMoveHdl( hWnd );
 
-        }
-
             ImplSalYieldMutexRelease();
         }
-    else
-    {
-        BOOL const ret = PostMessageW( hWnd, SAL_MSG_POSTMOVE, 0, 0 );
-        SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
-    }
 }
 
 static void ImplCallSizeHdl( HWND hWnd )
 {
     // as Windows can send these messages also, we have to use
     // the Solar semaphore
-    if ( ImplSalYieldMutexTryToAcquire() )
-    {
-        WinSalFrame* pFrame = GetWindowPtr( hWnd );
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, SAL_MSG_POSTCALLSIZE );
         if ( pFrame )
         {
             pFrame->CallCallback( SalEvent::Resize, nullptr );
             // to avoid double Paints by VCL and SAL
             if ( IsWindowVisible( hWnd ) && !pFrame->mbInShow )
                 UpdateWindow( hWnd );
-        }
 
             ImplSalYieldMutexRelease();
         }
-    else
-    {
-        BOOL const ret = PostMessageW( hWnd, SAL_MSG_POSTCALLSIZE, 0, 0 );
-        SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
-    }
 }
 
 static void ImplHandleSizeMsg( HWND hWnd, WPARAM wParam, LPARAM lParam )
@@ -3974,12 +3992,13 @@ static void ImplHandleSizeMsg( HWND hWnd, WPARAM wParam, LPARAM lParam )
 
 static void ImplHandleFocusMsg( HWND hWnd )
 {
-    if ( ImplSalYieldMutexTryToAcquire() )
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, SAL_MSG_POSTFOCUS );
+    if ( pFrame )
     {
-        WinSalFrame* pFrame = GetWindowPtr( hWnd );
-        if ( pFrame && !WinSalFrame::mbInReparent )
+        if ( !WinSalFrame::mbInReparent )
         {
-            if ( ::GetFocus() == hWnd )
+            bool bGotFocus = ::GetFocus() == hWnd;
+            if ( bGotFocus )
             {
                 if ( IsWindowVisible( hWnd ) && !pFrame->mbInShow )
                     UpdateWindow( hWnd );
@@ -3993,53 +4012,32 @@ static void ImplHandleFocusMsg( HWND hWnd )
                     pFrame->mbAtCursorIME = (nImeProps & IME_PROP_AT_CARET) != 0;
                     pFrame->mbHandleIME = !pFrame->mbSpezIME;
                 }
-
-                pFrame->CallCallback( SalEvent::GetFocus, nullptr );
             }
-            else
-            {
-                pFrame->CallCallback( SalEvent::LoseFocus, nullptr );
+            pFrame->CallCallback( bGotFocus ? SalEvent::GetFocus : SalEvent::LoseFocus, nullptr );
         }
-        }
-
         ImplSalYieldMutexRelease();
     }
-    else
-    {
-        BOOL const ret = PostMessageW( hWnd, SAL_MSG_POSTFOCUS, 0, 0 );
-        SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
-    }
 }
 
 static void ImplHandleCloseMsg( HWND hWnd )
 {
-    if ( ImplSalYieldMutexTryToAcquire() )
-    {
-        WinSalFrame* pFrame = GetWindowPtr( hWnd );
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, WM_CLOSE );
         if ( pFrame )
         {
             pFrame->CallCallback( SalEvent::Close, nullptr );
-        }
-
             ImplSalYieldMutexRelease();
         }
-    else
-    {
-        BOOL const ret = PostMessageW( hWnd, WM_CLOSE, 0, 0 );
-        SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
-    }
 }
 
 static long ImplHandleShutDownMsg( HWND hWnd )
 {
-    ImplSalYieldMutexAcquireWithWait();
     long nRet = 0;
-    WinSalFrame*   pFrame = GetWindowPtr( hWnd );
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, 0, 0, DeferPolicy::Blocked );
     if ( pFrame )
     {
         nRet = pFrame->CallCallback( SalEvent::Shutdown, nullptr );
-    }
         ImplSalYieldMutexRelease();
+    }
     return nRet;
 }
 
@@ -4074,9 +4072,7 @@ static void ImplHandleSettingsChangeMsg( HWND hWnd, UINT nMsg,
     if ( WM_SYSCOLORCHANGE == nMsg && GetSalData()->mhDitherPal )
         ImplUpdateSysColorEntries();
 
-    ImplSalYieldMutexAcquireWithWait();
-
-    WinSalFrame* pFrame = GetWindowPtr( hWnd );
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, 0, 0, DeferPolicy::Blocked );
     if ( pFrame )
     {
         if ( (nMsg == WM_DISPLAYCHANGE) || (nMsg == WM_WININICHANGE) )
@@ -4086,20 +4082,18 @@ static void ImplHandleSettingsChangeMsg( HWND hWnd, UINT nMsg,
         }
 
         pFrame->CallCallback( nSalEvent, nullptr );
-    }
-
         ImplSalYieldMutexRelease();
+    }
 }
 
 static void ImplHandleUserEvent( HWND hWnd, LPARAM lParam )
 {
-    ImplSalYieldMutexAcquireWithWait();
-    WinSalFrame* pFrame = GetWindowPtr( hWnd );
+    WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, 0, 0, DeferPolicy::Blocked );
     if ( pFrame )
     {
         pFrame->CallCallback( SalEvent::UserEvent, reinterpret_cast<void*>(lParam) );
-    }
         ImplSalYieldMutexRelease();
+    }
 }
 
 static void ImplHandleForcePalette( HWND hWnd )
@@ -4108,14 +4102,7 @@ static void ImplHandleForcePalette( HWND hWnd )
     HPALETTE    hPal = pSalData->mhDitherPal;
     if ( hPal )
     {
-        if ( !ImplSalYieldMutexTryToAcquire() )
-        {
-            BOOL const ret = PostMessageW( hWnd, SAL_MSG_FORCEPALETTE, 0, 0 );
-            SAL_WARN_IF(0 == ret, "vcl", "ERROR: PostMessage() failed!");
-            return;
-        }
-
-        WinSalFrame* pFrame = GetWindowPtr( hWnd );
+        WinSalFrame* pFrame = ProcessOrDeferMessage( hWnd, SAL_MSG_FORCEPALETTE );
         if ( pFrame && pFrame->mpGraphics )
         {
             WinSalGraphics* pGraphics = pFrame->mpGraphics;
@@ -4130,7 +4117,7 @@ static void ImplHandleForcePalette( HWND hWnd )
                 }
             }
         }
-
+        if ( pFrame )
             ImplSalYieldMutexRelease();
     }
 }