tdf#120774: in 6.2, restrict workaround to kde4 vclplug only

Fix of tdf#41996 is a workaround of kde4-specific condition and
has been since disabled on OS X (as tdf#51023). kde5 comes with
a new implementation of DnD and slide sorter in Impress now
exhibits exactly the same symptoms as on OS X in tdf#51023

Assuming that in 6.2 kde5 doesn't need this workaround anymore and
remaining platforms -- gtk[23] and Win -- never had issues with DnD
in slide sorter, keep it active only for kde4 vclplug.

We can't kill it with fire in its entirety, because kde4 has been
obsoleted only post-6.2

Change-Id: I1fd8bb9e5142effffbd43f3a8bead417832c808c
Reviewed-on: https://gerrit.libreoffice.org/73403
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

sd/source/ui/slidesorter/controller/SlsSelectionFunction.cxx

@@ -61,6 +61,7 @@
 #include <sfx2/dispatch.hxx>
 #include <svx/svdpagv.hxx>
 #include <svx/svxids.hrc>
+#include <vcl/svapp.hxx>
 #include <boost/optional.hpp>
 #include <sdmod.hxx>
 
@@ -225,17 +226,12 @@ public:
     MultiSelectionModeHandler (
         SlideSorter& rSlideSorter,
         SelectionFunction& rSelectionFunction,
-#ifndef MACOSX
-        const Point& rMouseModelPosition);
-#else
         const Point& rMouseModelPosition,
-        const sal_uInt32 nEventCode);
-#endif
+        const sal_uInt32 nEventCode,
+        bool bKDE4);
     virtual ~MultiSelectionModeHandler() override;
 
-#ifndef MACOSX
     void Initialize(const sal_uInt32 nEventCode);
-#endif
 
     virtual SelectionFunction::Mode GetMode() const override;
     virtual void Abort() override;
@@ -258,6 +254,7 @@ private:
     bool mbAutoScrollInstalled;
     sal_Int32 mnAnchorIndex;
     sal_Int32 mnSecondIndex;
+    bool mbKDE4;
 
     void UpdateModelPosition (const Point& rMouseModelPosition);
     void UpdateSelection();
@@ -281,18 +278,13 @@ class DragAndDropModeHandler : public SelectionFunction::ModeHandler
 public:
     DragAndDropModeHandler (
         SlideSorter& rSlideSorter,
-#ifndef MACOSX
-        SelectionFunction& rSelectionFunction);
-#else
         SelectionFunction& rSelectionFunction,
         const Point& rMousePosition,
-        vcl::Window* pWindow);
-#endif
+        vcl::Window* pWindow,
+        bool bKDE4);
     virtual ~DragAndDropModeHandler() override;
 
-#ifndef MACOSX
     void Initialize(const Point& rMousePosition, vcl::Window* pWindow);
-#endif
 
     virtual SelectionFunction::Mode GetMode() const override;
     virtual void Abort() override;
@@ -303,6 +295,7 @@ protected:
 
 private:
     std::unique_ptr<DragAndDropContext, o3tl::default_delete<DragAndDropContext>> mpDragAndDropContext;
+    bool mbKDE4;
 };
 
 //===== SelectionFunction =====================================================
@@ -322,6 +315,7 @@ SelectionFunction::SelectionFunction (
       mnShiftKeySelectionAnchor(-1),
       mpModeHandler(new NormalModeHandler(rSlideSorter, *this))
 {
+    mbKDE4 = Application::GetToolkitName() == "kde4";
 }
 
 SelectionFunction::~SelectionFunction()
@@ -684,18 +678,21 @@ void SelectionFunction::SwitchToDragAndDropMode (const Point& rMousePosition)
 {
     if (mpModeHandler->GetMode() != DragAndDropMode)
     {
-#ifndef MACOSX
-        std::shared_ptr<DragAndDropModeHandler> handler(
-            new DragAndDropModeHandler(mrSlideSorter, *this));
-        SwitchMode(handler);
-        // Delayed initialization, only after mpModeHanler is set, otherwise DND initialization
-        // could already trigger DND events, which would recursively trigger this code again,
-        // and without mpModeHandler set it would again try to set a new handler.
-        handler->Initialize(rMousePosition, mpWindow);
-#else
-        SwitchMode(std::shared_ptr<ModeHandler>(
-            new DragAndDropModeHandler(mrSlideSorter, *this, rMousePosition, mpWindow)));
-#endif
+        if (mbKDE4)
+        {
+            std::shared_ptr<DragAndDropModeHandler> handler(
+                new DragAndDropModeHandler(mrSlideSorter, *this, rMousePosition, mpWindow, mbKDE4));
+            SwitchMode(handler);
+            // Delayed initialization, only after mpModeHanler is set, otherwise DND initialization
+            // could already trigger DND events, which would recursively trigger this code again,
+            // and without mpModeHandler set it would again try to set a new handler.
+            handler->Initialize(rMousePosition, mpWindow);
+        }
+        else
+        {
+            SwitchMode(std::shared_ptr<ModeHandler>(
+                new DragAndDropModeHandler(mrSlideSorter, *this, rMousePosition, mpWindow, mbKDE4)));
+        }
     }
 }
 
@@ -704,19 +701,22 @@ void SelectionFunction::SwitchToMultiSelectionMode (
     const sal_uInt32 nEventCode)
 {
     if (mpModeHandler->GetMode() != MultiSelectionMode)
-#ifndef MACOSX
     {
-        std::shared_ptr<MultiSelectionModeHandler> handler(
-            new MultiSelectionModeHandler(mrSlideSorter, *this, rMousePosition));
-        SwitchMode(handler);
-        // Delayed initialization, only after mpModeHanler is set, the handle ctor
-        // is non-trivial, so it could possibly recurse just like the DND handler above.
-        handler->Initialize(nEventCode);
+        if (mbKDE4)
+        {
+            std::shared_ptr<MultiSelectionModeHandler> handler(
+                new MultiSelectionModeHandler(mrSlideSorter, *this, rMousePosition, nEventCode, mbKDE4));
+            SwitchMode(handler);
+            // Delayed initialization, only after mpModeHanler is set, the handle ctor
+            // is non-trivial, so it could possibly recurse just like the DND handler above.
+            handler->Initialize(nEventCode);
+        }
+        else
+        {
+            SwitchMode(std::shared_ptr<ModeHandler>(
+                new MultiSelectionModeHandler(mrSlideSorter, *this, rMousePosition, nEventCode, mbKDE4)));
+        }
     }
-#else
-        SwitchMode(std::shared_ptr<ModeHandler>(
-            new MultiSelectionModeHandler(mrSlideSorter, *this, rMousePosition, nEventCode)));
-#endif
 }
 
 void SelectionFunction::SwitchMode (const std::shared_ptr<ModeHandler>& rpHandler)
@@ -1233,26 +1233,24 @@ void NormalModeHandler::ResetButtonDownLocation()
 MultiSelectionModeHandler::MultiSelectionModeHandler (
     SlideSorter& rSlideSorter,
     SelectionFunction& rSelectionFunction,
-#ifndef MACOSX
-    const Point& rMouseModelPosition)
-#else
     const Point& rMouseModelPosition,
-    const sal_uInt32 nEventCode)
-#endif
+    const sal_uInt32 nEventCode,
+    bool bKDE4)
     : ModeHandler(rSlideSorter, rSelectionFunction, false),
       meSelectionMode(SM_Normal),
       maSecondCorner(rMouseModelPosition),
       maSavedPointer(mrSlideSorter.GetContentWindow()->GetPointer()),
       mbAutoScrollInstalled(false),
       mnAnchorIndex(-1),
-      mnSecondIndex(-1)
+      mnSecondIndex(-1),
+      mbKDE4(bKDE4)
 {
-#ifndef MACOSX
+    if (!mbKDE4)
+        Initialize(nEventCode);
 }
 
 void MultiSelectionModeHandler::Initialize(const sal_uInt32 nEventCode)
 {
-#endif
     const Pointer aSelectionPointer (PointerStyle::Text);
     mrSlideSorter.GetContentWindow()->SetPointer(aSelectionPointer);
     SetSelectionModeFromModifier(nEventCode);
@@ -1461,21 +1459,19 @@ void MultiSelectionModeHandler::UpdateSelection()
 
 DragAndDropModeHandler::DragAndDropModeHandler (
     SlideSorter& rSlideSorter,
-#ifndef MACOSX
-    SelectionFunction& rSelectionFunction)
-#else
     SelectionFunction& rSelectionFunction,
     const Point& rMousePosition,
-    vcl::Window* pWindow)
-#endif
-    : ModeHandler(rSlideSorter, rSelectionFunction, false)
+    vcl::Window* pWindow,
+    bool bKDE4)
+    : ModeHandler(rSlideSorter, rSelectionFunction, false),
+      mbKDE4(bKDE4)
 {
-#ifndef MACOSX
+    if (!mbKDE4)
+        Initialize(rMousePosition, pWindow);
 }
 
 void DragAndDropModeHandler::Initialize(const Point& rMousePosition, vcl::Window* pWindow)
 {
-#endif
     SdTransferable* pDragTransferable = SD_MOD()->pTransferDrag;
     if (pDragTransferable==nullptr && mrSlideSorter.GetViewShell() != nullptr)
     {

sd/source/ui/slidesorter/inc/controller/SlsSelectionFunction.hxx

@@ -116,6 +116,8 @@ private:
     */
     std::shared_ptr<ModeHandler> mpModeHandler;
 
+    bool mbKDE4;
+
     /** Make the slide nOffset slides away of the current one the new
         current slide.  When the new index is outside the range of valid
         page numbers it is clipped to that range.