tdf#93352 Fix horizontal swiping and scrolling when using an RTL UI

Starting with commit bfa21ce5fa08f2c634ccb6162914be55aef9f3c2,
horizontal swiping in Calc moved in the wrong direction scrollbars
were drawn mirrored.

So, revert parts of commit bfa21ce5fa08f2c634ccb6162914be55aef9f3c2
so that we are using Calc's previous "negative scrollbar range"
implementation for RTL UIs, but only for horizontal scrollbars since
vertical scrollbars are the same in LTR and RTL UIs.

Also, always disable RTL for scrollbars. Enabling RTL causes the
following bugs when clicking or dragging the mouse in scrollbars in
Calc's RTL UI:
- Click or drag events get mirrored so you must click or drag in
unexpected locations to move the scrollbar thumb in the desired
direction
- Repeatedly dragging the scrollbar thumb leftward can only move
no highter than the R, S, or T columns

Note: even though RTL is always disabled for Calc scrollbars, the arrows
must still be swapped in vcl's ScrollBar class.

Change-Id: I85aac94ffaf7df2eeb251a3ff150cc0363b5d770
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/164959
Reviewed-by: Stéphane Guillou <stephane.guillou@libreoffice.org>
Tested-by: Jenkins
Reviewed-by: Patrick Luby <guibomacdev@gmail.com>

3 files changed, 6 insertions, 0 deletions

diff --git a/include/svtools/scrolladaptor.hxx b/include/svtools/scrolladaptor.hxx
index cdc507078cf8..1eba1dfdf844 100644
--- a/include/svtools/scrolladaptor.hxx
+++ b/include/svtools/scrolladaptor.hxx
@@ -71,6 +71,8 @@ public:
 
     void SetThickness(int nThickness);
 
+    void SetSwapArrows(bool bSwap = true);
+
     ScrollAdaptor(vcl::Window* pParent, bool bHori);
     virtual void dispose() override;
 };
diff --git a/include/vcl/toolkit/scrbar.hxx b/include/vcl/toolkit/scrbar.hxx
index 408ca90d7483..e8b9d37584ed 100644
--- a/include/vcl/toolkit/scrbar.hxx
+++ b/include/vcl/toolkit/scrbar.hxx
@@ -58,6 +58,7 @@ private:
     ScrollType      meScrollType;
     bool            mbCalcSize;
     bool            mbFullDrag;
+    bool            mbSwapArrows;
     Link<ScrollBar*,void>       maScrollHdl;
     Link<ScrollBar*,void>       maEndScrollHdl;
 
@@ -133,6 +134,8 @@ public:
     void            SetEndScrollHdl( const Link<ScrollBar*,void>& rLink ) { maEndScrollHdl = rLink; }
 
     virtual Size    GetOptimalSize() const override;
+
+    void            SetSwapArrows( bool bSwap ) { mbSwapArrows = bSwap; }
 };
 
 
diff --git a/include/vcl/weld.hxx b/include/vcl/weld.hxx
index c93524e3bfd4..8b9495e9e4e8 100644
--- a/include/vcl/weld.hxx
+++ b/include/vcl/weld.hxx
@@ -2576,6 +2576,7 @@ public:
 
     virtual int get_scroll_thickness() const = 0;
     virtual void set_scroll_thickness(int nThickness) = 0;
+    virtual void set_scroll_swap_arrows(bool bSwap) = 0;
 
     virtual ScrollType get_scroll_type() const = 0;