tdf#82009 TreeList move painting of drag target into Paint func.

When we drag a entry in TreeListBox, we execute a PaintDDCursor
which paints a "cursor" of a possible drag target (for example
to show where the entry will be moved to if we want to change the
order). The problem with this fuction is that it paints a line
directlly at that location, and that it uses invert raster
operation to draw a line. So to hide the line it just needs to
draw again. On MacOS this invertion causes a problem and draws
the whole area black, which is the cause of this bug.

So instead of inverting the drawing of the drag target cursor
has now been moved into the main Paint method, where it redraws
the whole entry, and if present, also the drag target cursor.
This means that all we need to do is Invalidate the entry,
which then just gets redrawn in a normal Paint pass.

One exception is still MacOS, which doesn't invalidate the entry,
but redraws the entry directly. DnD is MacOS is a bit different
as it is not async (if I understand correctly) so the invalidate
has no effect.

Reviewed-on: https://gerrit.libreoffice.org/70521
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
(cherry picked from commit 14abbc6e86ba234996dfed477a54030adeac2a52)

Change-Id: I8542f47940a3b90114ea4bbbac57fd303ca3434b

1 files changed, 7 insertions, 0 deletions

diff --git a/include/svtools/viewdataentry.hxx b/include/svtools/viewdataentry.hxx
index 1a61b3f6c13a..91c51d39dc9a 100644
--- a/include/svtools/viewdataentry.hxx
+++ b/include/svtools/viewdataentry.hxx
@@ -51,6 +51,8 @@ class SVT_DLLPUBLIC SvViewDataEntry
     bool mbExpanded:1;
     bool mbFocused:1;
     bool mbSelectable:1;
+    bool mbDragTarget:1;
+
     tools::Rectangle maPaintRectangle;
 
 public:
@@ -63,11 +65,16 @@ public:
     bool IsExpanded() const { return mbExpanded;}
     bool HasFocus() const { return mbFocused;}
     bool IsSelectable() const { return mbSelectable;}
+    bool IsDragTarget() const { return mbDragTarget;}
     void SetFocus( bool bFocus );
     void SetSelected( bool bSelected );
     void SetHighlighted( bool bHighlighted );
     void SetExpanded( bool bExpanded );
     void SetSelectable( bool bSelectable );
+    void SetDragTarget( bool bDragTarget )
+    {
+        mbDragTarget = bDragTarget;
+    }
 
     void Init(size_t nSize);