Stop Navigator content view flashing

Redraw flashing occurs in the content tree when outlines are moved during
promote/demote chapter/level and when switching content navigation view
mode. Also, the focus rectangle is briefly shown.

This patch uses the m_bIsInPromoteDemote flag, that indicates when
outline levels are in the process of being moved, to not redraw the
content tree until after the moved outlines are reselected. To stop
focus rectangle flashing a check for tree emptiness is used in the Paint
function.

Change-Id: I252c5a0032157c0a8287c748071d180675b3a70d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89659
Tested-by: Jenkins
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 9 insertions, 2 deletions

diff --git a/sw/source/uibase/utlui/content.cxx b/sw/source/uibase/utlui/content.cxx
index d55c38febdf9..f8b8fb7bf425 100644
--- a/sw/source/uibase/utlui/content.cxx
+++ b/sw/source/uibase/utlui/content.cxx
@@ -1773,8 +1773,8 @@ void SwContentTree::Display( bool bActive )
             nEntryRelPos = GetModel()->GetAbsPos(pOldSelEntry) - GetModel()->GetAbsPos(pParentEntry);
         }
     }
-    Clear();
     SetUpdateMode( false );
+    SvTreeListBox::Clear();
     if (!bActive)
         m_eState = State::HIDDEN;
     else if (State::HIDDEN == m_eState)
@@ -1912,7 +1912,6 @@ void SwContentTree::Display( bool bActive )
                 SetCurEntry(pParent);
         }
     }
-    SetUpdateMode( true );
     ScrollBar* pVScroll = GetVScroll();
     if(GetEntryCount() == nOldEntryCount &&
         nOldScrollPos && pVScroll && pVScroll->IsVisible()
@@ -1921,6 +1920,8 @@ void SwContentTree::Display( bool bActive )
         sal_Int32 nDelta = pVScroll->GetThumbPos() - nOldScrollPos;
         ScrollOutputArea( static_cast<short>(nDelta) );
     }
+    if (!m_bIsInPromoteDemote)
+        SetUpdateMode( true );
 }
 
 void SwContentTree::Clear()
@@ -2720,6 +2721,8 @@ void SwContentTree::ExecCommand(const OUString& rCmd, bool bOutlineWithChildren)
             }
             SvTreeListBox::Invalidate();
         }
+        // SetUpdateMode is set false in the Display function
+        SetUpdateMode(true);
     }
 }
 
@@ -2731,6 +2734,10 @@ void SwContentTree::ShowTree()
 void SwContentTree::Paint( vcl::RenderContext& rRenderContext,
                            const tools::Rectangle& rRect )
 {
+    // prevent focus rect from flashing when tree is cleared
+    // SvTreeListBox::Paint shows focus rectangle when tree is empty
+    if (!GetEntryCount())
+        return;
     // Start the update timer on the first paint; avoids
     // flicker on the first reveal.
     m_aUpdTimer.Start();