[LyX features/biginset] Avoid full metrics computation when entering/leaving inset

[Jean-Marc Lasgouttes]

commit 73678dcde977802d5ff3ae07f0226484041fff48
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Mon Nov 27 15:57:09 2023 +0100

    Avoid full metrics computation when entering/leaving inset
    
    Annotate function LFUN_FINISHED_xxx to indicate that they do not
    require a full metrics computation.
    
    Remove an "optimization" that meant that when the cursor changed
    inset, a full metrics computation was requested.
    
    Part of bug #12297
---
 src/LyXAction.cpp |  8 ++++----
 src/Text.cpp      | 33 +++++++++++++++++----------------
 2 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/src/LyXAction.cpp b/src/LyXAction.cpp
index b6bb52152c..ece248e61c 100644
--- a/src/LyXAction.cpp
+++ b/src/LyXAction.cpp
@@ -1655,7 +1655,7 @@ void LyXAction::init()
  * \li Notion: See also #LFUN_FINISHED_FORWARD.
  * \endvar
  */
-		{ LFUN_FINISHED_BACKWARD, "", ReadOnly, Hidden },
+		{ LFUN_FINISHED_BACKWARD, "", ReadOnly | NoUpdate, Hidden },
 
 /*!
  * \var lyx::FuncCode lyx::LFUN_FINISHED_FORWARD
@@ -1668,7 +1668,7 @@ void LyXAction::init()
                back into the surrounding text.
  * \endvar
  */
-		{ LFUN_FINISHED_FORWARD, "", ReadOnly, Hidden },
+		{ LFUN_FINISHED_FORWARD, "", ReadOnly | NoUpdate, Hidden },
 
 /*!
  * \var lyx::FuncCode lyx::LFUN_FINISHED_LEFT
@@ -1676,7 +1676,7 @@ void LyXAction::init()
  * \li Notion: See also #LFUN_FINISHED_FORWARD.
  * \endvar
  */
-		{ LFUN_FINISHED_LEFT, "", ReadOnly, Hidden },
+		{ LFUN_FINISHED_LEFT, "", ReadOnly | NoUpdate, Hidden },
 
 
 /*!
@@ -1685,7 +1685,7 @@ void LyXAction::init()
  * \li Notion: See also #LFUN_FINISHED_FORWARD
  * \endvar
  */
-		{ LFUN_FINISHED_RIGHT, "", ReadOnly, Hidden },
+		{ LFUN_FINISHED_RIGHT, "", ReadOnly | NoUpdate, Hidden },
 
 /*!
  * \var lyx::FuncCode lyx::LFUN_FLEX_INSERT
diff --git a/src/Text.cpp b/src/Text.cpp
index 2684309dec..4749f36d2c 100644
--- a/src/Text.cpp
+++ b/src/Text.cpp
@@ -6393,23 +6393,24 @@ void Text::dispatch(Cursor & cur, FuncRequest & cmd)
 		cur.screenUpdateFlags(Update::SinglePar | Update::FitCursor);
 		return;
 	}
-	if (!needsUpdate
-	    && &oldTopSlice.inset() == &cur.inset()
-	    && oldTopSlice.idx() == cur.idx()
-	    && !oldSelection // oldSelection is a backup of cur.selection() at the beginning of the function.
-	    && !cur.selection())
-		// FIXME: it would be better if we could just do this
-		//
-		//if (cur.result().update() != Update::FitCursor)
-		//	cur.noScreenUpdate();
-		//
-		// But some LFUNs do not set Update::FitCursor when needed, so we
-		// do it for all. This is not very harmfull as FitCursor will provoke
-		// a full redraw only if needed but still, a proper review of all LFUN
-		// should be done and this needsUpdate boolean can then be removed.
-		cur.screenUpdateFlags(Update::FitCursor);
-	else
+	if (needsUpdate)
 		cur.screenUpdateFlags(Update::Force | Update::FitCursor);
+	else {
+		// oldSelection is a backup of cur.selection() at the beginning of the function.
+	    if (!oldSelection && !cur.selection())
+			// FIXME: it would be better if we could just do this
+			//
+			//if (cur.result().update() != Update::FitCursor)
+			//	cur.noScreenUpdate();
+			//
+			// But some LFUNs do not set Update::FitCursor when needed, so we
+			// do it for all. This is not very harmfull as FitCursor will provoke
+			// a full redraw only if needed but still, a proper review of all LFUN
+			// should be done and this needsUpdate boolean can then be removed.
+			cur.screenUpdateFlags(Update::FitCursor);
+		else
+			cur.screenUpdateFlags(Update::ForceDraw | Update::FitCursor);
+	}
 }