From 63be456c8d087ad3a43f20be351b36cc3b67b37a Mon Sep 17 00:00:00 2001
From: Guillaume Munch <gm@lyx.org>
Date: Sat, 18 Feb 2017 22:23:14 +0100
Subject: [PATCH] When pressing math with the mouse, move to the closest edge
 (#9748)

Unless it has some dialog that we want to activate.
---
 src/Cursor.cpp               | 16 ++++++++++++++++
 src/Cursor.h                 |  6 ++++++
 src/mathed/InsetMathNest.cpp | 13 +++++--------
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/Cursor.cpp b/src/Cursor.cpp
index 05389d9845..e694a13ddd 100644
--- a/src/Cursor.cpp
+++ b/src/Cursor.cpp
@@ -2435,4 +2435,20 @@ bool Cursor::confirmDeletion(bool const before) const
 }
 
 
+void Cursor::moveToClosestEdge(int const x, bool const edit)
+{
+	if (Inset const * inset = nextInset()) {
+		// stay in front of insets for which we want to open the dialog
+		// (e.g. InsetMathSpace).
+		if (edit && (inset->hasSettings() || !inset->contextMenuName().empty()))
+			return;
+		CoordCache::Insets const & insetCache = bv().coordCache().getInsets();
+		int const wid = insetCache.dim(inset).wid;
+		Point p = insetCache.xy(inset);
+		if (x > p.x_ + (wid + 1) / 2)
+			posForward();
+	}
+}
+
+
 } // namespace lyx
diff --git a/src/Cursor.h b/src/Cursor.h
index dbdd1569b8..1abc177ca4 100644
--- a/src/Cursor.h
+++ b/src/Cursor.h
@@ -399,6 +399,12 @@ public:
 	/// one inset in the selection has confirmDeletion.
 	bool confirmDeletion(bool before = false) const;
 
+	/// Determine if x falls to the left or to the side of the middle of the
+	/// inset, and advance the cursor to match this position. If edit is true,
+	/// keep the cursor in front of the inset if it matter for dialogs.
+	/// Note: it does not handle RTL text yet, and is only used in math for now.
+	void moveToClosestEdge(int x, bool edit = false);
+
 public:
 //private:
 	
diff --git a/src/mathed/InsetMathNest.cpp b/src/mathed/InsetMathNest.cpp
index ee0edd964f..0ba4bad38d 100644
--- a/src/mathed/InsetMathNest.cpp
+++ b/src/mathed/InsetMathNest.cpp
@@ -1581,6 +1581,10 @@ void InsetMathNest::lfunMousePress(Cursor & cur, FuncRequest & cmd)
 			return;
 		}
 	}
+
+	// set cursor after the inset if x is nearer to that position (bug 9748)
+	cur.moveToClosestEdge(cmd.x(), true);
+
 	bool do_selection = cmd.button() == mouse_button::button1
 		&& cmd.modifier() == ShiftModifier;
 	bv.mouseSetCursor(cur, do_selection);
@@ -1626,14 +1630,7 @@ void InsetMathNest::lfunMouseMotion(Cursor & cur, FuncRequest & cmd)
 	}
 
 	// set cursor after the inset if x is nearer to that position (bug 9748)
-	if (Inset const * inset = cur.nextInset()) {
-		CoordCache::Insets const & insetCache =
-			cur.bv().coordCache().getInsets();
-		int const wid = insetCache.dim(inset).wid;
-		Point p = insetCache.xy(inset);
-		if (cmd.x() > p.x_ + (wid + 1) / 2)
-			cur.posForward();
-	}
+	cur.moveToClosestEdge(cmd.x());
 
 	CursorSlice old = bvcur.top();