up/down tweaks

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@4915 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/math_cursor.C

@@ -380,11 +380,15 @@ void MathCursor::niceInsert(MathAtom const & t)
 	macroModeClose();
 	MathGridInset safe = grabAndEraseSelection();
 	plainInsert(t);
+	int x, y;
+	getPos(x, y);
 	// enter the new inset and move the contents of the selection if possible
 	if (t->isActive()) {
 		posLeft();
 		pushLeft(nextAtom());
 		paste(safe);
+		// lets pretend we've not moved too far away...
+		array().setXY(x, y);
 	}
 }
 

src/mathed/math_data.C

@@ -382,10 +382,9 @@ void MathArray::towards(int & x, int & y) const
 }
 
 
-/*
-std::ostream & operator<<(std::ostream & os, MathArray const & ar)
+void MathArray::setXY(int x, int y)
 {
-	os << ar.data();
+	xo_ = x;
+	yo_ = y;
 }
-*/
 

src/mathed/math_data.h

@@ -124,6 +124,8 @@ public:
 	int xm() const { return xo_ + dim_.w / 2; }
 	/// access to cached y coordinate of mid point of last drawing
 	int ym() const { return yo_ + (dim_.d - dim_.a) / 2; }
+	/// write access to coordinate;
+	void setXY(int x, int y);
 	/// returns x coordinate of given position in the array
 	int pos2x(size_type pos) const;
 	/// returns position of given x coordinate

src/mathed/math_scriptinset.C

@@ -325,17 +325,35 @@ bool MathScriptInset::idxLeft(idx_type &, pos_type &) const
 bool MathScriptInset::idxUpDown(idx_type & idx, pos_type & pos, bool up,
 	int) const
 {
-	if ((idx == 1 && up) || (idx == 0 && !up))
-		return false;
-
-	// in nuclues?
-	if (idx == 2) {
-		idx = up;
-		pos = 0;
-	} else {
+	if (idx == 1) {
+		// if we are 'up' we can't go further up
+		if (up)
+			return false;
+		// otherwise go to last base position
 		idx = 2;
 		pos = cell(2).size();	
 	}
+
+	else if (idx == 0) {
+		// if we are 'down' we can't go further down
+		if (!up)
+			return false;
+		idx = 2;
+		pos = cell(2).size();	
+	}
+	
+	else {
+		// in nucleus
+		// don't go up/down unless in last position
+		if (pos != cell(2).size())
+			return false;	
+		// don't go up/down if there is no cell.
+		if (!has(up))
+			return false;
+		// otherwise move into the first position
+		idx = up;
+		pos = 0;
+	}
 	return true;
 }