better handling of up/down

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@3123 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/math_cursor.C

@@ -1167,18 +1167,8 @@ bool MathCursor::goUp()
 	}
 
 	// if not, apply brute force.
-	int x0;
-	int y0;
-	getPos(x0, y0);
-	std::vector<MathCursorPos> save = Cursor_;
-	y0 -= xarray().ascent();
-	for (int y = y0 - 4; y > formula()->upperY(); y -= 4) {
-		setPos(x0, y);
-		if (save != Cursor_ && xarray().yo() < y0)
-			return true;	
-	}
-	Cursor_ = save;
-	return false;
+	return
+		bruteUpDown(formula()->upperY() + 24, xarray().yo() - 4 - xarray().ascent());
 }
 
 
@@ -1198,19 +1188,42 @@ bool MathCursor::goDown()
 		return true;
 	}
 
-	// does the inset know
-
 	// if not, apply brute force.
+	return
+		bruteUpDown(xarray().yo() + 4 + xarray().descent(), formula()->lowerY());
+}
+
+
+bool MathCursor::bruteUpDown(int ylow, int yhigh)
+{
+	//lyxerr << "looking at range: " << ylow << " " << yhigh << "\n";
 	int x0;
 	int y0;
 	getPos(x0, y0);
 	std::vector<MathCursorPos> save = Cursor_;
-	y0 += xarray().descent();
-	for (int y = y0 + 4; y < formula()->lowerY(); y += 4) {
+	std::vector<MathCursorPos> best;
+	double best_dist = 1e10; // large enough
+	bool found  = false;
+	for (int y = ylow; y < yhigh; y += 4) {
 		setPos(x0, y);
-		if (save != Cursor_ && xarray().yo() > y0)
+		int x1;
+		int y1;
+		getPos(x1, y1);
+		if (save != Cursor_ && y1 > ylow && y1 < yhigh) {
+			found = true;
+			double d = (x0 - x1) * (x0 - x1) + (y0 - y1) * (y0 - y1);
+			if (d < best_dist) {
+				best_dist = d;
+				best = Cursor_;
+			}	
+		}
+	}
+
+	if (found) {
+		Cursor_ = best;
 		return true;
 	}
+
 	Cursor_ = save;
 	return false;
 }

src/mathed/math_cursor.h

@@ -67,6 +67,8 @@ public:
 	typedef MathInset::row_type        row_type;
 	/// type for column numbers
 	typedef MathInset::col_type        col_type;
+	/// how to store a cursor
+	typedef std::vector<MathCursorPos> cursor_type;
 
 	///
 	explicit MathCursor(InsetFormulaBase *, bool left);
@@ -229,9 +231,9 @@ public:
 	MathCursorPos normalAnchor() const;
 
 	/// path of positions the cursor had to go if it were leving each inset
-	std::vector<MathCursorPos> Cursor_;
+	cursor_type Cursor_;
 	/// path of positions the anchor had to go if it were leving each inset
-	std::vector<MathCursorPos> Anchor_;
+	cursor_type Anchor_;
 
 	/// reference to the last item of the path
 	MathCursorPos & cursor();
@@ -261,6 +263,8 @@ private:
 	bool goUp();
 	/// moves position somehow down
 	bool goDown();
+	/// moves position somehow down
+	bool bruteUpDown(int ylow, int yhigh);
 
 	///
 	string macroName() const;

src/mathed/math_gridinset.C

@@ -488,23 +488,29 @@ int MathGridInset::cellYOffset(idx_type idx) const
 
 bool MathGridInset::idxUp(idx_type & idx, pos_type & pos) const
 {
+	return false;
+/*
 	if (idx < ncols())
 		return false;
 	int x = cellXOffset(idx) + xcell(idx).pos2x(pos);
 	idx -= ncols();
 	pos = xcell(idx).x2pos(x - cellXOffset(idx));
 	return true;
+*/
 }
 
 	
 bool MathGridInset::idxDown(idx_type & idx, pos_type & pos) const
 {
+	return false;
+/*
 	if (idx >= ncols() * (nrows() - 1))
 		return false;
 	int x = cellXOffset(idx) + xcell(idx).pos2x(pos);
 	idx += ncols();
 	pos = xcell(idx).x2pos(x - cellXOffset(idx));
 	return true;
+*/
 }