Fix on-screen alignment of multline equations

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@39882 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/InsetMathGrid.cpp

@@ -788,7 +788,7 @@ int InsetMathGrid::cellXOffset(BufferView const & bv, idx_type idx) const
 {
 	col_type c = col(idx);
 	int x = colinfo_[c].offset_;
-	char align = colinfo_[c].align_;
+	char align = displayColAlign(c, row(idx));
 	Dimension const & celldim = cell(idx).dimension(bv);
 	if (align == 'r' || align == 'R')
 		x += colinfo_[c].width_ - celldim.wid;

src/mathed/InsetMathGrid.h

@@ -242,6 +242,10 @@ protected:
 	virtual docstring eocString(col_type col, col_type lastcol) const;
 	/// splits cells and shifts right part to the next cell
 	void splitCell(Cursor & cur);
+	/// Column aligmment for display of cell at (\p row, \p col).
+	/// Must not be written to file!
+	virtual char displayColAlign(col_type col, row_type) const { return colinfo_[col].align_; }
+
 
 	/// row info.
 	/// rowinfo_[nrows()] is a dummy row used only for hlines.

src/mathed/InsetMathHull.cpp

@@ -342,6 +342,8 @@ char InsetMathHull::defaultColAlign(col_type col)
 {
 	if (type_ == hullEqnArray)
 		return "rcl"[col];
+	if (type_ == hullMultline)
+		return 'c';
 	if (type_ == hullGather)
 		return 'c';
 	if (type_ >= hullAlign)
@@ -350,6 +352,18 @@ char InsetMathHull::defaultColAlign(col_type col)
 }
 
 
+char InsetMathHull::displayColAlign(col_type col, row_type row) const
+{
+	if (type_ == hullMultline) {
+		if (row == 0)
+			return 'l';
+		if (row == nrows() - 1)
+			return 'r';
+	}
+	return InsetMathGrid::displayColAlign(col, row);
+}
+
+
 int InsetMathHull::defaultColSpace(col_type col)
 {
 	if (type_ == hullAlign || type_ == hullAlignAt)

src/mathed/InsetMathHull.h

@@ -101,6 +101,9 @@ public:
 	///
 	char defaultColAlign(col_type col);
 	///
+	///
+	char displayColAlign(col_type col, row_type row) const;
+	///
 	bool idxFirst(Cursor &) const;
 	///
 	bool idxLast(Cursor &) const;