backport rev. 23673 from sts, which partially fixes a major dataloss bug:

URL: http://www.lyx.org/trac/changeset/23673
Log:
* fix for http://bugzilla.lyx.org/show_bug.cgi?id=4566

  "Eqnarray multiple cells size change erases what they contain"

  We now loop over the selected cells and change the font in each of them.

Note that the bug still applies if a font change is done via the math panel.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_1_5_X@23789 a592a061-630c-0410-9148-cb99ea01b6c8

src/CutAndPaste.cpp

@@ -83,22 +83,6 @@ CutStack selectionBuffer(1);
 bool dirty_tabular_stack_ = false;
 
 
-void region(CursorSlice const & i1, CursorSlice const & i2,
-	Inset::row_type & r1, Inset::row_type & r2,
-	Inset::col_type & c1, Inset::col_type & c2)
-{
-	Inset & p = i1.inset();
-	c1 = p.col(i1.idx());
-	c2 = p.col(i2.idx());
-	if (c1 > c2)
-		std::swap(c1, c2);
-	r1 = p.row(i1.idx());
-	r2 = p.row(i2.idx());
-	if (r1 > r2)
-		std::swap(r1, r2);
-}
-
-
 bool checkPastePossible(int index)
 {
 	return size_t(index) < theCuts.size() && !theCuts[index].first.empty();
@@ -394,6 +378,22 @@ void copySelectionHelper(Buffer const & buf, ParagraphList & pars,
 
 namespace cap {
 
+void region(CursorSlice const & i1, CursorSlice const & i2,
+	Inset::row_type & r1, Inset::row_type & r2,
+	Inset::col_type & c1, Inset::col_type & c2)
+{
+	Inset & p = i1.inset();
+	c1 = p.col(i1.idx());
+	c2 = p.col(i2.idx());
+	if (c1 > c2)
+		std::swap(c1, c2);
+	r1 = p.row(i1.idx());
+	r2 = p.row(i2.idx());
+	if (r1 > r2)
+		std::swap(r1, r2);
+}
+
+
 docstring grabAndEraseSelection(Cursor & cur)
 {
 	if (!cur.selection())

src/CutAndPaste.h

@@ -15,6 +15,7 @@
 #define CUTANDPASTE_H
 
 #include "support/docstring.h"
+#include "insets/InsetTabular.h"
 
 #include <vector>
 
@@ -101,6 +102,10 @@ void pasteParagraphList(Cursor & cur, ParagraphList const & parlist,
 void switchBetweenClasses(textclass_type c1, textclass_type c2,
 			  InsetText & in, ErrorList &);
 
+/// Calculate rectangular region of cell between \c i1 and \c i2.
+void region(CursorSlice const & i1, CursorSlice const & i2,
+	Inset::row_type & r1, Inset::row_type & r2,
+	Inset::col_type & c1, Inset::col_type & c2);
 /// Get the current selection as a string. Does not change the selection.
 /// Does only work if the whole selection is in mathed.
 docstring grabSelection(Cursor const & cur);

src/mathed/InsetMathNest.cpp

@@ -417,9 +417,63 @@ void InsetMathNest::handleFont
 		recordUndoInset(cur, Undo::ATOMIC);
 		cur.handleFont(to_utf8(font));
 	} else {
-		recordUndo(cur, Undo::ATOMIC);
-		cur.handleNest(createInsetMath(font));
-		cur.insert(arg);
+		CursorSlice i1 = cur.selBegin();
+		CursorSlice i2 = cur.selEnd();
+		if (!i1.inset().asInsetMath())
+			return;
+		if (i1.idx() == i2.idx()) {
+			// the easy case where only one cell is selected
+			recordUndo(cur, Undo::ATOMIC);
+			cur.handleNest(createInsetMath(font));
+			cur.insert(arg);
+			return;
+		}
+		// multiple selected cells in a simple non-grid inset
+		if (i1.asInsetMath()->nrows() == 0 || i1.asInsetMath()->ncols() == 0) {
+			recordUndoInset(cur);
+			for (idx_type i = i1.idx(); i <= i2.idx(); ++i) {
+				// select cell
+				cur.idx() = i;
+				cur.pos() = 0;
+				cur.resetAnchor();
+				cur.pos() = cur.lastpos();
+				cur.setSelection();
+				
+				// change font of cell
+				cur.handleNest(createInsetMath(font));
+				cur.insert(arg);
+				
+				// cur is in the font inset now. If the loop continues,
+				// we need to get outside again for the next cell
+				if (i + 1 <= i2.idx())
+					cur.pop_back();
+			}
+			return;
+		}
+		// the complicated case with multiple selected cells in a grid
+		recordUndoInset(cur);
+		Inset::row_type r1, r2;
+		Inset::col_type c1, c2;
+		cap::region(i1, i2, r1, r2, c1, c2);
+		for (Inset::row_type row = r1; row <= r2; ++row) {
+			for (Inset::col_type col = c1; col <= c2; ++col) {
+				// select cell
+				cur.idx() = i1.asInsetMath()->index(row, col);
+				cur.pos() = 0;
+				cur.resetAnchor();
+				cur.pos() = cur.lastpos();
+				cur.setSelection();
+
+				// change font of cell
+				cur.handleNest(createInsetMath(font));
+				cur.insert(arg);
+
+				// cur is in the font inset now. If the loop continues,
+				// we need to get outside again for the next cell
+				if (col + 1 <= c2 || row + 1 <= r2)
+					cur.pop_back();
+			}
+		}
 	}
 }
 

status.15x

@@ -89,6 +89,9 @@ What's new
 
 * USER INTERFACE:
 
+- Correctly apply font changes when several math matrix cells are selected
+  (part of bug 4566).
+
 - Allow deleting a label in a formula as well as the numbering with the
   delete key (bug 2556).