Fix bug 2393 (from Dov Feldstern)

* src/lyxtext.h
	* src/text.C
	(LyXText::charsTranspose): New method for transposing characters

	* src/text.C
	(LyXText::dispatch): Call charsTranspose for LFUN_CHARS_TRANSPOSE


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_1_4_X@15952 a592a061-630c-0410-9148-cb99ea01b6c8

src/lyxtext.h

@@ -244,6 +244,8 @@ public:
 	};
 	/// Change the case of the word at cursor position.
 	void changeCase(LCursor & cur, TextCase action);
+	/// Transposes the character at the cursor with the one before it.
+	void charsTranspose(LCursor & cur);
 
 	/** the DTP switches for paragraphs. LyX will store the top settings
 	 always in the first physical paragraph, the bottom settings in the

src/text.C

@@ -1585,6 +1585,62 @@ void LyXText::changeCase(LCursor & cur, LyXText::TextCase action)
 }
 
 
+void LyXText::charsTranspose(LCursor & cur)
+{
+	BOOST_ASSERT(this == cur.text());
+
+	pos_type pos = cur.pos();
+
+	// If cursor is at beginning or end of paragraph, do nothing.
+	if (pos == cur.lastpos() || pos == 0)
+		return;
+
+	Paragraph & par = cur.paragraph();
+
+	// Get the positions of the characters to be transposed. 
+	pos_type pos1 = pos - 1;
+	pos_type pos2 = pos;
+
+	// In change tracking mode, ignore deleted characters.
+	while (pos2 < cur.lastpos() && isDeletedText(par, pos2))
+		++pos2;
+	if (pos2 == cur.lastpos())
+		return;
+
+	while (pos1 >= 0 && isDeletedText(par, pos1))
+		--pos1;
+	if (pos1 < 0)
+		return;
+
+	// Don't do anything if one of the "characters" is not regular text.
+	if (par.isInset(pos1) || par.isInset(pos2))
+		return;
+
+	// Store the characters to be transposed (including font information).
+	char char1 = par.getChar(pos1);
+	LyXFont const font1 = 
+		par.getFontSettings(cur.buffer().params(), pos1);
+
+	char char2 = par.getChar(pos2);
+	LyXFont const font2 = 
+		par.getFontSettings(cur.buffer().params(), pos2);
+
+	// And finally, we are ready to perform the transposition.
+	// We use erase() and insertChar(), which take care of tracking the
+	// change.
+	recordUndo(cur);
+
+	par.erase(pos2);
+	par.erase(pos1);
+	par.insertChar(pos1, char2, font2);
+	par.insertChar(pos2, char1, font1);
+
+	// After the transposition, move cursor to after the transposition.
+	setCursor(cur, cur.pit(), pos2);
+	cur.forwardPos();
+}
+
+
 bool LyXText::Delete(LCursor & cur)
 {
 	BOOST_ASSERT(this == cur.text());

src/text3.C

@@ -728,7 +728,7 @@ void LyXText::dispatch(LCursor & cur, FuncRequest & cmd)
 		break;
 
 	case LFUN_TRANSPOSE_CHARS:
-		recordUndo(cur);
+		charsTranspose(cur);
 		break;
 
 	case LFUN_PASTE:

status.14x

@@ -101,6 +101,8 @@ What's new
 
 - Fix insertion position for cross-reference in superscript (bug 2789)
 
+- Add support for the chars-transpose LFUN (bug 2939)
+
 * Build/installation: