[patch] bug 3201: restore cursor position in preamble

[Jürgen Spitzmüller]

http://bugzilla.lyx.org/show_bug.cgi?id=3201

This turned to be out more complicated than I thought, because both the cursor 
and the scrollbar position have to be saved for each buffer separately.

Attached is what I came up with.

Opinions?

Jürgen

Index: src/frontends/qt4/QDocument.cpp
===================================================================
--- src/frontends/qt4/QDocument.cpp	(Revision 18139)
+++ src/frontends/qt4/QDocument.cpp	(Arbeitskopie)
@@ -746,6 +746,11 @@
 	// preamble
 	params.preamble =
 		fromqstr(preambleModule->preambleTE->document()->toPlainText());
+	// store cursor and scrollbar position
+	preamble_coords_[&form_->controller().buffer()].first =
+		preambleModule->preambleTE->textCursor().position();
+	preamble_coords_[&form_->controller().buffer()].second =
+		preambleModule->preambleTE->verticalScrollBar()->value();
 
 	// biblio
 	params.setCiteEngine(biblio::ENGINE_BASIC);
@@ -1023,6 +1028,16 @@
 	// preamble
 	QString preamble = toqstr(params.preamble);
 	preambleModule->preambleTE->document()->setPlainText(preamble);
+	// restore cursor and scrollbar position, if possible
+	Buffer const & buffer = form_->controller().buffer();
+	if (preamble_coords_.find(&buffer) != preamble_coords_.end()) {
+		QTextCursor cur = preambleModule->preambleTE->textCursor();
+		cur.setPosition(preamble_coords_[&buffer].first);
+		preambleModule->preambleTE->setTextCursor(cur);
+		preambleModule->preambleTE->verticalScrollBar()->setValue(
+			preamble_coords_[&buffer].second);
+		preambleModule->preambleTE->setFocus();
+	}
 
 	// biblio
 	biblioModule->citeDefaultRB->setChecked(
Index: src/frontends/qt4/QDocument.h
===================================================================
--- src/frontends/qt4/QDocument.h	(Revision 18139)
+++ src/frontends/qt4/QDocument.h	(Arbeitskopie)
@@ -29,6 +29,7 @@
 
 #include <QCloseEvent>
 #include <QDialog>
+#include <QScrollBar>
 #include <vector>
 #include <string>
 
@@ -109,6 +110,8 @@
 
 	/// FIXME
 	std::vector<std::string> lang_;
+	///
+	std::map<Buffer const *, std::pair<int, int> > preamble_coords_;
 };
 
 
Index: src/frontends/controllers/ControlDocument.h
===================================================================
--- src/frontends/controllers/ControlDocument.h	(Revision 18139)
+++ src/frontends/controllers/ControlDocument.h	(Arbeitskopie)
@@ -50,6 +50,8 @@
 	///
 	BufferParams & params() const;
 	///
+	Buffer const & buffer() const { return kernel().buffer(); }
+	///
 	void setLanguage() const;
 	///
 	void saveAsDefault() const;