clean up QRegister vs. Buffer redundancies using TECODocument class

 * also encapsulates data properly (previously there were many public
   attributes to avoid permission issues)
 * new class also cares about saving/and restoring scroll state.
   now, buffer/q-reg edits and temporary accesses do not reset
   the scroll state anymore.

7 files changed, 234 insertions, 88 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 787d941..bd945e1 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -17,6 +17,7 @@ libsciteco_base_a_SOURCES = sciteco.h \
 			    cmdline.cpp cmdline.h \
 			    undo.cpp undo.h \
 			    expressions.cpp expressions.h \
+			    document.cpp document.h \
 			    qregisters.cpp qregisters.h \
 			    ring.cpp ring.h \
 			    parser.cpp parser.h \
diff --git a/src/document.cpp b/src/document.cpp
new file mode 100644
index 0000000..b6a99f5
--- /dev/null
+++ b/src/document.cpp
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2012-2013 Robin Haberkorn
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <glib.h>
+
+#include <Scintilla.h>
+
+#include "sciteco.h"
+#include "interface.h"
+#include "undo.h"
+#include "document.h"
+
+void
+TECODocument::edit(void)
+{
+	if (!is_initialized())
+		doc = (SciDoc)interface.ssm(SCI_CREATEDOCUMENT);
+
+	interface.ssm(SCI_SETDOCPOINTER, 0, (sptr_t)doc);
+	interface.ssm(SCI_SETFIRSTVISIBLELINE, first_line);
+	interface.ssm(SCI_SETXOFFSET, xoffset);
+	interface.ssm(SCI_GOTOPOS, dot);
+}
+
+void
+TECODocument::undo_edit(void)
+{
+	undo.push_msg(SCI_GOTOPOS, dot);
+	undo.push_msg(SCI_SETXOFFSET, xoffset);
+	undo.push_msg(SCI_SETFIRSTVISIBLELINE, first_line);
+	undo.push_msg(SCI_SETDOCPOINTER, 0, (sptr_t)doc);
+}
+
+void
+TECODocument::update(void)
+{
+	dot = interface.ssm(SCI_GETCURRENTPOS);
+	first_line = interface.ssm(SCI_GETFIRSTVISIBLELINE);
+	xoffset = interface.ssm(SCI_GETXOFFSET);
+}
+
+/*
+ * Only for QRegisterStack::pop() which does some clever
+ * exchanging of document data (without any deep copying)
+ */
+void
+TECODocument::exchange(TECODocument &other)
+{
+	SciDoc temp_doc = doc;
+	gint temp_dot = dot;
+	gint temp_first_line = first_line;
+	gint temp_xoffset = xoffset;
+
+	doc = other.doc;
+	dot = other.dot;
+	first_line = other.first_line;
+	xoffset = other.xoffset;
+
+	other.doc = temp_doc;
+	other.dot = temp_dot;
+	other.first_line = temp_first_line;
+	other.xoffset = temp_xoffset;
+}
diff --git a/src/document.h b/src/document.h
new file mode 100644
index 0000000..2ef71ba
--- /dev/null
+++ b/src/document.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2012-2013 Robin Haberkorn
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __DOCUMENT_H
+#define __DOCUMENT_H
+
+#include <glib.h>
+
+#include <Scintilla.h>
+
+#include "sciteco.h"
+#include "interface.h"
+#include "undo.h"
+
+/*
+ * Classes
+ */
+
+/*
+ * NOTE: The only reason this is called TECODocument
+ * is to prevent a nameclash with Scintilla which
+ * does not use a proper namespace for its public
+ * symbols...
+ */
+class TECODocument {
+	typedef const void *SciDoc;
+	SciDoc doc;
+
+	/* updated/restored only when required */
+	gint dot;
+	gint first_line;
+	gint xoffset;
+
+public:
+	TECODocument() : doc(NULL)
+	{
+		reset();
+	}
+	virtual ~TECODocument()
+	{
+		if (is_initialized())
+			interface.ssm(SCI_RELEASEDOCUMENT, 0, (sptr_t)doc);
+	}
+
+	inline bool
+	is_initialized(void)
+	{
+		return doc != NULL;
+	}
+
+	void edit(void);
+	void undo_edit(void);
+
+	void update(void);
+	inline void
+	update(const TECODocument &from)
+	{
+		dot = from.dot;
+		first_line = from.first_line;
+		xoffset = from.xoffset;
+	}
+
+	inline void
+	reset(void)
+	{
+		dot = first_line = xoffset = 0;
+	}
+	inline void
+	undo_reset(void)
+	{
+		undo.push_var(dot);
+		undo.push_var(first_line);
+		undo.push_var(xoffset);
+	}
+
+	void exchange(TECODocument &other);
+	inline void
+	undo_exchange(void)
+	{
+		undo.push_var(doc);
+		undo_reset();
+	}
+};
+
+#endif
diff --git a/src/qregisters.cpp b/src/qregisters.cpp
index a46b4da..df75679 100644
--- a/src/qregisters.cpp
+++ b/src/qregisters.cpp
@@ -33,6 +33,7 @@
 #include "undo.h"
 #include "parser.h"
 #include "expressions.h"
+#include "document.h"
 #include "ring.h"
 #include "qregisters.h"
 
@@ -59,7 +60,7 @@ namespace QRegisters {
 	void
 	undo_edit(void)
 	{
-		current->dot = interface.ssm(SCI_GETCURRENTPOS);
+		current->update_string();
 		undo.push_var(ring.current);
 		undo.push_var(current)->undo_edit();
 	}
@@ -82,7 +83,7 @@ void
 QRegisterData::set_string(const gchar *str)
 {
 	edit();
-	dot = 0;
+	string.reset();
 
 	interface.ssm(SCI_BEGINUNDOACTION);
 	interface.ssm(SCI_SETTEXT, 0, (sptr_t)(str ? : ""));
@@ -94,8 +95,8 @@ QRegisterData::set_string(const gchar *str)
 void
 QRegisterData::undo_set_string(void)
 {
-	/* set_string() assumes that dot has been saved */
-	current_save_dot();
+	/* set_string() assumes that parameters have been saved */
+	current_doc_update();
 
 	if (!must_undo)
 		return;
@@ -105,7 +106,7 @@ QRegisterData::undo_set_string(void)
 	else if (QRegisters::current)
 		QRegisters::current->undo_edit();
 
-	undo.push_var<gint>(dot);
+	string.undo_reset();
 	undo.push_msg(SCI_UNDO);
 
 	undo_edit();
@@ -132,7 +133,10 @@ QRegisterData::get_string(void)
 	gint size;
 	gchar *str;
 
-	current_save_dot();
+	if (!string.is_initialized())
+		return g_strdup("");
+
+	current_doc_update();
 	edit();
 
 	size = interface.ssm(SCI_GETLENGTH) + 1;
@@ -147,24 +151,20 @@ QRegisterData::get_string(void)
 void
 QRegisterData::edit(void)
 {
-	interface.ssm(SCI_SETDOCPOINTER, 0, (sptr_t)get_document());
-	interface.ssm(SCI_GOTOPOS, dot);
+	string.edit();
 }
 
 void
 QRegisterData::undo_edit(void)
 {
-	if (!must_undo)
-		return;
-
-	undo.push_msg(SCI_GOTOPOS, dot);
-	undo.push_msg(SCI_SETDOCPOINTER, 0, (sptr_t)get_document());
+	if (must_undo)
+		string.undo_edit();
 }
 
 void
 QRegister::edit(void)
 {
-	QRegisterData::edit();
+	string.edit();
 	interface.info_update(this);
 }
 
@@ -175,7 +175,7 @@ QRegister::undo_edit(void)
 		return;
 
 	interface.undo_info_update(this);
-	QRegisterData::undo_edit();
+	string.undo_edit();
 }
 
 void
@@ -204,7 +204,7 @@ QRegister::load(const gchar *filename)
 		return false;
 
 	edit();
-	dot = 0;
+	string.reset();
 
 	interface.ssm(SCI_BEGINUNDOACTION);
 	interface.ssm(SCI_CLEARALL);
@@ -268,7 +268,7 @@ QRegisterTable::QRegisterTable(bool _undo) : RBTree(), must_undo(_undo)
 void
 QRegisterTable::edit(QRegister *reg)
 {
-	current_save_dot();
+	current_doc_update();
 	reg->edit();
 
 	ring.current = NULL;
@@ -296,13 +296,12 @@ QRegisterStack::push(QRegister &reg)
 {
 	Entry *entry = new Entry();
 
-	entry->set_integer(reg.get_integer());
-	if (reg.string) {
-		gchar *str = reg.get_string();
+	gchar *str = reg.get_string();
+	if (*str)
 		entry->set_string(str);
-		g_free(str);
-	}
-	entry->dot = reg.dot;
+	g_free(str);
+	entry->string.update(reg.string);
+	entry->set_integer(reg.get_integer());
 
 	SLIST_INSERT_HEAD(&head, entry, entries);
 	undo.push(new UndoTokenPop(this));
@@ -312,7 +311,6 @@ bool
 QRegisterStack::pop(QRegister &reg)
 {
 	Entry *entry = SLIST_FIRST(&head);
-	QRegisterData::document *string;
 
 	if (!entry)
 		return false;
@@ -321,16 +319,10 @@ QRegisterStack::pop(QRegister &reg)
 	reg.set_integer(entry->get_integer());
 
 	/* exchange document ownership between Stack entry and Q-Register */
-	string = reg.string;
-	if (reg.must_undo)
-		undo.push_var(reg.string);
-	reg.string = entry->string;
-	undo.push_var(entry->string);
-	entry->string = string;
-
 	if (reg.must_undo)
-		undo.push_var(reg.dot);
-	reg.dot = entry->dot;
+		reg.string.undo_exchange();
+	entry->string.undo_exchange();
+	entry->string.exchange(reg.string);
 
 	SLIST_REMOVE_HEAD(&head, entries);
 	/* pass entry ownership to undo stack */
diff --git a/src/qregisters.h b/src/qregisters.h
index 15acd86..7e126fd 100644
--- a/src/qregisters.h
+++ b/src/qregisters.h
@@ -30,39 +30,24 @@
 #include "undo.h"
 #include "rbtree.h"
 #include "parser.h"
+#include "document.h"
 
 /*
  * Classes
  */
 
 class QRegisterData {
+protected:
 	gint64 integer;
+	TECODocument string;
 
 public:
-	typedef void document;
-	document *string;
-	gint dot;
-
 	/*
 	 * whether to generate UndoTokens (unnecessary in macro invocations)
 	 */
 	bool must_undo;
 
-	QRegisterData() : integer(0), string(NULL), dot(0), must_undo(true) {}
-	virtual
-	~QRegisterData()
-	{
-		if (string)
-			interface.ssm(SCI_RELEASEDOCUMENT, 0, (sptr_t)string);
-	}
-
-	inline document *
-	get_document(void)
-	{
-		if (!string)
-			string = (document *)interface.ssm(SCI_CREATEDOCUMENT);
-		return string;
-	}
+	QRegisterData() : integer(0), must_undo(true) {}
 
 	virtual gint64
 	set_integer(gint64 i)
@@ -81,6 +66,12 @@ public:
 		return integer;
 	}
 
+	inline void
+	update_string(void)
+	{
+		string.update();
+	}
+
 	virtual void set_string(const gchar *str);
 	virtual void undo_set_string(void);
 	virtual void append_string(const gchar *str);
@@ -93,6 +84,8 @@ public:
 
 	virtual void edit(void);
 	virtual void undo_edit(void);
+
+	friend class QRegisterStack;
 };
 
 class QRegister : public RBTree::RBEntry, public QRegisterData {
@@ -128,10 +121,7 @@ public:
 
 class QRegisterBufferInfo : public QRegister {
 public:
-	QRegisterBufferInfo() : QRegister("*")
-	{
-		get_document();
-	}
+	QRegisterBufferInfo() : QRegister("*") {}
 
 	gint64
 	set_integer(gint64 v)
@@ -191,10 +181,7 @@ public:
 	inline void
 	initialize(const gchar *name)
 	{
-		QRegister *reg = new QRegister(name);
-		insert(reg);
-		/* make sure document is initialized */
-		reg->get_document();
+		insert(new QRegister(name));
 	}
 	inline void
 	initialize(gchar name)
diff --git a/src/ring.cpp b/src/ring.cpp
index 8654686..138714f 100644
--- a/src/ring.cpp
+++ b/src/ring.cpp
@@ -233,7 +233,7 @@ Ring::edit(gint64 id)
 	if (!buffer)
 		return false;
 
-	current_save_dot();
+	current_doc_update();
 
 	QRegisters::current = NULL;
 	current = buffer;
@@ -249,7 +249,7 @@ Ring::edit(const gchar *filename)
 {
 	Buffer *buffer = find(filename);
 
-	current_save_dot();
+	current_doc_update();
 
 	QRegisters::current = NULL;
 	if (buffer) {
@@ -488,7 +488,7 @@ Ring::close(void)
 {
 	Buffer *buffer = current;
 
-	buffer->dot = interface.ssm(SCI_GETCURRENTPOS);
+	buffer->update();
 	close(buffer);
 	current = buffer->next() ? : buffer->prev();
 	/* transfer responsibility to UndoToken object */
diff --git a/src/ring.h b/src/ring.h
index 608b752..4ca7a5d 100644
--- a/src/ring.h
+++ b/src/ring.h
@@ -30,6 +30,7 @@
 #include "sciteco.h"
 #include "interface.h"
 #include "undo.h"
+#include "document.h"
 #include "qregisters.h"
 #include "parser.h"
 
@@ -53,7 +54,7 @@ gchar *get_absolute_path(const gchar *path);
  * Classes
  */
 
-class Buffer {
+class Buffer : public TECODocument {
 	class UndoTokenClose : public UndoToken {
 		Buffer *buffer;
 
@@ -68,24 +69,13 @@ public:
 	TAILQ_ENTRY(Buffer) buffers;
 
 	gchar *filename;
-	gint dot;
-
 	gint savepoint_id;
-
 	bool dirty;
 
-private:
-	typedef void document;
-	document *doc;
-
-public:
-	Buffer() : filename(NULL), dot(0), savepoint_id(0), dirty(false)
-	{
-		doc = (document *)interface.ssm(SCI_CREATEDOCUMENT);
-	}
+	Buffer() : TECODocument(),
+		   filename(NULL), savepoint_id(0), dirty(false) {}
 	~Buffer()
 	{
-		interface.ssm(SCI_RELEASEDOCUMENT, 0, (sptr_t)doc);
 		g_free(filename);
 	}
 
@@ -114,16 +104,14 @@ public:
 	inline void
 	edit(void)
 	{
-		interface.ssm(SCI_SETDOCPOINTER, 0, (sptr_t)doc);
-		interface.ssm(SCI_GOTOPOS, dot);
+		TECODocument::edit();
 		interface.info_update(this);
 	}
 	inline void
 	undo_edit(void)
 	{
 		interface.undo_info_update(this);
-		undo.push_msg(SCI_GOTOPOS, dot);
-		undo.push_msg(SCI_SETDOCPOINTER, 0, (sptr_t)doc);
+		TECODocument::undo_edit();
 	}
 
 	bool load(const gchar *filename);
@@ -207,7 +195,7 @@ public:
 	inline void
 	undo_edit(void)
 	{
-		current->dot = interface.ssm(SCI_GETCURRENTPOS);
+		current->update();
 		undo.push_var(QRegisters::current);
 		undo.push_var(current)->undo_edit();
 	}
@@ -248,16 +236,14 @@ namespace States {
 	extern StateSaveFile	savefile;
 }
 
-/* FIXME: clean up current_save_dot() usage */
+/* FIXME: clean up current_doc_update() usage */
 static inline void
-current_save_dot(void)
+current_doc_update(void)
 {
-	gint dot = interface.ssm(SCI_GETCURRENTPOS);
-
 	if (ring.current)
-		ring.current->dot = dot;
+		ring.current->update();
 	else if (QRegisters::current)
-		QRegisters::current->dot = dot;
+		QRegisters::current->update_string();
 }
 
 #endif