(svn r24324) -Codechange: Turn functions dealing with Textbufs into member functions.

14 files changed, 129 insertions, 134 deletions

diff --git a/src/ai/ai_gui.cpp b/src/ai/ai_gui.cpp
index 245057ae8..96b5fdfe8 100644
--- a/src/ai/ai_gui.cpp
+++ b/src/ai/ai_gui.cpp
@@ -1009,11 +1009,11 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 		this->last_vscroll_pos = 0;
 		this->autoscroll = true;
 		this->highlight_row = -1;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size, MAX_BREAK_STR_STRING_LENGTH);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size, MAX_BREAK_STR_STRING_LENGTH);
 
 		/* Restore the break string value from static variable */
 		strecpy(this->edit_str_buf, this->break_string, this->edit_str_buf + MAX_BREAK_STR_STRING_LENGTH);
-		UpdateTextBufferSize(&this->text);
+		this->text.UpdateSize();
 
 		/* Restore button state from static class variables */
 		if (ai_debug_company == OWNER_DEITY) {
diff --git a/src/console_gui.cpp b/src/console_gui.cpp
index 8d6e97492..ac7df2020 100644
--- a/src/console_gui.cpp
+++ b/src/console_gui.cpp
@@ -233,7 +233,7 @@ struct IConsoleWindow : Window
 
 	virtual void OnMouseLoop()
 	{
-		if (HandleCaret(&_iconsole_cmdline)) this->SetDirty();
+		if (_iconsole_cmdline.HandleCaret()) this->SetDirty();
 	}
 
 	virtual EventState OnKeyPress(uint16 key, uint16 keycode)
@@ -294,7 +294,7 @@ struct IConsoleWindow : Window
 			case (WKC_META | 'V'):
 #endif
 			case (WKC_CTRL | 'V'):
-				if (InsertTextBufferClipboard(&_iconsole_cmdline)) {
+				if (_iconsole_cmdline.InsertClipboard()) {
 					IConsoleResetHistoryPos();
 					this->SetDirty();
 				}
@@ -308,19 +308,19 @@ struct IConsoleWindow : Window
 			case (WKC_META | 'U'):
 #endif
 			case (WKC_CTRL | 'U'):
-				DeleteTextBufferAll(&_iconsole_cmdline);
+				_iconsole_cmdline.DeleteAll();
 				this->SetDirty();
 				break;
 
 			case WKC_BACKSPACE: case WKC_DELETE:
-				if (DeleteTextBufferChar(&_iconsole_cmdline, keycode)) {
+				if (_iconsole_cmdline.DeleteChar(keycode)) {
 					IConsoleResetHistoryPos();
 					this->SetDirty();
 				}
 				break;
 
 			case WKC_LEFT: case WKC_RIGHT: case WKC_END: case WKC_HOME:
-				if (MoveTextBufferPos(&_iconsole_cmdline, keycode)) {
+				if (_iconsole_cmdline.MovePos(keycode)) {
 					IConsoleResetHistoryPos();
 					this->SetDirty();
 				}
@@ -329,7 +329,7 @@ struct IConsoleWindow : Window
 			default:
 				if (IsValidChar(key, CS_ALPHANUMERAL)) {
 					IConsoleWindow::scroll = 0;
-					InsertTextBufferChar(&_iconsole_cmdline, key);
+					_iconsole_cmdline.InsertChar(key);
 					IConsoleResetHistoryPos();
 					this->SetDirty();
 				} else {
@@ -460,7 +460,7 @@ static void IConsoleHistoryNavigate(int direction)
 	} else {
 		ttd_strlcpy(_iconsole_cmdline.buf, _iconsole_history[_iconsole_historypos], _iconsole_cmdline.max_bytes);
 	}
-	UpdateTextBufferSize(&_iconsole_cmdline);
+	_iconsole_cmdline.UpdateSize();
 }
 
 /**
diff --git a/src/fios_gui.cpp b/src/fios_gui.cpp
index 5ae42897f..5266d6fc3 100644
--- a/src/fios_gui.cpp
+++ b/src/fios_gui.cpp
@@ -263,7 +263,7 @@ public:
 		}
 
 		this->afilter = CS_ALPHANUMERAL;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size);
 
 		this->CreateNestedTree(desc, true);
 		if (mode == SLD_LOAD_GAME) this->GetWidget<NWidgetStacked>(WID_SL_CONTENT_DOWNLOAD_SEL)->SetDisplayedPlane(SZSP_HORIZONTAL);
@@ -571,7 +571,7 @@ public:
 						if (_saveload_mode == SLD_SAVE_GAME || _saveload_mode == SLD_SAVE_SCENARIO || _saveload_mode == SLD_SAVE_HEIGHTMAP) {
 							/* Copy clicked name to editbox */
 							ttd_strlcpy(this->text.buf, file->title, this->text.max_bytes);
-							UpdateTextBufferSize(&this->text);
+							this->text.UpdateSize();
 							this->SetWidgetDirty(WID_SL_SAVE_OSK_TITLE);
 						}
 					} else if (!_load_check_data.HasErrors()) {
@@ -651,7 +651,7 @@ public:
 				if (_saveload_mode == SLD_SAVE_GAME) GenerateFileName();
 			}
 
-			UpdateTextBufferSize(&this->text);
+			this->text.UpdateSize();
 		} else if (this->IsWidgetLowered(WID_SL_SAVE_GAME)) { // Save button clicked
 			if (_saveload_mode  == SLD_SAVE_GAME || _saveload_mode == SLD_SAVE_SCENARIO) {
 				_switch_mode = SM_SAVE_GAME;
diff --git a/src/genworld_gui.cpp b/src/genworld_gui.cpp
index 3ce473e97..3dfff97db 100644
--- a/src/genworld_gui.cpp
+++ b/src/genworld_gui.cpp
@@ -318,7 +318,7 @@ struct GenerateLandscapeWindow : public QueryStringBaseWindow {
 
 		/* snprintf() always outputs trailing '\0', so whole buffer can be used */
 		snprintf(this->edit_str_buf, this->edit_str_size, "%u", _settings_newgame.game_creation.generation_seed);
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size);
 		this->caption = STR_NULL;
 		this->afilter = CS_NUMERAL;
 
@@ -556,7 +556,7 @@ struct GenerateLandscapeWindow : public QueryStringBaseWindow {
 			case WID_GL_RANDOM_BUTTON: // Random seed
 				_settings_newgame.game_creation.generation_seed = InteractiveRandom();
 				snprintf(this->edit_str_buf, this->edit_str_size, "%u", _settings_newgame.game_creation.generation_seed);
-				UpdateTextBufferSize(&this->text);
+				this->text.UpdateSize();
 				this->SetDirty();
 				break;
 
diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
index 9ff0c3dea..bd7832c39 100644
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -727,28 +727,28 @@ HandleEditBoxResult QueryString::HandleEditBoxKey(Window *w, int wid, uint16 key
 		case (WKC_META | 'V'):
 #endif
 		case (WKC_CTRL | 'V'):
-			if (InsertTextBufferClipboard(&this->text)) w->SetWidgetDirty(wid);
+			if (this->text.InsertClipboard()) w->SetWidgetDirty(wid);
 			break;
 
 #ifdef WITH_COCOA
 		case (WKC_META | 'U'):
 #endif
 		case (WKC_CTRL | 'U'):
-			DeleteTextBufferAll(&this->text);
+			this->text.DeleteAll();
 			w->SetWidgetDirty(wid);
 			break;
 
 		case WKC_BACKSPACE: case WKC_DELETE:
-			if (DeleteTextBufferChar(&this->text, keycode)) w->SetWidgetDirty(wid);
+			if (this->text.DeleteChar(keycode)) w->SetWidgetDirty(wid);
 			break;
 
 		case WKC_LEFT: case WKC_RIGHT: case WKC_END: case WKC_HOME:
-			if (MoveTextBufferPos(&this->text, keycode)) w->SetWidgetDirty(wid);
+			if (this->text.MovePos(keycode)) w->SetWidgetDirty(wid);
 			break;
 
 		default:
 			if (IsValidChar(key, this->afilter)) {
-				if (InsertTextBufferChar(&this->text, key)) w->SetWidgetDirty(wid);
+				if (this->text.InsertChar(key)) w->SetWidgetDirty(wid);
 			} else {
 				state = ES_NOT_HANDLED;
 			}
@@ -759,7 +759,7 @@ HandleEditBoxResult QueryString::HandleEditBoxKey(Window *w, int wid, uint16 key
 
 void QueryString::HandleEditBox(Window *w, int wid)
 {
-	if (HasEditBoxFocus(w, wid) && HandleCaret(&this->text)) {
+	if (HasEditBoxFocus(w, wid) && this->text.HandleCaret()) {
 		w->SetWidgetDirty(wid);
 		/* When we're not the OSK, notify 'our' OSK to redraw the widget,
 		 * so the caret changes appropriately. */
@@ -847,7 +847,7 @@ struct QueryStringWindow : public QueryStringBaseWindow
 		this->caption = caption;
 		this->afilter = afilter;
 		this->flags = flags;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, max_bytes, max_chars);
+		this->text.Initialize(this->edit_str_buf, max_bytes, max_chars);
 
 		this->InitNested(desc, WN_QUERY_STRING);
 
diff --git a/src/network/network_chat_gui.cpp b/src/network/network_chat_gui.cpp
index 5709386e3..9709bf263 100644
--- a/src/network/network_chat_gui.cpp
+++ b/src/network/network_chat_gui.cpp
@@ -300,7 +300,7 @@ struct NetworkChatWindow : public QueryStringBaseWindow {
 		this->dtype   = type;
 		this->dest    = dest;
 		this->afilter = CS_ALPHANUMERAL;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size);
 
 		static const StringID chat_captions[] = {
 			STR_NETWORK_CHAT_ALL_CAPTION,
@@ -442,7 +442,7 @@ struct NetworkChatWindow : public QueryStringBaseWindow {
 				}
 
 				/* Update the textbuffer */
-				UpdateTextBufferSize(&this->text);
+				this->text.UpdateSize();
 
 				this->SetDirty();
 				free(pre_buf);
@@ -456,7 +456,7 @@ struct NetworkChatWindow : public QueryStringBaseWindow {
 			_chat_tab_completion_active = false;
 
 			/* Update the textbuffer */
-			UpdateTextBufferSize(&this->text);
+			this->text.UpdateSize();
 
 			this->SetDirty();
 		}
diff --git a/src/network/network_content_gui.cpp b/src/network/network_content_gui.cpp
index 5b1d97329..f3ebfc4f4 100644
--- a/src/network/network_content_gui.cpp
+++ b/src/network/network_content_gui.cpp
@@ -371,7 +371,7 @@ public:
 		this->GetWidget<NWidgetStacked>(WID_NCL_SEL_ALL_UPDATE)->SetDisplayedPlane(select_all);
 
 		this->afilter = CS_ALPHANUMERAL;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size, EDITBOX_MAX_LENGTH);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size, EDITBOX_MAX_LENGTH);
 		this->SetFocusedWidget(WID_NCL_FILTER);
 
 		_network_content_client.AddCallback(this);
diff --git a/src/network/network_gui.cpp b/src/network/network_gui.cpp
index 151776d74..b5e04d828 100644
--- a/src/network/network_gui.cpp
+++ b/src/network/network_gui.cpp
@@ -447,7 +447,7 @@ public:
 
 		ttd_strlcpy(this->edit_str_buf, _settings_client.network.client_name, this->edit_str_size);
 		this->afilter = CS_ALPHANUMERAL;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size, 120);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size, 120);
 		this->SetFocusedWidget(WID_NG_CLIENT);
 
 		this->field = WID_NG_CLIENT;
@@ -1019,7 +1019,7 @@ struct NetworkStartServerWindow : public QueryStringBaseWindow {
 		ttd_strlcpy(this->edit_str_buf, _settings_client.network.server_name, this->edit_str_size);
 
 		this->afilter = CS_ALPHANUMERAL;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size, 160);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size, 160);
 		this->SetFocusedWidget(WID_NSS_GAMENAME);
 
 		this->field = WID_NSS_GAMENAME;
@@ -2142,7 +2142,7 @@ struct NetworkCompanyPasswordWindow : public QueryStringBaseWindow {
 
 		this->parent = parent;
 		this->afilter = CS_ALPHANUMERAL;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size);
 		this->SetFocusedWidget(WID_NCP_PASSWORD);
 	}
 
diff --git a/src/newgrf_gui.cpp b/src/newgrf_gui.cpp
index 6df352324..a62003c8d 100644
--- a/src/newgrf_gui.cpp
+++ b/src/newgrf_gui.cpp
@@ -637,7 +637,7 @@ struct NewGRFWindow : public QueryStringBaseWindow, NewGRFScanCallback {
 		this->GetWidget<NWidgetStacked>(WID_NS_SHOW_APPLY)->SetDisplayedPlane(this->editable ? 0 : this->show_params ? 1 : SZSP_HORIZONTAL);
 		this->FinishInitNested(desc, WN_GAME_OPTIONS_NEWGRF_STATE);
 
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size);
 		this->SetFocusedWidget(WID_NS_FILTER);
 
 		this->avails.SetListing(this->last_sorting);
diff --git a/src/osk_gui.cpp b/src/osk_gui.cpp
index 792f1161f..9724a6c46 100644
--- a/src/osk_gui.cpp
+++ b/src/osk_gui.cpp
@@ -124,7 +124,7 @@ struct OskWindow : public Window {
 
 			if (!IsValidChar(c, this->qs->afilter)) return;
 
-			if (InsertTextBufferChar(&this->qs->text, c)) this->InvalidateParent();
+			if (this->qs->text.InsertChar(c)) this->InvalidateParent();
 
 			if (HasBit(_keystate, KEYS_SHIFT)) {
 				ToggleBit(_keystate, KEYS_SHIFT);
@@ -139,7 +139,7 @@ struct OskWindow : public Window {
 
 		switch (widget) {
 			case WID_OSK_BACKSPACE:
-				if (DeleteTextBufferChar(&this->qs->text, WKC_BACKSPACE)) this->InvalidateParent();
+				if (this->qs->text.DeleteChar(WKC_BACKSPACE)) this->InvalidateParent();
 				break;
 
 			case WID_OSK_SPECIAL:
@@ -163,15 +163,15 @@ struct OskWindow : public Window {
 				break;
 
 			case WID_OSK_SPACE:
-				if (InsertTextBufferChar(&this->qs->text, ' ')) this->InvalidateParent();
+				if (this->qs->text.InsertChar(' ')) this->InvalidateParent();
 				break;
 
 			case WID_OSK_LEFT:
-				if (MoveTextBufferPos(&this->qs->text, WKC_LEFT)) this->InvalidateParent();
+				if (this->qs->text.MovePos(WKC_LEFT)) this->InvalidateParent();
 				break;
 
 			case WID_OSK_RIGHT:
-				if (MoveTextBufferPos(&this->qs->text, WKC_RIGHT)) this->InvalidateParent();
+				if (this->qs->text.MovePos(WKC_RIGHT)) this->InvalidateParent();
 				break;
 
 			case WID_OSK_OK:
@@ -193,8 +193,8 @@ struct OskWindow : public Window {
 					return;
 				} else { // or reset to original string
 					strcpy(qs->text.buf, this->orig_str_buf);
-					UpdateTextBufferSize(&qs->text);
-					MoveTextBufferPos(&qs->text, WKC_END);
+					qs->text.UpdateSize();
+					qs->text.MovePos(WKC_END);
 					this->InvalidateParent();
 					delete this;
 				}
diff --git a/src/signs_gui.cpp b/src/signs_gui.cpp
index 91004f7ae..55a527136 100644
--- a/src/signs_gui.cpp
+++ b/src/signs_gui.cpp
@@ -167,7 +167,7 @@ struct SignListWindow : QueryStringBaseWindow, SignList {
 
 		/* Initialize the text edit widget */
 		this->afilter = CS_ALPHANUMERAL;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, MAX_LENGTH_SIGN_NAME_CHARS * MAX_CHAR_LENGTH, MAX_LENGTH_SIGN_NAME_CHARS);
+		this->text.Initialize(this->edit_str_buf, MAX_LENGTH_SIGN_NAME_CHARS * MAX_CHAR_LENGTH, MAX_LENGTH_SIGN_NAME_CHARS);
 		ClearFilterTextWidget();
 
 		/* Initialize the filtering variables */
@@ -186,7 +186,7 @@ struct SignListWindow : QueryStringBaseWindow, SignList {
 	void ClearFilterTextWidget()
 	{
 		this->edit_str_buf[0] = '\0';
-		UpdateTextBufferSize(&this->text);
+		this->text.UpdateSize();
 
 		this->SetWidgetDirty(WID_SIL_FILTER_TEXT);
 	}
@@ -500,7 +500,7 @@ struct SignWindow : QueryStringBaseWindow, SignList {
 		*last_of = '\0';
 
 		this->cur_sign = si->index;
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size, this->max_chars);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size, this->max_chars);
 
 		this->SetWidgetDirty(WID_QES_TEXT);
 		this->SetFocusedWidget(WID_QES_TEXT);
diff --git a/src/textbuf.cpp b/src/textbuf.cpp
index 49bc78e24..a7e1d83d8 100644
--- a/src/textbuf.cpp
+++ b/src/textbuf.cpp
@@ -30,42 +30,41 @@ int _caret_timer;
 /* Delete a character at the caret position in a text buf.
  * If backspace is set, delete the character before the caret,
  * else delete the character after it. */
-static void DelChar(Textbuf *tb, bool backspace)
+void Textbuf::DelChar(bool backspace)
 {
 	WChar c;
-	char *s = tb->buf + tb->caretpos;
+	char *s = this->buf + this->caretpos;
 
 	if (backspace) s = Utf8PrevChar(s);
 
 	uint16 len = (uint16)Utf8Decode(&c, s);
 	uint width = GetCharacterWidth(FS_NORMAL, c);
 
-	tb->pixels -= width;
+	this->pixels -= width;
 	if (backspace) {
-		tb->caretpos   -= len;
-		tb->caretxoffs -= width;
+		this->caretpos   -= len;
+		this->caretxoffs -= width;
 	}
 
 	/* Move the remaining characters over the marker */
-	memmove(s, s + len, tb->bytes - (s - tb->buf) - len);
-	tb->bytes -= len;
-	tb->chars--;
+	memmove(s, s + len, this->bytes - (s - this->buf) - len);
+	this->bytes -= len;
+	this->chars--;
 }
 
 /**
  * Delete a character from a textbuffer, either with 'Delete' or 'Backspace'
  * The character is delete from the position the caret is at
- * @param tb Textbuf type to be changed
  * @param delmode Type of deletion, either WKC_BACKSPACE or WKC_DELETE
  * @return Return true on successful change of Textbuf, or false otherwise
  */
-bool DeleteTextBufferChar(Textbuf *tb, int delmode)
+bool Textbuf::DeleteChar(int delmode)
 {
-	if (delmode == WKC_BACKSPACE && tb->caretpos != 0) {
-		DelChar(tb, true);
+	if (delmode == WKC_BACKSPACE && this->caretpos != 0) {
+		this->DelChar(true);
 		return true;
-	} else if (delmode == WKC_DELETE && tb->caretpos < tb->bytes - 1) {
-		DelChar(tb, false);
+	} else if (delmode == WKC_DELETE && this->caretpos < this->bytes - 1) {
+		this->DelChar(false);
 		return true;
 	}
 
@@ -74,36 +73,34 @@ bool DeleteTextBufferChar(Textbuf *tb, int delmode)
 
 /**
  * Delete every character in the textbuffer
- * @param tb Textbuf buffer to be emptied
  */
-void DeleteTextBufferAll(Textbuf *tb)
+void Textbuf::DeleteAll()
 {
-	memset(tb->buf, 0, tb->max_bytes);
-	tb->bytes = tb->chars = 1;
-	tb->pixels = tb->caretpos = tb->caretxoffs = 0;
+	memset(this->buf, 0, this->max_bytes);
+	this->bytes = this->chars = 1;
+	this->pixels = this->caretpos = this->caretxoffs = 0;
 }
 
 /**
  * Insert a character to a textbuffer. If maxwidth of the Textbuf is zero,
  * we don't care about the visual-length but only about the physical
  * length of the string
- * @param tb Textbuf type to be changed
  * @param key Character to be inserted
  * @return Return true on successful change of Textbuf, or false otherwise
  */
-bool InsertTextBufferChar(Textbuf *tb, WChar key)
+bool Textbuf::InsertChar(WChar key)
 {
 	const byte charwidth = GetCharacterWidth(FS_NORMAL, key);
 	uint16 len = (uint16)Utf8CharLen(key);
-	if (tb->bytes + len <= tb->max_bytes && tb->chars + 1 <= tb->max_chars) {
-		memmove(tb->buf + tb->caretpos + len, tb->buf + tb->caretpos, tb->bytes - tb->caretpos);
-		Utf8Encode(tb->buf + tb->caretpos, key);
-		tb->chars++;
-		tb->bytes  += len;
-		tb->pixels += charwidth;
-
-		tb->caretpos   += len;
-		tb->caretxoffs += charwidth;
+	if (this->bytes + len <= this->max_bytes && this->chars + 1 <= this->max_chars) {
+		memmove(this->buf + this->caretpos + len, this->buf + this->caretpos, this->bytes - this->caretpos);
+		Utf8Encode(this->buf + this->caretpos, key);
+		this->chars++;
+		this->bytes  += len;
+		this->pixels += charwidth;
+
+		this->caretpos   += len;
+		this->caretxoffs += charwidth;
 		return true;
 	}
 	return false;
@@ -113,10 +110,9 @@ bool InsertTextBufferChar(Textbuf *tb, WChar key)
  * Insert a chunk of text from the clipboard onto the textbuffer. Get TEXT clipboard
  * and append this up to the maximum length (either absolute or screenlength). If maxlength
  * is zero, we don't care about the screenlength but only about the physical length of the string
- * @param tb Textbuf type to be changed
  * @return true on successful change of Textbuf, or false otherwise
  */
-bool InsertTextBufferClipboard(Textbuf *tb)
+bool Textbuf::InsertClipboard()
 {
 	char utf8_buf[512];
 
@@ -128,8 +124,8 @@ bool InsertTextBufferClipboard(Textbuf *tb)
 		if (!IsPrintable(c)) break;
 
 		byte len = Utf8CharLen(c);
-		if (tb->bytes + bytes + len > tb->max_bytes) break;
-		if (tb->chars + chars + 1   > tb->max_chars) break;
+		if (this->bytes + bytes + len > this->max_bytes) break;
+		if (this->chars + chars + 1   > this->max_chars) break;
 
 		byte char_pixels = GetCharacterWidth(FS_NORMAL, c);
 
@@ -140,17 +136,17 @@ bool InsertTextBufferClipboard(Textbuf *tb)
 
 	if (bytes == 0) return false;
 
-	memmove(tb->buf + tb->caretpos + bytes, tb->buf + tb->caretpos, tb->bytes - tb->caretpos);
-	memcpy(tb->buf + tb->caretpos, utf8_buf, bytes);
-	tb->pixels += pixels;
-	tb->caretxoffs += pixels;
+	memmove(this->buf + this->caretpos + bytes, this->buf + this->caretpos, this->bytes - this->caretpos);
+	memcpy(this->buf + this->caretpos, utf8_buf, bytes);
+	this->pixels += pixels;
+	this->caretxoffs += pixels;
 
-	tb->bytes += bytes;
-	tb->chars += chars;
-	tb->caretpos += bytes;
-	assert(tb->bytes <= tb->max_bytes);
-	assert(tb->chars <= tb->max_chars);
-	tb->buf[tb->bytes - 1] = '\0'; // terminating zero
+	this->bytes += bytes;
+	this->chars += chars;
+	this->caretpos += bytes;
+	assert(this->bytes <= this->max_bytes);
+	assert(this->chars <= this->max_chars);
+	this->buf[this->bytes - 1] = '\0'; // terminating zero
 
 	return true;
 }
@@ -158,44 +154,43 @@ bool InsertTextBufferClipboard(Textbuf *tb)
 /**
  * Handle text navigation with arrow keys left/right.
  * This defines where the caret will blink and the next characer interaction will occur
- * @param tb Textbuf type where navigation occurs
  * @param navmode Direction in which navigation occurs WKC_LEFT, WKC_RIGHT, WKC_END, WKC_HOME
  * @return Return true on successful change of Textbuf, or false otherwise
  */
-bool MoveTextBufferPos(Textbuf *tb, int navmode)
+bool Textbuf::MovePos(int navmode)
 {
 	switch (navmode) {
 		case WKC_LEFT:
-			if (tb->caretpos != 0) {
+			if (this->caretpos != 0) {
 				WChar c;
-				const char *s = Utf8PrevChar(tb->buf + tb->caretpos);
+				const char *s = Utf8PrevChar(this->buf + this->caretpos);
 				Utf8Decode(&c, s);
-				tb->caretpos    = s - tb->buf; // -= (tb->buf + tb->caretpos - s)
-				tb->caretxoffs -= GetCharacterWidth(FS_NORMAL, c);
+				this->caretpos    = s - this->buf; // -= (this->buf + this->caretpos - s)
+				this->caretxoffs -= GetCharacterWidth(FS_NORMAL, c);
 
 				return true;
 			}
 			break;
 
 		case WKC_RIGHT:
-			if (tb->caretpos < tb->bytes - 1) {
+			if (this->caretpos < this->bytes - 1) {
 				WChar c;
 
-				tb->caretpos   += (uint16)Utf8Decode(&c, tb->buf + tb->caretpos);
-				tb->caretxoffs += GetCharacterWidth(FS_NORMAL, c);
+				this->caretpos   += (uint16)Utf8Decode(&c, this->buf + this->caretpos);
+				this->caretxoffs += GetCharacterWidth(FS_NORMAL, c);
 
 				return true;
 			}
 			break;
 
 		case WKC_HOME:
-			tb->caretpos = 0;
-			tb->caretxoffs = 0;
+			this->caretpos = 0;
+			this->caretxoffs = 0;
 			return true;
 
 		case WKC_END:
-			tb->caretpos = tb->bytes - 1;
-			tb->caretxoffs = tb->pixels;
+			this->caretpos = this->bytes - 1;
+			this->caretxoffs = this->pixels;
 			return true;
 
 		default:
@@ -208,74 +203,70 @@ bool MoveTextBufferPos(Textbuf *tb, int navmode)
 /**
  * Initialize the textbuffer by supplying it the buffer to write into
  * and the maximum length of this buffer
- * @param tb Textbuf type which is getting initialized
  * @param buf the buffer that will be holding the data for input
  * @param max_bytes maximum size in bytes, including terminating '\0'
  */
-void InitializeTextBuffer(Textbuf *tb, char *buf, uint16 max_bytes)
+void Textbuf::Initialize(char *buf, uint16 max_bytes)
 {
-	InitializeTextBuffer(tb, buf, max_bytes, max_bytes);
+	this->Initialize(buf, max_bytes, max_bytes);
 }
 
 /**
  * Initialize the textbuffer by supplying it the buffer to write into
  * and the maximum length of this buffer
- * @param tb Textbuf type which is getting initialized
  * @param buf the buffer that will be holding the data for input
  * @param max_bytes maximum size in bytes, including terminating '\0'
  * @param max_chars maximum size in chars, including terminating '\0'
  */
-void InitializeTextBuffer(Textbuf *tb, char *buf, uint16 max_bytes, uint16 max_chars)
+void Textbuf::Initialize(char *buf, uint16 max_bytes, uint16 max_chars)
 {
 	assert(max_bytes != 0);
 	assert(max_chars != 0);
 
-	tb->buf        = buf;
-	tb->max_bytes  = max_bytes;
-	tb->max_chars  = max_chars;
-	tb->caret      = true;
-	UpdateTextBufferSize(tb);
+	this->buf        = buf;
+	this->max_bytes  = max_bytes;
+	this->max_chars  = max_chars;
+	this->caret      = true;
+	this->UpdateSize();
 }
 
 /**
  * Update Textbuf type with its actual physical character and screenlength
  * Get the count of characters in the string as well as the width in pixels.
  * Useful when copying in a larger amount of text at once
- * @param tb Textbuf type which length is calculated
  */
-void UpdateTextBufferSize(Textbuf *tb)
+void Textbuf::UpdateSize()
 {
-	const char *buf = tb->buf;
+	const char *buf = this->buf;
 
-	tb->pixels = 0;
-	tb->chars = tb->bytes = 1; // terminating zero
+	this->pixels = 0;
+	this->chars = this->bytes = 1; // terminating zero
 
 	WChar c;
 	while ((c = Utf8Consume(&buf)) != '\0') {
-		tb->pixels += GetCharacterWidth(FS_NORMAL, c);
-		tb->bytes += Utf8CharLen(c);
-		tb->chars++;
+		this->pixels += GetCharacterWidth(FS_NORMAL, c);
+		this->bytes += Utf8CharLen(c);
+		this->chars++;
 	}
 
-	assert(tb->bytes <= tb->max_bytes);
-	assert(tb->chars <= tb->max_chars);
+	assert(this->bytes <= this->max_bytes);
+	assert(this->chars <= this->max_chars);
 
-	tb->caretpos = tb->bytes - 1;
-	tb->caretxoffs = tb->pixels;
+	this->caretpos = this->bytes - 1;
+	this->caretxoffs = this->pixels;
 }
 
 /**
  * Handle the flashing of the caret.
- * @param tb The text buffer to handle the caret of.
  * @return True if the caret state changes.
  */
-bool HandleCaret(Textbuf *tb)
+bool Textbuf::HandleCaret()
 {
 	/* caret changed? */
 	bool b = !!(_caret_timer & 0x20);
 
-	if (b != tb->caret) {
-		tb->caret = b;
+	if (b != this->caret) {
+		this->caret = b;
 		return true;
 	}
 	return false;
diff --git a/src/textbuf_type.h b/src/textbuf_type.h
index 717630230..0c4208f53 100644
--- a/src/textbuf_type.h
+++ b/src/textbuf_type.h
@@ -23,17 +23,21 @@ struct Textbuf {
 	bool caret;               ///< is the caret ("_") visible or not
 	uint16 caretpos;          ///< the current position of the caret in the buffer, in bytes
 	uint16 caretxoffs;        ///< the current position of the caret in pixels
-};
 
-bool HandleCaret(Textbuf *tb);
+	void Initialize(char *buf, uint16 max_bytes);
+	void Initialize(char *buf, uint16 max_bytes, uint16 max_chars);
+
+	void DeleteAll();
+	bool DeleteChar(int delmode);
+	bool InsertChar(uint32 key);
+	bool InsertClipboard();
+	bool MovePos(int navmode);
 
-void DeleteTextBufferAll(Textbuf *tb);
-bool DeleteTextBufferChar(Textbuf *tb, int delmode);
-bool InsertTextBufferChar(Textbuf *tb, uint32 key);
-bool InsertTextBufferClipboard(Textbuf *tb);
-bool MoveTextBufferPos(Textbuf *tb, int navmode);
-void InitializeTextBuffer(Textbuf *tb, char *buf, uint16 max_bytes);
-void InitializeTextBuffer(Textbuf *tb, char *buf, uint16 max_bytes, uint16 max_chars);
-void UpdateTextBufferSize(Textbuf *tb);
+	bool HandleCaret();
+	void UpdateSize();
+
+private:
+	void DelChar(bool backspace);
+};
 
 #endif /* TEXTBUF_TYPE_H */
diff --git a/src/town_gui.cpp b/src/town_gui.cpp
index bd8d44087..6a6a32b3f 100644
--- a/src/town_gui.cpp
+++ b/src/town_gui.cpp
@@ -995,7 +995,7 @@ public:
 			params(_settings_game.game_creation.town_name)
 	{
 		this->InitNested(desc, window_number);
-		InitializeTextBuffer(&this->text, this->edit_str_buf, this->edit_str_size, this->max_chars);
+		this->text.Initialize(this->edit_str_buf, this->edit_str_size, this->max_chars);
 		this->RandomTownName();
 		this->UpdateButtons(true);
 	}
@@ -1009,7 +1009,7 @@ public:
 		} else {
 			GetTownName(this->edit_str_buf, &this->params, this->townnameparts, &this->edit_str_buf[this->edit_str_size - 1]);
 		}
-		UpdateTextBufferSize(&this->text);
+		this->text.UpdateSize();
 		UpdateOSKOriginalText(this, WID_TF_TOWN_NAME_EDITBOX);
 
 		this->SetWidgetDirty(WID_TF_TOWN_NAME_EDITBOX);