Converted menu_file_create to use std::string for its filename buffer

src/frontend/mame/ui/filesel.cpp

@@ -53,24 +53,25 @@ namespace ui {
 //  into a buffer
 //-------------------------------------------------
 
-template <std::size_t N, typename F>
-static void input_character(char (&buffer)[N], unicode_char unichar, F &&filter)
+template <typename F>
+static void input_character(std::string &buffer, unicode_char unichar, F &&filter)
 {
-	auto buflen = std::strlen(buffer);
+	auto buflen = buffer.size();
 
 	if ((unichar == 8) || (unichar == 0x7f))
 	{
+		// backspace
 		if (0 < buflen)
-			*const_cast<char *>(utf8_previous_char(&buffer[buflen])) = 0;
+		{
+			auto buffer_oldend = buffer.c_str() + buflen;
+			auto buffer_newend = utf8_previous_char(buffer_oldend);
+			buffer.resize(buffer_newend - buffer.c_str());
+		}
 	}
 	else if ((unichar >= ' ') && (!filter || filter(unichar)))
 	{
-		auto const chlen = utf8_from_uchar(&buffer[buflen], N - buflen - 1, unichar);
-		if (0 <= chlen)
-		{
-			buflen += chlen;
-			buffer[buflen] = 0;
-		}
+		// append this character
+		buffer += utf8_from_uchar(unichar);
 	}
 }
 
@@ -175,7 +176,11 @@ menu_file_create::menu_file_create(mame_ui_manager &mui, render_container *conta
 	m_ok = ok;
 	*m_ok = true;
 	auto const sep = current_file.rfind(PATH_SEPARATOR);
-	std::strncpy(m_filename_buffer, current_file.c_str() + ((std::string::npos == sep) ? 0 : (sep + 1)), sizeof(m_filename_buffer));
+
+	m_filename.reserve(1024);
+	m_filename = sep != std::string::npos
+		? current_file.substr(sep + strlen(PATH_SEPARATOR), current_file.size() - sep - strlen(PATH_SEPARATOR))
+		: current_file;
 }
 
 
@@ -208,19 +213,19 @@ void menu_file_create::populate()
 {
 	std::string buffer;
 	const image_device_format *format;
-	const char *new_image_name;
+	const std::string *new_image_name;
 
 	// append the "New Image Name" item
 	if (get_selection() == ITEMREF_NEW_IMAGE_NAME)
 	{
-		buffer.append(m_filename_buffer).append("_");
-		new_image_name = buffer.c_str();
+		buffer = m_filename + "_";
+		new_image_name = &buffer;
 	}
 	else
 	{
-		new_image_name = m_filename_buffer;
+		new_image_name = &m_filename;
 	}
-	item_append(_("New Image Name:"), new_image_name, 0, ITEMREF_NEW_IMAGE_NAME);
+	item_append(_("New Image Name:"), *new_image_name, 0, ITEMREF_NEW_IMAGE_NAME);
 
 	// do we support multiple formats?
 	if (ENABLE_FORMATS) format = m_image->formatlist().front().get();
@@ -256,10 +261,10 @@ void menu_file_create::handle()
 		case IPT_UI_SELECT:
 			if ((event->itemref == ITEMREF_CREATE) || (event->itemref == ITEMREF_NEW_IMAGE_NAME))
 			{
-				std::string tmp_file(m_filename_buffer);
+				std::string tmp_file(m_filename);
 				if (tmp_file.find(".") != -1 && tmp_file.find(".") < tmp_file.length() - 1)
 				{
-					m_current_file = m_filename_buffer;
+					m_current_file = m_filename;
 					menu::stack_pop(machine());
 				}
 				else
@@ -270,7 +275,7 @@ void menu_file_create::handle()
 		case IPT_SPECIAL:
 			if (get_selection() == ITEMREF_NEW_IMAGE_NAME)
 			{
-				input_character(m_filename_buffer,event->unichar, &is_valid_filename_char);
+				input_character(m_filename, event->unichar, &is_valid_filename_char);
 				reset(reset_options::REMEMBER_POSITION);
 			}
 			break;

src/frontend/mame/ui/filesel.h

@@ -49,7 +49,7 @@ private:
 	std::string &                   m_current_directory;
 	std::string &                   m_current_file;
 	const image_device_format *     m_current_format;
-	char                            m_filename_buffer[1024];
+	std::string						m_filename;
 
 protected:
 	bool *                          m_ok;

src/lib/util/unicode.cpp

@@ -246,6 +246,19 @@ int utf8_from_uchar(char *utf8string, size_t count, unicode_char uchar)
 }
 
 
+//-------------------------------------------------
+//  utf8_from_uchar - convert a unicode character
+//  into a UTF-8 sequence
+//-------------------------------------------------
+
+std::string utf8_from_uchar(unicode_char uchar)
+{
+	char buffer[UTF8_CHAR_MAX];
+	auto len = utf8_from_uchar(buffer, ARRAY_LENGTH(buffer), uchar);
+	return std::string(buffer, len);
+}
+
+
 //-------------------------------------------------
 //  utf16_from_uchar - convert a unicode character
 //  into a UTF-16 sequence

src/lib/util/unicode.h

@@ -97,6 +97,7 @@ int uchar_from_utf16f(unicode_char *uchar, const utf16_char *utf16char, size_t c
 
 // converting 32-bit Unicode chars to strings
 int utf8_from_uchar(char *utf8string, size_t count, unicode_char uchar);
+std::string utf8_from_uchar(unicode_char uchar);
 int utf16_from_uchar(utf16_char *utf16string, size_t count, unicode_char uchar);
 int utf16f_from_uchar(utf16_char *utf16string, size_t count, unicode_char uchar);