Initial commit

src/chat.cpp

@@ -0,0 +1,845 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "chat.h"
+
+#include <algorithm>
+#include <cctype>
+#include <sstream>
+
+#include "config.h"
+#include "debug.h"
+#include "util/strfnd.h"
+#include "util/string.h"
+#include "util/numeric.h"
+
+ChatBuffer::ChatBuffer(u32 scrollback):
+	m_scrollback(scrollback)
+{
+	if (m_scrollback == 0)
+		m_scrollback = 1;
+	m_empty_formatted_line.first = true;
+
+	m_cache_clickable_chat_weblinks = false;
+	// Curses mode cannot access g_settings here
+	if (g_settings != nullptr) {
+		m_cache_clickable_chat_weblinks = g_settings->getBool("clickable_chat_weblinks");
+		if (m_cache_clickable_chat_weblinks) {
+			std::string colorval = g_settings->get("chat_weblink_color");
+			parseColorString(colorval, m_cache_chat_weblink_color, false, 255);
+			m_cache_chat_weblink_color.setAlpha(255);
+		}
+	}
+}
+
+void ChatBuffer::addLine(const std::wstring &name, const std::wstring &text)
+{
+	m_lines_modified = true;
+
+	ChatLine line(name, text);
+	m_unformatted.push_back(line);
+
+	if (m_rows > 0) {
+		// m_formatted is valid and must be kept valid
+		bool scrolled_at_bottom = (m_scroll == getBottomScrollPos());
+		u32 num_added = formatChatLine(line, m_cols, m_formatted);
+		if (scrolled_at_bottom)
+			m_scroll += num_added;
+	}
+
+	// Limit number of lines by m_scrollback
+	if (m_unformatted.size() > m_scrollback) {
+		deleteOldest(m_unformatted.size() - m_scrollback);
+	}
+}
+
+void ChatBuffer::clear()
+{
+	m_unformatted.clear();
+	m_formatted.clear();
+	m_scroll = 0;
+	m_lines_modified = true;
+}
+
+u32 ChatBuffer::getLineCount() const
+{
+	return m_unformatted.size();
+}
+
+const ChatLine& ChatBuffer::getLine(u32 index) const
+{
+	assert(index < getLineCount());	// pre-condition
+	return m_unformatted[index];
+}
+
+void ChatBuffer::step(f32 dtime)
+{
+	for (ChatLine &line : m_unformatted) {
+		line.age += dtime;
+	}
+}
+
+void ChatBuffer::deleteOldest(u32 count)
+{
+	bool at_bottom = (m_scroll == getBottomScrollPos());
+
+	u32 del_unformatted = 0;
+	u32 del_formatted = 0;
+
+	while (count > 0 && del_unformatted < m_unformatted.size()) {
+		++del_unformatted;
+
+		// keep m_formatted in sync
+		if (del_formatted < m_formatted.size()) {
+			sanity_check(m_formatted[del_formatted].first);
+			++del_formatted;
+			while (del_formatted < m_formatted.size() &&
+					!m_formatted[del_formatted].first)
+				++del_formatted;
+		}
+
+		--count;
+	}
+
+	m_unformatted.erase(m_unformatted.begin(), m_unformatted.begin() + del_unformatted);
+	m_formatted.erase(m_formatted.begin(), m_formatted.begin() + del_formatted);
+
+	if (del_unformatted > 0)
+		m_lines_modified = true;
+
+	if (at_bottom)
+		m_scroll = getBottomScrollPos();
+	else
+		scrollAbsolute(m_scroll - del_formatted);
+}
+
+void ChatBuffer::deleteByAge(f32 maxAge)
+{
+	u32 count = 0;
+	while (count < m_unformatted.size() && m_unformatted[count].age > maxAge)
+		++count;
+	deleteOldest(count);
+}
+
+u32 ChatBuffer::getRows() const
+{
+	return m_rows;
+}
+
+void ChatBuffer::reformat(u32 cols, u32 rows)
+{
+	if (cols == 0 || rows == 0)
+	{
+		// Clear formatted buffer
+		m_cols = 0;
+		m_rows = 0;
+		m_scroll = 0;
+		m_formatted.clear();
+	}
+	else if (cols != m_cols || rows != m_rows)
+	{
+		// TODO: Avoid reformatting ALL lines (even invisible ones)
+		// each time the console size changes.
+
+		// Find out the scroll position in *unformatted* lines
+		u32 restore_scroll_unformatted = 0;
+		u32 restore_scroll_formatted = 0;
+		bool at_bottom = (m_scroll == getBottomScrollPos());
+		if (!at_bottom)
+		{
+			for (s32 i = 0; i < m_scroll; ++i)
+			{
+				if (m_formatted[i].first)
+					++restore_scroll_unformatted;
+			}
+		}
+
+		// If number of columns change, reformat everything
+		if (cols != m_cols)
+		{
+			m_formatted.clear();
+			for (u32 i = 0; i < m_unformatted.size(); ++i)
+			{
+				if (i == restore_scroll_unformatted)
+					restore_scroll_formatted = m_formatted.size();
+				formatChatLine(m_unformatted[i], cols, m_formatted);
+			}
+		}
+
+		// Update the console size
+		m_cols = cols;
+		m_rows = rows;
+
+		// Restore the scroll position
+		if (at_bottom)
+		{
+			scrollBottom();
+		}
+		else
+		{
+			scrollAbsolute(restore_scroll_formatted);
+		}
+	}
+}
+
+const ChatFormattedLine& ChatBuffer::getFormattedLine(u32 row) const
+{
+	s32 index = m_scroll + (s32) row;
+	if (index >= 0 && index < (s32) m_formatted.size())
+		return m_formatted[index];
+
+	return m_empty_formatted_line;
+}
+
+void ChatBuffer::scroll(s32 rows)
+{
+	scrollAbsolute(m_scroll + rows);
+}
+
+void ChatBuffer::scrollAbsolute(s32 scroll)
+{
+	s32 top = getTopScrollPos();
+	s32 bottom = getBottomScrollPos();
+
+	m_scroll = scroll;
+	if (m_scroll < top)
+		m_scroll = top;
+	if (m_scroll > bottom)
+		m_scroll = bottom;
+}
+
+void ChatBuffer::scrollBottom()
+{
+	m_scroll = getBottomScrollPos();
+}
+
+u32 ChatBuffer::formatChatLine(const ChatLine& line, u32 cols,
+		std::vector<ChatFormattedLine>& destination) const
+{
+	u32 num_added = 0;
+	std::vector<ChatFormattedFragment> next_frags;
+	ChatFormattedLine next_line;
+	ChatFormattedFragment temp_frag;
+	u32 out_column = 0;
+	u32 in_pos = 0;
+	u32 hanging_indentation = 0;
+
+	// Format the sender name and produce fragments
+	if (!line.name.empty()) {
+		temp_frag.text = L"<";
+		temp_frag.column = 0;
+		//temp_frag.bold = 0;
+		next_frags.push_back(temp_frag);
+		temp_frag.text = line.name;
+		temp_frag.column = 0;
+		//temp_frag.bold = 1;
+		next_frags.push_back(temp_frag);
+		temp_frag.text = L"> ";
+		temp_frag.column = 0;
+		//temp_frag.bold = 0;
+		next_frags.push_back(temp_frag);
+	}
+
+	std::wstring name_sanitized = line.name.c_str();
+
+	// Choose an indentation level
+	if (line.name.empty()) {
+		// Server messages
+		hanging_indentation = 0;
+	} else if (name_sanitized.size() + 3 <= cols/2) {
+		// Names shorter than about half the console width
+		hanging_indentation = line.name.size() + 3;
+	} else {
+		// Very long names
+		hanging_indentation = 2;
+	}
+	//EnrichedString line_text(line.text);
+
+	next_line.first = true;
+	// Set/use forced newline after the last frag in each line
+	bool mark_newline = false;
+
+	// Produce fragments and layout them into lines
+	while (!next_frags.empty() || in_pos < line.text.size()) {
+		mark_newline = false; // now using this to USE line-end frag
+
+		// Layout fragments into lines
+		while (!next_frags.empty()) {
+			ChatFormattedFragment& frag = next_frags[0];
+
+			// Force newline after this frag, if marked
+			if (frag.column == INT_MAX)
+				mark_newline = true;
+
+			if (frag.text.size() <= cols - out_column) {
+				// Fragment fits into current line
+				frag.column = out_column;
+				next_line.fragments.push_back(frag);
+				out_column += frag.text.size();
+				next_frags.erase(next_frags.begin());
+			} else {
+				// Fragment does not fit into current line
+				// So split it up
+				temp_frag.text = frag.text.substr(0, cols - out_column);
+				temp_frag.column = out_column;
+				temp_frag.weblink = frag.weblink;
+
+				next_line.fragments.push_back(temp_frag);
+				frag.text = frag.text.substr(cols - out_column);
+				frag.column = 0;
+				out_column = cols;
+			}
+
+			if (out_column == cols || mark_newline) {
+				// End the current line
+				destination.push_back(next_line);
+				num_added++;
+				next_line.fragments.clear();
+				next_line.first = false;
+
+				out_column = hanging_indentation;
+				mark_newline = false;
+			}
+		}
+
+		// Produce fragment(s) for next formatted line
+		if (!(in_pos < line.text.size()))
+			continue;
+
+		const std::wstring &linestring = line.text.getString();
+		u32 remaining_in_output = cols - out_column;
+		size_t http_pos = std::wstring::npos;
+		mark_newline = false;  // now using this to SET line-end frag
+
+		// Construct all frags for next output line
+		while (!mark_newline) {
+			// Determine a fragment length <= the minimum of
+			// remaining_in_{in,out}put. Try to end the fragment
+			// on a word boundary.
+			u32 frag_length = 0, space_pos = 0;
+			u32 remaining_in_input = line.text.size() - in_pos;
+
+			if (m_cache_clickable_chat_weblinks) {
+				// Note: unsigned(-1) on fail
+				http_pos = linestring.find(L"https://", in_pos);
+				if (http_pos == std::wstring::npos)
+					http_pos = linestring.find(L"http://", in_pos);
+				if (http_pos != std::wstring::npos)
+					http_pos -= in_pos;
+			}
+
+			while (frag_length < remaining_in_input &&
+					frag_length < remaining_in_output) {
+				if (iswspace(linestring[in_pos + frag_length]))
+					space_pos = frag_length;
+				++frag_length;
+			}
+
+			if (http_pos >= remaining_in_output) {
+				// Http not in range, grab until space or EOL, halt as normal.
+				// Note this works because (http_pos = npos) is unsigned(-1)
+
+				mark_newline = true;
+			} else if (http_pos == 0) {
+				// At http, grab ALL until FIRST whitespace or end marker. loop.
+				// If at end of string, next loop will be empty string to mark end of weblink.
+
+				frag_length = 6;  // Frag is at least "http://"
+
+				// Chars to mark end of weblink
+				// TODO? replace this with a safer (slower) regex whitelist?
+				static const std::wstring delim_chars = L"\'\";";
+				wchar_t tempchar = linestring[in_pos+frag_length];
+				while (frag_length < remaining_in_input &&
+						!iswspace(tempchar) &&
+						delim_chars.find(tempchar) == std::wstring::npos) {
+					++frag_length;
+					tempchar = linestring[in_pos+frag_length];
+				}
+
+				space_pos = frag_length - 1;
+				// This frag may need to be force-split. That's ok, urls aren't "words"
+				if (frag_length >= remaining_in_output) {
+					mark_newline = true;
+				}
+			} else {
+				// Http in range, grab until http, loop
+
+				space_pos = http_pos - 1;
+				frag_length = http_pos;
+			}
+
+			// Include trailing space in current frag
+			if (space_pos != 0 && frag_length < remaining_in_input)
+				frag_length = space_pos + 1;
+
+			temp_frag.text = line.text.substr(in_pos, frag_length);
+			// A hack so this frag remembers mark_newline for the layout phase
+			temp_frag.column = mark_newline ? INT_MAX : 0;
+
+			if (http_pos == 0) {
+				// Discard color stuff from the source frag
+				temp_frag.text = EnrichedString(temp_frag.text.getString());
+				temp_frag.text.setDefaultColor(m_cache_chat_weblink_color);
+				// Set weblink in the frag meta
+				temp_frag.weblink = wide_to_utf8(temp_frag.text.getString());
+			} else {
+				temp_frag.weblink.clear();
+			}
+			next_frags.push_back(temp_frag);
+			in_pos += frag_length;
+			remaining_in_output -= std::min(frag_length, remaining_in_output);
+		}
+	}
+
+	// End the last line
+	if (num_added == 0 || !next_line.fragments.empty()) {
+		destination.push_back(next_line);
+		num_added++;
+	}
+
+	return num_added;
+}
+
+s32 ChatBuffer::getTopScrollPos() const
+{
+	s32 formatted_count = (s32) m_formatted.size();
+	s32 rows = (s32) m_rows;
+	if (rows == 0)
+		return 0;
+
+	if (formatted_count <= rows)
+		return formatted_count - rows;
+
+	return 0;
+}
+
+s32 ChatBuffer::getBottomScrollPos() const
+{
+	s32 formatted_count = (s32) m_formatted.size();
+	s32 rows = (s32) m_rows;
+	if (rows == 0)
+		return 0;
+
+	return formatted_count - rows;
+}
+
+void ChatBuffer::resize(u32 scrollback)
+{
+	m_scrollback = scrollback;
+	if (m_unformatted.size() > m_scrollback)
+		deleteOldest(m_unformatted.size() - m_scrollback);
+}
+
+
+ChatPrompt::ChatPrompt(const std::wstring &prompt, u32 history_limit):
+	m_prompt(prompt),
+	m_history_limit(history_limit)
+{
+}
+
+void ChatPrompt::input(wchar_t ch)
+{
+	m_line.insert(m_cursor, 1, ch);
+	m_cursor++;
+	clampView();
+	m_nick_completion_start = 0;
+	m_nick_completion_end = 0;
+}
+
+void ChatPrompt::input(const std::wstring &str)
+{
+	m_line.insert(m_cursor, str);
+	m_cursor += str.size();
+	clampView();
+	m_nick_completion_start = 0;
+	m_nick_completion_end = 0;
+}
+
+void ChatPrompt::addToHistory(const std::wstring &line)
+{
+	if (!line.empty() &&
+			(m_history.size() == 0 || m_history.back() != line)) {
+		// Remove all duplicates
+		m_history.erase(std::remove(m_history.begin(), m_history.end(),
+			line), m_history.end());
+		// Push unique line
+		m_history.push_back(line);
+	}
+	if (m_history.size() > m_history_limit)
+		m_history.erase(m_history.begin());
+	m_history_index = m_history.size();
+}
+
+void ChatPrompt::clear()
+{
+	m_line.clear();
+	m_view = 0;
+	m_cursor = 0;
+	m_nick_completion_start = 0;
+	m_nick_completion_end = 0;
+}
+
+std::wstring ChatPrompt::replace(const std::wstring &line)
+{
+	std::wstring old_line = m_line;
+	m_line =  line;
+	m_view = m_cursor = line.size();
+	clampView();
+	m_nick_completion_start = 0;
+	m_nick_completion_end = 0;
+	return old_line;
+}
+
+void ChatPrompt::historyPrev()
+{
+	if (m_history_index != 0)
+	{
+		--m_history_index;
+		replace(m_history[m_history_index]);
+	}
+}
+
+void ChatPrompt::historyNext()
+{
+	if (m_history_index + 1 >= m_history.size())
+	{
+		m_history_index = m_history.size();
+		replace(L"");
+	}
+	else
+	{
+		++m_history_index;
+		replace(m_history[m_history_index]);
+	}
+}
+
+void ChatPrompt::nickCompletion(const std::list<std::string>& names, bool backwards)
+{
+	// Two cases:
+	// (a) m_nick_completion_start == m_nick_completion_end == 0
+	//     Then no previous nick completion is active.
+	//     Get the word around the cursor and replace with any nick
+	//     that has that word as a prefix.
+	// (b) else, continue a previous nick completion.
+	//     m_nick_completion_start..m_nick_completion_end are the
+	//     interval where the originally used prefix was. Cycle
+	//     through the list of completions of that prefix.
+	u32 prefix_start = m_nick_completion_start;
+	u32 prefix_end = m_nick_completion_end;
+	bool initial = (prefix_end == 0);
+	if (initial)
+	{
+		// no previous nick completion is active
+		prefix_start = prefix_end = m_cursor;
+		while (prefix_start > 0 && !iswspace(m_line[prefix_start-1]))
+			--prefix_start;
+		while (prefix_end < m_line.size() && !iswspace(m_line[prefix_end]))
+			++prefix_end;
+		if (prefix_start == prefix_end)
+			return;
+	}
+	std::wstring prefix = m_line.substr(prefix_start, prefix_end - prefix_start);
+
+	// find all names that start with the selected prefix
+	std::vector<std::wstring> completions;
+	for (const std::string &name : names) {
+		std::wstring completion = utf8_to_wide(name);
+		if (str_starts_with(completion, prefix, true)) {
+			if (prefix_start == 0)
+				completion += L": ";
+			completions.push_back(completion);
+		}
+	}
+
+	if (completions.empty())
+		return;
+
+	// find a replacement string and the word that will be replaced
+	u32 word_end = prefix_end;
+	u32 replacement_index = 0;
+	if (!initial)
+	{
+		while (word_end < m_line.size() && !iswspace(m_line[word_end]))
+			++word_end;
+		std::wstring word = m_line.substr(prefix_start, word_end - prefix_start);
+
+		// cycle through completions
+		for (u32 i = 0; i < completions.size(); ++i)
+		{
+			if (str_equal(word, completions[i], true))
+			{
+				if (backwards)
+					replacement_index = i + completions.size() - 1;
+				else
+					replacement_index = i + 1;
+				replacement_index %= completions.size();
+				break;
+			}
+		}
+	}
+	std::wstring replacement = completions[replacement_index];
+	if (word_end < m_line.size() && iswspace(m_line[word_end]))
+		++word_end;
+
+	// replace existing word with replacement word,
+	// place the cursor at the end and record the completion prefix
+	m_line.replace(prefix_start, word_end - prefix_start, replacement);
+	m_cursor = prefix_start + replacement.size();
+	clampView();
+	m_nick_completion_start = prefix_start;
+	m_nick_completion_end = prefix_end;
+}
+
+void ChatPrompt::reformat(u32 cols)
+{
+	if (cols <= m_prompt.size())
+	{
+		m_cols = 0;
+		m_view = m_cursor;
+	}
+	else
+	{
+		s32 length = m_line.size();
+		bool was_at_end = (m_view + m_cols >= length + 1);
+		m_cols = cols - m_prompt.size();
+		if (was_at_end)
+			m_view = length;
+		clampView();
+	}
+}
+
+std::wstring ChatPrompt::getVisiblePortion() const
+{
+	return m_prompt + m_line.substr(m_view, m_cols);
+}
+
+s32 ChatPrompt::getVisibleCursorPosition() const
+{
+	return m_cursor - m_view + m_prompt.size();
+}
+
+void ChatPrompt::cursorOperation(CursorOp op, CursorOpDir dir, CursorOpScope scope)
+{
+	s32 old_cursor = m_cursor;
+	s32 new_cursor = m_cursor;
+
+	s32 length = m_line.size();
+	s32 increment = (dir == CURSOROP_DIR_RIGHT) ? 1 : -1;
+
+	switch (scope) {
+	case CURSOROP_SCOPE_CHARACTER:
+		new_cursor += increment;
+		break;
+	case CURSOROP_SCOPE_WORD:
+		if (dir == CURSOROP_DIR_RIGHT) {
+			// skip one word to the right
+			while (new_cursor < length && iswspace(m_line[new_cursor]))
+				new_cursor++;
+			while (new_cursor < length && !iswspace(m_line[new_cursor]))
+				new_cursor++;
+			while (new_cursor < length && iswspace(m_line[new_cursor]))
+				new_cursor++;
+		} else {
+			// skip one word to the left
+			while (new_cursor >= 1 && iswspace(m_line[new_cursor - 1]))
+				new_cursor--;
+			while (new_cursor >= 1 && !iswspace(m_line[new_cursor - 1]))
+				new_cursor--;
+		}
+		break;
+	case CURSOROP_SCOPE_LINE:
+		new_cursor += increment * length;
+		break;
+	case CURSOROP_SCOPE_SELECTION:
+		break;
+	}
+
+	new_cursor = MYMAX(MYMIN(new_cursor, length), 0);
+
+	switch (op) {
+	case CURSOROP_MOVE:
+		m_cursor = new_cursor;
+		m_cursor_len = 0;
+		break;
+	case CURSOROP_DELETE:
+		if (m_cursor_len > 0) { // Delete selected text first
+			m_line.erase(m_cursor, m_cursor_len);
+		} else {
+			m_cursor = MYMIN(new_cursor, old_cursor);
+			m_line.erase(m_cursor, abs(new_cursor - old_cursor));
+		}
+		m_cursor_len = 0;
+		break;
+	case CURSOROP_SELECT:
+		if (scope == CURSOROP_SCOPE_LINE) {
+			m_cursor = 0;
+			m_cursor_len = length;
+		} else {
+			m_cursor = MYMIN(new_cursor, old_cursor);
+			m_cursor_len += abs(new_cursor - old_cursor);
+			m_cursor_len = MYMIN(m_cursor_len, length - m_cursor);
+		}
+		break;
+	}
+
+	clampView();
+
+	m_nick_completion_start = 0;
+	m_nick_completion_end = 0;
+}
+
+void ChatPrompt::clampView()
+{
+	s32 length = m_line.size();
+	if (length + 1 <= m_cols)
+	{
+		m_view = 0;
+	}
+	else
+	{
+		m_view = MYMIN(m_view, length + 1 - m_cols);
+		m_view = MYMIN(m_view, m_cursor);
+		m_view = MYMAX(m_view, m_cursor - m_cols + 1);
+		m_view = MYMAX(m_view, 0);
+	}
+}
+
+
+
+ChatBackend::ChatBackend():
+	m_console_buffer(500),
+	m_recent_buffer(6),
+	m_prompt(L"]", 500)
+{
+}
+
+void ChatBackend::addMessage(const std::wstring &name, std::wstring text)
+{
+	// Note: A message may consist of multiple lines, for example the MOTD.
+	text = translate_string(text);
+	WStrfnd fnd(text);
+	while (!fnd.at_end())
+	{
+		std::wstring line = fnd.next(L"\n");
+		m_console_buffer.addLine(name, line);
+		m_recent_buffer.addLine(name, line);
+	}
+}
+
+void ChatBackend::addUnparsedMessage(std::wstring message)
+{
+	// TODO: Remove the need to parse chat messages client-side, by sending
+	// separate name and text fields in TOCLIENT_CHAT_MESSAGE.
+
+	if (message.size() >= 2 && message[0] == L'<')
+	{
+		std::size_t closing = message.find_first_of(L'>', 1);
+		if (closing != std::wstring::npos &&
+				closing + 2 <= message.size() &&
+				message[closing+1] == L' ')
+		{
+			std::wstring name = message.substr(1, closing - 1);
+			std::wstring text = message.substr(closing + 2);
+			addMessage(name, text);
+			return;
+		}
+	}
+
+	// Unable to parse, probably a server message.
+	addMessage(L"", message);
+}
+
+ChatBuffer& ChatBackend::getConsoleBuffer()
+{
+	return m_console_buffer;
+}
+
+ChatBuffer& ChatBackend::getRecentBuffer()
+{
+	return m_recent_buffer;
+}
+
+EnrichedString ChatBackend::getRecentChat() const
+{
+	EnrichedString result;
+	for (u32 i = 0; i < m_recent_buffer.getLineCount(); ++i) {
+		const ChatLine& line = m_recent_buffer.getLine(i);
+		if (i != 0)
+			result += L"\n";
+		if (!line.name.empty()) {
+			result += L"<";
+			result += line.name;
+			result += L"> ";
+		}
+		result += line.text;
+	}
+	return result;
+}
+
+ChatPrompt& ChatBackend::getPrompt()
+{
+	return m_prompt;
+}
+
+void ChatBackend::reformat(u32 cols, u32 rows)
+{
+	m_console_buffer.reformat(cols, rows);
+
+	// no need to reformat m_recent_buffer, its formatted lines
+	// are not used
+
+	m_prompt.reformat(cols);
+}
+
+void ChatBackend::clearRecentChat()
+{
+	m_recent_buffer.clear();
+}
+
+
+void ChatBackend::applySettings()
+{
+	u32 recent_lines = g_settings->getU32("recent_chat_messages");
+	recent_lines = rangelim(recent_lines, 2, 20);
+	m_recent_buffer.resize(recent_lines);
+}
+
+void ChatBackend::step(float dtime)
+{
+	m_recent_buffer.step(dtime);
+	m_recent_buffer.deleteByAge(60.0);
+
+	// no need to age messages in anything but m_recent_buffer
+}
+
+void ChatBackend::scroll(s32 rows)
+{
+	m_console_buffer.scroll(rows);
+}
+
+void ChatBackend::scrollPageDown()
+{
+	m_console_buffer.scroll(m_console_buffer.getRows());
+}
+
+void ChatBackend::scrollPageUp()
+{
+	m_console_buffer.scroll(-(s32)m_console_buffer.getRows());
+}