xC/xP: relay and render channel topics

4 files changed, 223 insertions, 173 deletions

diff --git a/xC-proto b/xC-proto
index ea39b86..25d48e8 100644
--- a/xC-proto
+++ b/xC-proto
@@ -53,12 +53,12 @@ struct EventMessage {
 	u32 event_seq;
 	union EventData switch (enum Event {
 		PING,
+		BUFFER_LINE,
 		BUFFER_UPDATE,
 		BUFFER_STATS,
 		BUFFER_RENAME,
 		BUFFER_REMOVE,
 		BUFFER_ACTIVATE,
-		BUFFER_LINE,
 		BUFFER_CLEAR,
 		SERVER_UPDATE,
 		SERVER_RENAME,
@@ -69,41 +69,6 @@ struct EventMessage {
 	case PING:
 		void;
 
-	case BUFFER_UPDATE:
-		string buffer_name;
-		bool hide_unimportant;
-		union BufferContext switch (enum BufferKind {
-			GLOBAL,
-			SERVER,
-			CHANNEL,
-			PRIVATE_MESSAGE,
-		} kind) {
-		case GLOBAL:
-			void;
-		case SERVER:
-			string server_name;
-		case CHANNEL:
-			string server_name;
-		case PRIVATE_MESSAGE:
-			string server_name;
-		} context;
-	case BUFFER_STATS:
-		string buffer_name;
-		// These are cumulative, even for lines flushed out from buffers.
-		// Updates to these values aren't broadcasted, thus handle:
-		//  - BUFFER_LINE by bumping/setting them as appropriate,
-		//  - BUFFER_ACTIVATE by clearing them for the previous buffer
-		//    (this way, they can be used to mark unread messages).
-		u32 new_messages;
-		u32 new_unimportant_messages;
-		bool highlighted;
-	case BUFFER_RENAME:
-		string buffer_name;
-		string new;
-	case BUFFER_REMOVE:
-		string buffer_name;
-	case BUFFER_ACTIVATE:
-		string buffer_name;
 	case BUFFER_LINE:
 		string buffer_name;
 		// Whether the line should also be displayed in the active buffer.
@@ -150,6 +115,42 @@ struct EventMessage {
 		case FLIP_MONOSPACE:
 			void;
 		} items<>;
+	case BUFFER_UPDATE:
+		string buffer_name;
+		bool hide_unimportant;
+		union BufferContext switch (enum BufferKind {
+			GLOBAL,
+			SERVER,
+			CHANNEL,
+			PRIVATE_MESSAGE,
+		} kind) {
+		case GLOBAL:
+			void;
+		case SERVER:
+			string server_name;
+		case CHANNEL:
+			string server_name;
+			ItemData topic<>;
+		case PRIVATE_MESSAGE:
+			string server_name;
+		} context;
+	case BUFFER_STATS:
+		string buffer_name;
+		// These are cumulative, even for lines flushed out from buffers.
+		// Updates to these values aren't broadcasted, thus handle:
+		//  - BUFFER_LINE by bumping/setting them as appropriate,
+		//  - BUFFER_ACTIVATE by clearing them for the previous buffer
+		//    (this way, they can be used to mark unread messages).
+		u32 new_messages;
+		u32 new_unimportant_messages;
+		bool highlighted;
+	case BUFFER_RENAME:
+		string buffer_name;
+		string new;
+	case BUFFER_REMOVE:
+		string buffer_name;
+	case BUFFER_ACTIVATE:
+		string buffer_name;
 	case BUFFER_CLEAR:
 		string buffer_name;
 
diff --git a/xC.c b/xC.c
index 2027a6a..38f2c00 100644
--- a/xC.c
+++ b/xC.c
@@ -2883,84 +2883,9 @@ relay_prepare_ping (struct app_context *ctx)
 	relay_prepare (ctx)->data.event = RELAY_EVENT_PING;
 }
 
-static void
-relay_prepare_buffer_update (struct app_context *ctx, struct buffer *buffer)
-{
-	struct relay_event_message *m = relay_prepare (ctx);
-	struct relay_event_data_buffer_update *e = &m->data.buffer_update;
-	e->event = RELAY_EVENT_BUFFER_UPDATE;
-	e->buffer_name = str_from_cstr (buffer->name);
-	e->hide_unimportant = buffer->hide_unimportant;
-
-	struct str *server_name = NULL;
-	switch (buffer->type)
-	{
-	case BUFFER_GLOBAL:
-		e->context.kind = RELAY_BUFFER_KIND_GLOBAL;
-		break;
-	case BUFFER_SERVER:
-		e->context.kind = RELAY_BUFFER_KIND_SERVER;
-		server_name = &e->context.server.server_name;
-		break;
-	case BUFFER_CHANNEL:
-		e->context.kind = RELAY_BUFFER_KIND_CHANNEL;
-		server_name = &e->context.channel.server_name;
-		break;
-	case BUFFER_PM:
-		e->context.kind = RELAY_BUFFER_KIND_PRIVATE_MESSAGE;
-		server_name = &e->context.private_message.server_name;
-		break;
-	}
-	if (server_name)
-		*server_name = str_from_cstr (buffer->server->name);
-}
-
-static void
-relay_prepare_buffer_stats (struct app_context *ctx, struct buffer *buffer)
-{
-	struct relay_event_message *m = relay_prepare (ctx);
-	struct relay_event_data_buffer_stats *e = &m->data.buffer_stats;
-	e->event = RELAY_EVENT_BUFFER_STATS;
-	e->buffer_name = str_from_cstr (buffer->name);
-	e->new_messages = MIN (UINT32_MAX,
-		buffer->new_messages_count - buffer->new_unimportant_count);
-	e->new_unimportant_messages = MIN (UINT32_MAX,
-		buffer->new_unimportant_count);
-	e->highlighted = buffer->highlighted;
-}
-
-static void
-relay_prepare_buffer_rename (struct app_context *ctx, struct buffer *buffer,
-	const char *new_name)
-{
-	struct relay_event_message *m = relay_prepare (ctx);
-	struct relay_event_data_buffer_rename *e = &m->data.buffer_rename;
-	e->event = RELAY_EVENT_BUFFER_RENAME;
-	e->buffer_name = str_from_cstr (buffer->name);
-	e->new = str_from_cstr (new_name);
-}
-
-static void
-relay_prepare_buffer_remove (struct app_context *ctx, struct buffer *buffer)
-{
-	struct relay_event_message *m = relay_prepare (ctx);
-	struct relay_event_data_buffer_remove *e = &m->data.buffer_remove;
-	e->event = RELAY_EVENT_BUFFER_REMOVE;
-	e->buffer_name = str_from_cstr (buffer->name);
-}
-
-static void
-relay_prepare_buffer_activate (struct app_context *ctx, struct buffer *buffer)
-{
-	struct relay_event_message *m = relay_prepare (ctx);
-	struct relay_event_data_buffer_activate *e = &m->data.buffer_activate;
-	e->event = RELAY_EVENT_BUFFER_ACTIVATE;
-	e->buffer_name = str_from_cstr (buffer->name);
-}
-
 static union relay_item_data *
 relay_translate_formatter (struct app_context *ctx, union relay_item_data *p,
-	struct formatter_item *i)
+	const struct formatter_item *i)
 {
 	// XXX: See attr_printer_decode_color(), this is a footgun.
 	int16_t c16  = i->color;
@@ -3016,6 +2941,23 @@ relay_translate_formatter (struct app_context *ctx, union relay_item_data *p,
 	return p;
 }
 
+static union relay_item_data *
+relay_items (struct app_context *ctx, const struct formatter_item *items,
+	uint32_t *len)
+{
+	size_t items_len = 0;
+	for (size_t i = 0; items[i].type; i++)
+		items_len++;
+
+	// Beware of the upper bound, currently dominated by FORMATTER_ITEM_ATTR.
+	union relay_item_data *a = xcalloc (items_len * 9, sizeof *a), *p = a;
+	for (const struct formatter_item *i = items; items_len--; i++)
+		p = relay_translate_formatter (ctx, p, i);
+
+	*len = p - a;
+	return a;
+}
+
 static void
 relay_prepare_buffer_line (struct app_context *ctx, struct buffer *buffer,
 	struct buffer_line *line, bool leak_to_active)
@@ -3029,17 +2971,94 @@ relay_prepare_buffer_line (struct app_context *ctx, struct buffer *buffer,
 	e->rendition = 1 + line->r;
 	e->when = line->when * 1000;
 	e->leak_to_active = leak_to_active;
+	e->items = relay_items (ctx, line->items, &e->items_len);
+}
 
-	size_t len = 0;
-	for (size_t i = 0; line->items[i].type; i++)
-		len++;
+// TODO: Consider pushing this whole block of code much further down.
+static void formatter_add (struct formatter *self, const char *format, ...);
 
-	// Beware of the upper bound, currently dominated by FORMATTER_ITEM_ATTR.
-	union relay_item_data *p = e->items = xcalloc (len * 9, sizeof *e->items);
-	for (struct formatter_item *i = line->items; len--; i++)
-		p = relay_translate_formatter (ctx, p, i);
+static void
+relay_prepare_buffer_update (struct app_context *ctx, struct buffer *buffer)
+{
+	struct relay_event_message *m = relay_prepare (ctx);
+	struct relay_event_data_buffer_update *e = &m->data.buffer_update;
+	e->event = RELAY_EVENT_BUFFER_UPDATE;
+	e->buffer_name = str_from_cstr (buffer->name);
+	e->hide_unimportant = buffer->hide_unimportant;
+
+	struct str *server_name = NULL;
+	switch (buffer->type)
+	{
+	case BUFFER_GLOBAL:
+		e->context.kind = RELAY_BUFFER_KIND_GLOBAL;
+		break;
+	case BUFFER_SERVER:
+		e->context.kind = RELAY_BUFFER_KIND_SERVER;
+		server_name = &e->context.server.server_name;
+		break;
+	case BUFFER_CHANNEL:
+	{
+		e->context.kind = RELAY_BUFFER_KIND_CHANNEL;
+		server_name = &e->context.channel.server_name;
 
-	e->items_len = p - e->items;
+		struct formatter f = formatter_make (ctx, buffer->server);
+		if (buffer->channel->topic)
+			formatter_add (&f, "#m", buffer->channel->topic);
+		e->context.channel.topic =
+			relay_items (ctx, f.items, &e->context.channel.topic_len);
+		formatter_free (&f);
+		break;
+	}
+	case BUFFER_PM:
+		e->context.kind = RELAY_BUFFER_KIND_PRIVATE_MESSAGE;
+		server_name = &e->context.private_message.server_name;
+		break;
+	}
+	if (server_name)
+		*server_name = str_from_cstr (buffer->server->name);
+}
+
+static void
+relay_prepare_buffer_stats (struct app_context *ctx, struct buffer *buffer)
+{
+	struct relay_event_message *m = relay_prepare (ctx);
+	struct relay_event_data_buffer_stats *e = &m->data.buffer_stats;
+	e->event = RELAY_EVENT_BUFFER_STATS;
+	e->buffer_name = str_from_cstr (buffer->name);
+	e->new_messages = MIN (UINT32_MAX,
+		buffer->new_messages_count - buffer->new_unimportant_count);
+	e->new_unimportant_messages = MIN (UINT32_MAX,
+		buffer->new_unimportant_count);
+	e->highlighted = buffer->highlighted;
+}
+
+static void
+relay_prepare_buffer_rename (struct app_context *ctx, struct buffer *buffer,
+	const char *new_name)
+{
+	struct relay_event_message *m = relay_prepare (ctx);
+	struct relay_event_data_buffer_rename *e = &m->data.buffer_rename;
+	e->event = RELAY_EVENT_BUFFER_RENAME;
+	e->buffer_name = str_from_cstr (buffer->name);
+	e->new = str_from_cstr (new_name);
+}
+
+static void
+relay_prepare_buffer_remove (struct app_context *ctx, struct buffer *buffer)
+{
+	struct relay_event_message *m = relay_prepare (ctx);
+	struct relay_event_data_buffer_remove *e = &m->data.buffer_remove;
+	e->event = RELAY_EVENT_BUFFER_REMOVE;
+	e->buffer_name = str_from_cstr (buffer->name);
+}
+
+static void
+relay_prepare_buffer_activate (struct app_context *ctx, struct buffer *buffer)
+{
+	struct relay_event_message *m = relay_prepare (ctx);
+	struct relay_event_data_buffer_activate *e = &m->data.buffer_activate;
+	e->event = RELAY_EVENT_BUFFER_ACTIVATE;
+	e->buffer_name = str_from_cstr (buffer->name);
 }
 
 static void
@@ -5291,6 +5310,20 @@ irc_make_channel (struct server *s, char *name)
 	return channel;
 }
 
+static void
+irc_channel_set_topic (struct channel *channel, const char *topic)
+{
+	cstr_set (&channel->topic, xstrdup (topic));
+
+	struct server *s = channel->s;
+	struct buffer *buffer = str_map_find (&s->irc_buffer_map, channel->name);
+	if (buffer)
+	{
+		relay_prepare_buffer_update (s->ctx, buffer);
+		relay_broadcast (s->ctx);
+	}
+}
+
 static struct channel_user *
 irc_channel_get_user (struct channel *channel, struct user *user)
 {
@@ -8074,7 +8107,7 @@ irc_handle_topic (struct server *s, const struct irc_message *msg)
 
 	// It would be weird for this to be false
 	if (channel)
-		cstr_set (&channel->topic, xstrdup (topic));
+		irc_channel_set_topic (channel, topic);
 
 	if (buffer)
 	{
@@ -8486,7 +8519,7 @@ irc_handle_rpl_topic (struct server *s, const struct irc_message *msg)
 	hard_assert (channel || !buffer);
 
 	if (channel)
-		cstr_set (&channel->topic, xstrdup (topic));
+		irc_channel_set_topic (channel, topic);
 
 	if (buffer)
 		log_server_status (s, buffer, "The topic is: #m", topic);
diff --git a/xP/public/xP.css b/xP/public/xP.css
index 5c02d7e..87cfec2 100644
--- a/xP/public/xP.css
+++ b/xP/public/xP.css
@@ -30,11 +30,16 @@ body {
 	display: flex;
 	justify-content: space-between;
 	align-items: baseline;
+	column-gap: .3em;
 
 	position: relative;
 	border-top: 3px solid #ccc;
 	border-bottom: 2px solid #888;
 }
+.title {
+	/* To approximate right-aligned space-between. */
+	flex-direction: row-reverse;
+}
 .title:before, .status:before {
 	content: " ";
 	position: absolute;
@@ -57,7 +62,7 @@ body {
 .toolbar {
 	display: flex;
 	align-items: baseline;
-	gap: .3em;
+	column-gap: .3em;
 }
 button {
 	font: inherit;
@@ -129,11 +134,13 @@ button:hover:active {
 	overflow-y: auto;
 }
 .log, .content {
-	padding: .1em .3em;
 	/* Note: https://bugs.chromium.org/p/chromium/issues/detail?id=1261435 */
 	white-space: break-spaces;
 	overflow-wrap: break-word;
 }
+.log, .buffer .content {
+	padding: .1em .3em;
+}
 
 .leaked {
 	opacity: 50%;
diff --git a/xP/public/xP.js b/xP/public/xP.js
index 8820251..c8ceed0 100644
--- a/xP/public/xP.js
+++ b/xP/public/xP.js
@@ -254,12 +254,58 @@ rpc.addEventListener('event', event => {
 	}
 })
 
-rpcEventHandlers['Ping'] = e => {
+rpcEventHandlers.set(Relay.Event.Ping, e => {
 	rpc.send({command: 'PingResponse', eventSeq: e.eventSeq})
-}
+})
 
 // ~~~ Buffer events ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+rpcEventHandlers.set(Relay.Event.BufferLine, e => {
+	let b = buffers.get(e.bufferName), line = {...e}
+	delete line.event
+	delete line.eventSeq
+	delete line.leakToActive
+	if (b === undefined)
+		return
+
+	// Initial sync: skip all other processing, let highlights be.
+	if (bufferCurrent === undefined) {
+		b.lines.push(line)
+		return
+	}
+
+	let visible = document.visibilityState !== 'hidden' &&
+		bufferLog === undefined &&
+		bufferAutoscroll &&
+		(e.bufferName == bufferCurrent || e.leakToActive)
+	b.lines.push({...line})
+	if (!(visible || e.leakToActive) ||
+			b.newMessages || b.newUnimportantMessages) {
+		if (line.isUnimportant)
+			b.newUnimportantMessages++
+		else
+			b.newMessages++
+	}
+
+	if (e.leakToActive) {
+		let bc = buffers.get(bufferCurrent)
+		bc.lines.push({...line, leaked: true})
+		if (!visible || bc.newMessages || bc.newUnimportantMessages) {
+			if (line.isUnimportant)
+				bc.newUnimportantMessages++
+			else
+				bc.newMessages++
+		}
+	}
+
+	if (line.isHighlight || (!visible && !line.isUnimportant &&
+			b.kind === Relay.BufferKind.PrivateMessage)) {
+		beep()
+		if (!visible)
+			b.highlighted = true
+	}
+})
+
 rpcEventHandlers.set(Relay.Event.BufferUpdate, e => {
 	let b = buffers.get(e.bufferName)
 	if (b === undefined) {
@@ -274,6 +320,7 @@ rpcEventHandlers.set(Relay.Event.BufferUpdate, e => {
 	b.hideUnimportant = e.hideUnimportant
 	b.kind = e.context.kind
 	b.server = servers.get(e.context.serverName)
+	b.topic = e.context.topic
 })
 
 rpcEventHandlers.set(Relay.Event.BufferStats, e => {
@@ -332,52 +379,6 @@ rpcEventHandlers.set(Relay.Event.BufferActivate, e => {
 	}
 })
 
-rpcEventHandlers.set(Relay.Event.BufferLine, e => {
-	let b = buffers.get(e.bufferName), line = {...e}
-	delete line.event
-	delete line.eventSeq
-	delete line.leakToActive
-	if (b === undefined)
-		return
-
-	// Initial sync: skip all other processing, let highlights be.
-	if (bufferCurrent === undefined) {
-		b.lines.push(line)
-		return
-	}
-
-	let visible = document.visibilityState !== 'hidden' &&
-		bufferLog === undefined &&
-		bufferAutoscroll &&
-		(e.bufferName == bufferCurrent || e.leakToActive)
-	b.lines.push({...line})
-	if (!(visible || e.leakToActive) ||
-			b.newMessages || b.newUnimportantMessages) {
-		if (line.isUnimportant)
-			b.newUnimportantMessages++
-		else
-			b.newMessages++
-	}
-
-	if (e.leakToActive) {
-		let bc = buffers.get(bufferCurrent)
-		bc.lines.push({...line, leaked: true})
-		if (!visible || bc.newMessages || bc.newUnimportantMessages) {
-			if (line.isUnimportant)
-				bc.newUnimportantMessages++
-			else
-				bc.newMessages++
-		}
-	}
-
-	if (line.isHighlight || (!visible && !line.isUnimportant &&
-			b.kind === Relay.BufferKind.PrivateMessage)) {
-		beep()
-		if (!visible)
-			b.highlighted = true
-	}
-})
-
 rpcEventHandlers.set(Relay.Event.BufferClear, e => {
 	let b = buffers.get(e.bufferName)
 	if (b !== undefined)
@@ -548,6 +549,14 @@ let Content = {
 	},
 }
 
+let Topic = {
+	view: vnode => {
+		let b = buffers.get(bufferCurrent)
+		if (b !== undefined && b.topic !== undefined)
+			return m(Content, {}, {items: b.topic})
+	},
+}
+
 let Buffer = {
 	controller: new AbortController(),
 
@@ -945,7 +954,7 @@ let Main = {
 
 		return m('.xP', {}, [
 			overlay,
-			m('.title', {}, `xP`),
+			m('.title', {}, [m('b', {}, `xP`), m(Topic)]),
 			m('.middle', {}, [m(BufferList), m(BufferContainer)]),
 			m(Status),
 			m('.input', {}, [m(Prompt), m(Input)]),