From 68378cf8e5b79ede04f77857cc7ab322302c0db5 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 19 Nov 2021 16:42:28 +0400
Subject: [PATCH] Support reversed order in the playlist.

---
 .../media/player/media_player_instance.cpp    | 30 +++++++++++++------
 .../media/player/media_player_instance.h      |  4 +--
 .../media/player/media_player_widget.cpp      |  4 +--
 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/Telegram/SourceFiles/media/player/media_player_instance.cpp b/Telegram/SourceFiles/media/player/media_player_instance.cpp
index 617d4b189a..7bf1f1c39f 100644
--- a/Telegram/SourceFiles/media/player/media_player_instance.cpp
+++ b/Telegram/SourceFiles/media/player/media_player_instance.cpp
@@ -364,12 +364,13 @@ bool Instance::moveInPlaylist(
 	if (!data->playlistIndex) {
 		return false;
 	}
-	const auto newIndex = *data->playlistIndex + delta;
+	const auto newIndex = *data->playlistIndex
+		+ (data->order.current() == OrderMode::Reverse ? -delta : delta);
 	if (const auto item = itemByIndex(data, newIndex)) {
 		if (const auto media = item->media()) {
 			if (const auto document = media->document()) {
 				if (autonext) {
-					_switchToNextStream.fire({
+					_switchToNext.fire({
 						data->current,
 						item->fullId()
 					});
@@ -389,24 +390,35 @@ bool Instance::moveInPlaylist(
 bool Instance::previousAvailable(AudioMsgId::Type type) const {
 	const auto data = getData(type);
 	Assert(data != nullptr);
-	return data->playlistIndex
-		&& data->playlistSlice
-		&& (*data->playlistIndex > 0);
+
+	if (!data->playlistIndex || !data->playlistSlice) {
+		return false;
+	}
+	return (data->order.current() == OrderMode::Reverse)
+		? (*data->playlistIndex + 1 < data->playlistSlice->size())
+		: (*data->playlistIndex > 0);
 }
 
 bool Instance::nextAvailable(AudioMsgId::Type type) const {
 	const auto data = getData(type);
 	Assert(data != nullptr);
-	return data->playlistIndex
-		&& data->playlistSlice
-		&& (*data->playlistIndex + 1 < data->playlistSlice->size());
+
+	if (!data->playlistIndex || !data->playlistSlice) {
+		return false;
+	}
+	return (data->order.current() == OrderMode::Reverse)
+		? (*data->playlistIndex > 0)
+		: (*data->playlistIndex + 1 < data->playlistSlice->size());
 }
 
 rpl::producer<> Media::Player::Instance::playlistChanges(
 		AudioMsgId::Type type) const {
 	const auto data = getData(type);
 	Assert(data != nullptr);
-	return data->playlistChanges.events();
+
+	return rpl::merge(
+		data->playlistChanges.events(),
+		data->order.changes() | rpl::to_empty);
 }
 
 rpl::producer<> Media::Player::Instance::stops(AudioMsgId::Type type) const {
diff --git a/Telegram/SourceFiles/media/player/media_player_instance.h b/Telegram/SourceFiles/media/player/media_player_instance.h
index 9645c3ec50..185d80765c 100644
--- a/Telegram/SourceFiles/media/player/media_player_instance.h
+++ b/Telegram/SourceFiles/media/player/media_player_instance.h
@@ -189,7 +189,7 @@ public:
 	};
 
 	[[nodiscard]] rpl::producer<Switch> switchToNextEvents() const {
-		return _switchToNextStream.events();
+		return _switchToNext.events();
 	}
 	[[nodiscard]] rpl::producer<AudioMsgId::Type> tracksFinished() const {
 		return _tracksFinished.events();
@@ -322,7 +322,7 @@ private:
 	Data _voiceData;
 	bool _roundPlaying = false;
 
-	rpl::event_stream<Switch> _switchToNextStream;
+	rpl::event_stream<Switch> _switchToNext;
 	rpl::event_stream<AudioMsgId::Type> _tracksFinished;
 	rpl::event_stream<AudioMsgId::Type> _trackChanged;
 	rpl::event_stream<AudioMsgId::Type> _playerStopped;
diff --git a/Telegram/SourceFiles/media/player/media_player_widget.cpp b/Telegram/SourceFiles/media/player/media_player_widget.cpp
index c0c5836bcb..96f513df41 100644
--- a/Telegram/SourceFiles/media/player/media_player_widget.cpp
+++ b/Telegram/SourceFiles/media/player/media_player_widget.cpp
@@ -826,10 +826,10 @@ void Widget::handlePlaylistUpdate() {
 		createPrevNextButtons();
 		_previousTrack->setIconOverride(previousEnabled ? nullptr : &st::mediaPlayerPreviousDisabledIcon);
 		_previousTrack->setRippleColorOverride(previousEnabled ? nullptr : &st::mediaPlayerBg);
-		_previousTrack->setCursor(previousEnabled ? style::cur_pointer : style::cur_default);
+		_previousTrack->setPointerCursor(previousEnabled);
 		_nextTrack->setIconOverride(nextEnabled ? nullptr : &st::mediaPlayerNextDisabledIcon);
 		_nextTrack->setRippleColorOverride(nextEnabled ? nullptr : &st::mediaPlayerBg);
-		_nextTrack->setCursor(nextEnabled ? style::cur_pointer : style::cur_default);
+		_nextTrack->setPointerCursor(nextEnabled);
 	}
 }