From ec9fa00f4625967d99dee7c3eced665135e18a82 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Mon, 31 May 2021 00:05:01 +0400
Subject: [PATCH] Bring second large peer video to the top.

---
 .../calls/group/calls_group_viewport.cpp      | 62 ++++++++++++++-----
 .../calls/group/calls_group_viewport.h        |  2 +
 2 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/Telegram/SourceFiles/calls/group/calls_group_viewport.cpp b/Telegram/SourceFiles/calls/group/calls_group_viewport.cpp
index 1fea883da..0d2395d48 100644
--- a/Telegram/SourceFiles/calls/group/calls_group_viewport.cpp
+++ b/Telegram/SourceFiles/calls/group/calls_group_viewport.cpp
@@ -415,24 +415,12 @@ void Viewport::updateTilesGeometryWide(int outerWidth, int outerHeight) {
 }
 
 void Viewport::updateTilesGeometryNarrow(int outerWidth) {
-	const auto y = -_scrollTop;
-
 	if (outerWidth <= st::groupCallNarrowMembersWidth) {
-		auto top = 0;
-		for (const auto &tile : _tiles) {
-			const auto video = tile.get();
-			const auto size = video->trackSize();
-			const auto shown = !size.isEmpty() && _large && video != _large;
-			const auto height = shown
-				? st::groupCallNarrowVideoHeight
-				: 0;
-			video->setGeometry({ 0, y + top, outerWidth, height });
-			top += height ? (height + st::groupCallVideoSmallSkip) : 0;
-		}
-		_fullHeight = top;
+		updateTilesGeometryColumn(outerWidth);
 		return;
 	}
 
+	const auto y = -_scrollTop;
 	auto sizes = base::flat_map<not_null<VideoTile*>, QSize>();
 	sizes.reserve(_tiles.size());
 	for (const auto &tile : _tiles) {
@@ -493,7 +481,53 @@ void Viewport::updateTilesGeometryNarrow(int outerWidth) {
 		}
 	}
 	_fullHeight = rows * (min + skip);
+}
 
+void Viewport::updateTilesGeometryColumn(int outerWidth) {
+	const auto y = -_scrollTop;
+	auto top = 0;
+	const auto layoutNext = [&](not_null<VideoTile*> tile) {
+		const auto size = tile->trackSize();
+		const auto shown = !size.isEmpty() && _large && tile != _large;
+		const auto height = shown
+			? st::groupCallNarrowVideoHeight
+			: 0;
+		tile->setGeometry({ 0, y + top, outerWidth, height });
+		top += height ? (height + st::groupCallVideoSmallSkip) : 0;
+	};
+	const auto topPeer = _large ? _large->row()->peer().get() : nullptr;
+	const auto reorderNeeded = [&] {
+		if (!_large) {
+			return false;
+		}
+		for (const auto &tile : _tiles) {
+			if (tile.get() != _large && tile->row()->peer() == topPeer) {
+				return (tile.get() != _tiles.front().get())
+					&& !tile->trackSize().isEmpty();
+			}
+		}
+		return false;
+	}();
+	if (reorderNeeded) {
+		_tilesForOrder.clear();
+		_tilesForOrder.reserve(_tiles.size());
+		for (const auto &tile : _tiles) {
+			_tilesForOrder.push_back(tile.get());
+		}
+		ranges::stable_partition(
+			_tilesForOrder,
+			[&](not_null<VideoTile*> tile) {
+				return (tile->row()->peer() == topPeer);
+			});
+		for (const auto &tile : _tilesForOrder) {
+			layoutNext(tile);
+		}
+	} else {
+		for (const auto &tile : _tiles) {
+			layoutNext(tile.get());
+		}
+	}
+	_fullHeight = top;
 }
 
 void Viewport::setTileGeometry(not_null<VideoTile*> tile, QRect geometry) {
diff --git a/Telegram/SourceFiles/calls/group/calls_group_viewport.h b/Telegram/SourceFiles/calls/group/calls_group_viewport.h
index 6361bf013..d4250a500 100644
--- a/Telegram/SourceFiles/calls/group/calls_group_viewport.h
+++ b/Telegram/SourceFiles/calls/group/calls_group_viewport.h
@@ -117,6 +117,7 @@ private:
 	void updateTilesGeometry(int outerWidth);
 	void updateTilesGeometryWide(int outerWidth, int outerHeight);
 	void updateTilesGeometryNarrow(int outerWidth);
+	void updateTilesGeometryColumn(int outerWidth);
 	void setTileGeometry(not_null<VideoTile*> tile, QRect geometry);
 	void refreshHasTwoOrMore();
 	void updateTopControlsVisibility();
@@ -138,6 +139,7 @@ private:
 	bool _geometryStaleAfterModeChange = false;
 	const std::unique_ptr<Ui::RpWidgetWrap> _content;
 	std::vector<std::unique_ptr<VideoTile>> _tiles;
+	std::vector<not_null<VideoTile*>> _tilesForOrder;
 	rpl::variable<int> _fullHeight = 0;
 	bool _hasTwoOrMore = false;
 	int _scrollTop = 0;