From c737e2f91bcc8f9c8c320e01bd3ae15f45ac282a Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 3 Feb 2023 20:48:12 +0400
Subject: [PATCH] Track window activation history.

---
 Telegram/SourceFiles/core/application.cpp | 54 ++++++++++++++++++-----
 Telegram/SourceFiles/core/application.h   |  1 +
 Telegram/SourceFiles/mainwidget.cpp       |  2 +
 3 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/Telegram/SourceFiles/core/application.cpp b/Telegram/SourceFiles/core/application.cpp
index f771af00f..5a33ab1d0 100644
--- a/Telegram/SourceFiles/core/application.cpp
+++ b/Telegram/SourceFiles/core/application.cpp
@@ -191,6 +191,7 @@ Application::~Application() {
 		Local::writeSettings();
 	}
 
+	_windowStack.clear();
 	setLastActiveWindow(nullptr);
 	_windowInSettings = _lastActivePrimaryWindow = nullptr;
 	_closingAsyncWindows.clear();
@@ -514,18 +515,26 @@ void Application::startTray() {
 }
 
 void Application::activate() {
-	const auto last = _lastActiveWindow;
-	const auto primary = _lastActivePrimaryWindow;
-	enumerateWindows([&](not_null<Window::Controller*> w) {
-		if (w != last && w != primary) {
-			w->widget()->showFromTray();
+	for (const auto &window : _windowStack) {
+		if (window == _lastActiveWindow) {
+			break;
+		}
+		const auto widget = window->widget();
+		const auto wasHidden = !widget->isVisible();
+		const auto state = widget->windowState();
+		if (state & Qt::WindowMinimized) {
+			widget->setWindowState(state & ~Qt::WindowMinimized);
+		}
+		widget->setVisible(true);
+		widget->activateWindow();
+		if (wasHidden) {
+			if (const auto session = window->sessionController()) {
+				session->content()->windowShown();
+			}
 		}
-	});
-	if (primary) {
-		primary->widget()->showFromTray();
 	}
-	if (last && last != primary) {
-		last->widget()->showFromTray();
+	if (_lastActiveWindow) {
+		_lastActiveWindow->widget()->showFromTray();
 	}
 }
 
@@ -1312,6 +1321,14 @@ void Application::setLastActiveWindow(Window::Controller *window) {
 		}
 	}
 	_lastActiveWindow = window;
+	if (window) {
+		const auto i = ranges::find(_windowStack, not_null(window));
+		if (i == end(_windowStack)) {
+			_windowStack.push_back(window);
+		} else if (i + 1 != end(_windowStack)) {
+			std::rotate(i, i + 1, end(_windowStack));
+		}
+	}
 	if (!window) {
 		_floatPlayers = nullptr;
 		return;
@@ -1333,17 +1350,32 @@ void Application::setLastActiveWindow(Window::Controller *window) {
 }
 
 void Application::closeWindow(not_null<Window::Controller*> window) {
-	const auto next = (_primaryWindows.front().second.get() != window)
+	const auto stackIt = ranges::find(_windowStack, window);
+	const auto nextFromStack = _windowStack.empty()
+		? nullptr
+		: (stackIt == end(_windowStack) || stackIt + 1 != end(_windowStack))
+		? _windowStack.back().get()
+		: (_windowStack.size() > 1)
+		? (stackIt - 1)->get()
+		: nullptr;
+	const auto next = nextFromStack
+		? nextFromStack
+		: (_primaryWindows.front().second.get() != window)
 		? _primaryWindows.front().second.get()
 		: (_primaryWindows.back().second.get() != window)
 		? _primaryWindows.back().second.get()
 		: nullptr;
+	Assert(next != window);
+
 	if (_lastActivePrimaryWindow == window) {
 		_lastActivePrimaryWindow = next;
 	}
 	if (_windowInSettings == window) {
 		_windowInSettings = next;
 	}
+	if (stackIt != end(_windowStack)) {
+		_windowStack.erase(stackIt);
+	}
 	if (_lastActiveWindow == window) {
 		setLastActiveWindow(next);
 		if (_lastActiveWindow) {
diff --git a/Telegram/SourceFiles/core/application.h b/Telegram/SourceFiles/core/application.h
index 462e4370b..8671b89d7 100644
--- a/Telegram/SourceFiles/core/application.h
+++ b/Telegram/SourceFiles/core/application.h
@@ -397,6 +397,7 @@ private:
 	base::flat_map<
 		not_null<History*>,
 		std::unique_ptr<Window::Controller>> _secondaryWindows;
+	std::vector<not_null<Window::Controller*>> _windowStack;
 	Window::Controller *_lastActiveWindow = nullptr;
 	Window::Controller *_lastActivePrimaryWindow = nullptr;
 	Window::Controller *_windowInSettings = nullptr;
diff --git a/Telegram/SourceFiles/mainwidget.cpp b/Telegram/SourceFiles/mainwidget.cpp
index e6f4ba5c6..d787bc21f 100644
--- a/Telegram/SourceFiles/mainwidget.cpp
+++ b/Telegram/SourceFiles/mainwidget.cpp
@@ -1287,6 +1287,8 @@ bool MainWidget::showHistoryInDifferentWindow(
 			return true;
 		}
 		return false;
+	} else if (!peerId) {
+		return true;
 	} else if (singlePeer()->id == peerId) {
 		return false;
 	}