Adjust outgoing bubble text and icon colors.

Telegram/SourceFiles/data/data_cloud_themes.cpp

@@ -421,8 +421,6 @@ void CloudThemes::parseChatThemes(const QVector<MTPChatTheme> &list) {
 				.light = CloudTheme::Parse(_session, data.vtheme(), true),
 				.dark = CloudTheme::Parse(_session, data.vdark_theme(), true),
 			});
-			AssertIsDebug();
-			std::swap(_chatThemes.back().light, _chatThemes.back().dark);
 		});
 	}
 }

Telegram/SourceFiles/history/history_widget.cpp

@@ -180,11 +180,6 @@ const auto kPsaAboutPrefix = "cloud_lng_about_psa_";
 
 } // namespace
 
-struct HistoryWidget::CustomStyles {
-	style::TwoIconButton historyToDown;
-	style::TwoIconButton historyUnreadMentions;
-};
-
 HistoryWidget::HistoryWidget(
 	QWidget *parent,
 	not_null<Window::SessionController*> controller)
@@ -192,17 +187,23 @@ HistoryWidget::HistoryWidget(
 	parent,
 	controller,
 	ActivePeerValue(controller))
-, _styles(MakeCustomStyles(controller))
 , _api(&controller->session().mtp())
 , _updateEditTimeLeftDisplay([=] { updateField(); })
 , _fieldBarCancel(this, st::historyReplyCancel)
 , _previewTimer([=] { requestPreview(); })
 , _previewState(Data::PreviewState::Allowed)
 , _topBar(this, controller)
-, _scroll(this, st::historyScroll, false)
+, _scroll(
+	this,
+	controller->chatStyle()->value(lifetime(), st::historyScroll),
+	false)
 , _updateHistoryItems([=] { updateHistoryItemsByTimer(); })
-, _historyDown(_scroll, _styles->historyToDown)
-, _unreadMentions(_scroll, _styles->historyUnreadMentions)
+, _historyDown(
+	_scroll,
+	controller->chatStyle()->value(lifetime(), st::historyToDown))
+, _unreadMentions(
+	_scroll,
+	controller->chatStyle()->value(lifetime(), st::historyUnreadMentions))
 , _fieldAutocomplete(this, controller)
 , _supportAutocomplete(session().supportMode()
 	? object_ptr<Support::Autocomplete>(this, &session())
@@ -323,7 +324,7 @@ HistoryWidget::HistoryWidget(
 	_scroll->hide();
 	_kbScroll->hide();
 
-	style::PaletteChanged(
+	controller->chatStyle()->paletteChanged(
 	) | rpl::start_with_next([=] {
 		_scroll->updateBars();
 	}, lifetime());
@@ -3991,17 +3992,6 @@ bool HistoryWidget::kbWasHidden() const {
 	return _history && (_keyboard->forMsgId() == FullMsgId(_history->channelId(), _history->lastKeyboardHiddenId));
 }
 
-auto HistoryWidget::MakeCustomStyles(
-	not_null<Window::SessionController*> controller)
--> std::unique_ptr<CustomStyles> {
-	const auto st = controller->chatStyle();
-
-	auto result = std::make_unique<CustomStyles>();
-	result->historyToDown = st->value(st::historyToDown);
-	result->historyUnreadMentions = st->value(st::historyUnreadMentions);
-	return result;
-}
-
 void HistoryWidget::toggleKeyboard(bool manual) {
 	auto fieldEnabled = canWriteMessage() && !_a_show.animating();
 	if (_kbShown || _kbReplyTo) {

Telegram/SourceFiles/history/history_widget.h

@@ -300,7 +300,6 @@ protected:
 private:
 	using TabbedPanel = ChatHelpers::TabbedPanel;
 	using TabbedSelector = ChatHelpers::TabbedSelector;
-	struct CustomStyles;
 	enum ScrollChangeType {
 		ScrollChangeNone,
 
@@ -604,11 +603,6 @@ private:
 
 	bool kbWasHidden() const;
 
-	[[nodiscard]] static std::unique_ptr<CustomStyles> MakeCustomStyles(
-		not_null<Window::SessionController*> controller);
-
-	const std::unique_ptr<CustomStyles> _styles;
-
 	MTP::Sender _api;
 	MsgId _replyToId = 0;
 	Ui::Text::String _replyToName;

Telegram/SourceFiles/history/view/history_view_pinned_section.cpp

@@ -17,6 +17,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/widgets/shadow.h"
 #include "ui/layers/generic_box.h"
 #include "ui/item_text_options.h"
+#include "ui/chat/chat_style.h"
 #include "ui/toast/toast.h"
 #include "ui/text/format_values.h"
 #include "ui/text/text_utilities.h"
@@ -95,12 +96,22 @@ PinnedWidget::PinnedWidget(
 , _migratedPeer(_history->peer->migrateFrom())
 , _topBar(this, controller)
 , _topBarShadow(this)
-, _scroll(std::make_unique<Ui::ScrollArea>(this, st::historyScroll, false))
+, _scroll(std::make_unique<Ui::ScrollArea>(
+	this,
+	controller->chatStyle()->value(lifetime(), st::historyScroll),
+	false))
 , _clearButton(std::make_unique<Ui::FlatButton>(
 	this,
 	QString(),
 	st::historyComposeButton))
-, _scrollDown(_scroll.get(), st::historyToDown) {
+, _scrollDown(
+		_scroll.get(),
+		controller->chatStyle()->value(lifetime(), st::historyToDown)) {
+	controller->chatStyle()->paletteChanged(
+	) | rpl::start_with_next([=] {
+		_scroll->updateBars();
+	}, _scroll->lifetime());
+
 	Window::ChatThemeValueFromPeer(
 		controller,
 		history->peer

Telegram/SourceFiles/history/view/history_view_replies_section.cpp

@@ -18,6 +18,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "history/history_item.h"
 #include "chat_helpers/send_context_menu.h" // SendMenu::Type.
 #include "ui/chat/pinned_bar.h"
+#include "ui/chat/chat_style.h"
 #include "ui/widgets/scroll_area.h"
 #include "ui/widgets/shadow.h"
 #include "ui/wrap/slide_wrap.h"
@@ -162,9 +163,19 @@ RepliesWidget::RepliesWidget(
 	controller,
 	ComposeControls::Mode::Normal,
 	SendMenu::Type::SilentOnly))
-, _scroll(std::make_unique<Ui::ScrollArea>(this, st::historyScroll, false))
-, _scrollDown(_scroll.get(), st::historyToDown)
+, _scroll(std::make_unique<Ui::ScrollArea>(
+	this,
+	controller->chatStyle()->value(lifetime(), st::historyScroll),
+	false))
+, _scrollDown(
+	_scroll.get(),
+	controller->chatStyle()->value(lifetime(), st::historyToDown))
 , _readRequestTimer([=] { sendReadTillRequest(); }) {
+	controller->chatStyle()->paletteChanged(
+	) | rpl::start_with_next([=] {
+		_scroll->updateBars();
+	}, _scroll->lifetime());
+
 	Window::ChatThemeValueFromPeer(
 		controller,
 		history->peer

Telegram/SourceFiles/history/view/history_view_scheduled_section.cpp

@@ -21,6 +21,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/layers/generic_box.h"
 #include "ui/item_text_options.h"
 #include "ui/toast/toast.h"
+#include "ui/chat/chat_style.h"
 #include "ui/chat/attach/attach_prepare.h"
 #include "ui/chat/attach/attach_send_files_way.h"
 #include "ui/special_buttons.h"
@@ -91,7 +92,10 @@ ScheduledWidget::ScheduledWidget(
 	not_null<History*> history)
 : Window::SectionWidget(parent, controller, history->peer)
 , _history(history)
-, _scroll(this, st::historyScroll, false)
+, _scroll(
+	this,
+	controller->chatStyle()->value(lifetime(), st::historyScroll),
+	false)
 , _topBar(this, controller)
 , _topBarShadow(this)
 , _composeControls(std::make_unique<ComposeControls>(
@@ -99,7 +103,14 @@ ScheduledWidget::ScheduledWidget(
 	controller,
 	ComposeControls::Mode::Scheduled,
 	SendMenu::Type::Disabled))
-, _scrollDown(_scroll, st::historyToDown) {
+, _scrollDown(
+		_scroll,
+		controller->chatStyle()->value(lifetime(), st::historyToDown)) {
+	controller->chatStyle()->paletteChanged(
+	) | rpl::start_with_next([=] {
+		_scroll->updateBars();
+	}, _scroll->lifetime());
+
 	Window::ChatThemeValueFromPeer(
 		controller,
 		history->peer

Telegram/SourceFiles/ui/chat/chat_style.cpp

@@ -472,6 +472,8 @@ void ChatStyle::assignPalette(not_null<const style::palette*> palette) {
 	_msgBotKbOverBgAddCorners = {};
 	_msgSelectOverlayCornersSmall = {};
 	_msgSelectOverlayCornersLarge = {};
+
+	_paletteChanged.fire({});
 }
 
 const CornersPixmaps &ChatStyle::serviceBgCornersNormal() const {
@@ -616,6 +618,17 @@ void ChatStyle::make(
 	make(my.ripple.color, original.ripple.color);
 }
 
+void ChatStyle::make(
+		style::ScrollArea &my,
+		const style::ScrollArea &original) const {
+	my = original;
+	make(my.bg, original.bg);
+	make(my.bgOver, original.bgOver);
+	make(my.barBg, original.barBg);
+	make(my.barBgOver, original.barBgOver);
+	make(my.shColor, original.shColor);
+}
+
 template <typename Type>
 void ChatStyle::make(
 		Type MessageStyle::*my,

Telegram/SourceFiles/ui/chat/chat_style.h

@@ -15,6 +15,7 @@ enum class ImageRoundRadius;
 
 namespace style {
 struct TwoIconButton;
+struct ScrollArea;
 } // namespace style
 
 namespace Ui {
@@ -138,6 +139,10 @@ public:
 
 	void apply(not_null<ChatTheme*> theme);
 
+	[[nodiscard]] rpl::producer<> paletteChanged() const {
+		return _paletteChanged.events();
+	}
+
 	template <typename Type>
 	[[nodiscard]] Type value(const Type &original) const {
 		auto my = Type();
@@ -145,6 +150,15 @@ public:
 		return my;
 	}
 
+	template <typename Type>
+	[[nodiscard]] const Type &value(
+			rpl::lifetime &parentLifetime,
+			const Type &original) const {
+		const auto my = parentLifetime.make_state<Type>();
+		make(*my, original);
+		return *my;
+	}
+
 	[[nodiscard]] const CornersPixmaps &serviceBgCornersNormal() const;
 	[[nodiscard]] const CornersPixmaps &serviceBgCornersInverted() const;
 
@@ -241,6 +255,9 @@ private:
 	void make(
 		style::TwoIconButton &my,
 		const style::TwoIconButton &original) const;
+	void make(
+		style::ScrollArea &my,
+		const style::ScrollArea &original) const;
 
 	[[nodiscard]] MessageStyle &messageStyleRaw(
 		bool outbg,
@@ -303,6 +320,8 @@ private:
 	style::icon _historyPollChoiceRight = { Qt::Uninitialized };
 	style::icon _historyPollChoiceWrong = { Qt::Uninitialized };
 
+	rpl::event_stream<> _paletteChanged;
+
 	rpl::lifetime _defaultPaletteChangeLifetime;
 
 };

Telegram/SourceFiles/ui/chat/chat_theme.cpp

@@ -25,6 +25,8 @@ constexpr auto kCacheBackgroundFastTimeout = crl::time(200);
 constexpr auto kBackgroundFadeDuration = crl::time(200);
 constexpr auto kMinimumTiledSize = 512;
 constexpr auto kMaxSize = 2960;
+constexpr auto kMaxContrastValue = 21.;
+constexpr auto kMinAcceptableContrast = 1.14;// 4.5;
 
 [[nodiscard]] QColor DefaultBackgroundColor() {
 	return QColor(213, 223, 233);
@@ -133,6 +135,25 @@ constexpr auto kMaxSize = 2960;
 	return Images::GenerateLinearGradient(QSize(kSize, kSize), data.colors);
 }
 
+// https://stackoverflow.com/a/9733420
+[[nodiscard]] float64 CountContrast(const QColor &a, const QColor &b) {
+	const auto luminance = [](const QColor &c) {
+		const auto map = [](double value) {
+			return (value <= 0.03928)
+				? (value / 12.92)
+				: std::pow((value + 0.055) / 1.055, 2.4);
+		};
+		return map(c.redF()) * 0.2126
+			+ map(c.greenF()) * 0.7152
+			+ map(c.blueF()) * 0.0722;
+	};
+	const auto luminance1 = luminance(a);
+	const auto luminance2 = luminance(b);
+	const auto brightest = std::max(luminance1, luminance2);
+	const auto darkest = std::min(luminance1, luminance2);
+	return (brightest + 0.05) / (darkest + 0.05);
+}
+
 } // namespace
 
 bool operator==(const ChatThemeBackground &a, const ChatThemeBackground &b) {
@@ -201,7 +222,7 @@ void ChatTheme::adjustPalette(const ChatThemeDescriptor &descriptor) {
 	}
 	const auto bubblesAccent = descriptor.bubblesData.accent
 		? descriptor.bubblesData.accent
-		: !descriptor.bubblesData.colors.empty()
+		: (!descriptor.bubblesData.colors.empty())
 		? ThemeAdjustedColor(
 			p.msgOutReplyBarColor()->c,
 			CountAverageColor(descriptor.bubblesData.colors))
@@ -230,6 +251,55 @@ void ChatTheme::adjustPalette(const ChatThemeDescriptor &descriptor) {
 		adjust(p.historyCallArrowOutFg(), by);
 		adjust(p.historyFileOutIconFg(), by);
 	}
+	auto outBgColors = descriptor.bubblesData.colors;
+	if (outBgColors.empty()) {
+		outBgColors.push_back(p.msgOutBg()->c);
+	}
+	const auto colors = {
+		p.msgOutServiceFg(),
+		p.msgOutDateFg(),
+		p.msgFileThumbLinkOutFg(),
+		p.msgFileOutBg(),
+		p.msgOutReplyBarColor(),
+		p.msgWaveformOutActive(),
+		p.historyTextOutFg(),
+		p.mediaOutFg(),
+		p.historyLinkOutFg(),
+		p.msgOutMonoFg(),
+		p.historyOutIconFg(),
+		p.historyCallArrowOutFg(),
+	};
+	const auto minimal = [&](const QColor &with) {
+		auto result = kMaxContrastValue;
+		for (const auto &color : colors) {
+			result = std::min(result, CountContrast(color->c, with));
+		}
+		return result;
+	};
+	const auto withBg = [&](auto &&count) {
+		auto result = kMaxContrastValue;
+		for (const auto &bg : outBgColors) {
+			result = std::min(result, count(bg));
+		}
+		return result;
+	};
+	const auto singleWithBg = [&](const QColor &c) {
+		return withBg([&](const QColor &with) {
+			return CountContrast(c, with);
+		});
+	};
+	if (withBg(minimal) < kMinAcceptableContrast) {
+		const auto white = QColor(255, 255, 255);
+		const auto black = QColor(0, 0, 0);
+		// This one always gives black :)
+		//const auto now = (singleWithBg(white) >= singleWithBg(black))
+		//	? white
+		//	: black;
+		const auto now = descriptor.basedOnDark ? white : black;
+		for (const auto &color : colors) {
+			set(color, now);
+		}
+	}
 }
 
 void ChatTheme::set(const style::color &my, const QColor &color) {

Telegram/SourceFiles/ui/chat/chat_theme.h

@@ -101,6 +101,7 @@ struct ChatThemeDescriptor {
 	Fn<void(style::palette&)> preparePalette;
 	ChatThemeBackgroundData backgroundData;
 	ChatThemeBubblesData bubblesData;
+	bool basedOnDark = false;
 };
 
 class ChatTheme final : public base::has_weak_ptr {

Telegram/SourceFiles/window/window_session_controller.cpp

@@ -1452,6 +1452,7 @@ void SessionController::cacheChatTheme(const Data::CloudTheme &data) {
 			data.accentColor),
 		.backgroundData = backgroundData(theme),
 		.bubblesData = PrepareBubblesData(data),
+		.basedOnDark = data.basedOnDark,
 	};
 	crl::async([
 		this,