Cross-fade login QR.

Telegram/SourceFiles/intro/intro.style

@@ -174,6 +174,7 @@ introQrTitle: FlatLabel(defaultFlatLabel) {
 		linkFontOver: font(20px semibold underline);
 	}
 }
+introQrErrorTop: 336px;
 introQrTitleTop: 196px;
 introQrStep: defaultFlatLabel;
 introQrStepsTop: 232px;

Telegram/SourceFiles/intro/intro_qr.cpp

@@ -56,7 +56,14 @@ namespace {
 	if (max > 0 && data.size * pixel > max) {
 		pixel = std::max(max / data.size, 1);
 	}
-	return TelegramQrExact(data, pixel * style::DevicePixelRatio());
+	const auto qr = TelegramQrExact(data, pixel * style::DevicePixelRatio());
+	auto result = QImage(qr.size(), QImage::Format_ARGB32_Premultiplied);
+	result.fill(st::windowBg->c);
+	{
+		auto p = QPainter(&result);
+		p.drawImage(QRect(QPoint(), qr.size()), qr);
+	}
+	return result;
 }
 
 [[nodiscard]] not_null<Ui::RpWidget*> PrepareQrWidget(
@@ -67,8 +74,10 @@ namespace {
 		: waiting(callback, st::defaultInfiniteRadialAnimation) {
 		}
 
+		QImage previous;
 		QImage qr;
 		QImage center;
+		Ui::Animations::Simple shown;
 		Ui::InfiniteRadialAnimation waiting;
 	};
 	auto qrs = std::move(
@@ -92,9 +101,15 @@ namespace {
 	) | rpl::map([](const Qr::Data &code, const auto &) {
 		return TelegramQr(code, st::introQrPixel, st::introQrMaxSize);
 	}) | rpl::start_with_next([=](QImage &&image) {
+		state->previous = std::move(state->qr);
 		state->qr = std::move(image);
 		state->waiting.stop();
-		result->update();
+		state->shown.stop();
+		state->shown.start(
+			[=] { result->update(); },
+			0.,
+			1.,
+			st::fadeWrapDuration);
 	}, result->lifetime());
 	std::move(
 		palettes
@@ -106,7 +121,24 @@ namespace {
 	result->paintRequest(
 	) | rpl::start_with_next([=](QRect clip) {
 		auto p = QPainter(result);
-		auto rect = QRect(
+		const auto shown = state->qr.isNull() ? 0. : state->shown.value(1.);
+		if (!state->qr.isNull()) {
+			const auto size = state->qr.size() / cIntRetinaFactor();
+			const auto qr = QRect(
+				(result->width() - size.width()) / 2,
+				(result->height() - size.height()) / 2,
+				size.width(),
+				size.height());
+			if (shown == 1.) {
+				state->previous = QImage();
+			} else if (!state->previous.isNull()) {
+				p.drawImage(qr, state->previous);
+			}
+			p.setOpacity(shown);
+			p.drawImage(qr, state->qr);
+			p.setOpacity(1.);
+		}
+		const auto rect = QRect(
 			(result->width() - st::introQrCenterSize) / 2,
 			(result->height() - st::introQrCenterSize) / 2,
 			st::introQrCenterSize,
@@ -119,7 +151,7 @@ namespace {
 			auto pen = st::activeButtonBg->p;
 			pen.setWidth(line);
 			pen.setCapStyle(Qt::RoundCap);
-			p.setOpacity(radial.shown);
+			p.setOpacity(radial.shown * (1. - shown));
 			p.setPen(pen);
 			p.drawArc(
 				rect.marginsAdded({ line, line, line, line }),
@@ -127,16 +159,6 @@ namespace {
 				radial.arcLength);
 			p.setOpacity(1.);
 		}
-		if (!state->qr.isNull()) {
-			const auto size = state->qr.size() / cIntRetinaFactor();
-			p.drawImage(
-				QRect(
-					(result->width() - size.width()) / 2,
-					(result->height() - size.height()) / 2,
-					size.width(),
-					size.height()),
-				state->qr);
-		}
 	}, result->lifetime());
 	return result;
 }
@@ -148,7 +170,7 @@ QrWidget::QrWidget(
 	not_null<Main::Account*> account,
 	not_null<Data*> data)
 : Step(parent, account, data)
-	, _refreshTimer([=] { refreshCode(); }) {
+, _refreshTimer([=] { refreshCode(); }) {
 	setTitleText(rpl::single(QString()));
 	setDescriptionText(rpl::single(QString()));
 	setErrorCentered(true);
@@ -163,6 +185,10 @@ QrWidget::QrWidget(
 	refreshCode();
 }
 
+int QrWidget::errorTop() const {
+	return contentTop() + st::introQrErrorTop;
+}
+
 void QrWidget::checkForTokenUpdate(const MTPUpdates &updates) {
 	updates.match([&](const MTPDupdateShort &data) {
 		checkForTokenUpdate(data.vupdate());
@@ -256,9 +282,7 @@ void QrWidget::setupControls() {
 			contentTop() + st::introQrSkipTop);
 	}, skip->lifetime());
 
-	skip->setClickedCallback([=] {
+	skip->setClickedCallback([=] { submit(); });
-		goNext<PhoneWidget>();
-	});
 }
 
 void QrWidget::refreshCode() {

Telegram/SourceFiles/intro/intro_qr.h

@@ -40,6 +40,8 @@ public:
 	}
 
 private:
+	int errorTop() const override;
+
 	void setupControls();
 	void refreshCode();
 	void checkForTokenUpdate(const MTPUpdates &updates);

Telegram/SourceFiles/intro/intro_step.cpp

@@ -179,11 +179,14 @@ void Step::updateLabelsPosition() {
 		}
 		Ui::SendPendingMoveResizeEvents(_error->entity());
 		auto errorLeft = _errorCentered ? 0 : (contentLeft() + st::buttonRadius);
-		auto errorTop = contentTop() + (_errorBelowLink ? st::introErrorBelowLinkTop : st::introErrorTop);
+		_error->moveToLeft(errorLeft, errorTop());
-		_error->moveToLeft(errorLeft, errorTop);
 	}
 }
 
+int Step::errorTop() const {
+	return contentTop() + st::introErrorTop;
+}
+
 void Step::setTitleText(rpl::producer<QString> titleText) {
 	_titleText = std::move(titleText);
 }
@@ -364,13 +367,6 @@ void Step::setErrorCentered(bool centered) {
 	_error.destroy();
 }
 
-void Step::setErrorBelowLink(bool below) {
-	_errorBelowLink = below;
-	if (_error) {
-		updateLabelsPosition();
-	}
-}
-
 void Step::showError(rpl::producer<QString> text) {
 	_errorText = std::move(text);
 }

Telegram/SourceFiles/intro/intro_step.h

@@ -78,7 +78,6 @@ public:
 	[[nodiscard]] int contentTop() const;
 
 	void setErrorCentered(bool centered);
-	void setErrorBelowLink(bool below);
 	void showError(rpl::producer<QString> text);
 	void hideError() {
 		showError(rpl::single(QString()));
@@ -128,6 +127,8 @@ protected:
 		}
 	}
 
+	virtual int errorTop() const;
+
 private:
 	struct CoverAnimation {
 		CoverAnimation() = default;

Telegram/SourceFiles/intro/introcode.cpp

@@ -95,7 +95,6 @@ CodeWidget::CodeWidget(
 	_noTelegramCode->addClickHandler([=] { onNoTelegramCode(); });
 
 	_code->setDigitsCountMax(getData()->codeLength);
-	setErrorBelowLink(true);
 
 	setTitleText(rpl::single(App::formatPhone(getData()->phone)));
 	updateDescText();
@@ -107,6 +106,10 @@ void CodeWidget::refreshLang() {
 	updateControlsGeometry();
 }
 
+int CodeWidget::errorTop() const {
+	return contentTop() + st::introErrorBelowLinkTop;
+}
+
 void CodeWidget::updateDescText() {
 	const auto byTelegram = getData()->codeByTelegram;
 	setDescriptionText(

Telegram/SourceFiles/intro/introcode.h

@@ -69,6 +69,8 @@ private slots:
 	void onCheckRequest();
 
 private:
+	int errorTop() const override;
+
 	void updateCallText();
 	void refreshLang();
 	void updateControlsGeometry();

Telegram/SourceFiles/intro/intropwdcheck.cpp

@@ -50,7 +50,6 @@ PwdCheckWidget::PwdCheckWidget(
 
 	setTitleText(tr::lng_signin_title());
 	updateDescriptionText();
-	setErrorBelowLink(true);
 
 	if (_hint.isEmpty()) {
 		_pwdHint->hide();
@@ -79,6 +78,10 @@ void PwdCheckWidget::refreshLang() {
 	updateControlsGeometry();
 }
 
+int PwdCheckWidget::errorTop() const {
+	return contentTop() + st::introErrorBelowLinkTop;
+}
+
 void PwdCheckWidget::resizeEvent(QResizeEvent *e) {
 	Step::resizeEvent(e);
 	updateControlsGeometry();

Telegram/SourceFiles/intro/intropwdcheck.h

@@ -46,6 +46,8 @@ private slots:
 	void onCheckRequest();
 
 private:
+	int errorTop() const override;
+
 	void showReset();
 	void refreshLang();
 	void updateControlsGeometry();

Telegram/SourceFiles/intro/introwidget.cpp

@@ -122,7 +122,7 @@ void Widget::createLanguageLink() {
 			Lang::CurrentCloudManager().switchToLanguage(languageId);
 		});
 		_changeLanguage->toggle(
-			!_resetAccount && !_terms,
+			!_resetAccount && !_terms && _nextShown,
 			anim::type::normal);
 		updateControlsGeometry();
 	};
@@ -230,11 +230,6 @@ void Widget::historyMove(Direction direction) {
 	setupNextButton();
 	if (_resetAccount) _resetAccount->show(anim::type::normal);
 	if (_terms) _terms->show(anim::type::normal);
-	if (_changeLanguage) {
-		_changeLanguage->toggle(
-			!_resetAccount && !_terms,
-			anim::type::normal);
-	}
 	getStep()->showAnimated(direction);
 	fixOrder();
 }
@@ -253,6 +248,7 @@ void Widget::hideAndDestroy(object_ptr<Ui::FadeWrap<Ui::RpWidget>> widget) {
 void Widget::fixOrder() {
 	_next->raise();
 	if (_update) _update->raise();
+	if (_changeLanguage) _changeLanguage->raise();
 	_settings->raise();
 	_back->raise();
 	_connecting->raise();
@@ -333,7 +329,7 @@ void Widget::showTerms() {
 	}
 	if (_changeLanguage) {
 		_changeLanguage->toggle(
-			!_terms && !_resetAccount,
+			!_terms && !_resetAccount && _nextShown,
 			anim::type::normal);
 	}
 }
@@ -491,7 +487,7 @@ void Widget::showControls() {
 	}
 	if (_changeLanguage) {
 		_changeLanguage->toggle(
-			!_resetAccount && !_terms,
+			!_resetAccount && !_terms && _nextShown,
 			anim::type::instant);
 	}
 	if (_terms) {
@@ -508,12 +504,19 @@ void Widget::setupNextButton() {
 	auto visible = getStep()->nextButtonText(
 	) | rpl::map([](const QString &text) {
 		return !text.isEmpty();
-	}) | rpl::distinct_until_changed();
+	});
 	std::move(
 		visible
-	) | rpl::start_with_next([=](bool visible) {
+	) | rpl::filter([=](bool visible) {
+		return visible != _nextShown;
+	}) | rpl::start_with_next([=](bool visible) {
 		_next->toggle(visible, anim::type::normal);
 		_nextShown = visible;
+		if (_changeLanguage) {
+			_changeLanguage->toggle(
+				!_resetAccount && !_terms && _nextShown,
+				anim::type::normal);
+		}
 		_nextShownAnimation.start(
 			[=] { updateControlsGeometry(); },
 			_nextShown ? 0. : 1.,

Telegram/SourceFiles/intro/introwidget.h

@@ -152,7 +152,7 @@ private:
 
 	std::unique_ptr<Window::ConnectionState> _connecting;
 
-	bool _nextShown = false;
+	bool _nextShown = true;
 	Ui::Animations::Simple _nextShownAnimation;
 
 	mtpRequestId _resetRequest = 0;