From 766e7dadb127b2999bd9238714e410ee7013e7a8 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Mon, 18 Sep 2017 20:04:45 +0300
Subject: [PATCH] Use improved rpl::start().

---
 .../SourceFiles/boxes/edit_privacy_box.cpp    |  6 +--
 .../SourceFiles/boxes/notifications_box.cpp   |  3 +-
 Telegram/SourceFiles/boxes/peer_list_box.cpp  |  5 ++-
 .../SourceFiles/boxes/sticker_set_box.cpp     |  5 +--
 Telegram/SourceFiles/boxes/stickers_box.cpp   |  3 +-
 .../SourceFiles/chat_helpers/tabbed_panel.cpp |  5 ++-
 .../chat_helpers/tabbed_selector.cpp          |  8 ++--
 .../history/history_shared_media.cpp          | 35 +++++++--------
 .../history/history_user_photos.cpp           | 16 +++----
 Telegram/SourceFiles/info/info_layer_wrap.cpp | 15 +++----
 Telegram/SourceFiles/info/info_memento.cpp    | 11 +++--
 .../SourceFiles/info/info_narrow_wrap.cpp     |  5 +--
 .../info/info_profile_inner_widget.cpp        | 44 ++++++++-----------
 .../SourceFiles/info/info_profile_lines.cpp   | 30 ++++++-------
 Telegram/SourceFiles/info/info_side_wrap.cpp  |  3 +-
 Telegram/SourceFiles/info/info_top_bar.cpp    |  5 +--
 Telegram/SourceFiles/mainwidget.cpp           | 10 ++---
 Telegram/SourceFiles/mediaview.cpp            |  8 ++--
 .../settings/settings_block_widget.cpp        | 15 ++++---
 .../settings/settings_inner_widget.cpp        |  9 ++--
 .../SourceFiles/settings/settings_layer.cpp   | 10 ++---
 .../settings/settings_scale_widget.cpp        |  3 +-
 .../SourceFiles/settings/settings_widget.h    |  2 -
 .../storage/storage_shared_media.cpp          |  5 +--
 .../storage/storage_user_photos.cpp           |  4 +-
 Telegram/SourceFiles/ui/rp_widget.h           |  2 +-
 Telegram/SourceFiles/ui/widgets/labels.cpp    | 10 ++---
 .../SourceFiles/ui/wrap/vertical_layout.cpp   |  8 ++--
 Telegram/SourceFiles/ui/wrap/wrap.h           | 29 +++++-------
 .../SourceFiles/window/player_wrap_widget.cpp |  5 +--
 .../SourceFiles/window/top_bar_widget.cpp     |  5 ++-
 31 files changed, 145 insertions(+), 179 deletions(-)

diff --git a/Telegram/SourceFiles/boxes/edit_privacy_box.cpp b/Telegram/SourceFiles/boxes/edit_privacy_box.cpp
index f66802e93..81f80243b 100644
--- a/Telegram/SourceFiles/boxes/edit_privacy_box.cpp
+++ b/Telegram/SourceFiles/boxes/edit_privacy_box.cpp
@@ -288,9 +288,9 @@ void EditPrivacyBox::createWidgets() {
 	auto createExceptionLink = [this](Exception exception) {
 		exceptionLink(exception).create(this, object_ptr<Ui::LinkButton>(this, exceptionLinkText(exception)), exceptionLinkMargins());
 		exceptionLink(exception)->heightValue()
-			| rpl::start(
-				[this](int) { resizeToWidth(width()); },
-				lifetime());
+			| rpl::start([this](int) {
+				resizeToWidth(width());
+			}, lifetime());
 		exceptionLink(exception)->entity()->setClickedCallback([this, exception] { editExceptionUsers(exception); });
 	};
 
diff --git a/Telegram/SourceFiles/boxes/notifications_box.cpp b/Telegram/SourceFiles/boxes/notifications_box.cpp
index 141daf59a..b61cc10d4 100644
--- a/Telegram/SourceFiles/boxes/notifications_box.cpp
+++ b/Telegram/SourceFiles/boxes/notifications_box.cpp
@@ -128,8 +128,7 @@ void NotificationsBox::prepare() {
 	}
 	_countSlider->setActiveSectionFast(_oldCount - 1);
 	_countSlider->sectionActivated()
-		| rpl::on_next([this](int) { countChanged(); })
-		| rpl::start(lifetime());
+		| rpl::start([this](int) { countChanged(); }, lifetime());
 
 	setMouseTracking(true);
 
diff --git a/Telegram/SourceFiles/boxes/peer_list_box.cpp b/Telegram/SourceFiles/boxes/peer_list_box.cpp
index 85ce75236..e018bd1a1 100644
--- a/Telegram/SourceFiles/boxes/peer_list_box.cpp
+++ b/Telegram/SourceFiles/boxes/peer_list_box.cpp
@@ -46,8 +46,9 @@ void PeerListBox::createMultiSelect() {
 	auto entity = object_ptr<Ui::MultiSelect>(this, st::contactsMultiSelect, langFactory(lng_participant_filter));
 	_select.create(this, std::move(entity));
 	_select->heightValue()
-		| rpl::on_next([this](int) { updateScrollSkips(); })
-		| rpl::start(lifetime());
+		| rpl::start(
+			[this](int) { updateScrollSkips(); },
+			lifetime());
 	_select->entity()->setSubmittedCallback([this](bool chtrlShiftEnter) { _inner->submitted(); });
 	_select->entity()->setQueryChangedCallback([this](const QString &query) { searchQueryChanged(query); });
 	_select->entity()->setItemRemovedCallback([this](uint64 itemId) {
diff --git a/Telegram/SourceFiles/boxes/sticker_set_box.cpp b/Telegram/SourceFiles/boxes/sticker_set_box.cpp
index 84605f166..9c13ac9d9 100644
--- a/Telegram/SourceFiles/boxes/sticker_set_box.cpp
+++ b/Telegram/SourceFiles/boxes/sticker_set_box.cpp
@@ -57,11 +57,10 @@ void StickerSetBox::prepare() {
 
 	connect(_inner, SIGNAL(updateButtons()), this, SLOT(onUpdateButtons()));
 	_inner->setInstalled()
-		| rpl::on_next([this](auto &&setId) {
+		| rpl::start([this](auto &&setId) {
 			Auth().api().stickerSetInstalled(setId);
 			closeBox();
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 void StickerSetBox::onAddStickers() {
diff --git a/Telegram/SourceFiles/boxes/stickers_box.cpp b/Telegram/SourceFiles/boxes/stickers_box.cpp
index 64855d810..54fe058c7 100644
--- a/Telegram/SourceFiles/boxes/stickers_box.cpp
+++ b/Telegram/SourceFiles/boxes/stickers_box.cpp
@@ -244,8 +244,7 @@ void StickersBox::prepare() {
 		}
 		setNoContentMargin(true);
 		_tabs->sectionActivated()
-			| rpl::on_next([this](int) { switchTab(); })
-			| rpl::start(lifetime());
+			| rpl::start([this](int) { switchTab(); }, lifetime());
 		refreshTabs();
 	}
 	if (_installed.widget() && _section != Section::Installed) _installed.widget()->hide();
diff --git a/Telegram/SourceFiles/chat_helpers/tabbed_panel.cpp b/Telegram/SourceFiles/chat_helpers/tabbed_panel.cpp
index 921c23ca9..f0e8d6c4b 100644
--- a/Telegram/SourceFiles/chat_helpers/tabbed_panel.cpp
+++ b/Telegram/SourceFiles/chat_helpers/tabbed_panel.cpp
@@ -63,8 +63,9 @@ TabbedPanel::TabbedPanel(
 		}
 	});
 	_selector->showRequests()
-		| rpl::on_next([this](auto&&) { showFromSelector(); })
-		| rpl::start(lifetime());
+		| rpl::start([this](auto&&) {
+			showFromSelector();
+		}, lifetime());
 
 	resize(QRect(0, 0, st::emojiPanWidth, st::emojiPanMaxHeight).marginsAdded(innerPadding()).size());
 
diff --git a/Telegram/SourceFiles/chat_helpers/tabbed_selector.cpp b/Telegram/SourceFiles/chat_helpers/tabbed_selector.cpp
index 3ecea89aa..690ef2e2c 100644
--- a/Telegram/SourceFiles/chat_helpers/tabbed_selector.cpp
+++ b/Telegram/SourceFiles/chat_helpers/tabbed_selector.cpp
@@ -347,12 +347,11 @@ TabbedSelector::TabbedSelector(QWidget *parent, not_null<Window::Controller*> co
 	}));
 
 	Auth().api().stickerSetInstalled()
-		| rpl::on_next([this](uint64 setId) {
+		| rpl::start([this](uint64 setId) {
 			_tabsSlider->setActiveSection(static_cast<int>(SelectorTab::Stickers));
 			stickers()->showStickerSet(setId);
 			_showRequests.fire({});
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 
 	//	setAttribute(Qt::WA_AcceptTouchEvents);
 	setAttribute(Qt::WA_OpaquePaintEvent, false);
@@ -608,8 +607,7 @@ void TabbedSelector::createTabsSlider() {
 
 	_tabsSlider->setActiveSectionFast(static_cast<int>(_currentTabType));
 	_tabsSlider->sectionActivated()
-		| rpl::on_next([this](int) { switchTab(); })
-		| rpl::start(lifetime());
+		| rpl::start([this](int) { switchTab(); }, lifetime());
 
 	_tabsSlider->resizeToWidth(width());
 	_tabsSlider->moveToLeft(0, 0);
diff --git a/Telegram/SourceFiles/history/history_shared_media.cpp b/Telegram/SourceFiles/history/history_shared_media.cpp
index 9717943f6..7979011db 100644
--- a/Telegram/SourceFiles/history/history_shared_media.cpp
+++ b/Telegram/SourceFiles/history/history_shared_media.cpp
@@ -449,26 +449,23 @@ rpl::producer<SharedMediaSlice> SharedMediaViewer(
 				data.second);
 		};
 		builder->insufficientMediaAround()
-			| rpl::on_next(requestMediaAround)
-			| rpl::start(lifetime);
+			| rpl::start(requestMediaAround, lifetime);
 
 		Auth().storage().sharedMediaSliceUpdated()
-			| rpl::on_next(applyUpdate)
-			| rpl::start(lifetime);
+			| rpl::start(applyUpdate, lifetime);
 		Auth().storage().sharedMediaOneRemoved()
-			| rpl::on_next(applyUpdate)
-			| rpl::start(lifetime);
+			| rpl::start(applyUpdate, lifetime);
 		Auth().storage().sharedMediaAllRemoved()
-			| rpl::on_next(applyUpdate)
-			| rpl::start(lifetime);
+			| rpl::start(applyUpdate, lifetime);
 
 		Auth().storage().query(Storage::SharedMediaQuery(
 			key,
 			limitBefore,
 			limitAfter))
-			| rpl::on_next(applyUpdate)
-			| rpl::on_done([=] { builder->checkInsufficientMedia(); })
-			| rpl::start(lifetime);
+			| rpl::start(
+				applyUpdate,
+				[=] { builder->checkInsufficientMedia(); },
+				lifetime);
 
 		return lifetime;
 	};
@@ -600,20 +597,20 @@ rpl::producer<SharedMediaMergedSlice> SharedMediaMergedViewer(
 			SharedMediaMergedSlice::PartKey(key),
 			limitBefore,
 			limitAfter
-		) | rpl::on_next([=](SharedMediaSlice &&update) {
+		) | rpl::start([=](SharedMediaSlice &&update) {
 			builder->applyPartUpdate(std::move(update));
 			consumer.put_next(builder->snapshot());
-		}) | rpl::start(lifetime);
+		}, lifetime);
 
 		if (key.migratedPeerId) {
 			SharedMediaViewer(
 				SharedMediaMergedSlice::MigratedKey(key),
 				limitBefore,
 				limitAfter
-			) | rpl::on_next([=](SharedMediaSlice &&update) {
+			) | rpl::start([=](SharedMediaSlice &&update) {
 				builder->applyMigratedUpdate(std::move(update));
 				consumer.put_next(builder->snapshot());
-			}) | rpl::start(lifetime);
+			}, lifetime);
 		}
 
 		return lifetime;
@@ -752,20 +749,20 @@ rpl::producer<SharedMediaWithLastSlice> SharedMediaWithLastViewer(
 			SharedMediaWithLastSlice::ViewerKey(key),
 			limitBefore,
 			limitAfter
-		) | rpl::on_next([=](SharedMediaMergedSlice &&update) {
+		) | rpl::start([=](SharedMediaMergedSlice &&update) {
 			builder->applyViewerUpdate(std::move(update));
 			consumer.put_next(builder->snapshot());
-		}) | rpl::start(lifetime);
+		}, lifetime);
 
 		if (base::get_if<SharedMediaWithLastSlice::MessageId>(&key.universalId)) {
 			SharedMediaMergedViewer(
 				SharedMediaWithLastSlice::EndingKey(key),
 				1,
 				1
-			) | rpl::on_next([=](SharedMediaMergedSlice &&update) {
+			) | rpl::start([=](SharedMediaMergedSlice &&update) {
 				builder->applyEndingUpdate(std::move(update));
 				consumer.put_next(builder->snapshot());
-			}) | rpl::start(lifetime);
+			}, lifetime);
 		}
 
 		return lifetime;
diff --git a/Telegram/SourceFiles/history/history_user_photos.cpp b/Telegram/SourceFiles/history/history_user_photos.cpp
index 1e4b9fe60..59990db2d 100644
--- a/Telegram/SourceFiles/history/history_user_photos.cpp
+++ b/Telegram/SourceFiles/history/history_user_photos.cpp
@@ -231,21 +231,19 @@ rpl::producer<UserPhotosSlice> UserPhotosViewer(
 			Auth().api().requestUserPhotos(user, photoId);
 		};
 		builder->insufficientPhotosAround()
-			| rpl::on_next(requestPhotosAround)
-			| rpl::start(lifetime);
+			| rpl::start(requestPhotosAround, lifetime);
 
 		Auth().storage().userPhotosSliceUpdated()
-			| rpl::on_next(applyUpdate)
-			| rpl::start(lifetime);
+			| rpl::start(applyUpdate, lifetime);
 
 		Auth().storage().query(Storage::UserPhotosQuery(
 			key,
 			limitBefore,
-			limitAfter
-		))
-			| rpl::on_next(applyUpdate)
-			| rpl::on_done([=] { builder->checkInsufficientPhotos(); })
-			| rpl::start(lifetime);
+			limitAfter))
+			| rpl::start(
+				applyUpdate,
+				[=] { builder->checkInsufficientPhotos(); },
+				lifetime);
 
 		return lifetime;
 	};
diff --git a/Telegram/SourceFiles/info/info_layer_wrap.cpp b/Telegram/SourceFiles/info/info_layer_wrap.cpp
index 24fb408d1..5038a8b4f 100644
--- a/Telegram/SourceFiles/info/info_layer_wrap.cpp
+++ b/Telegram/SourceFiles/info/info_layer_wrap.cpp
@@ -54,18 +54,16 @@ LayerWrap::LayerWrap(
 
 void LayerWrap::setupHeightConsumers() {
 	_content->desiredHeightValue()
-		| rpl::on_next([this](int height) {
+		| rpl::start([this](int height) {
 			_desiredHeight = height;
 			resizeToWidth(width());
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 	heightValue()
-		| rpl::on_next([this](int height) {
+		| rpl::start([this](int height) {
 			_content->resize(
 				width(),
 				height - _topBar->bottomNoMargins() - st::boxRadius);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 object_ptr<TopBar> LayerWrap::createTopBar() {
@@ -76,10 +74,9 @@ object_ptr<TopBar> LayerWrap::createTopBar() {
 		result.data(),
 		st::infoLayerTopBarClose));
 	close->clicks()
-		| rpl::on_next([this](auto&&) {
+		| rpl::start([this](auto&&) {
 			_controller->hideSpecialLayer();
-		})
-		| rpl::start(close->lifetime());
+		}, close->lifetime());
 	result->setTitle(TitleValue(
 		_content->section(),
 		_content->peer()));
diff --git a/Telegram/SourceFiles/info/info_memento.cpp b/Telegram/SourceFiles/info/info_memento.cpp
index 490b318ed..994eb2a2b 100644
--- a/Telegram/SourceFiles/info/info_memento.cpp
+++ b/Telegram/SourceFiles/info/info_memento.cpp
@@ -104,12 +104,11 @@ Ui::RpWidget *ContentWidget::doSetInnerWidget(
 	_inner->move(0, 0);
 
 	scrollTopValue()
-		| rpl::on_next([this, inner = _inner](int value) {
+		| rpl::start([this, inner = _inner](int value) {
 			inner->setVisibleTopBottom(
 				value,
 				value + _scroll->height()); // TODO rpl::combine
-		})
-		| rpl::start(_inner->lifetime());
+		}, _inner->lifetime());
 	return _inner;
 }
 
@@ -208,14 +207,14 @@ object_ptr<Window::SectionWidget> MoveMemento::createWidget(
 			controller,
 			this);
 		result->setGeometry(geometry);
-		return result;
+		return std::move(result);
 	} else if (_wrap == Wrap::Side && column == Window::Column::Third) {
 		auto result = object_ptr<SideWrap>(
 			parent,
 			controller,
 			this);
 		result->setGeometry(geometry);
-		return result;
+		return std::move(result);
 	}
 	return nullptr;
 }
@@ -226,7 +225,7 @@ object_ptr<LayerWidget> MoveMemento::createLayer(
 		auto result = object_ptr<LayerWrap>(
 			controller,
 			this);
-		return result;
+		return std::move(result);
 	}
 	return nullptr;
 }
diff --git a/Telegram/SourceFiles/info/info_narrow_wrap.cpp b/Telegram/SourceFiles/info/info_narrow_wrap.cpp
index cf60e9c5f..8d54f9175 100644
--- a/Telegram/SourceFiles/info/info_narrow_wrap.cpp
+++ b/Telegram/SourceFiles/info/info_narrow_wrap.cpp
@@ -87,10 +87,9 @@ object_ptr<TopBar> NarrowWrap::createTopBar() {
 		st::infoLayerTopBar);
 	result->enableBackButton(true);
 	result->backRequest()
-		| rpl::on_next([this](auto&&) {
+		| rpl::start([this](auto&&) {
 			controller()->showBackFromStack();
-		})
-		| rpl::start(result->lifetime());
+		}, result->lifetime());
 	result->setTitle(TitleValue(
 		_content->section(),
 		_content->peer()));
diff --git a/Telegram/SourceFiles/info/info_profile_inner_widget.cpp b/Telegram/SourceFiles/info/info_profile_inner_widget.cpp
index 43fcef6ab..a19165555 100644
--- a/Telegram/SourceFiles/info/info_profile_inner_widget.cpp
+++ b/Telegram/SourceFiles/info/info_profile_inner_widget.cpp
@@ -55,9 +55,9 @@ void InnerWidget::setupContent() {
 			std::move(hiddenDetailsContent)));
 		cover->setHasToggle(true);
 		cover->toggled()
-		| rpl::on_next([=](bool expanded) {
+		| rpl::start([=](bool expanded) {
 			hiddenDetails->toggleAnimated(expanded);
-		}) | rpl::start(_lifetime);
+		}, _lifetime);
 		hiddenDetails->hideFast();
 	} else {
 		_content->add(setupDetailsContent(_content));
@@ -65,9 +65,9 @@ void InnerWidget::setupContent() {
 	_content->add(object_ptr<BoxContentDivider>(this));
 
 	_content->heightValue()
-		| rpl::on_next([this](int height) {
+		| rpl::start([this](int height) {
 			TWidget::resizeToWidth(width());
-		}) | rpl::start(_lifetime);
+		}, _lifetime);
 }
 
 object_ptr<Ui::RpWidget> InnerWidget::setupDetailsContent(
@@ -87,7 +87,7 @@ object_ptr<Ui::RpWidget> InnerWidget::setupDetailsContent(
 
 	result->add(object_ptr<Ui::PaddingWrap<>>(result, skipPadding));
 
-	return result;
+	return std::move(result);
 }
 
 object_ptr<Ui::RpWidget> InnerWidget::setupMuteToggle(
@@ -98,24 +98,22 @@ object_ptr<Ui::RpWidget> InnerWidget::setupMuteToggle(
 		Lang::Viewer(lng_profile_enable_notifications),
 		st::infoNotificationsButton));
 	NotificationsEnabledViewer(_peer)
-		| rpl::on_next([button](bool enabled) {
+		| rpl::start([button](bool enabled) {
 			button->setToggled(enabled);
-		})
-		| rpl::start(button->lifetime());
+		}, button->lifetime());
 	button->clicks()
-		| rpl::on_next([this](auto) {
+		| rpl::start([this](auto) {
 			App::main()->updateNotifySetting(
 				_peer,
 				_peer->isMuted()
 					? NotifySettingSetNotify
 					: NotifySettingSetMuted);
-		})
-		| rpl::start(button->lifetime());
+		}, button->lifetime());
 
 	object_ptr<FloatingIcon>(
 		result,
 		st::infoIconNotifications);
-	return result;
+	return std::move(result);
 }
 
 void InnerWidget::setupMainUserButtons(
@@ -126,12 +124,11 @@ void InnerWidget::setupMainUserButtons(
 		Lang::Viewer(lng_profile_send_message) | ToUpperValue(),
 		st::infoMainButton));
 	sendMessage->clicks()
-		| rpl::on_next([this, user](auto&&) {
+		| rpl::start([this, user](auto&&) {
 			_controller->showPeerHistory(
 				user,
 				Ui::ShowWay::Forward);
-		})
-		| rpl::start(sendMessage->lifetime());
+		}, sendMessage->lifetime());
 
 	auto addContact = wrap->add(object_ptr<Ui::SlideWrap<Button>>(
 		wrap,
@@ -140,16 +137,14 @@ void InnerWidget::setupMainUserButtons(
 			Lang::Viewer(lng_info_add_as_contact) | ToUpperValue(),
 			st::infoMainButton)));
 	CanAddContactViewer(user)
-		| rpl::on_next([addContact](bool canAdd) {
+		| rpl::start([addContact](bool canAdd) {
 			addContact->toggleAnimated(canAdd);
-		})
-		| rpl::start(addContact->lifetime());
+		}, addContact->lifetime());
 	addContact->finishAnimations();
 	addContact->entity()->clicks()
-		| rpl::on_next([user](auto&&) {
+		| rpl::start([user](auto&&) {
 			App::main()->shareContactLayer(user);
-		})
-		| rpl::start(addContact->lifetime());
+		}, addContact->lifetime());
 }
 
 object_ptr<Ui::RpWidget> InnerWidget::setupInfoLines(
@@ -181,15 +176,14 @@ object_ptr<Ui::RpWidget> InnerWidget::setupInfoLines(
 			return base::find(values, true) != values.end();
 		})
 		| rpl::distinct_until_changed()
-		| rpl::on_next([separator](bool someShown) {
+		| rpl::start([separator](bool someShown) {
 			separator->toggleAnimated(someShown);
-		})
-		| rpl::start(separator->lifetime());
+		}, separator->lifetime());
 	separator->finishAnimations();
 
 	object_ptr<FloatingIcon>(result, st::infoIconInformation);
 
-	return result;
+	return std::move(result);
 }
 
 void InnerWidget::visibleTopBottomUpdated(
diff --git a/Telegram/SourceFiles/info/info_profile_lines.cpp b/Telegram/SourceFiles/info/info_profile_lines.cpp
index 3919c3cb9..9ae45ea54 100644
--- a/Telegram/SourceFiles/info/info_profile_lines.cpp
+++ b/Telegram/SourceFiles/info/info_profile_lines.cpp
@@ -232,13 +232,12 @@ FloatingIcon::FloatingIcon(
 	setAttribute(Qt::WA_TransparentForMouseEvents);
 	if (above) {
 		above->geometryValue()
-			| rpl::on_next([this](QRect &&geometry) {
+			| rpl::start([this](const QRect &geometry) {
 				auto topLeft = rtlpoint(
 					geometry.topLeft(),
 					parentWidget()->width());
 				moveToLeft(topLeft.x(), topLeft.y() + geometry.height());
-			})
-			| rpl::start(lifetime());
+			}, lifetime());
 	} else {
 		moveToLeft(0, 0);
 	}
@@ -323,15 +322,18 @@ void CoverLine::setHasToggle(bool hasToggle) {
 void CoverLine::initViewers() {
 	using Flag = Notify::PeerUpdate::Flag;
 	PeerUpdateViewer(_peer, Flag::PhotoChanged)
-		| rpl::on_next([this](auto&&) { refreshUserpicLink(); })
-		| rpl::start(_lifetime);
+		| rpl::start(
+			[this](auto&&) { refreshUserpicLink(); },
+			_lifetime);
 	PeerUpdateViewer(_peer, Flag::NameChanged)
-		| rpl::on_next([this](auto&&) { refreshNameText(); })
-		| rpl::start(_lifetime);
+		| rpl::start(
+			[this](auto&&) { refreshNameText(); },
+			_lifetime);
 	PeerUpdateViewer(_peer,
 		Flag::UserOnlineChanged | Flag::MembersChanged)
-		| rpl::on_next([this](auto&&) { refreshStatusText(); })
-		| rpl::start(_lifetime);
+		| rpl::start(
+			[this](auto&&) { refreshStatusText(); },
+			_lifetime);
 }
 
 void CoverLine::initUserpicButton() {
@@ -449,10 +451,9 @@ Button::Button(
 : RippleButton(parent, st.ripple)
 , _st(st) {
 	std::move(text)
-		| rpl::on_next([this](QString &&value) {
+		| rpl::start([this](QString &&value) {
 			setText(std::move(value));
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 void Button::setToggled(bool toggled) {
@@ -462,10 +463,9 @@ void Button::setToggled(bool toggled) {
 			toggled,
 			[this] { rtlupdate(toggleRect()); });
 		clicks()
-			| rpl::on_next([this](auto) {
+			| rpl::start([this](auto) {
 				_toggle->setCheckedAnimated(!_toggle->checked());
-			})
-			| rpl::start(lifetime());
+			}, lifetime());
 	} else {
 		_toggle->setCheckedAnimated(toggled);
 	}
diff --git a/Telegram/SourceFiles/info/info_side_wrap.cpp b/Telegram/SourceFiles/info/info_side_wrap.cpp
index c6506fc9a..29494ce7e 100644
--- a/Telegram/SourceFiles/info/info_side_wrap.cpp
+++ b/Telegram/SourceFiles/info/info_side_wrap.cpp
@@ -62,8 +62,7 @@ void SideWrap::setupTabs() {
 	_tabs->setSections(sections);
 	_tabs->sectionActivated()
 		| rpl::map([](int index) { return static_cast<Tab>(index); })
-		| rpl::on_next([this](Tab tab) { showTab(tab); })
-		| rpl::start(_lifetime);
+		| rpl::start([this](Tab tab) { showTab(tab); }, _lifetime);
 
 	_tabs->move(0, 0);
 	_tabs->resizeToWidth(width());
diff --git a/Telegram/SourceFiles/info/info_top_bar.cpp b/Telegram/SourceFiles/info/info_top_bar.cpp
index 79498f527..fd21ab5b2 100644
--- a/Telegram/SourceFiles/info/info_top_bar.cpp
+++ b/Telegram/SourceFiles/info/info_top_bar.cpp
@@ -59,10 +59,9 @@ void TopBar::pushButton(object_ptr<Ui::RpWidget> button) {
 	auto weak = Ui::AttachParentChild(this, button);
 	_buttons.push_back(std::move(button));
 	weak->widthValue()
-		| rpl::on_next([this](auto) {
+		| rpl::start([this](auto) {
 			updateControlsGeometry(width());
-		})
-		| rpl::start(_lifetime);
+		}, _lifetime);
 }
 
 int TopBar::resizeGetHeight(int newWidth) {
diff --git a/Telegram/SourceFiles/mainwidget.cpp b/Telegram/SourceFiles/mainwidget.cpp
index 0b5b25444..62d876403 100644
--- a/Telegram/SourceFiles/mainwidget.cpp
+++ b/Telegram/SourceFiles/mainwidget.cpp
@@ -1846,8 +1846,9 @@ void MainWidget::createPlayer() {
 	if (!_player) {
 		_player.create(this);
 		_player->heightValue()
-			| rpl::on_next([this](int) { playerHeightUpdated(); })
-			| rpl::start(lifetime());
+			| rpl::start(
+				[this](int) { playerHeightUpdated(); },
+				lifetime());
 		_player->entity()->setCloseCallback([this] { closeBothPlayers(); });
 		_playerVolume.create(this);
 		_player->entity()->volumeWidgetCreated(_playerVolume);
@@ -1906,10 +1907,9 @@ void MainWidget::createCallTopBar() {
 	Expects(_currentCall != nullptr);
 	_callTopBar.create(this, object_ptr<Calls::TopBar>(this, _currentCall));
 	_callTopBar->heightValue()
-		| rpl::on_next([this](int value) {
+		| rpl::start([this](int value) {
 			callTopBarHeightUpdated(value);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 	orderWidgets();
 	if (_a_show.animating()) {
 		_callTopBar->showFast();
diff --git a/Telegram/SourceFiles/mediaview.cpp b/Telegram/SourceFiles/mediaview.cpp
index cc8615a25..35743e0c1 100644
--- a/Telegram/SourceFiles/mediaview.cpp
+++ b/Telegram/SourceFiles/mediaview.cpp
@@ -1064,9 +1064,9 @@ void MediaView::validateSharedMedia() {
 			*key,
 			kIdsLimit,
 			kIdsLimit
-		) | rpl::on_next([this](SharedMediaWithLastSlice &&update) {
+		) | rpl::start([this](SharedMediaWithLastSlice &&update) {
 			handleSharedMediaUpdate(std::move(update));
-		}) | rpl::start(_sharedMedia->lifetime);
+		}, _sharedMedia->lifetime);
 	} else {
 		_sharedMedia = nullptr;
 		_sharedMediaData = base::none;
@@ -1123,9 +1123,9 @@ void MediaView::validateUserPhotos() {
 			*key,
 			kIdsLimit,
 			kIdsLimit
-		) | rpl::on_next([this](UserPhotosSlice &&update) {
+		) | rpl::start([this](UserPhotosSlice &&update) {
 			handleUserPhotosUpdate(std::move(update));
-		}) | rpl::start(_userPhotos->lifetime);
+		}, _userPhotos->lifetime);
 	} else {
 		_userPhotos = nullptr;
 		_userPhotosData = base::none;
diff --git a/Telegram/SourceFiles/settings/settings_block_widget.cpp b/Telegram/SourceFiles/settings/settings_block_widget.cpp
index 61c238994..fa20dac07 100644
--- a/Telegram/SourceFiles/settings/settings_block_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_block_widget.cpp
@@ -28,14 +28,17 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 namespace Settings {
 
 BlockWidget::BlockWidget(QWidget *parent, UserData *self, const QString &title) : RpWidget(parent)
+, _content(this)
 , _self(self)
-, _title(title)
-, _content(this) {
+, _title(title) {
 	_content->heightValue()
-		| rpl::on_next([this](int contentHeight) {
-			resize(width(), contentTop() + contentHeight + st::settingsBlockMarginBottom);
-		})
-		| rpl::start(lifetime());
+		| rpl::start([this](int contentHeight) {
+			resize(
+				width(),
+				contentTop()
+					+ contentHeight
+					+ st::settingsBlockMarginBottom);
+		}, lifetime());
 }
 
 void BlockWidget::setContentLeft(int contentLeft) {
diff --git a/Telegram/SourceFiles/settings/settings_inner_widget.cpp b/Telegram/SourceFiles/settings/settings_inner_widget.cpp
index bc529ad4c..460fa3619 100644
--- a/Telegram/SourceFiles/settings/settings_inner_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_inner_widget.cpp
@@ -36,8 +36,8 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 namespace Settings {
 
 InnerWidget::InnerWidget(QWidget *parent) : LayerInner(parent)
-, _self(App::self())
-, _blocks(this) {
+, _blocks(this)
+, _self(App::self()) {
 	refreshBlocks();
 	subscribe(Global::RefSelfChanged(), [this] { fullRebuild(); });
 	subscribe(Lang::Current().updated(), [this] { fullRebuild(); });
@@ -83,10 +83,9 @@ void InnerWidget::refreshBlocks() {
 	}
 	_blocks->show();
 	_blocks->heightValue()
-		| rpl::on_next([this](int blocksHeight) {
+		| rpl::start([this](int blocksHeight) {
 			resize(width(), _blocks->y() + blocksHeight);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 void InnerWidget::showFinished() {
diff --git a/Telegram/SourceFiles/settings/settings_layer.cpp b/Telegram/SourceFiles/settings/settings_layer.cpp
index 12bfd1c14..3c20825fb 100644
--- a/Telegram/SourceFiles/settings/settings_layer.cpp
+++ b/Telegram/SourceFiles/settings/settings_layer.cpp
@@ -53,10 +53,9 @@ Layer::Layer()
 	_scroll->scrollTopValue()
 		| rpl::map([](int scrollTop) { return scrollTop > 0; })
 		| rpl::distinct_until_changed()
-		| rpl::on_next([this](bool scrolled) {
+		| rpl::start([this](bool scrolled) {
 			_fixedBarShadow->toggleAnimated(scrolled);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 void Layer::setCloseClickHandler(base::lambda<void()> callback) {
@@ -74,10 +73,9 @@ void Layer::resizeToWidth(int newWidth, int newContentLeft) {
 void Layer::doSetInnerWidget(object_ptr<LayerInner> widget) {
 	_inner = _scroll->setOwnedWidget(std::move(widget));
 	_inner->heightValue()
-		| rpl::on_next([this](int innerHeight) {
+		| rpl::start([this](int innerHeight) {
 			resizeUsingInnerHeight(width(), innerHeight);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 void Layer::paintEvent(QPaintEvent *e) {
diff --git a/Telegram/SourceFiles/settings/settings_scale_widget.cpp b/Telegram/SourceFiles/settings/settings_scale_widget.cpp
index e555b4b47..412156c58 100644
--- a/Telegram/SourceFiles/settings/settings_scale_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_scale_widget.cpp
@@ -61,8 +61,7 @@ void ScaleWidget::createControls() {
 	_scale->addSection(scaleLabel(dbisTwo));
 	_scale->setActiveSectionFast(cEvalScale(cConfigScale()) - 1);
 	_scale->sectionActivated()
-		| rpl::on_next([this](int) { scaleChanged(); })
-		| rpl::start(lifetime());
+		| rpl::start([this](int) { scaleChanged(); }, lifetime());
 }
 
 void ScaleWidget::onAutoChanged() {
diff --git a/Telegram/SourceFiles/settings/settings_widget.h b/Telegram/SourceFiles/settings/settings_widget.h
index e432ca67d..f99417cc0 100644
--- a/Telegram/SourceFiles/settings/settings_widget.h
+++ b/Telegram/SourceFiles/settings/settings_widget.h
@@ -43,8 +43,6 @@ private:
 
 	QPointer<InnerWidget> _inner;
 
-	int _contentLeft = 0;
-
 };
 
 } // namespace Settings
diff --git a/Telegram/SourceFiles/storage/storage_shared_media.cpp b/Telegram/SourceFiles/storage/storage_shared_media.cpp
index 1d0f1e5e9..df1be97b1 100644
--- a/Telegram/SourceFiles/storage/storage_shared_media.cpp
+++ b/Telegram/SourceFiles/storage/storage_shared_media.cpp
@@ -234,15 +234,14 @@ std::map<PeerId, SharedMedia::Lists>::iterator
 		auto type = static_cast<SharedMediaType>(index);
 
 		list.sliceUpdated()
-			| rpl::on_next([this, peer, type](const SliceUpdate &update) {
+			| rpl::start([this, peer, type](const SliceUpdate &update) {
 				_sliceUpdated.fire(SharedMediaSliceUpdate(
 					peer,
 					type,
 					update.messages,
 					update.range,
 					update.count));
-			})
-			| rpl::start(_lifetime);
+			}, _lifetime);
 	}
 	return result;
 }
diff --git a/Telegram/SourceFiles/storage/storage_user_photos.cpp b/Telegram/SourceFiles/storage/storage_user_photos.cpp
index 817f043e9..6398a982f 100644
--- a/Telegram/SourceFiles/storage/storage_user_photos.cpp
+++ b/Telegram/SourceFiles/storage/storage_user_photos.cpp
@@ -122,12 +122,12 @@ UserPhotos::enforceLists(UserId user) {
 	}
 	result = _lists.emplace(user, List {}).first;
 	result->second.sliceUpdated(
-	) | rpl::on_next([this, user](const SliceUpdate &update) {
+	) | rpl::start([this, user](const SliceUpdate &update) {
 		_sliceUpdated.fire(UserPhotosSliceUpdate(
 			user,
 			update.photoIds,
 			update.count));
-	}) | rpl::start(_lifetime);
+	}, _lifetime);
 	return result;
 }
 
diff --git a/Telegram/SourceFiles/ui/rp_widget.h b/Telegram/SourceFiles/ui/rp_widget.h
index 3c2320692..3fd489eb5 100644
--- a/Telegram/SourceFiles/ui/rp_widget.h
+++ b/Telegram/SourceFiles/ui/rp_widget.h
@@ -28,7 +28,7 @@ namespace Ui {
 
 class RpWidget : public TWidget {
 public:
-	RpWidget::RpWidget(QWidget *parent = nullptr) : TWidget(parent) {
+	RpWidget(QWidget *parent = nullptr) : TWidget(parent) {
 		setGeometry(0, 0, 0, 0);
 	}
 
diff --git a/Telegram/SourceFiles/ui/widgets/labels.cpp b/Telegram/SourceFiles/ui/widgets/labels.cpp
index d3d932530..83132dc6f 100644
--- a/Telegram/SourceFiles/ui/widgets/labels.cpp
+++ b/Telegram/SourceFiles/ui/widgets/labels.cpp
@@ -171,10 +171,9 @@ FlatLabel::FlatLabel(
 , _st(st)
 , _contextCopyText(lang(lng_context_copy_text)) {
 	std::move(text)
-		| rpl::on_next([this](const QString &value) {
+		| rpl::start([this](const QString &value) {
 			setText(value);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 FlatLabel::FlatLabel(
@@ -186,10 +185,9 @@ FlatLabel::FlatLabel(
 , _st(st)
 , _contextCopyText(lang(lng_context_copy_text)) {
 	std::move(text)
-		| rpl::on_next([this](const TextWithEntities &value) {
+		| rpl::start([this](const TextWithEntities &value) {
 			setMarkedText(value);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 void FlatLabel::init() {
diff --git a/Telegram/SourceFiles/ui/wrap/vertical_layout.cpp b/Telegram/SourceFiles/ui/wrap/vertical_layout.cpp
index a56187070..1875a5d43 100644
--- a/Telegram/SourceFiles/ui/wrap/vertical_layout.cpp
+++ b/Telegram/SourceFiles/ui/wrap/vertical_layout.cpp
@@ -115,13 +115,11 @@ RpWidget *VerticalLayout::addChild(
 			width() - margins.left() - margins.right(),
 			height() - margins.top() - margins.bottom());
 		weak->heightValue()
-			| rpl::on_next([this, weak](int) {
+			| rpl::start([this, weak](int) {
 				childHeightUpdated(weak);
-			})
-			| rpl::on_done([this, weak] {
+			}, [this, weak] {
 				removeChild(weak);
-			})
-			| rpl::start(lifetime());
+			}, lifetime());
 		return weak;
 	}
 	return nullptr;
diff --git a/Telegram/SourceFiles/ui/wrap/wrap.h b/Telegram/SourceFiles/ui/wrap/wrap.h
index 27285f3c5..89258ff1e 100644
--- a/Telegram/SourceFiles/ui/wrap/wrap.h
+++ b/Telegram/SourceFiles/ui/wrap/wrap.h
@@ -30,20 +30,12 @@ class Wrap;
 namespace details {
 
 struct UnwrapHelper {
-	struct Large {
-		char data[2];
-	};
-	static char Check(...);
-	template <typename Widget, typename Parent>
-	static Large Check(Wrap<Widget, Parent>*);
-	template <typename Widget, typename Parent>
-	static Large Check(const Wrap<Widget, Parent>*);
+	template <
+		typename Widget,
+		typename = typename std::decay_t<Widget>::WrapParentType>
+	static std::true_type Is(Widget &&widget);
+	static std::false_type Is(...);
 
-	template <typename Entity>
-	static constexpr bool Is() {
-		return sizeof(Check(std::declval<Entity>()))
-			== sizeof(Large);
-	}
 	template <typename Entity>
 	static auto Unwrap(Entity *entity, std::true_type) {
 		return entity
@@ -56,10 +48,12 @@ struct UnwrapHelper {
 	}
 	template <typename Entity>
 	static auto Unwrap(Entity *entity) {
+		using Selector = decltype(Is(std::declval<Entity>()));
 		return Unwrap(
 			entity,
-			std::integral_constant<bool, Is<Entity*>()>());
+			Selector());
 	}
+
 };
 
 } // namespace details
@@ -126,10 +120,9 @@ Wrap<Widget, RpWidget>::Wrap(QWidget *parent, object_ptr<Widget> child)
 , _wrapped(std::move(child)) {
 	if (_wrapped) {
 		_wrapped->sizeValue()
-			| rpl::on_next([this](const QSize &value) {
+			| rpl::start([this](const QSize &value) {
 				wrappedSizeUpdated(value);
-			})
-			| rpl::start(lifetime());
+			}, lifetime());
 		AttachParentChild(this, _wrapped);
 		_wrapped->move(0, 0);
 		_wrapped->alive()
@@ -160,6 +153,8 @@ public:
 		return details::UnwrapHelper::Unwrap(wrapped());
 	}
 
+	using WrapParentType = ParentType;
+
 };
 
 } // namespace Ui
diff --git a/Telegram/SourceFiles/window/player_wrap_widget.cpp b/Telegram/SourceFiles/window/player_wrap_widget.cpp
index 235967106..d35876a70 100644
--- a/Telegram/SourceFiles/window/player_wrap_widget.cpp
+++ b/Telegram/SourceFiles/window/player_wrap_widget.cpp
@@ -27,10 +27,9 @@ namespace Window {
 PlayerWrapWidget::PlayerWrapWidget(QWidget *parent)
 : Parent(parent, object_ptr<Media::Player::Widget>(parent)) {
 	sizeValue()
-		| rpl::on_next([this](const QSize &size) {
+		| rpl::start([this](const QSize &size) {
 			updateShadowGeometry(size);
-		})
-		| rpl::start(lifetime());
+		}, lifetime());
 }
 
 void PlayerWrapWidget::updateShadowGeometry(const QSize &size) {
diff --git a/Telegram/SourceFiles/window/top_bar_widget.cpp b/Telegram/SourceFiles/window/top_bar_widget.cpp
index 77e504773..a83719dce 100644
--- a/Telegram/SourceFiles/window/top_bar_widget.cpp
+++ b/Telegram/SourceFiles/window/top_bar_widget.cpp
@@ -98,8 +98,9 @@ TopBarWidget::TopBarWidget(QWidget *parent, not_null<Window::Controller*> contro
 		updateControlsVisibility(); });
 
 	Auth().data().thirdSectionInfoEnabledValue()
-		| rpl::on_next([this](bool) { updateInfoToggleActive(); })
-		| rpl::start(lifetime());
+		| rpl::start(
+			[this](bool) { updateInfoToggleActive(); },
+			lifetime());
 
 	setCursor(style::cur_pointer);
 	updateControlsVisibility();