diff --git a/Telegram/SourceFiles/boxes/abstractbox.h b/Telegram/SourceFiles/boxes/abstractbox.h
index 5e3861c17b..26520c20d3 100644
--- a/Telegram/SourceFiles/boxes/abstractbox.h
+++ b/Telegram/SourceFiles/boxes/abstractbox.h
@@ -47,7 +47,7 @@ private:
 
 };
 
-class AbstractBox : public LayerWidget {
+class AbstractBox : public LayerWidget, protected base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/boxes/addcontactbox.cpp b/Telegram/SourceFiles/boxes/addcontactbox.cpp
index 52377b0665..4dc8f29c88 100644
--- a/Telegram/SourceFiles/boxes/addcontactbox.cpp
+++ b/Telegram/SourceFiles/boxes/addcontactbox.cpp
@@ -1362,8 +1362,8 @@ RevokePublicLinkBox::RevokePublicLinkBox(base::lambda_unique<void()> &&revokeCal
 
 	updateMaxHeight();
 
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
 	connect(_cancel, SIGNAL(clicked()), this, SLOT(onClose()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 
 	prepare();
 }
diff --git a/Telegram/SourceFiles/boxes/backgroundbox.cpp b/Telegram/SourceFiles/boxes/backgroundbox.cpp
index b5a56f8d02..9f2700dea4 100644
--- a/Telegram/SourceFiles/boxes/backgroundbox.cpp
+++ b/Telegram/SourceFiles/boxes/backgroundbox.cpp
@@ -29,13 +29,14 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 
 BackgroundInner::BackgroundInner() :
 _bgCount(0), _rows(0), _over(-1), _overDown(-1) {
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
 	if (App::cServerBackgrounds().isEmpty()) {
 		resize(BackgroundsInRow * (st::backgroundSize.width() + st::backgroundPadding) + st::backgroundPadding, 2 * (st::backgroundSize.height() + st::backgroundPadding) + st::backgroundPadding);
 		MTP::send(MTPaccount_GetWallPapers(), rpcDone(&BackgroundInner::gotWallpapers));
 	} else {
 		updateWallpapers();
 	}
+
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 	setMouseTracking(true);
 }
 
diff --git a/Telegram/SourceFiles/boxes/backgroundbox.h b/Telegram/SourceFiles/boxes/backgroundbox.h
index 66866f1655..ebdcab053a 100644
--- a/Telegram/SourceFiles/boxes/backgroundbox.h
+++ b/Telegram/SourceFiles/boxes/backgroundbox.h
@@ -23,7 +23,7 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 #include "abstractbox.h"
 #include "core/lambda_wrap.h"
 
-class BackgroundInner : public QWidget, public RPCSender {
+class BackgroundInner : public TWidget, public RPCSender, private base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/boxes/confirmbox.cpp b/Telegram/SourceFiles/boxes/confirmbox.cpp
index 10d67a9cae..61107ba4a1 100644
--- a/Telegram/SourceFiles/boxes/confirmbox.cpp
+++ b/Telegram/SourceFiles/boxes/confirmbox.cpp
@@ -546,7 +546,7 @@ ConfirmInviteBox::ConfirmInviteBox(const QString &title, const MTPChatPhoto &pho
 		if (!location.isNull()) {
 			_photo = ImagePtr(location);
 			if (!_photo->loaded()) {
-				connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
+				subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 				_photo->load();
 			}
 		}
diff --git a/Telegram/SourceFiles/boxes/contactsbox.cpp b/Telegram/SourceFiles/boxes/contactsbox.cpp
index f903768da1..16f02d661f 100644
--- a/Telegram/SourceFiles/boxes/contactsbox.cpp
+++ b/Telegram/SourceFiles/boxes/contactsbox.cpp
@@ -106,7 +106,7 @@ ContactsInner::ContactsInner(UserData *bot) : TWidget()
 }
 
 void ContactsInner::init() {
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 	connect(&_addContactLnk, SIGNAL(clicked()), App::wnd(), SLOT(onShowAddContact()));
 	connect(&_allAdmins, SIGNAL(changed()), this, SLOT(onAllAdminsChanged()));
 
@@ -1750,7 +1750,8 @@ MembersInner::MembersInner(ChannelData *channel, MembersFilter filter) : TWidget
 , _aboutWidth(st::boxWideWidth - st::contactsPadding.left() - st::contactsPadding.right())
 , _about(_aboutWidth)
 , _aboutHeight(0) {
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
+
 	connect(App::main(), SIGNAL(peerNameChanged(PeerData*,const PeerData::Names&,const PeerData::NameFirstChars&)), this, SLOT(onPeerNameChanged(PeerData*, const PeerData::Names&, const PeerData::NameFirstChars&)));
 	connect(App::main(), SIGNAL(peerPhotoChanged(PeerData*)), this, SLOT(peerUpdated(PeerData*)));
 
diff --git a/Telegram/SourceFiles/boxes/contactsbox.h b/Telegram/SourceFiles/boxes/contactsbox.h
index 59c41c09a0..27a13294a7 100644
--- a/Telegram/SourceFiles/boxes/contactsbox.h
+++ b/Telegram/SourceFiles/boxes/contactsbox.h
@@ -36,7 +36,7 @@ using MembersAlreadyIn = OrderedSet<UserData*>;
 QString cantInviteError();
 
 class ConfirmBox;
-class ContactsInner : public TWidget, public RPCSender {
+class ContactsInner : public TWidget, public RPCSender, private base::Subscriber {
 	Q_OBJECT
 
 private:
@@ -269,7 +269,7 @@ private:
 
 };
 
-class MembersInner : public TWidget, public RPCSender {
+class MembersInner : public TWidget, public RPCSender, private base::Subscriber {
 	Q_OBJECT
 
 private:
diff --git a/Telegram/SourceFiles/boxes/localstoragebox.cpp b/Telegram/SourceFiles/boxes/localstoragebox.cpp
index 29b3e62790..23057c10aa 100644
--- a/Telegram/SourceFiles/boxes/localstoragebox.cpp
+++ b/Telegram/SourceFiles/boxes/localstoragebox.cpp
@@ -33,10 +33,11 @@ LocalStorageBox::LocalStorageBox() : AbstractBox()
 	connect(_clear, SIGNAL(clicked()), this, SLOT(onClear()));
 	connect(_close, SIGNAL(clicked()), this, SLOT(onClose()));
 
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
 	connect(App::wnd(), SIGNAL(tempDirCleared(int)), this, SLOT(onTempDirCleared(int)));
 	connect(App::wnd(), SIGNAL(tempDirClearFailed(int)), this, SLOT(onTempDirClearFailed(int)));
 
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
+
 	checkLocalStoredCounts();
 	prepare();
 }
diff --git a/Telegram/SourceFiles/boxes/sharebox.cpp b/Telegram/SourceFiles/boxes/sharebox.cpp
index 19b249b365..b3fbec61b3 100644
--- a/Telegram/SourceFiles/boxes/sharebox.cpp
+++ b/Telegram/SourceFiles/boxes/sharebox.cpp
@@ -243,8 +243,6 @@ namespace internal {
 
 ShareInner::ShareInner(QWidget *parent) : ScrolledWidget(parent)
 , _chatsIndexed(std_::make_unique<Dialogs::IndexedList>(Dialogs::SortMode::Add)) {
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
-
 	_rowsTop = st::shareRowsTop;
 	_rowHeight = st::shareRowHeight;
 	setAttribute(Qt::WA_OpaquePaintEvent);
@@ -264,7 +262,12 @@ ShareInner::ShareInner(QWidget *parent) : ScrolledWidget(parent)
 
 	using UpdateFlag = Notify::PeerUpdate::Flag;
 	auto observeEvents = UpdateFlag::NameChanged | UpdateFlag::PhotoChanged;
-	Notify::registerPeerObserver(observeEvents, this, &ShareInner::notifyPeerUpdated);
+
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
+
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 }
 
 void ShareInner::setVisibleTopBottom(int visibleTop, int visibleBottom) {
diff --git a/Telegram/SourceFiles/boxes/sharebox.h b/Telegram/SourceFiles/boxes/sharebox.h
index 675fb92aab..d486e6e12e 100644
--- a/Telegram/SourceFiles/boxes/sharebox.h
+++ b/Telegram/SourceFiles/boxes/sharebox.h
@@ -108,7 +108,7 @@ private:
 
 namespace internal {
 
-class ShareInner : public ScrolledWidget, public RPCSender, public Notify::Observer {
+class ShareInner : public ScrolledWidget, public RPCSender, public Notify::Observer, private base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/boxes/stickersetbox.cpp b/Telegram/SourceFiles/boxes/stickersetbox.cpp
index 728cee6907..6c20fbc79e 100644
--- a/Telegram/SourceFiles/boxes/stickersetbox.cpp
+++ b/Telegram/SourceFiles/boxes/stickersetbox.cpp
@@ -41,7 +41,6 @@ constexpr int kArchivedLimitPerPage = 30;
 
 StickerSetInner::StickerSetInner(const MTPInputStickerSet &set) : ScrolledWidget()
 , _input(set) {
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
 	switch (set.type()) {
 	case mtpc_inputStickerSetID: _setId = set.c_inputStickerSetID().vid.v; _setAccess = set.c_inputStickerSetID().vaccess_hash.v; break;
 	case mtpc_inputStickerSetShortName: _setShortName = qs(set.c_inputStickerSetShortName().vshort_name); break;
@@ -49,6 +48,8 @@ StickerSetInner::StickerSetInner(const MTPInputStickerSet &set) : ScrolledWidget
 	MTP::send(MTPmessages_GetStickerSet(_input), rpcDone(&StickerSetInner::gotSet), rpcFail(&StickerSetInner::failedSet));
 	App::main()->updateStickers();
 
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
+
 	setMouseTracking(true);
 
 	_previewTimer.setSingleShot(true);
@@ -515,7 +516,7 @@ StickersInner::StickersInner(const Stickers::Order &archivedIds) : ScrolledWidge
 }
 
 void StickersInner::setup() {
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(onImageLoaded()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 	setMouseTracking(true);
 }
 
diff --git a/Telegram/SourceFiles/boxes/stickersetbox.h b/Telegram/SourceFiles/boxes/stickersetbox.h
index 3c7a936a32..1626fd08a4 100644
--- a/Telegram/SourceFiles/boxes/stickersetbox.h
+++ b/Telegram/SourceFiles/boxes/stickersetbox.h
@@ -25,7 +25,7 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 
 class ConfirmBox;
 
-class StickerSetInner : public ScrolledWidget, public RPCSender {
+class StickerSetInner : public ScrolledWidget, public RPCSender, private base::Subscriber {
 	Q_OBJECT
 
 public:
@@ -207,7 +207,7 @@ int32 stickerPacksCount(bool includeDisabledOfficial = false);
 
 namespace internal {
 
-class StickersInner : public ScrolledWidget, public RPCSender {
+class StickersInner : public ScrolledWidget, public RPCSender, private base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/core/basic_types.h b/Telegram/SourceFiles/core/basic_types.h
index 778aff01b1..2b22bc4cda 100644
--- a/Telegram/SourceFiles/core/basic_types.h
+++ b/Telegram/SourceFiles/core/basic_types.h
@@ -1064,7 +1064,7 @@ extern QAtomicInt ComponentIndexLast;
 template <typename Type>
 struct BaseComponent {
 	BaseComponent() {
-		static_assert(alignof(Type) <= sizeof(SmallestSizeType), "Components should align to a pointer!");
+		static_assert(alignof(Type) <= alignof(SmallestSizeType), "Components should align to a pointer!");
 	}
 	BaseComponent(const BaseComponent &other) = delete;
 	BaseComponent &operator=(const BaseComponent &other) = delete;
diff --git a/Telegram/SourceFiles/core/lambda_wrap.h b/Telegram/SourceFiles/core/lambda_wrap.h
index 9bc1fe084a..9305c66945 100644
--- a/Telegram/SourceFiles/core/lambda_wrap.h
+++ b/Telegram/SourceFiles/core/lambda_wrap.h
@@ -20,6 +20,10 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 */
 #pragma once
 
+#ifndef OS_MAC_OLD
+#include <memory>
+#endif // OS_MAC_OLD
+
 namespace base {
 namespace internal {
 
@@ -50,7 +54,7 @@ struct lambda_wrap_helper_base {
 	const call_type call;
 	const destruct_type destruct;
 
-	static constexpr size_t kFullStorageSize = 40U;
+	static constexpr size_t kFullStorageSize = sizeof(void*) + 24U;
 	static constexpr size_t kStorageSize = kFullStorageSize - sizeof(void*);
 
 	template <typename Lambda>
@@ -90,43 +94,47 @@ const lambda_wrap_empty<Return, Args...> lambda_wrap_empty<Return, Args...>::ins
 
 template <typename Lambda, typename IsLarge, typename Return, typename ...Args> struct lambda_wrap_helper_move_impl;
 
-template <typename Lambda, typename Return, typename ...Args>
-struct lambda_wrap_helper_move_impl<Lambda, std_::true_type, Return, Args...> : public lambda_wrap_helper_base<Return, Args...> {
-	using JustLambda = std_::decay_simple_t<Lambda>;
-	using LambdaPtr = std_::unique_ptr<JustLambda>;
-	using Parent = lambda_wrap_helper_base<Return, Args...>;
-	static void construct_move_other_method(void *lambda, void *source) {
-		auto source_lambda = static_cast<LambdaPtr*>(source);
-		new (lambda) LambdaPtr(std_::move(*source_lambda));
-	}
-	static void construct_move_lambda_method(void *lambda, void *source) {
-		auto source_lambda = static_cast<JustLambda*>(source);
-		new (lambda) LambdaPtr(std_::make_unique<JustLambda>(static_cast<JustLambda&&>(*source_lambda)));
-	}
-	static Return call_method(const void *lambda, Args... args) {
-		return (**static_cast<const LambdaPtr*>(lambda))(std_::forward<Args>(args)...);
-	}
-	static void destruct_method(const void *lambda) {
-		static_cast<const LambdaPtr*>(lambda)->~LambdaPtr();
-	}
-	lambda_wrap_helper_move_impl() : Parent(
-		&Parent::bad_construct_copy,
-		&lambda_wrap_helper_move_impl::construct_move_other_method,
-		&lambda_wrap_helper_move_impl::call_method,
-		&lambda_wrap_helper_move_impl::destruct_method) {
-	}
-
-protected:
-	lambda_wrap_helper_move_impl(
-		typename Parent::construct_copy_other_type construct_copy_other
-	) : Parent(
-		construct_copy_other,
-		&lambda_wrap_helper_move_impl::construct_move_other_method,
-		&lambda_wrap_helper_move_impl::call_method,
-		&lambda_wrap_helper_move_impl::destruct_method) {
-	}
-
-};
+//
+// Disable large lambda support.
+// If you really need it, just store data in some std_::unique_ptr<struct>.
+//
+//template <typename Lambda, typename Return, typename ...Args>
+//struct lambda_wrap_helper_move_impl<Lambda, std_::true_type, Return, Args...> : public lambda_wrap_helper_base<Return, Args...> {
+//	using JustLambda = std_::decay_simple_t<Lambda>;
+//	using LambdaPtr = std_::unique_ptr<JustLambda>;
+//	using Parent = lambda_wrap_helper_base<Return, Args...>;
+//	static void construct_move_other_method(void *lambda, void *source) {
+//		auto source_lambda = static_cast<LambdaPtr*>(source);
+//		new (lambda) LambdaPtr(std_::move(*source_lambda));
+//	}
+//	static void construct_move_lambda_method(void *lambda, void *source) {
+//		auto source_lambda = static_cast<JustLambda*>(source);
+//		new (lambda) LambdaPtr(std_::make_unique<JustLambda>(static_cast<JustLambda&&>(*source_lambda)));
+//	}
+//	static Return call_method(const void *lambda, Args... args) {
+//		return (**static_cast<const LambdaPtr*>(lambda))(std_::forward<Args>(args)...);
+//	}
+//	static void destruct_method(const void *lambda) {
+//		static_cast<const LambdaPtr*>(lambda)->~LambdaPtr();
+//	}
+//	lambda_wrap_helper_move_impl() : Parent(
+//		&Parent::bad_construct_copy,
+//		&lambda_wrap_helper_move_impl::construct_move_other_method,
+//		&lambda_wrap_helper_move_impl::call_method,
+//		&lambda_wrap_helper_move_impl::destruct_method) {
+//	}
+//
+//protected:
+//	lambda_wrap_helper_move_impl(
+//		typename Parent::construct_copy_other_type construct_copy_other
+//	) : Parent(
+//		construct_copy_other,
+//		&lambda_wrap_helper_move_impl::construct_move_other_method,
+//		&lambda_wrap_helper_move_impl::call_method,
+//		&lambda_wrap_helper_move_impl::destruct_method) {
+//	}
+//
+//};
 
 template <typename Lambda, typename Return, typename ...Args>
 struct lambda_wrap_helper_move_impl<Lambda, std_::false_type, Return, Args...> : public lambda_wrap_helper_base<Return, Args...> {
@@ -137,6 +145,12 @@ struct lambda_wrap_helper_move_impl<Lambda, std_::false_type, Return, Args...> :
 		new (lambda) JustLambda(static_cast<JustLambda&&>(*source_lambda));
 	}
 	static void construct_move_lambda_method(void *lambda, void *source) {
+		static_assert(alignof(JustLambda) <= alignof(void*), "Bad lambda alignment.");
+#ifndef OS_MAC_OLD
+		auto space = sizeof(JustLambda);
+		auto aligned = std::align(alignof(JustLambda), space, lambda, space);
+		t_assert(aligned == lambda);
+#endif // OS_MAC_OLD
 		auto source_lambda = static_cast<JustLambda*>(source);
 		new (lambda) JustLambda(static_cast<JustLambda&&>(*source_lambda));
 	}
@@ -177,23 +191,27 @@ const lambda_wrap_helper_move<Lambda, Return, Args...> lambda_wrap_helper_move<L
 
 template <typename Lambda, typename IsLarge, typename Return, typename ...Args> struct lambda_wrap_helper_copy_impl;
 
-template <typename Lambda, typename Return, typename ...Args>
-struct lambda_wrap_helper_copy_impl<Lambda, std_::true_type, Return, Args...> : public lambda_wrap_helper_move_impl<Lambda, std_::true_type, Return, Args...> {
-	using JustLambda = std_::decay_simple_t<Lambda>;
-	using LambdaPtr = std_::unique_ptr<JustLambda>;
-	using Parent = lambda_wrap_helper_move_impl<Lambda, std_::true_type, Return, Args...>;
-	static void construct_copy_other_method(void *lambda, const void *source) {
-		auto source_lambda = static_cast<const LambdaPtr*>(source);
-		new (lambda) LambdaPtr(std_::make_unique<JustLambda>(*source_lambda->get()));
-	}
-	static void construct_copy_lambda_method(void *lambda, const void *source) {
-		auto source_lambda = static_cast<const JustLambda*>(source);
-		new (lambda) LambdaPtr(std_::make_unique<JustLambda>(static_cast<const JustLambda &>(*source_lambda)));
-	}
-	lambda_wrap_helper_copy_impl() : Parent(&lambda_wrap_helper_copy_impl::construct_copy_other_method) {
-	}
-
-};
+//
+// Disable large lambda support.
+// If you really need it, just store data in some QSharedPointer<struct>.
+//
+//template <typename Lambda, typename Return, typename ...Args>
+//struct lambda_wrap_helper_copy_impl<Lambda, std_::true_type, Return, Args...> : public lambda_wrap_helper_move_impl<Lambda, std_::true_type, Return, Args...> {
+//	using JustLambda = std_::decay_simple_t<Lambda>;
+//	using LambdaPtr = std_::unique_ptr<JustLambda>;
+//	using Parent = lambda_wrap_helper_move_impl<Lambda, std_::true_type, Return, Args...>;
+//	static void construct_copy_other_method(void *lambda, const void *source) {
+//		auto source_lambda = static_cast<const LambdaPtr*>(source);
+//		new (lambda) LambdaPtr(std_::make_unique<JustLambda>(*source_lambda->get()));
+//	}
+//	static void construct_copy_lambda_method(void *lambda, const void *source) {
+//		auto source_lambda = static_cast<const JustLambda*>(source);
+//		new (lambda) LambdaPtr(std_::make_unique<JustLambda>(static_cast<const JustLambda &>(*source_lambda)));
+//	}
+//	lambda_wrap_helper_copy_impl() : Parent(&lambda_wrap_helper_copy_impl::construct_copy_other_method) {
+//	}
+//
+//};
 
 template <typename Lambda, typename Return, typename ...Args>
 struct lambda_wrap_helper_copy_impl<Lambda, std_::false_type, Return, Args...> : public lambda_wrap_helper_move_impl<Lambda, std_::false_type, Return, Args...> {
@@ -204,6 +222,12 @@ struct lambda_wrap_helper_copy_impl<Lambda, std_::false_type, Return, Args...> :
 		new (lambda) JustLambda(static_cast<const JustLambda &>(*source_lambda));
 	}
 	static void construct_copy_lambda_method(void *lambda, const void *source) {
+		static_assert(alignof(JustLambda) <= alignof(void*), "Bad lambda alignment.");
+#ifndef OS_MAC_OLD
+		auto space = sizeof(JustLambda);
+		auto aligned = std::align(alignof(JustLambda), space, lambda, space);
+		t_assert(aligned == lambda);
+#endif // OS_MAC_OLD
 		auto source_lambda = static_cast<const JustLambda*>(source);
 		new (lambda) JustLambda(static_cast<const JustLambda &>(*source_lambda));
 	}
@@ -356,7 +380,7 @@ public:
 		auto temp = other;
 		this->helper_->destruct(this->storage_);
 		this->helper_ = &internal::lambda_wrap_helper_copy<Lambda, Return, Args...>::instance;
-		internal::lambda_wrap_helper_copy<Lambda, Return, Args...>::construct_move_lambda_method(this->storage_, &other);
+		internal::lambda_wrap_helper_copy<Lambda, Return, Args...>::construct_copy_lambda_method(this->storage_, &other);
 		return *this;
 	}
 
diff --git a/Telegram/SourceFiles/dialogswidget.cpp b/Telegram/SourceFiles/dialogswidget.cpp
index eed96774f3..38e9caf2b3 100644
--- a/Telegram/SourceFiles/dialogswidget.cpp
+++ b/Telegram/SourceFiles/dialogswidget.cpp
@@ -46,13 +46,15 @@ DialogsInner::DialogsInner(QWidget *parent, MainWidget *main) : SplittedWidget(p
 	if (Global::DialogsModeEnabled()) {
 		importantDialogs = std_::make_unique<Dialogs::IndexedList>(Dialogs::SortMode::Date);
 	}
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
 	connect(main, SIGNAL(peerNameChanged(PeerData*, const PeerData::Names&, const PeerData::NameFirstChars&)), this, SLOT(onPeerNameChanged(PeerData*, const PeerData::Names&, const PeerData::NameFirstChars&)));
 	connect(main, SIGNAL(peerPhotoChanged(PeerData*)), this, SLOT(onPeerPhotoChanged(PeerData*)));
 	connect(main, SIGNAL(dialogRowReplaced(Dialogs::Row*,Dialogs::Row*)), this, SLOT(onDialogRowReplaced(Dialogs::Row*,Dialogs::Row*)));
 	connect(&_addContactLnk, SIGNAL(clicked()), App::wnd(), SLOT(onShowAddContact()));
 	connect(&_cancelSearchInPeer, SIGNAL(clicked()), this, SIGNAL(cancelSearchInPeer()));
 	_cancelSearchInPeer.hide();
+
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
+
 	refresh();
 }
 
diff --git a/Telegram/SourceFiles/dialogswidget.h b/Telegram/SourceFiles/dialogswidget.h
index 8891478f6c..743705025d 100644
--- a/Telegram/SourceFiles/dialogswidget.h
+++ b/Telegram/SourceFiles/dialogswidget.h
@@ -42,7 +42,7 @@ enum DialogsSearchRequestType {
 	DialogsSearchMigratedFromOffset,
 };
 
-class DialogsInner : public SplittedWidget, public RPCSender {
+class DialogsInner : public SplittedWidget, public RPCSender, private base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/history/field_autocomplete.cpp b/Telegram/SourceFiles/history/field_autocomplete.cpp
index bf8687542c..5b710363fc 100644
--- a/Telegram/SourceFiles/history/field_autocomplete.cpp
+++ b/Telegram/SourceFiles/history/field_autocomplete.cpp
@@ -44,8 +44,6 @@ FieldAutocomplete::FieldAutocomplete(QWidget *parent) : TWidget(parent)
 	connect(_inner, SIGNAL(stickerChosen(DocumentData*,FieldAutocomplete::ChooseMethod)), this, SIGNAL(stickerChosen(DocumentData*,FieldAutocomplete::ChooseMethod)));
 	connect(_inner, SIGNAL(mustScrollTo(int, int)), _scroll, SLOT(scrollToY(int, int)));
 
-	connect(App::wnd(), SIGNAL(imageLoaded()), _inner, SLOT(update()));
-
 	setFocusPolicy(Qt::NoFocus);
 	_scroll->setFocusPolicy(Qt::NoFocus);
 	_scroll->viewport()->setFocusPolicy(Qt::NoFocus);
@@ -539,6 +537,7 @@ FieldAutocompleteInner::FieldAutocompleteInner(FieldAutocomplete *parent, Mentio
 , _previewShown(false) {
 	_previewTimer.setSingleShot(true);
 	connect(&_previewTimer, SIGNAL(timeout()), this, SLOT(onPreview()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 }
 
 void FieldAutocompleteInner::paintEvent(QPaintEvent *e) {
@@ -933,7 +932,4 @@ void FieldAutocompleteInner::onPreview() {
 	}
 }
 
-FieldAutocompleteInner::~FieldAutocompleteInner() {
-}
-
 } // namespace internal
diff --git a/Telegram/SourceFiles/history/field_autocomplete.h b/Telegram/SourceFiles/history/field_autocomplete.h
index 71b4cba99d..9f824a8297 100644
--- a/Telegram/SourceFiles/history/field_autocomplete.h
+++ b/Telegram/SourceFiles/history/field_autocomplete.h
@@ -138,7 +138,7 @@ private:
 
 namespace internal {
 
-class FieldAutocompleteInner final : public TWidget {
+class FieldAutocompleteInner final : public TWidget, private base::Subscriber {
 	Q_OBJECT
 
 public:
@@ -150,8 +150,6 @@ public:
 
 	void setRecentInlineBotsInRows(int32 bots);
 
-	~FieldAutocompleteInner();
-
 signals:
 	void mentionChosen(UserData *user, FieldAutocomplete::ChooseMethod method) const;
 	void hashtagChosen(QString hashtag, FieldAutocomplete::ChooseMethod method) const;
diff --git a/Telegram/SourceFiles/historywidget.cpp b/Telegram/SourceFiles/historywidget.cpp
index 9b38e8eb5d..198a634b1a 100644
--- a/Telegram/SourceFiles/historywidget.cpp
+++ b/Telegram/SourceFiles/historywidget.cpp
@@ -3040,7 +3040,7 @@ HistoryWidget::HistoryWidget(QWidget *parent) : TWidget(parent)
 
 	setAcceptDrops(true);
 
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 	connect(&_scroll, SIGNAL(scrolled()), this, SLOT(onScroll()));
 	connect(&_reportSpamPanel, SIGNAL(reportClicked()), this, SLOT(onReportSpamClicked()));
 	connect(&_reportSpamPanel, SIGNAL(hideClicked()), this, SLOT(onReportSpamHide()));
diff --git a/Telegram/SourceFiles/layerwidget.cpp b/Telegram/SourceFiles/layerwidget.cpp
index 9c38039f1d..fb5374dd31 100644
--- a/Telegram/SourceFiles/layerwidget.cpp
+++ b/Telegram/SourceFiles/layerwidget.cpp
@@ -437,7 +437,7 @@ MediaPreviewWidget::MediaPreviewWidget(QWidget *parent) : TWidget(parent)
 , _a_shown(animation(this, &MediaPreviewWidget::step_shown))
 , _emojiSize(EmojiSizes[EIndex + 1] / cIntRetinaFactor()) {
 	setAttribute(Qt::WA_TransparentForMouseEvents);
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 }
 
 void MediaPreviewWidget::paintEvent(QPaintEvent *e) {
diff --git a/Telegram/SourceFiles/layerwidget.h b/Telegram/SourceFiles/layerwidget.h
index 14d1fbc84e..3161e00435 100644
--- a/Telegram/SourceFiles/layerwidget.h
+++ b/Telegram/SourceFiles/layerwidget.h
@@ -129,7 +129,7 @@ private:
 
 };
 
-class MediaPreviewWidget : public TWidget {
+class MediaPreviewWidget : public TWidget, private base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/mainwindow.cpp b/Telegram/SourceFiles/mainwindow.cpp
index cc3abdd4a4..f69dfd2fc6 100644
--- a/Telegram/SourceFiles/mainwindow.cpp
+++ b/Telegram/SourceFiles/mainwindow.cpp
@@ -406,8 +406,7 @@ MainWindow::MainWindow() {
 
 	connect(&_autoLockTimer, SIGNAL(timeout()), this, SLOT(checkAutoLock()));
 
-	connect(this, SIGNAL(imageLoaded()), this, SLOT(notifyUpdateAllPhotos()));
-
+	subscribe(FileDownload::ImageLoaded(), [this] { notifyUpdateAllPhotos(); });
 	subscribe(Global::RefSelfChanged(), [this]() { updateGlobalMenu(); });
 
 	setAttribute(Qt::WA_NoSystemBackground);
diff --git a/Telegram/SourceFiles/mainwindow.h b/Telegram/SourceFiles/mainwindow.h
index edd20a7945..804a6b01ad 100644
--- a/Telegram/SourceFiles/mainwindow.h
+++ b/Telegram/SourceFiles/mainwindow.h
@@ -292,8 +292,6 @@ signals:
 	void tempDirClearFailed(int task);
 	void newAuthorization();
 
-	void imageLoaded();
-
 private slots:
 	void onStateChanged(Qt::WindowState state);
 	void onSettingsDestroyed(QObject *was);
diff --git a/Telegram/SourceFiles/mtproto/facade.cpp b/Telegram/SourceFiles/mtproto/facade.cpp
index a5293f3535..6aa4064cb8 100644
--- a/Telegram/SourceFiles/mtproto/facade.cpp
+++ b/Telegram/SourceFiles/mtproto/facade.cpp
@@ -206,7 +206,7 @@ namespace {
 				}
 				req = i.value();
 			}
-			if (internal::Session *session = internal::getSession(newdcWithShift)) {
+			if (auto session = internal::getSession(newdcWithShift)) {
 				internal::registerRequest(requestId, (dcWithShift < 0) ? -newdcWithShift : newdcWithShift);
 				session->sendPrepared(req);
 			}
diff --git a/Telegram/SourceFiles/mtproto/file_download.cpp b/Telegram/SourceFiles/mtproto/file_download.cpp
index e4623dbc97..513fbfd8e0 100644
--- a/Telegram/SourceFiles/mtproto/file_download.cpp
+++ b/Telegram/SourceFiles/mtproto/file_download.cpp
@@ -207,9 +207,8 @@ void FileLoader::localLoaded(const StorageImageSaved &result, const QByteArray &
 		_fileIsOpen = false;
 		psPostprocessFile(QFileInfo(_file).absoluteFilePath());
 	}
-	emit App::wnd()->imageLoaded();
 	emit progress(this);
-	FileDownload::internal::notifyImageLoaded();
+	FileDownload::ImageLoaded().notify();
 	loadNext();
 }
 
@@ -516,8 +515,6 @@ void mtpFileLoader::partLoaded(int32 offset, const MTPupload_File &result, mtpRe
 		}
 		removeFromQueue();
 
-		emit App::wnd()->imageLoaded();
-
 		if (!_queue->queries) {
 			App::app()->killDownloadSessionsStart(_dc);
 		}
@@ -544,7 +541,7 @@ void mtpFileLoader::partLoaded(int32 offset, const MTPupload_File &result, mtpRe
 	}
 	emit progress(this);
 	if (_complete) {
-		FileDownload::internal::notifyImageLoaded();
+		FileDownload::ImageLoaded().notify();
 	}
 	loadNext();
 }
@@ -669,13 +666,11 @@ void webFileLoader::onFinished(const QByteArray &data) {
 	}
 	removeFromQueue();
 
-	emit App::wnd()->imageLoaded();
-
 	if (_localStatus == LocalNotFound || _localStatus == LocalFailed) {
 		Local::writeWebFile(_url, _data);
 	}
 	emit progress(this);
-	FileDownload::internal::notifyImageLoaded();
+	FileDownload::ImageLoaded().notify();
 	loadNext();
 }
 
@@ -1093,21 +1088,12 @@ namespace MTP {
 namespace FileDownload {
 namespace {
 
-using internal::ImageLoadedHandler;
-
-Notify::SimpleObservedEventRegistrator<ImageLoadedHandler> creator(nullptr, nullptr);
+base::Observable<void> ImageLoadedObservable;
 
 } // namespace
 
-namespace internal {
-
-Notify::ConnectionId plainRegisterImageLoadedObserver(ImageLoadedHandler &&handler) {
-	return creator.registerObserver(std_::forward<ImageLoadedHandler>(handler));
+base::Observable<void> &ImageLoaded() {
+	return ImageLoadedObservable;
 }
 
-void notifyImageLoaded() {
-	creator.notify();
-}
-
-} // namespace internal
-}
+} // namespace FileDownload
diff --git a/Telegram/SourceFiles/mtproto/file_download.h b/Telegram/SourceFiles/mtproto/file_download.h
index 0d883504bd..f4453ee7f3 100644
--- a/Telegram/SourceFiles/mtproto/file_download.h
+++ b/Telegram/SourceFiles/mtproto/file_download.h
@@ -397,21 +397,6 @@ void stopWebLoadManager();
 
 namespace FileDownload {
 
-namespace internal {
-
-using ImageLoadedHandler = base::lambda_unique<void()>;
-Notify::ConnectionId plainRegisterImageLoadedObserver(ImageLoadedHandler &&handler);
-
-void notifyImageLoaded();
-
-} // namespace internal
-
-template <typename ObserverType>
-void registerImageLoadedObserver(ObserverType *observer, void (ObserverType::*handler)()) {
-	auto connection = internal::plainRegisterImageLoadedObserver([observer, handler]() {
-		(observer->*handler)();
-	});
-	Notify::observerRegistered(observer, connection);
-}
+base::Observable<void> &ImageLoaded();
 
 } // namespace FileDownload
diff --git a/Telegram/SourceFiles/observer_peer.h b/Telegram/SourceFiles/observer_peer.h
index aee59e5c3d..53955b68c4 100644
--- a/Telegram/SourceFiles/observer_peer.h
+++ b/Telegram/SourceFiles/observer_peer.h
@@ -96,11 +96,9 @@ ConnectionId plainRegisterPeerObserver(PeerUpdate::Flags events, PeerUpdateHandl
 
 } // namespace internal
 
-template <typename ObserverType>
-void registerPeerObserver(PeerUpdate::Flags events, ObserverType *observer, void (ObserverType::*handler)(const PeerUpdate &)) {
-	auto connection = internal::plainRegisterPeerObserver(events, [observer, handler](const PeerUpdate &update) {
-		(observer->*handler)(update);
-	});
+template <typename ObserverType, typename Lambda>
+void registerPeerObserver(PeerUpdate::Flags events, ObserverType *observer, Lambda &&other) {
+	auto connection = internal::plainRegisterPeerObserver(events, std_::move(other));
 	observerRegistered(observer, connection);
 }
 
diff --git a/Telegram/SourceFiles/overviewwidget.cpp b/Telegram/SourceFiles/overviewwidget.cpp
index efbf98167c..db99a6a3df 100644
--- a/Telegram/SourceFiles/overviewwidget.cpp
+++ b/Telegram/SourceFiles/overviewwidget.cpp
@@ -89,7 +89,7 @@ OverviewInner::OverviewInner(OverviewWidget *overview, ScrollArea *scroll, PeerD
 , _touchAccelerationTime(0)
 , _touchTime(0)
 , _menu(0) {
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(update()));
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 
 	resize(_width, st::wndMinHeight);
 
diff --git a/Telegram/SourceFiles/overviewwidget.h b/Telegram/SourceFiles/overviewwidget.h
index 016d14ad22..cd785b2b8a 100644
--- a/Telegram/SourceFiles/overviewwidget.h
+++ b/Telegram/SourceFiles/overviewwidget.h
@@ -33,7 +33,7 @@ class Date;
 } // namespace Overview
 
 class OverviewWidget;
-class OverviewInner : public QWidget, public AbstractTooltipShower, public RPCSender {
+class OverviewInner : public QWidget, public AbstractTooltipShower, public RPCSender, private base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/profile/profile_actions_widget.cpp b/Telegram/SourceFiles/profile/profile_actions_widget.cpp
index df96da74bb..49f64ee4d4 100644
--- a/Telegram/SourceFiles/profile/profile_actions_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_actions_widget.cpp
@@ -39,7 +39,9 @@ ActionsWidget::ActionsWidget(QWidget *parent, PeerData *peer) : BlockWidget(pare
 		| UpdateFlag::UserIsBlocked
 		| UpdateFlag::BotCommandsChanged
 		| UpdateFlag::MembersChanged;
-	Notify::registerPeerObserver(observeEvents, this, &ActionsWidget::notifyPeerUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
 
 	validateBlockStatus();
 	refreshButtons();
diff --git a/Telegram/SourceFiles/profile/profile_block_widget.h b/Telegram/SourceFiles/profile/profile_block_widget.h
index 7b77d27702..541c9dedec 100644
--- a/Telegram/SourceFiles/profile/profile_block_widget.h
+++ b/Telegram/SourceFiles/profile/profile_block_widget.h
@@ -24,7 +24,7 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 
 namespace Profile {
 
-class BlockWidget : public ScrolledWidget, public Notify::Observer {
+class BlockWidget : public ScrolledWidget, public Notify::Observer, protected base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/profile/profile_cover.cpp b/Telegram/SourceFiles/profile/profile_cover.cpp
index 16e2cb6ccf..cdcc561511 100644
--- a/Telegram/SourceFiles/profile/profile_cover.cpp
+++ b/Telegram/SourceFiles/profile/profile_cover.cpp
@@ -68,8 +68,12 @@ CoverWidget::CoverWidget(QWidget *parent, PeerData *peer) : TWidget(parent)
 	auto observeEvents = ButtonsUpdateFlags
 		| UpdateFlag::NameChanged
 		| UpdateFlag::UserOnlineChanged;
-	Notify::registerPeerObserver(observeEvents, this, &CoverWidget::notifyPeerUpdated);
-	FileDialog::registerObserver(this, &CoverWidget::notifyFileQueryUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
+	subscribe(FileDialog::QueryDone(), [this](const FileDialog::QueryUpdate &update) {
+		notifyFileQueryUpdated(update);
+	});
 
 	connect(App::app(), SIGNAL(peerPhotoDone(PeerId)), this, SLOT(onPhotoUploadStatusChanged(PeerId)));
 	connect(App::app(), SIGNAL(peerPhotoFail(PeerId)), this, SLOT(onPhotoUploadStatusChanged(PeerId)));
diff --git a/Telegram/SourceFiles/profile/profile_cover.h b/Telegram/SourceFiles/profile/profile_cover.h
index 5b3c8023b8..a735c10622 100644
--- a/Telegram/SourceFiles/profile/profile_cover.h
+++ b/Telegram/SourceFiles/profile/profile_cover.h
@@ -40,7 +40,7 @@ class BackButton;
 class UserpicButton;
 class CoverDropArea;
 
-class CoverWidget final : public TWidget, public Notify::Observer {
+class CoverWidget final : public TWidget, public Notify::Observer, private base::Subscriber {
 	Q_OBJECT
 
 public:
diff --git a/Telegram/SourceFiles/profile/profile_fixed_bar.cpp b/Telegram/SourceFiles/profile/profile_fixed_bar.cpp
index 8d2cde28b9..36d44ee865 100644
--- a/Telegram/SourceFiles/profile/profile_fixed_bar.cpp
+++ b/Telegram/SourceFiles/profile/profile_fixed_bar.cpp
@@ -83,7 +83,9 @@ FixedBar::FixedBar(QWidget *parent, PeerData *peer) : TWidget(parent)
 
 	auto observeEvents = ButtonsUpdateFlags
 		| UpdateFlag::MigrationChanged;
-	Notify::registerPeerObserver(observeEvents, this, &FixedBar::notifyPeerUpdate);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdate(update);
+	});
 
 	refreshRightActions();
 }
diff --git a/Telegram/SourceFiles/profile/profile_info_widget.cpp b/Telegram/SourceFiles/profile/profile_info_widget.cpp
index 032f6cd6f4..c844fcb2f1 100644
--- a/Telegram/SourceFiles/profile/profile_info_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_info_widget.cpp
@@ -36,7 +36,9 @@ InfoWidget::InfoWidget(QWidget *parent, PeerData *peer) : BlockWidget(parent, pe
 		| UpdateFlag::UsernameChanged
 		| UpdateFlag::UserPhoneChanged
 		| UpdateFlag::UserCanShareContact;
-	Notify::registerPeerObserver(observeEvents, this, &InfoWidget::notifyPeerUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
 
 	refreshLabels();
 }
diff --git a/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp b/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp
index 294d4626b3..e5c3f29a9b 100644
--- a/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_invite_link_widget.cpp
@@ -33,7 +33,9 @@ using UpdateFlag = Notify::PeerUpdate::Flag;
 
 InviteLinkWidget::InviteLinkWidget(QWidget *parent, PeerData *peer) : BlockWidget(parent, peer, lang(lng_profile_invite_link_section)) {
 	auto observeEvents = UpdateFlag::InviteLinkChanged | UpdateFlag::UsernameChanged;
-	Notify::registerPeerObserver(observeEvents, this, &InviteLinkWidget::notifyPeerUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
 
 	refreshLink();
 	refreshVisibility();
diff --git a/Telegram/SourceFiles/profile/profile_members_widget.cpp b/Telegram/SourceFiles/profile/profile_members_widget.cpp
index 78db1d3c9e..f6bcc2f50e 100644
--- a/Telegram/SourceFiles/profile/profile_members_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_members_widget.cpp
@@ -49,16 +49,14 @@ MembersWidget::MembersWidget(QWidget *parent, PeerData *peer, TitleVisibility ti
 	auto observeEvents = UpdateFlag::AdminsChanged
 		| UpdateFlag::MembersChanged
 		| UpdateFlag::UserOnlineChanged;
-	Notify::registerPeerObserver(observeEvents, this, &MembersWidget::notifyPeerUpdated);
-	FileDownload::registerImageLoadedObserver(this, &MembersWidget::repaintCallback);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
+	subscribe(FileDownload::ImageLoaded(), [this] { update(); });
 
 	refreshMembers();
 }
 
-void MembersWidget::repaintCallback() {
-	update();
-}
-
 void MembersWidget::notifyPeerUpdated(const Notify::PeerUpdate &update) {
 	if (update.peer != peer()) {
 		if (update.flags & UpdateFlag::UserOnlineChanged) {
@@ -83,7 +81,7 @@ void MembersWidget::notifyPeerUpdated(const Notify::PeerUpdate &update) {
 			}
 		}
 	}
-	repaintCallback();
+	this->update();
 }
 
 void MembersWidget::refreshUserOnline(UserData *user) {
@@ -606,7 +604,9 @@ ChannelMembersWidget::ChannelMembersWidget(QWidget *parent, PeerData *peer) : Bl
 		| UpdateFlag::ChannelCanViewMembers
 		| UpdateFlag::AdminsChanged
 		| UpdateFlag::MembersChanged;
-	Notify::registerPeerObserver(observeEvents, this, &ChannelMembersWidget::notifyPeerUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
 
 	refreshButtons();
 }
diff --git a/Telegram/SourceFiles/profile/profile_members_widget.h b/Telegram/SourceFiles/profile/profile_members_widget.h
index 83ed921af1..6e7cb28b31 100644
--- a/Telegram/SourceFiles/profile/profile_members_widget.h
+++ b/Telegram/SourceFiles/profile/profile_members_widget.h
@@ -78,7 +78,6 @@ private slots:
 private:
 	// Observed notifications.
 	void notifyPeerUpdated(const Notify::PeerUpdate &update);
-	void repaintCallback();
 
 	void preloadUserPhotos();
 
diff --git a/Telegram/SourceFiles/profile/profile_settings_widget.cpp b/Telegram/SourceFiles/profile/profile_settings_widget.cpp
index c79d9e180e..ed47209ded 100644
--- a/Telegram/SourceFiles/profile/profile_settings_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_settings_widget.cpp
@@ -51,7 +51,9 @@ SettingsWidget::SettingsWidget(QWidget *parent, PeerData *peer) : BlockWidget(pa
 			observeEvents |= UpdateFlag::UsernameChanged | UpdateFlag::InviteLinkChanged;
 		}
 	}
-	Notify::registerPeerObserver(observeEvents, this, &SettingsWidget::notifyPeerUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
 
 	refreshButtons();
 	_enableNotifications->finishAnimations();
diff --git a/Telegram/SourceFiles/profile/profile_shared_media_widget.cpp b/Telegram/SourceFiles/profile/profile_shared_media_widget.cpp
index 23c4063956..1f6e4679e7 100644
--- a/Telegram/SourceFiles/profile/profile_shared_media_widget.cpp
+++ b/Telegram/SourceFiles/profile/profile_shared_media_widget.cpp
@@ -51,7 +51,9 @@ QString getButtonText(MediaOverviewType type, int count) {
 SharedMediaWidget::SharedMediaWidget(QWidget *parent, PeerData *peer) : BlockWidget(parent, peer, lang(lng_profile_shared_media))
 , _history(App::history(peer))
 , _migrated(peer->migrateFrom() ? App::history(peer->migrateFrom()) : nullptr) {
-	Notify::registerPeerObserver(Notify::PeerUpdate::Flag::SharedMediaChanged, this, &SharedMediaWidget::notifyPeerUpdated);
+	Notify::registerPeerObserver(Notify::PeerUpdate::Flag::SharedMediaChanged, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
 
 	App::main()->preloadOverviews(peer);
 	if (_migrated) {
diff --git a/Telegram/SourceFiles/profile/profile_userpic_button.cpp b/Telegram/SourceFiles/profile/profile_userpic_button.cpp
index e1b92dedba..6b7b1ed91c 100644
--- a/Telegram/SourceFiles/profile/profile_userpic_button.cpp
+++ b/Telegram/SourceFiles/profile/profile_userpic_button.cpp
@@ -36,8 +36,15 @@ UserpicButton::UserpicButton(QWidget *parent, PeerData *peer) : Button(parent),
 		_userpic = prepareUserpicPixmap();
 	}
 
-	Notify::registerPeerObserver(Notify::PeerUpdate::Flag::PhotoChanged, this, &UserpicButton::notifyPeerUpdated);
-	FileDownload::registerImageLoadedObserver(this, &UserpicButton::notifyImageLoaded);
+	Notify::registerPeerObserver(Notify::PeerUpdate::Flag::PhotoChanged, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
+	subscribe(FileDownload::ImageLoaded(), [this] {
+		if (_waiting && _peer->userpicLoaded()) {
+			_waiting = false;
+			startNewPhotoShowing();
+		}
+	});
 }
 
 void UserpicButton::showFinished() {
@@ -68,13 +75,6 @@ void UserpicButton::notifyPeerUpdated(const Notify::PeerUpdate &update) {
 	this->update();
 }
 
-void UserpicButton::notifyImageLoaded() {
-	if (_waiting && _peer->userpicLoaded()) {
-		_waiting = false;
-		startNewPhotoShowing();
-	}
-}
-
 void UserpicButton::processPeerPhoto() {
 	bool hasPhoto = (_peer->photoId && _peer->photoId != UnknownPeerPhotoId);
 	setCursor(hasPhoto ? style::cur_pointer : style::cur_default);
diff --git a/Telegram/SourceFiles/profile/profile_userpic_button.h b/Telegram/SourceFiles/profile/profile_userpic_button.h
index cd75d80a44..cfac826e1f 100644
--- a/Telegram/SourceFiles/profile/profile_userpic_button.h
+++ b/Telegram/SourceFiles/profile/profile_userpic_button.h
@@ -28,7 +28,7 @@ struct PeerUpdate;
 
 namespace Profile {
 
-class UserpicButton final : public Button, public Notify::Observer {
+class UserpicButton final : public Button, public Notify::Observer, private base::Subscriber {
 public:
 	UserpicButton(QWidget *parent, PeerData *peer);
 
@@ -41,7 +41,6 @@ protected:
 
 private:
 	void notifyPeerUpdated(const Notify::PeerUpdate &update);
-	void notifyImageLoaded();
 
 	void processPeerPhoto();
 	void processNewPeerPhoto();
diff --git a/Telegram/SourceFiles/settings/settings_background_widget.cpp b/Telegram/SourceFiles/settings/settings_background_widget.cpp
index 61c7cf27f9..ac25cbd539 100644
--- a/Telegram/SourceFiles/settings/settings_background_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_background_widget.cpp
@@ -163,9 +163,11 @@ void BackgroundRow::updateImage() {
 }
 
 BackgroundWidget::BackgroundWidget(QWidget *parent, UserData *self) : BlockWidget(parent, self, lang(lng_settings_section_background)) {
-	FileDialog::registerObserver(this, &BackgroundWidget::notifyFileQueryUpdated);
 	createControls();
 
+	subscribe(FileDialog::QueryDone(), [this](const FileDialog::QueryUpdate &update) {
+		notifyFileQueryUpdated(update);
+	});
 	subscribe(Window::chatBackground(), [this](const Window::ChatBackgroundUpdate &update) {
 		using Update = Window::ChatBackgroundUpdate;
 		if (update.type == Update::Type::New) {
diff --git a/Telegram/SourceFiles/settings/settings_cover.cpp b/Telegram/SourceFiles/settings/settings_cover.cpp
index 50d57b2997..a6f7f112d4 100644
--- a/Telegram/SourceFiles/settings/settings_cover.cpp
+++ b/Telegram/SourceFiles/settings/settings_cover.cpp
@@ -57,8 +57,13 @@ CoverWidget::CoverWidget(QWidget *parent, UserData *self) : BlockWidget(parent,
 	connect(_editNameInline, SIGNAL(clicked()), this, SLOT(onEditName()));
 
 	auto observeEvents = Notify::PeerUpdate::Flag::NameChanged;
-	Notify::registerPeerObserver(observeEvents, this, &CoverWidget::notifyPeerUpdated);
-	FileDialog::registerObserver(this, &CoverWidget::notifyFileQueryUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
+
+	subscribe(FileDialog::QueryDone(), [this](const FileDialog::QueryUpdate &update) {
+		notifyFileQueryUpdated(update);
+	});
 
 	connect(App::app(), SIGNAL(peerPhotoDone(PeerId)), this, SLOT(onPhotoUploadStatusChanged(PeerId)));
 	connect(App::app(), SIGNAL(peerPhotoFail(PeerId)), this, SLOT(onPhotoUploadStatusChanged(PeerId)));
diff --git a/Telegram/SourceFiles/settings/settings_general_widget.cpp b/Telegram/SourceFiles/settings/settings_general_widget.cpp
index 60b2a15e28..4945dd5c8c 100644
--- a/Telegram/SourceFiles/settings/settings_general_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_general_widget.cpp
@@ -171,7 +171,9 @@ GeneralWidget::GeneralWidget(QWidget *parent, UserData *self) : BlockWidget(pare
 , _changeLanguage(this, lang(lng_settings_change_lang), st::defaultBoxLinkButton) {
 	connect(_changeLanguage, SIGNAL(clicked()), this, SLOT(onChangeLanguage()));
 	subscribe(Global::RefChooseCustomLang(), [this]() { chooseCustomLang(); });
-	FileDialog::registerObserver(this, &GeneralWidget::notifyFileQueryUpdated);
+	subscribe(FileDialog::QueryDone(), [this](const FileDialog::QueryUpdate &update) {
+		notifyFileQueryUpdated(update);
+	});
 	refreshControls();
 }
 
diff --git a/Telegram/SourceFiles/settings/settings_info_widget.cpp b/Telegram/SourceFiles/settings/settings_info_widget.cpp
index 28219a8583..e6b83ca0ab 100644
--- a/Telegram/SourceFiles/settings/settings_info_widget.cpp
+++ b/Telegram/SourceFiles/settings/settings_info_widget.cpp
@@ -34,7 +34,9 @@ using UpdateFlag = Notify::PeerUpdate::Flag;
 
 InfoWidget::InfoWidget(QWidget *parent, UserData *self) : BlockWidget(parent, self, lang(lng_settings_section_info)) {
 	auto observeEvents = UpdateFlag::UsernameChanged | UpdateFlag::UserPhoneChanged;
-	Notify::registerPeerObserver(observeEvents, this, &InfoWidget::notifyPeerUpdated);
+	Notify::registerPeerObserver(observeEvents, this, [this](const Notify::PeerUpdate &update) {
+		notifyPeerUpdated(update);
+	});
 
 	createControls();
 }
diff --git a/Telegram/SourceFiles/stickers/emoji_pan.cpp b/Telegram/SourceFiles/stickers/emoji_pan.cpp
index a6060ffda4..d7a73e2217 100644
--- a/Telegram/SourceFiles/stickers/emoji_pan.cpp
+++ b/Telegram/SourceFiles/stickers/emoji_pan.cpp
@@ -801,7 +801,6 @@ StickerPanInner::StickerPanInner() : ScrolledWidget()
 	setFocusPolicy(Qt::NoFocus);
 	setAttribute(Qt::WA_OpaquePaintEvent);
 
-	connect(App::wnd(), SIGNAL(imageLoaded()), this, SLOT(onImageLoaded()));
 	connect(&_settings, SIGNAL(clicked()), this, SLOT(onSettings()));
 
 	_previewTimer.setSingleShot(true);
@@ -809,6 +808,11 @@ StickerPanInner::StickerPanInner() : ScrolledWidget()
 
 	_updateInlineItems.setSingleShot(true);
 	connect(&_updateInlineItems, SIGNAL(timeout()), this, SLOT(onUpdateInlineItems()));
+
+	subscribe(FileDownload::ImageLoaded(), [this] {
+		update();
+		readVisibleSets();
+	});
 }
 
 void StickerPanInner::setMaxHeight(int32 h) {
@@ -855,11 +859,6 @@ void StickerPanInner::readVisibleSets() {
 	}
 }
 
-void StickerPanInner::onImageLoaded() {
-	update();
-	readVisibleSets();
-}
-
 int StickerPanInner::featuredRowHeight() const {
 	return st::featuredStickersHeader + st::stickerPanSize.height() + st::featuredStickersSkip;
 }
diff --git a/Telegram/SourceFiles/stickers/emoji_pan.h b/Telegram/SourceFiles/stickers/emoji_pan.h
index 92da29b81f..71b542af7f 100644
--- a/Telegram/SourceFiles/stickers/emoji_pan.h
+++ b/Telegram/SourceFiles/stickers/emoji_pan.h
@@ -207,7 +207,7 @@ struct StickerIcon {
 	int pixh = 0;
 };
 
-class StickerPanInner : public ScrolledWidget {
+class StickerPanInner : public ScrolledWidget, private base::Subscriber {
 	Q_OBJECT
 
 public:
@@ -274,7 +274,6 @@ private slots:
 	void onPreview();
 	void onUpdateInlineItems();
 	void onSwitchPm();
-	void onImageLoaded();
 
 signals:
 	void selected(DocumentData *sticker);
diff --git a/Telegram/SourceFiles/structs.h b/Telegram/SourceFiles/structs.h
index f9627501ce..85c8bd0284 100644
--- a/Telegram/SourceFiles/structs.h
+++ b/Telegram/SourceFiles/structs.h
@@ -27,12 +27,11 @@ static const ChannelId NoChannel = 0;
 
 typedef int32 MsgId;
 struct FullMsgId {
-	FullMsgId() : channel(NoChannel), msg(0) {
-	}
+	FullMsgId() = default;
 	FullMsgId(ChannelId channel, MsgId msg) : channel(channel), msg(msg) {
 	}
-	ChannelId channel;
-	MsgId msg;
+	ChannelId channel = NoChannel;
+	MsgId msg = 0;
 };
 
 typedef uint64 PeerId;
diff --git a/Telegram/SourceFiles/ui/filedialog.cpp b/Telegram/SourceFiles/ui/filedialog.cpp
index 45a947ceb8..4601b616e8 100644
--- a/Telegram/SourceFiles/ui/filedialog.cpp
+++ b/Telegram/SourceFiles/ui/filedialog.cpp
@@ -255,7 +255,7 @@ QString filedialogAllFilesFilter() {
 namespace FileDialog {
 namespace {
 
-using internal::QueryUpdateHandler;
+base::Observable<QueryUpdate> QueryDoneObservable;
 
 struct Query {
 	enum class Type {
@@ -285,16 +285,10 @@ void StartCallback() {
 	Queries.makeIfNull();
 }
 
-void FinishCallback() {
-	Queries.clear();
-}
-
-Notify::SimpleObservedEventRegistrator<QueryUpdateHandler> creator(StartCallback, FinishCallback);
-
 } // namespace
 
 QueryId queryReadFile(const QString &caption, const QString &filter) {
-	t_assert(creator.started());
+	Queries.makeIfNull();
 
 	Queries->push_back(Query(Query::Type::ReadFile, caption, filter));
 	Global::RefHandleFileDialogQueue().call();
@@ -302,7 +296,7 @@ QueryId queryReadFile(const QString &caption, const QString &filter) {
 }
 
 QueryId queryReadFiles(const QString &caption, const QString &filter) {
-	t_assert(creator.started());
+	Queries.makeIfNull();
 
 	Queries->push_back(Query(Query::Type::ReadFiles, caption, filter));
 	Global::RefHandleFileDialogQueue().call();
@@ -310,7 +304,7 @@ QueryId queryReadFiles(const QString &caption, const QString &filter) {
 }
 
 QueryId queryWriteFile(const QString &caption, const QString &filter, const QString &filePath) {
-	t_assert(creator.started());
+	Queries.makeIfNull();
 
 	Queries->push_back(Query(Query::Type::WriteFile, caption, filter, filePath));
 	Global::RefHandleFileDialogQueue().call();
@@ -318,7 +312,7 @@ QueryId queryWriteFile(const QString &caption, const QString &filter, const QStr
 }
 
 QueryId queryReadFolder(const QString &caption) {
-	t_assert(creator.started());
+	Queries.makeIfNull();
 
 	Queries->push_back(Query(Query::Type::ReadFolder, caption));
 	Global::RefHandleFileDialogQueue().call();
@@ -326,7 +320,7 @@ QueryId queryReadFolder(const QString &caption) {
 }
 
 bool processQuery() {
-	if (!creator.started() || !Global::started() || Queries->isEmpty()) return false;
+	if (!Queries || !Global::started() || Queries->isEmpty()) return false;
 
 	auto query = Queries->front();
 	Queries->pop_front();
@@ -374,17 +368,14 @@ bool processQuery() {
 	}
 
 	// No one knows what happened during filedialogGet*() call in the event loop.
-	if (!creator.started() || !Global::started()) return false;
+	if (!Queries || !Global::started()) return false;
 
-	creator.notify(update);
+	QueryDone().notify(std_::move(update));
 	return true;
 }
 
-namespace internal {
-
-Notify::ConnectionId plainRegisterObserver(QueryUpdateHandler &&handler) {
-	return creator.registerObserver(std_::forward<QueryUpdateHandler>(handler));
+base::Observable<QueryUpdate> &QueryDone() {
+	return QueryDoneObservable;
 }
 
-} // namespace internal
 } // namespace FileDialog
diff --git a/Telegram/SourceFiles/ui/filedialog.h b/Telegram/SourceFiles/ui/filedialog.h
index a73b97603c..fac4b2a7de 100644
--- a/Telegram/SourceFiles/ui/filedialog.h
+++ b/Telegram/SourceFiles/ui/filedialog.h
@@ -63,19 +63,6 @@ QueryId queryReadFolder(const QString &caption);
 // NB! This function enters an event loop.
 bool processQuery();
 
-namespace internal {
-
-using QueryUpdateHandler = base::lambda_unique<void(const QueryUpdate&)>;
-Notify::ConnectionId plainRegisterObserver(QueryUpdateHandler &&handler);
-
-} // namespace internal
-
-template <typename ObserverType>
-void registerObserver(ObserverType *observer, void (ObserverType::*handler)(const QueryUpdate &)) {
-	auto connection = internal::plainRegisterObserver([observer, handler](const QueryUpdate &update) {
-		(observer->*handler)(update);
-	});
-	Notify::observerRegistered(observer, connection);
-}
+base::Observable<QueryUpdate> &QueryDone();
 
 } // namespace FileDialog