Support swipe-back from main menu.

Telegram/SourceFiles/window/window_main_menu.cpp

@@ -8,6 +8,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "window/window_main_menu.h"
 
 #include "apiwrap.h"
+#include "base/event_filter.h"
 #include "base/qt_signal_producer.h"
 #include "boxes/about_box.h"
 #include "boxes/peer_list_controllers.h"
@@ -39,12 +40,14 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "support/support_templates.h"
 #include "ui/boxes/confirm_box.h"
 #include "ui/chat/chat_theme.h"
+#include "ui/controls/swipe_handler.h"
 #include "ui/controls/userpic_button.h"
 #include "ui/effects/snowflakes.h"
 #include "ui/effects/toggle_arrow.h"
 #include "ui/painter.h"
 #include "ui/text/text_options.h"
 #include "ui/text/text_utilities.h"
+#include "ui/ui_utility.h"
 #include "ui/unread_badge_paint.h"
 #include "ui/vertical_list.h"
 #include "ui/widgets/menu/menu_add_action_callback_factory.h"
@@ -532,6 +535,8 @@ MainMenu::MainMenu(
 			}
 		}, lifetime());
 	}
+
+	setupSwipe();
 }
 
 MainMenu::~MainMenu() = default;
@@ -896,6 +901,19 @@ void MainMenu::chooseEmojiStatus() {
 	}
 }
 
+bool MainMenu::eventHook(QEvent *event) {
+	const auto type = event->type();
+	if (type == QEvent::TouchBegin
+		|| type == QEvent::TouchUpdate
+		|| type == QEvent::TouchEnd
+		|| type == QEvent::TouchCancel) {
+		QTouchEvent ev = *static_cast<QTouchEvent*>(event);
+		ev.setTimestamp(crl::now());
+		QGuiApplication::sendEvent(_inner, &ev);
+	}
+	return RpWidget::eventHook(event);
+}
+
 void MainMenu::paintEvent(QPaintEvent *e) {
 	auto p = Painter(this);
 	const auto clip = e->rect();
@@ -996,4 +1014,60 @@ rpl::producer<OthersUnreadState> OtherAccountsUnreadState(
 	});
 }
 
+void MainMenu::setupSwipe() {
+	const auto outer = _controller->widget()->body();
+	base::install_event_filter(this, outer, [=](not_null<QEvent*> e) {
+		const auto type = e->type();
+		if (type == QEvent::TouchBegin
+			|| type == QEvent::TouchUpdate
+			|| type == QEvent::TouchEnd
+			|| type == QEvent::TouchCancel) {
+			QGuiApplication::sendEvent(_inner, e);
+			return base::EventFilterResult::Cancel;
+		} else if (type == QEvent::Wheel) {
+			const auto w = static_cast<QWheelEvent*>(e.get());
+			const auto d = Ui::ScrollDeltaF(w);
+			if (std::abs(d.x()) > std::abs(d.y())) {
+				QGuiApplication::sendEvent(_inner, e);
+				return base::EventFilterResult::Cancel;
+			}
+		}
+		return base::EventFilterResult::Continue;
+	});
+	const auto handles = outer->testAttribute(Qt::WA_AcceptTouchEvents);
+	if (!handles) {
+		outer->setAttribute(Qt::WA_AcceptTouchEvents);
+		lifetime().add([=] {
+			outer->setAttribute(Qt::WA_AcceptTouchEvents, false);
+		});
+	}
+
+	Ui::Controls::SetupSwipeHandler(_inner, _scroll.data(), [=](
+			Ui::Controls::SwipeContextData data) {
+		if (data.translation < 0) {
+			if (!_swipeBackData.callback) {
+				_swipeBackData = Ui::Controls::SetupSwipeBack(
+					this,
+					[=]() -> std::pair<QColor, QColor> {
+						return {
+							st::historyForwardChooseBg->c,
+							st::historyForwardChooseFg->c,
+						};
+					});
+			}
+			_swipeBackData.callback(data);
+			return;
+		} else if (_swipeBackData.lifetime) {
+			_swipeBackData = {};
+		}
+	}, [=](int, Qt::LayoutDirection direction) {
+		if (direction != Qt::LeftToRight) {
+			return Ui::Controls::SwipeHandlerFinishData();
+		}
+		return Ui::Controls::DefaultSwipeBackHandlerFinishData([=] {
+			closeLayer();
+		});
+	});
+}
+
 } // namespace Window

Telegram/SourceFiles/window/window_main_menu.h

@@ -12,6 +12,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/binary_guard.h"
 #include "ui/rp_widget.h"
 #include "ui/unread_badge.h"
+#include "ui/controls/swipe_handler_data.h"
 #include "ui/layers/layer_widget.h"
 
 namespace Ui {
@@ -49,7 +50,11 @@ public:
 	void parentResized() override;
 	void showFinished() override;
 
-protected:
+private:
+	class ToggleAccountsButton;
+	class ResetScaleButton;
+
+	bool eventHook(QEvent *event) override;
 	void paintEvent(QPaintEvent *e) override;
 	void resizeEvent(QResizeEvent *e) override;
 
@@ -57,10 +62,6 @@ protected:
 		setFocus();
 	}
 
-private:
-	class ToggleAccountsButton;
-	class ResetScaleButton;
-
 	void moveBadge();
 	void setupUserpicButton();
 	void setupAccounts();
@@ -73,6 +74,7 @@ private:
 	void initResetScaleButton();
 	void toggleAccounts();
 	void chooseEmojiStatus();
+	void setupSwipe();
 
 	void drawName(Painter &p);
 
@@ -99,6 +101,8 @@ private:
 	base::Timer _nightThemeSwitch;
 	base::unique_qptr<Ui::PopupMenu> _contextMenu;
 
+	Ui::Controls::SwipeBackResult _swipeBackData;
+
 	rpl::variable<bool> _showFinished = false;
 
 };