Get rid of modal parent hack

It was introduced to workaround the absence of size hints propagating in Qt 5.12 Wayland backend, there's no need in it anymore

Telegram/SourceFiles/calls/calls_group_panel.cpp

@@ -253,7 +253,6 @@ std::unique_ptr<PeerListRow> InviteContactsController::createRow(
 Panel::Panel(not_null<GroupCall*> call)
 : _call(call)
 , _peer(call->peer())
-, _window(std::make_unique<Ui::Window>(Core::App().getModalParent()))
 , _layerBg(std::make_unique<Ui::LayerManager>(_window->body()))
 #ifndef Q_OS_MAC
 , _controls(std::make_unique<Ui::Platform::TitleControls>(

Telegram/SourceFiles/calls/calls_panel.cpp

@@ -33,7 +33,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/empty_userpic.h"
 #include "ui/emoji_config.h"
 #include "core/application.h"
-#include "mainwindow.h"
 #include "lang/lang_keys.h"
 #include "main/main_session.h"
 #include "apiwrap.h"
@@ -185,7 +184,6 @@ void Panel::Incoming::fillBottomShadow(QPainter &p) {
 Panel::Panel(not_null<Call*> call)
 : _call(call)
 , _user(call->user())
-, _window(std::make_unique<Ui::Window>(Core::App().getModalParent()))
 #ifndef Q_OS_MAC
 , _controls(std::make_unique<Ui::Platform::TitleControls>(
 	_window->body(),

Telegram/SourceFiles/core/application.cpp

@@ -23,7 +23,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "core/ui_integration.h"
 #include "chat_helpers/emoji_keywords.h"
 #include "chat_helpers/stickers_emoji_image_loader.h"
-#include "base/platform/base_platform_info.h"
 #include "base/platform/base_platform_last_input.h"
 #include "platform/platform_specific.h"
 #include "mainwindow.h"
@@ -977,13 +976,6 @@ void Application::notifyFileDialogShown(bool shown) {
 	}
 }
 
-QWidget *Application::getModalParent() {
-	return (Platform::IsWayland() && activeWindow())
-		? activeWindow()->widget().get()
-		: nullptr;
-}
-
-
 void Application::checkMediaViewActivation() {
 	if (_mediaView && !_mediaView->isHidden()) {
 		_mediaView->activateWindow();

Telegram/SourceFiles/core/application.h

@@ -139,7 +139,6 @@ public:
 	bool minimizeActiveWindow();
 	[[nodiscard]] QWidget *getFileDialogParent();
 	void notifyFileDialogShown(bool shown);
-	[[nodiscard]] QWidget *getModalParent();
 	void checkSystemDarkMode();
 
 	// Media view interface.

Telegram/SourceFiles/media/view/media_view_pip.cpp

@@ -373,8 +373,7 @@ QImage RotateFrameImage(QImage image, int rotation) {
 PipPanel::PipPanel(
 	QWidget *parent,
 	Fn<void(QPainter&, FrameRequest)> paint)
-: PipParent(Core::App().getModalParent())
-, _parent(parent)
+: _parent(parent)
 , _paint(std::move(paint)) {
 	setWindowFlags(Qt::Tool
 		| Qt::WindowStaysOnTopHint

Telegram/SourceFiles/settings/settings_notifications.cpp

@@ -20,7 +20,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "platform/platform_specific.h"
 #include "platform/platform_notifications_manager.h"
 #include "base/platform/base_platform_info.h"
-#include "mainwindow.h"
 #include "core/application.h"
 #include "main/main_session.h"
 #include "main/main_account.h"
@@ -438,8 +437,7 @@ NotificationsCount::~NotificationsCount() {
 NotificationsCount::SampleWidget::SampleWidget(
 	NotificationsCount *owner,
 	const QPixmap &cache)
-: QWidget(Core::App().getModalParent())
-, _owner(owner)
+: _owner(owner)
 , _cache(cache) {
 	const QSize size(
 		cache.width() / cache.devicePixelRatio(),

Telegram/SourceFiles/ui/widgets/separate_panel.cpp

@@ -31,8 +31,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 namespace Ui {
 
 SeparatePanel::SeparatePanel()
-: RpWidget(Core::App().getModalParent())
-, _close(this, st::separatePanelClose)
+: _close(this, st::separatePanelClose)
 , _back(this, object_ptr<Ui::IconButton>(this, st::separatePanelBack))
 , _body(this) {
 	setMouseTracking(true);

Telegram/SourceFiles/window/notifications_manager_default.cpp

@@ -30,7 +30,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/call_delayed.h"
 #include "facades.h"
 #include "app.h"
-#include "mainwindow.h"
 #include "styles/style_dialogs.h"
 #include "styles/style_layers.h"
 #include "styles/style_window.h"
@@ -422,8 +421,7 @@ Widget::Widget(
 	QPoint startPosition,
 	int shift,
 	Direction shiftDirection)
-: RpWidget(Core::App().getModalParent())
-, _manager(manager)
+: _manager(manager)
 , _startPosition(startPosition)
 , _direction(shiftDirection)
 , _shift(shift)