Added implementation of drag'n'drop in section of scheduled messages.

Telegram/SourceFiles/history/history_drag_area.cpp

@@ -49,7 +49,8 @@ DragArea::Areas DragArea::SetupDragAreaToContainer(
 	auto &lifetime = container->lifetime();
 	container->setAcceptDrops(true);
 
-	const auto attachDragDocument = Ui::CreateChild<DragArea>(container.get());
+	const auto attachDragDocument =
+		Ui::CreateChild<DragArea>(container.get());
 	const auto attachDragPhoto = Ui::CreateChild<DragArea>(container.get());
 
 	attachDragDocument->hide();
@@ -183,34 +184,37 @@ DragArea::Areas DragArea::SetupDragAreaToContainer(
 		e->acceptProposedAction();
 	};
 
+	const auto processDragEvents = [=](not_null<QEvent*> event) {
+		switch (event->type()) {
+		case QEvent::DragEnter:
+			dragEnterEvent(static_cast<QDragEnterEvent*>(event.get()));
+			return true;
+		case QEvent::DragLeave:
+			dragLeaveEvent(static_cast<QDragLeaveEvent*>(event.get()));
+			return true;
+		case QEvent::Drop:
+			dropEvent(static_cast<QDropEvent*>(event.get()));
+			return true;
+		};
+		return false;
+	};
+
 	container->events(
 	) | rpl::filter([=](not_null<QEvent*> event) {
 		return ranges::contains(kDragAreaEvents, event->type());
 	}) | rpl::start_with_next([=](not_null<QEvent*> event) {
 		const auto type = event->type();
 
-		if (type == QEvent::DragEnter) {
-			dragEnterEvent(static_cast<QDragEnterEvent*>(event.get()));
-		} else if (type == QEvent::DragLeave) {
-			dragLeaveEvent(static_cast<QDragLeaveEvent*>(event.get()));
-		} else if (type == QEvent::Drop) {
-			dropEvent(static_cast<QDropEvent*>(event.get()));
-		} else if (type == QEvent::Leave) {
-			resetDragStateIfNeeded();
-		} else if (type == QEvent::MouseButtonRelease) {
+		if (processDragEvents(event)) {
+			return;
+		} else if (type == QEvent::Leave
+			|| type == QEvent::MouseButtonRelease) {
 			resetDragStateIfNeeded();
 		}
 	}, lifetime);
 
 	const auto eventFilter = [=](not_null<QEvent*> event) {
-		const auto type = event->type();
-		if (type == QEvent::DragEnter) {
-			dragEnterEvent(static_cast<QDragEnterEvent*>(event.get()));
-		} else if (type == QEvent::DragLeave) {
-			dragLeaveEvent(static_cast<QDragLeaveEvent*>(event.get()));
-		} else if (type == QEvent::Drop) {
-			dropEvent(static_cast<QDropEvent*>(event.get()));
-		}
+		processDragEvents(event);
 		return base::EventFilterResult::Continue;
 	};
 	base::install_event_filter(attachDragDocument, eventFilter);

Telegram/SourceFiles/history/view/history_view_scheduled_section.cpp

@@ -12,8 +12,10 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "history/view/history_view_list_widget.h"
 #include "history/view/history_view_schedule_box.h"
 #include "history/history.h"
+#include "history/history_drag_area.h"
 #include "history/history_item.h"
 #include "chat_helpers/message_field.h" // SendMenuType.
+#include "ui/delayed_activation.h"
 #include "ui/widgets/scroll_area.h"
 #include "ui/widgets/shadow.h"
 #include "ui/layers/generic_box.h"
@@ -34,6 +36,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/call_delayed.h"
 #include "core/file_utilities.h"
 #include "main/main_session.h"
+#include "mainwindow.h"
 #include "data/data_session.h"
 #include "data/data_user.h"
 #include "data/data_scheduled_messages.h"
@@ -1010,6 +1013,11 @@ void ScheduledWidget::showAnimatedHook(
 void ScheduledWidget::showFinishedHook() {
 	_topBar->setAnimatingMode(false);
 	_composeControls->showFinished();
+
+	// We should setup the drag area only after
+	// the section animation is finished,
+	// because after that the method showChildren() is called.
+	setupDragArea();
 }
 
 bool ScheduledWidget::floatPlayerHandleWheelEvent(QEvent *e) {
@@ -1172,4 +1180,23 @@ void ScheduledWidget::clearSelected() {
 	_inner->cancelSelection();
 }
 
+void ScheduledWidget::setupDragArea() {
+	const auto areas = DragArea::SetupDragAreaToContainer(
+		this,
+		[=] { return !_history; },
+		nullptr,
+		[=] { updateControlsGeometry(); });
+
+	const auto droppedCallback = [=](CompressConfirm compressed) {
+		return [=](const QMimeData *data) {
+			confirmSendingFiles(data, compressed);
+			const auto window = controller()->widget();
+			window->activateWindow();
+			Ui::ActivateWindowDelayed(window);
+		};
+	};
+	areas.document->setDroppedCallback(droppedCallback(CompressConfirm::No));
+	areas.photo->setDroppedCallback(droppedCallback(CompressConfirm::Yes));
+}
+
 } // namespace HistoryView

Telegram/SourceFiles/history/view/history_view_scheduled_section.h

@@ -129,6 +129,8 @@ private:
 
 	void setupComposeControls();
 
+	void setupDragArea();
+
 	void setupScrollDownButton();
 	void scrollDownClicked();
 	void scrollDownAnimationFinish();