Added preview of reaction to posts on right click.

Telegram/CMakeLists.txt

@@ -924,6 +924,8 @@ PRIVATE
     history/view/history_view_pinned_tracker.h
     history/view/history_view_quick_action.cpp
     history/view/history_view_quick_action.h
+    history/view/history_view_reaction_preview.cpp
+    history/view/history_view_reaction_preview.h
     history/view/history_view_reply.cpp
     history/view/history_view_reply.h
     history/view/history_view_requests_bar.cpp

Telegram/SourceFiles/history/history_inner_widget.cpp

@@ -26,6 +26,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "history/view/history_view_service_message.h"
 #include "history/view/history_view_cursor_state.h"
 #include "history/view/history_view_context_menu.h"
+#include "history/view/history_view_reaction_preview.h"
 #include "history/view/history_view_quick_action.h"
 #include "history/view/history_view_emoji_interactions.h"
 #include "history/history_item_components.h"
@@ -2373,6 +2374,11 @@ void HistoryInner::showContextMenu(QContextMenuEvent *e, bool showFromTouch) {
 				_whoReactedMenuLifetime);
 			e->accept();
 			return;
+		} else if (HistoryView::ShowReactionPreview(
+				_controller,
+				leaderOrSelf->fullId(),
+				clickedReaction)) {
+			return;
 		}
 	}
 	if (!linkPhoneNumber.isEmpty()) {

Telegram/SourceFiles/history/view/history_view_reaction_preview.cpp

@@ -0,0 +1,164 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "history/view/history_view_reaction_preview.h"
+
+#include "base/call_delayed.h"
+#include "boxes/sticker_set_box.h"
+#include "data/data_document.h"
+#include "data/data_message_reactions.h"
+#include "data/data_session.h"
+#include "data/stickers/data_custom_emoji.h"
+#include "lang/lang_keys.h"
+#include "main/main_session.h"
+#include "mainwindow.h"
+#include "ui/cached_special_layer_shadow_corners.h"
+#include "ui/effects/show_animation.h"
+#include "ui/widgets/buttons.h"
+#include "ui/widgets/labels.h"
+#include "ui/widgets/shadow.h"
+#include "ui/painter.h"
+#include "ui/rect.h"
+#include "ui/text/text_utilities.h"
+#include "window/window_media_preview.h"
+#include "window/window_session_controller.h"
+#include "styles/style_chat.h"
+#include "styles/style_layers.h"
+
+namespace HistoryView {
+
+bool ShowReactionPreview(
+		not_null<Window::SessionController*> controller,
+		FullMsgId origin,
+		Data::ReactionId reactionId) {
+	auto document = (DocumentData*)(nullptr);
+	if (const auto custom = reactionId.custom()) {
+		document = controller->session().data().document(custom);
+	} else if (const auto resolved
+			= controller->session().data().reactions().lookupTemporary(
+				reactionId)) {
+		document = resolved->selectAnimation;
+	}
+	if (!document) {
+		return false;
+	}
+	struct State {
+		base::unique_qptr<Window::MediaPreviewWidget> mediaPreview;
+		base::unique_qptr<Ui::AbstractButton> clickable;
+		base::unique_qptr<Ui::AbstractButton> background;
+		base::unique_qptr<Ui::FlatLabel> label;
+	};
+	const auto state = std::make_shared<State>();
+
+	const auto mainwidget = controller->widget();
+	state->mediaPreview = base::make_unique_q<Window::MediaPreviewWidget>(
+		mainwidget,
+		controller);
+	state->mediaPreview->setCustomDuration(st::defaultToggle.duration);
+	state->clickable = base::make_unique_q<Ui::AbstractButton>(mainwidget);
+	const auto hideAll = [=] {
+		state->clickable->setAttribute(Qt::WA_TransparentForMouseEvents);
+		state->mediaPreview->hidePreview();
+		if (state->label && state->background) {
+			Ui::Animations::HideWidgets({
+				state->background.get(),
+				state->label.get(),
+			});
+		}
+		base::call_delayed(
+			st::defaultToggle.duration,
+			crl::guard(state->clickable.get(), [=] {
+				state->clickable.reset();
+			}));
+	};
+	state->clickable->setClickedCallback(hideAll);
+	state->mediaPreview->showPreview(origin, document);
+	state->clickable->show();
+	const auto mediaPreviewRaw = state->mediaPreview.get();
+	const auto clickableRaw = state->clickable.get();
+	const auto shadowExtend = st::boxRoundShadow.extend;
+
+	if (reactionId.custom() && document->sticker()) {
+		const auto setId = document->sticker()->set;
+		const auto packName
+			= document->owner().customEmojiManager().lookupSetName(setId.id);
+		if (!packName.isEmpty()) {
+			state->background = base::make_unique_q<Ui::AbstractButton>(
+				mainwidget);
+			const auto show = controller->uiShow();
+			state->background->setClickedCallback([=] {
+				hideAll();
+				show->show(Box<StickerSetBox>(
+					show,
+					setId,
+					Data::StickersType::Emoji));
+			});
+			state->label = base::make_unique_q<Ui::FlatLabel>(
+				state->background.get(),
+				tr::lng_context_animated_reaction(
+					lt_name,
+					rpl::single(Ui::Text::Colorized(packName)),
+					Ui::Text::RichLangValue));
+			state->label->setAttribute(Qt::WA_TransparentForMouseEvents);
+			const auto backgroundRaw = state->background.get();
+			const auto labelRaw = state->label.get();
+
+			backgroundRaw->paintOn([=](QPainter &p) {
+				const auto innerRect = backgroundRaw->rect() - shadowExtend;
+				Ui::Shadow::paint(
+					p,
+					innerRect,
+					backgroundRaw->width(),
+					st::boxRoundShadow,
+					Ui::SpecialLayerShadowCorners(),
+					RectPart::Full);
+				auto hq = PainterHighQualityEnabler(p);
+				p.setPen(Qt::NoPen);
+				p.setBrush(st::windowBg);
+				p.drawRoundedRect(
+					innerRect,
+					st::boxRadius,
+					st::boxRadius);
+			});
+
+			labelRaw->show();
+			Ui::Animations::ShowWidgets({ backgroundRaw });
+		}
+	}
+	const auto backgroundRaw = state->background.get();
+	const auto labelRaw = state->label.get();
+
+	mainwidget->sizeValue() | rpl::start_with_next([=](QSize size) {
+		mediaPreviewRaw->setGeometry(Rect(size));
+		clickableRaw->setGeometry(Rect(size));
+		clickableRaw->raise();
+
+		if (backgroundRaw && labelRaw) {
+			const auto maxLabelWidth = labelRaw->textMaxWidth() / 2;
+			labelRaw->resizeToWidth(maxLabelWidth);
+			const auto labelHeight = labelRaw->height() * 2;
+			const auto padding = st::msgServicePadding;
+			const auto innerWidth = maxLabelWidth + rect::m::sum::h(padding);
+			const auto innerHeight = labelHeight + rect::m::sum::v(padding);
+			const auto bgWidth = innerWidth + rect::m::sum::h(shadowExtend);
+			const auto bgHeight = innerHeight + rect::m::sum::v(shadowExtend);
+			const auto bgX = (size.width() - bgWidth) / 2;
+			const auto bgY = (size.height() * 3 / 4) - (bgHeight / 2);
+
+			backgroundRaw->setGeometry(bgX, bgY, bgWidth, bgHeight);
+			labelRaw->setGeometry(
+				shadowExtend.left() + padding.left(),
+				shadowExtend.top() + padding.top(),
+				maxLabelWidth,
+				labelHeight);
+			backgroundRaw->raise();
+		}
+	}, mediaPreviewRaw->lifetime());
+	return true;
+}
+
+} // namespace HistoryView

Telegram/SourceFiles/history/view/history_view_reaction_preview.h

@@ -0,0 +1,25 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+namespace Data {
+struct ReactionId;
+} // namespace Data
+
+namespace Window {
+class SessionController;
+} // namespace Window
+
+namespace HistoryView {
+
+[[nodiscard]] bool ShowReactionPreview(
+	not_null<Window::SessionController*> controller,
+	FullMsgId origin,
+	Data::ReactionId reactionId);
+
+} // namespace HistoryView