Added bubble widget for empty list info in modern history view list.

Telegram/CMakeLists.txt

@@ -564,6 +564,8 @@ PRIVATE
     history/view/history_view_cursor_state.h
     history/view/history_view_element.cpp
     history/view/history_view_element.h
+    history/view/history_view_empty_list_bubble.cpp
+    history/view/history_view_empty_list_bubble.h
     history/view/history_view_group_call_tracker.cpp
     history/view/history_view_group_call_tracker.h
     history/view/history_view_list_widget.cpp

Telegram/SourceFiles/history/view/history_view_empty_list_bubble.cpp

@@ -0,0 +1,76 @@
+/*
+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_empty_list_bubble.h"
+
+#include "history/view/history_view_list_widget.h"
+#include "history/view/history_view_service_message.h"
+
+namespace HistoryView {
+
+EmptyListBubbleWidget::EmptyListBubbleWidget(
+	not_null<ListWidget*> parent,
+	const style::margins &padding)
+: RpWidget(parent)
+, _padding(padding) {
+
+	parent->sizeValue(
+	) | rpl::start_with_next([=](const QSize &s) {
+		updateGeometry(s);
+	}, lifetime());
+}
+
+void EmptyListBubbleWidget::updateGeometry(const QSize &size) {
+	const auto w = _forceWidth
+		? _forceWidth
+		: std::min(
+			_text.maxWidth() + _padding.left() + _padding.right(),
+			size.width());
+	_innerWidth = w - _padding.left() - _padding.right();
+	const auto h = _padding.top()
+		+ _text.countHeight(_innerWidth)
+		+ _padding.bottom();
+	resize(w, h);
+	move((size.width() - w) / 2, (size.height() - h) / 3);
+}
+
+void EmptyListBubbleWidget::paintEvent(QPaintEvent *e) {
+	Painter p(this);
+
+	const auto r = rect();
+	HistoryView::ServiceMessagePainter::paintBubble(
+		p,
+		r.x(),
+		r.y(),
+		r.width(),
+		r.height());
+
+	p.setPen(st::msgServiceFg);
+	_text.draw(
+		p,
+		r.x() + _padding.left(),
+		r.y() + _padding.top(),
+		_innerWidth,
+		style::al_top);
+}
+
+void EmptyListBubbleWidget::setText(
+		const TextWithEntities &textWithEntities) {
+	auto options = _defaultOptions;
+	options.flags |= TextParseMarkdown;
+	_text.setMarkedText(st::defaultTextStyle, textWithEntities, options);
+	updateGeometry(size());
+}
+
+void EmptyListBubbleWidget::setForceWidth(int width) {
+	if (_forceWidth != width) {
+		_forceWidth = width;
+		updateGeometry(size());
+	}
+}
+
+} // namespace HistoryView

Telegram/SourceFiles/history/view/history_view_empty_list_bubble.h

@@ -0,0 +1,38 @@
+/*
+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
+
+#include "ui/rp_widget.h"
+
+namespace HistoryView {
+
+class ListWidget;
+
+class EmptyListBubbleWidget : public Ui::RpWidget {
+public:
+	EmptyListBubbleWidget(
+		not_null<ListWidget*> parent,
+		const style::margins &padding);
+
+	void setText(const TextWithEntities &textWithEntities);
+	void setForceWidth(int width);
+
+protected:
+	void paintEvent(QPaintEvent *e) override;
+
+private:
+	void updateGeometry(const QSize &size);
+
+	const style::margins &_padding;
+	Ui::Text::String _text;
+	int _innerWidth = 0;
+	int _forceWidth = 0;
+
+};
+
+} // namespace HistoryView

Telegram/SourceFiles/history/view/history_view_list_widget.cpp

@@ -382,6 +382,9 @@ void ListWidget::refreshRows(const Data::MessagesSlice &old) {
 	if (!_itemsRevealHeight) {
 		mouseActionUpdate(QCursor::pos());
 	}
+	if (_emptyInfo) {
+		_emptyInfo->setVisible(isEmpty());
+	}
 	_delegate->listContentRefreshed();
 }
 
@@ -2940,6 +2943,10 @@ void ListWidget::replyNextMessage(FullMsgId fullId, bool next) {
 	}
 }
 
+void ListWidget::setEmptyInfoWidget(base::unique_qptr<Ui::RpWidget> &&w) {
+	_emptyInfo = std::move(w);
+}
+
 ListWidget::~ListWidget() = default;
 
 void ConfirmDeleteSelectedItems(not_null<ListWidget*> widget) {

Telegram/SourceFiles/history/view/history_view_list_widget.h

@@ -257,6 +257,8 @@ public:
 	bool elementIsChatWide() override;
 	not_null<Ui::PathShiftGradient*> elementPathShiftGradient() override;
 
+	void setEmptyInfoWidget(base::unique_qptr<Ui::RpWidget> &&w);
+
 	~ListWidget();
 
 protected:
@@ -524,6 +526,8 @@ private:
 
 	const std::unique_ptr<Ui::PathShiftGradient> _pathGradient;
 
+	base::unique_qptr<Ui::RpWidget> _emptyInfo = nullptr;
+
 	int _minHeight = 0;
 	int _visibleTop = 0;
 	int _visibleBottom = 0;