Limit the CalendarBox selectable days.

Use available information (first and last message date) to limit
the days you can choose in jump-to-date calendar box.

Telegram/SourceFiles/boxes/boxes.style

@@ -517,7 +517,7 @@ backgroundScroll: ScrollArea(boxLayerScroll) {
 }
 
 calendarTitleHeight: boxTitleHeight;
-calendarLeft: IconButton {
+calendarPrevious: IconButton {
 	width: calendarTitleHeight;
 	height: calendarTitleHeight;
 
@@ -530,9 +530,11 @@ calendarLeft: IconButton {
 		color: windowBgOver;
 	}
 }
-calendarRight: IconButton(calendarLeft) {
+calendarPreviousDisabled: icon {{ "title_back", menuIconFg }};
+calendarNext: IconButton(calendarPrevious) {
 	icon: icon {{ "title_back-flip_horizontal", boxTitleFg }};
 }
+calendarNextDisabled: icon {{ "title_back-flip_horizontal", menuIconFg }};
 calendarTitleFont: boxTitleFont;
 calendarDaysFont: normalFont;
 calendarDaysFg: boxTitleAdditionalFg;

Telegram/SourceFiles/boxes/calendarbox.cpp

@@ -40,6 +40,16 @@ public:
 		_month.setForced(_month.value(), true);
 	}
 
+	void setMinDate(QDate date);
+	void setMaxDate(QDate date);
+
+	int minDayIndex() const {
+		return _minDayIndex;
+	}
+	int maxDayIndex() const {
+		return _maxDayIndex;
+	}
+
 	void skipMonth(int skip);
 	void showMonth(QDate month);
 
@@ -56,7 +66,7 @@ public:
 		return _daysCount;
 	}
 	bool isEnabled(int index) const {
-		return (_currentDayIndex < 0) || (index <= _currentDayIndex);
+		return (index >= _minDayIndex) && (index <= _maxDayIndex);
 	}
 
 	const base::Variable<QDate> &month() {
@@ -67,14 +77,18 @@ public:
 	QString labelFromIndex(int index) const;
 
 private:
+	void applyMonth(const QDate &month, bool forced = false);
+
 	static int daysShiftForMonth(QDate month);
 	static int rowsCountForMonth(QDate month);
 
 	base::Variable<QDate> _month;
+	QDate _min, _max;
 	QDate _highlighted;
 
 	int _highlightedIndex = 0;
-	int _currentDayIndex = 0;
+	int _minDayIndex = 0;
+	int _maxDayIndex = 0;
 	int _daysCount = 0;
 	int _daysShift = 0;
 	int _rowsCount = 0;
@@ -85,18 +99,37 @@ CalendarBox::Context::Context(QDate month, QDate highlighted) : _highlighted(hig
 	showMonth(month);
 }
 
+void CalendarBox::Context::setMinDate(QDate date) {
+	_min = date;
+	applyMonth(_month.value(), true);
+}
+
+void CalendarBox::Context::setMaxDate(QDate date) {
+	_max = date;
+	applyMonth(_month.value(), true);
+}
+
 void CalendarBox::Context::showMonth(QDate month) {
 	if (month.day() != 1) {
 		month = QDate(month.year(), month.month(), 1);
 	}
-	_month.set(month);
+	applyMonth(month);
+}
+
+void CalendarBox::Context::applyMonth(const QDate &month, bool forced) {
+	if (forced) {
+		_month.setForced(month);
+	} else {
+		_month.set(month);
+	}
 	_daysCount = month.daysInMonth();
 	_daysShift = daysShiftForMonth(month);
 	_rowsCount = rowsCountForMonth(month);
 	auto yearIndex = month.year();
 	auto monthIndex = month.month();
 	_highlightedIndex = month.daysTo(_highlighted);
-	_currentDayIndex = month.daysTo(QDate::currentDate());
+	_minDayIndex = _min.isNull() ? INT_MIN : month.daysTo(_min);
+	_maxDayIndex = _max.isNull() ? INT_MAX : month.daysTo(_max);
 }
 
 void CalendarBox::Context::skipMonth(int skip) {
@@ -235,7 +268,7 @@ void CalendarBox::Inner::paintDayNames(Painter &p, QRect clip) {
 	p.setFont(st::calendarDaysFont);
 	p.setPen(st::calendarDaysFg);
 	auto y = st::calendarPadding.top();
-	auto x = st::calendarPadding.left();
+	auto x = rowsLeft();
 	if (!myrtlrect(x, y, st::calendarCellSize.width() * kDaysInWeek, st::calendarDaysHeight).intersects(clip)) {
 		return;
 	}
@@ -402,17 +435,29 @@ CalendarBox::CalendarBox(QWidget*, QDate month, QDate highlighted, base::lambda<
 : _context(std::make_unique<Context>(month, highlighted))
 , _inner(this, _context.get())
 , _title(this, _context.get())
-, _left(this, st::calendarLeft)
-, _right(this, st::calendarRight)
+, _previous(this, st::calendarPrevious)
+, _next(this, st::calendarNext)
 , _callback(std::move(callback)) {
 }
 
+void CalendarBox::setMinDate(QDate date) {
+	_context->setMinDate(date);
+}
+
+void CalendarBox::setMaxDate(QDate date) {
+	_context->setMaxDate(date);
+}
+
 void CalendarBox::prepare() {
-	_left->setClickedCallback([this] {
-		_context->skipMonth(-1);
+	_previous->setClickedCallback([this] {
+		if (isPreviousEnabled()) {
+			_context->skipMonth(-1);
+		}
 	});
-	_right->setClickedCallback([this] {
-		_context->skipMonth(1);
+	_next->setClickedCallback([this] {
+		if (isNextEnabled()) {
+			_context->skipMonth(1);
+		}
 	});
 
 //	_inner = setInnerWidget(object_ptr<Inner>(this, _context.get()), st::calendarScroll, st::calendarTitleHeight);
@@ -425,14 +470,30 @@ void CalendarBox::prepare() {
 	_context->start();
 }
 
+bool CalendarBox::isPreviousEnabled() const {
+	return (_context->minDayIndex() < 0);
+}
+
+bool CalendarBox::isNextEnabled() const {
+	return (_context->maxDayIndex() >= _context->daysCount());
+}
+
 void CalendarBox::monthChanged(QDate month) {
 	setDimensions(st::boxWideWidth, st::calendarTitleHeight + _inner->countHeight());
+	auto previousEnabled = isPreviousEnabled();
+	_previous->setIconOverride(previousEnabled ? nullptr : &st::calendarPreviousDisabled);
+	_previous->setRippleColorOverride(previousEnabled ? nullptr : &st::boxBg);
+	_previous->setCursor(previousEnabled ? style::cur_pointer : style::cur_default);
+	auto nextEnabled = isNextEnabled();
+	_next->setIconOverride(nextEnabled ? nullptr : &st::calendarNextDisabled);
+	_next->setRippleColorOverride(nextEnabled ? nullptr : &st::boxBg);
+	_next->setCursor(nextEnabled ? style::cur_pointer : style::cur_default);
 }
 
 void CalendarBox::resizeEvent(QResizeEvent *e) {
-	_left->moveToLeft(0, 0);
-	_right->moveToRight(0, 0);
-	_title->setGeometryToLeft(_left->width(), 0, width() - _left->width() - _right->width(), st::calendarTitleHeight);
+	_previous->moveToLeft(0, 0);
+	_next->moveToRight(0, 0);
+	_title->setGeometryToLeft(_previous->width(), 0, width() - _previous->width() - _next->width(), st::calendarTitleHeight);
 	_inner->setGeometryToLeft(0, st::calendarTitleHeight, width(), height() - st::calendarTitleHeight);
 	BoxContent::resizeEvent(e);
 }

Telegram/SourceFiles/boxes/calendarbox.h

@@ -29,6 +29,10 @@ class IconButton;
 class CalendarBox : public BoxContent {
 public:
 	CalendarBox(QWidget*, QDate month, QDate highlighted, base::lambda<void(QDate date)> callback);
+
+	void setMinDate(QDate date);
+	void setMaxDate(QDate date);
+
 	~CalendarBox();
 
 protected:
@@ -39,6 +43,9 @@ protected:
 private:
 	void monthChanged(QDate month);
 
+	bool isPreviousEnabled() const;
+	bool isNextEnabled() const;
+
 	class Context;
 	std::unique_ptr<Context> _context;
 
@@ -47,8 +54,8 @@ private:
 
 	class Title;
 	object_ptr<Title> _title;
-	object_ptr<Ui::IconButton> _left;
-	object_ptr<Ui::IconButton> _right;
+	object_ptr<Ui::IconButton> _previous;
+	object_ptr<Ui::IconButton> _next;
 
 	base::lambda<void(QDate date)> _callback;
 

Telegram/SourceFiles/mainwidget.cpp

@@ -2765,20 +2765,55 @@ void MainWidget::showJumpToDate(PeerData *peer) {
 		if (auto history = App::historyLoaded(peer)) {
 			if (history->scrollTopItem) {
 				return history->scrollTopItem->date.date();
+			} else if (history->loadedAtTop() && !history->isEmpty() && history->peer->migrateFrom()) {
+				if (auto migrated = App::historyLoaded(history->peer->migrateFrom())) {
+					if (migrated->scrollTopItem) {
+						// We're up in the migrated history.
+						// So current date is the date of first message here.
+						return history->blocks.front()->items.front()->date.date();
+					}
+				}
 			} else if (!history->lastMsgDate.isNull()) {
 				return history->lastMsgDate.date();
 			}
 		}
 		return QDate::currentDate();
 	};
+	auto maxPeerDate = [peer] {
+		if (auto history = App::historyLoaded(peer)) {
+			if (!history->lastMsgDate.isNull()) {
+				return history->lastMsgDate.date();
+			}
+		}
+		return QDate::currentDate();
+	};
+	auto minPeerDate = [peer] {
+		if (auto history = App::historyLoaded(peer)) {
+			if (history->loadedAtTop()) {
+				if (history->isEmpty()) {
+					return QDate::currentDate();
+				}
+				return history->blocks.front()->items.front()->date.date();
+			}
+		}
+		return QDate(2013, 8, 1); // Telegram was launched in August 2013 :)
+	};
 	auto highlighted = currentPeerDate(), month = highlighted;
-	Ui::show(Box<CalendarBox>(month, highlighted, [this, peer](const QDate &date) { jumpToDate(peer, date); }));
+	auto box = Box<CalendarBox>(month, highlighted, [this, peer](const QDate &date) { jumpToDate(peer, date); });
+	box->setMinDate(minPeerDate());
+	box->setMaxDate(maxPeerDate());
+	Ui::show(std::move(box));
 }
 
 void MainWidget::jumpToDate(PeerData *peer, const QDate &date) {
-	auto time = static_cast<int>(QDateTime(date).toTime_t());
+	// API returns a message with date <= offset_date.
+	// So we request a message with offset_date = desired_date - 1 and add_offset = -1.
+	// This should give us the first message with date >= desired_date.
+	auto offset_date = static_cast<int>(QDateTime(date).toTime_t()) - 1;
+	auto add_offset = -1;
+	auto limit = 1;
 	auto flags = MTPmessages_Search::Flags(0);
-	auto request = MTPmessages_GetHistory(peer->input, MTP_int(0), MTP_int(time), MTP_int(-1), MTP_int(1), MTP_int(0), MTP_int(0));
+	auto request = MTPmessages_GetHistory(peer->input, MTP_int(0), MTP_int(offset_date), MTP_int(add_offset), MTP_int(limit), MTP_int(0), MTP_int(0));
 	MTP::send(request, ::rpcDone([peer](const MTPmessages_Messages &result) {
 		auto getMessagesList = [&result, peer]() -> const QVector<MTPMessage>* {
 			auto handleMessages = [](auto &messages) {