tdesktop/Telegram/SourceFiles/ui/boxes/time_picker_box.cpp

/*
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 "ui/boxes/time_picker_box.h"

#include "base/event_filter.h"
#include "lang/lang_keys.h"
#include "ui/layers/generic_box.h"
#include "ui/effects/animation_value.h"
#include "ui/ui_utility.h"
#include "ui/widgets/vertical_drum_picker.h"
#include "styles/style_chat_helpers.h"
#include "styles/style_layers.h"

namespace Ui {

namespace {

constexpr auto kMinYScale = 0.2;

} // namespace

std::vector<TimeId> DefaultTimePickerValues() {
	return {
		(60 * 15),
		(60 * 30),
		(3600 * 1),
		(3600 * 2),
		(3600 * 3),
		(3600 * 4),
		(3600 * 8),
		(3600 * 12),
		(86400 * 1),
		(86400 * 2),
		(86400 * 3),
		(86400 * 7 * 1),
		(86400 * 7 * 2),
		(86400 * 31 * 1),
		(86400 * 31 * 2),
		(86400 * 31 * 3),
	};
}

Fn<TimeId()> TimePickerBox(
		not_null<GenericBox*> box,
		std::vector<TimeId> values,
		std::vector<QString> phrases,
		TimeId startValue) {
	Expects(phrases.size() == values.size());

	const auto startIndex = [&, &v = startValue] {
		const auto it = ranges::lower_bound(values, v);
		if (it == begin(values)) {
			return 0;
		}
		const auto left = *(it - 1);
		const auto right = *it;
		const auto shift = (std::abs(v - left) < std::abs(v - right))
			? -1
			: 0;
		return int(std::distance(begin(values), it - shift));
	}();

	const auto content = box->addRow(object_ptr<Ui::FixedHeightWidget>(
		box,
		st::historyMessagesTTLPickerHeight));

	const auto font = st::boxTextFont;
	const auto maxPhraseWidth = [&] {
		// We have to use QFontMetricsF instead of
		// FontData::width for more precise calculation.
		const auto mf = QFontMetricsF(font->f);
		const auto maxPhrase = ranges::max_element(
			phrases,
			std::less<>(),
			[&](const QString &s) { return mf.horizontalAdvance(s); });
		return std::ceil(mf.horizontalAdvance(*maxPhrase));
	}();
	const auto itemHeight = st::historyMessagesTTLPickerItemHeight;
	auto paintCallback = [=](
			QPainter &p,
			int index,
			float64 y,
			float64 distanceFromCenter,
			int outerWidth) {
		const auto r = QRectF(0, y, outerWidth, itemHeight);
		const auto progress = std::abs(distanceFromCenter);
		const auto revProgress = 1. - progress;
		p.save();
		p.translate(r.center());
		const auto yScale = kMinYScale
			+ (1. - kMinYScale) * anim::easeOutCubic(1., revProgress);
		p.scale(1., yScale);
		p.translate(-r.center());
		p.setOpacity(revProgress);
		p.setFont(font);
		p.setPen(st::defaultFlatLabel.textFg);
		p.drawText(r, phrases[index], style::al_center);
		p.restore();
	};

	const auto picker = Ui::CreateChild<Ui::VerticalDrumPicker>(
		content,
		std::move(paintCallback),
		phrases.size(),
		itemHeight,
		startIndex);

	content->sizeValue(
	) | rpl::start_with_next([=](const QSize &s) {
		picker->resize(maxPhraseWidth, s.height());
		picker->moveToLeft((s.width() - picker->width()) / 2, 0);
	}, content->lifetime());

	content->paintRequest(
	) | rpl::start_with_next([=](const QRect &r) {
		auto p = QPainter(content);

		p.fillRect(r, Qt::transparent);

		const auto lineRect = QRect(
			0,
			content->height() / 2,
			content->width(),
			st::defaultInputField.borderActive);
		p.fillRect(lineRect.translated(0, itemHeight / 2), st::activeLineFg);
		p.fillRect(lineRect.translated(0, -itemHeight / 2), st::activeLineFg);
	}, content->lifetime());

	base::install_event_filter(content, [=](not_null<QEvent*> e) {
		if ((e->type() == QEvent::MouseButtonPress)
			|| (e->type() == QEvent::MouseButtonRelease)
			|| (e->type() == QEvent::MouseMove)) {
			picker->handleMouseEvent(static_cast<QMouseEvent*>(e.get()));
		} else if (e->type() == QEvent::Wheel) {
			picker->handleWheelEvent(static_cast<QWheelEvent*>(e.get()));
		}
		return base::EventFilterResult::Continue;
	});
	base::install_event_filter(box, [=](not_null<QEvent*> e) {
		if (e->type() == QEvent::KeyPress) {
			picker->handleKeyEvent(static_cast<QKeyEvent*>(e.get()));
		}
		return base::EventFilterResult::Continue;
	});

	return [=] { return values[picker->index()]; };
}

} // namespace Ui