tdesktop/Telegram/SourceFiles/ui/effects/slide_animation.h

/*
This file is part of Telegram Desktop,
the official desktop version of Telegram messaging app, see https://telegram.org

Telegram Desktop is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

It is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

In addition, as a special exception, the copyright holders give permission
to link the code of portions of this program with the OpenSSL library.

Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
*/
#pragma once

namespace Ui {

class SlideAnimation {
public:
	void setSnapshots(QPixmap leftSnapshot, QPixmap rightSnapshot);

	void setOverflowHidden(bool hidden) {
		_overflowHidden = hidden;
	}

	template <typename Lambda>
	void start(bool slideLeft, Lambda &&updateCallback, float64 duration);

	void paintFrame(Painter &p, int x, int y, int outerWidth, TimeMs ms);

	bool animating() const {
		return _animation.animating();
	}

private:
	Animation _animation;
	QPixmap _leftSnapshot;
	QPixmap _rightSnapshot;
	bool _slideLeft = false;
	bool _overflowHidden = true;
	int _leftSnapshotWidth = 0;
	int _leftSnapshotHeight = 0;
	int _rightSnapshotWidth = 0;

};

template <typename Lambda>
void SlideAnimation::start(bool slideLeft, Lambda &&updateCallback, float64 duration) {
	_slideLeft = slideLeft;
	if (_slideLeft) {
		std::swap(_leftSnapshot, _rightSnapshot);
	}
	_leftSnapshotWidth = _leftSnapshot.width() / cIntRetinaFactor();
	_leftSnapshotHeight = _leftSnapshot.height() / cIntRetinaFactor();
	_rightSnapshotWidth = _rightSnapshot.width() / cIntRetinaFactor();
	_animation.start(std::forward<Lambda>(updateCallback), 0., 1., duration);
}

} // namespace Ui