tdesktop/Telegram/SourceFiles/media/view/media_clip_volume_controller.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 Media {
namespace Clip {

class VolumeController : public TWidget {
	Q_OBJECT

public:
	VolumeController(QWidget *parent);

	void setVolume(float64 volume);

signals:
	void volumeChanged(float64 volume);

protected:
	void paintEvent(QPaintEvent *e) override;
	void mouseMoveEvent(QMouseEvent *e) override;
	void mousePressEvent(QMouseEvent *e) override;
	void mouseReleaseEvent(QMouseEvent *e) override;
	void enterEventHook(QEvent *e) override;
	void leaveEventHook(QEvent *e) override;

private:
	void setOver(bool over);
	void changeVolume(float64 newVolume);

	float64 _volume = 0.;
	int _downCoord = -1; // < 0 means mouse is not pressed

	bool _over = false;
	Animation _a_over;

};

} // namespace Clip
} // namespace Media