tdesktop/Telegram/SourceFiles/window/window_slide_animation.cpp

/*
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
*/
#include "window/window_slide_animation.h"

#include "styles/style_window.h"

namespace Window {

void SlideAnimation::paintContents(Painter &p, const QRect &update) const {
	int retina = cIntRetinaFactor();

	// Animation callback can destroy "this", so we don't pass "ms".
	auto progress = _animation.current((_direction == SlideDirection::FromLeft) ? 0. : 1.);
	auto coordUnder = anim::interpolate(0, -st::slideShift, progress);
	auto coordOver = anim::interpolate(_cacheOver.width() / cIntRetinaFactor(), 0, progress);
	if (coordOver) {
		p.drawPixmap(QRect(0, 0, coordOver, _cacheUnder.height() / retina), _cacheUnder, QRect(-coordUnder * retina, 0, coordOver * retina, _cacheUnder.height()));
		p.setOpacity(progress);
		p.fillRect(0, 0, coordOver, _cacheUnder.height() / retina, st::slideFadeOutBg);
		p.setOpacity(1);
	}
	p.drawPixmap(QRect(coordOver, 0, _cacheOver.width() / retina, _cacheOver.height() / retina), _cacheOver, QRect(0, 0, _cacheOver.width(), _cacheOver.height()));
	p.setOpacity(progress);
	st::slideShadow.fill(p, QRect(coordOver - st::slideShadow.width(), 0, st::slideShadow.width(), _cacheOver.height() / retina));

	if (_topBarShadowEnabled) {
		p.setOpacity(1);
		p.fillRect(0, st::topBarHeight, _cacheOver.width() / retina, st::lineWidth, st::shadowFg);
	}
}

void SlideAnimation::setDirection(SlideDirection direction) {
	_direction = direction;
}

void SlideAnimation::setPixmaps(const QPixmap &oldContentCache, const QPixmap &newContentCache) {
	_cacheUnder = oldContentCache;
	_cacheOver = newContentCache;
}

void SlideAnimation::setTopBarShadow(bool enabled) {
	_topBarShadowEnabled = enabled;
}

void SlideAnimation::setRepaintCallback(RepaintCallback &&callback) {
	_repaintCallback = std::move(callback);
}

void SlideAnimation::setFinishedCallback(FinishedCallback &&callback) {
	_finishedCallback = std::move(callback);
}

void SlideAnimation::start() {
	auto delta = st::slideShift;
	auto fromLeft = (_direction == SlideDirection::FromLeft);
	if (fromLeft) std::swap(_cacheUnder, _cacheOver);
	_animation.start([this] { animationCallback(); }, fromLeft ? 1. : 0., fromLeft ? 0. : 1., st::slideDuration, transition());
	_repaintCallback();
}

void SlideAnimation::animationCallback() {
	_repaintCallback();
	if (!_animation.animating()) {
		if (_finishedCallback) {
			_finishedCallback();
		}
	}
}

} // namespace Window