tdesktop/Telegram/SourceFiles/ui/chat/select_scroll_manager.cpp

51 lines
1.1 KiB
C++

/*
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/chat/select_scroll_manager.h"
#include "ui/widgets/scroll_area.h"
namespace Ui {
SelectScrollManager::SelectScrollManager()
: _timer([=] { scrollByTimer(); }) {
}
void SelectScrollManager::scrollByTimer() {
const auto d = (_delta > 0)
? std::min(_delta * 3 / 20 + 1, kMaxScrollSpeed)
: std::max(_delta * 3 / 20 - 1, -kMaxScrollSpeed);
_scrolls.fire_copy(d);
}
void SelectScrollManager::checkDeltaScroll(
const QPoint &point,
int top,
int bottom) {
const auto diff = point.y() - top;
_delta = (diff < 0)
? diff
: (point.y() >= bottom)
? (point.y() - bottom + 1)
: 0;
if (_delta) {
_timer.callEach(15);
} else {
_timer.cancel();
}
}
void SelectScrollManager::cancel() {
_timer.cancel();
}
rpl::producer<int> SelectScrollManager::scrolls() {
return _scrolls.events();
}
} // namespace Ui