Files
tdesktop/Telegram/SourceFiles/info/info_flexible_scroll.cpp
2025-12-10 21:28:33 +03:00

362 lines
9.8 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 "info/info_flexible_scroll.h"
#include "ui/effects/animation_value.h"
#include "ui/widgets/scroll_area.h"
#include "base/event_filter.h"
#include "base/options.h"
#include "styles/style_info.h"
#include <QtWidgets/QApplication>
#include <QtWidgets/QScrollBar>
namespace Info {
base::options::toggle AlternativeScrollProcessing({
.id = kAlternativeScrollProcessing,
.name = "Use legacy scroll processing in profiles.",
});
const char kAlternativeScrollProcessing[] = "alternative-scroll-processing";
FlexibleScrollHelper::FlexibleScrollHelper(
not_null<Ui::ScrollArea*> scroll,
not_null<Ui::RpWidget*> inner,
not_null<Ui::RpWidget*> pinnedToTop,
Fn<void(QMargins)> setPaintPadding,
Fn<void(rpl::producer<not_null<QEvent*>>&&)> setViewport,
FlexibleScrollData &data)
: _scroll(scroll)
, _inner(inner)
, _pinnedToTop(pinnedToTop)
, _setPaintPadding(setPaintPadding)
, _setViewport(setViewport)
, _data(data) {
setupScrollAnimation();
if (AlternativeScrollProcessing.value()) {
setupScrollHandling();
} else {
setupScrollHandlingWithFilter();
}
}
void FlexibleScrollHelper::setupScrollAnimation() {
constexpr auto kScrollStepTime = crl::time(260);
const auto clearScrollState = [=] {
_scrollAnimation.stop();
_scrollTopFrom = 0;
_scrollTopTo = 0;
_timeOffset = 0;
_lastScrollApplied = 0;
};
_scrollAnimation.init([=](crl::time now) {
const auto progress = float64(now
- _scrollAnimation.started()
- _timeOffset) / kScrollStepTime;
const auto eased = anim::easeOutQuint(1.0, progress);
const auto scrollCurrent = anim::interpolate(
_scrollTopFrom,
_scrollTopTo,
std::clamp(eased, 0., 1.));
scrollToY(scrollCurrent);
_lastScrollApplied = scrollCurrent;
if (progress >= 1) {
clearScrollState();
}
});
}
void FlexibleScrollHelper::setupScrollHandling() {
const auto heightDiff = [=] {
return _pinnedToTop->maximumHeight()
- _pinnedToTop->minimumHeight();
};
rpl::combine(
_pinnedToTop->heightValue(),
_inner->heightValue()
) | rpl::on_next([=](int, int h) {
_data.contentHeightValue.fire(h + heightDiff());
}, _pinnedToTop->lifetime());
const auto singleStep = _scroll->verticalScrollBar()->singleStep()
* QApplication::wheelScrollLines();
const auto step1 = (_pinnedToTop->maximumHeight()
< st::infoProfileTopBarHeightMax)
? (st::infoProfileTopBarStep2 + st::lineWidth)
: st::infoProfileTopBarStep1;
const auto step2 = st::infoProfileTopBarStep2;
// const auto stepDepreciation = singleStep
// - st::infoProfileTopBarActionButtonsHeight;
_scrollTopPrevious = _scroll->scrollTop();
_scroll->scrollTopValue(
) | rpl::on_next([=](int top) {
if (_applyingFakeScrollState) {
return;
}
const auto diff = top - _scrollTopPrevious;
if (std::abs(diff) == singleStep) {
const auto previousValue = top - diff;
const auto nextStep = (diff > 0)
? ((previousValue == 0)
? step1
: (previousValue == step1)
? step2
: -1)
// : ((top < step1
// && (top + stepDepreciation != step1
// || _scrollAnimation.animating()))
: ((top < step1)
? 0
: (top < step2)
? step1
: -1);
{
_applyingFakeScrollState = true;
scrollToY(previousValue);
_applyingFakeScrollState = false;
}
if (_scrollAnimation.animating()
&& ((_scrollTopTo > _scrollTopFrom) != (diff > 0))) {
auto overriddenDirection = true;
if (_scrollTopTo > _scrollTopFrom) {
// From going down to going up.
if (_scrollTopTo == step1) {
_scrollTopTo = 0;
} else if (_scrollTopTo == step2) {
_scrollTopTo = step1;
} else {
overriddenDirection = false;
}
} else {
// From going up to going down.
if (_scrollTopTo == 0) {
_scrollTopTo = step1;
} else if (_scrollTopTo == step1) {
_scrollTopTo = step2;
} else {
overriddenDirection = false;
}
}
if (overriddenDirection) {
_timeOffset = crl::now() - _scrollAnimation.started();
_scrollTopFrom = _lastScrollApplied
? _lastScrollApplied
: previousValue;
return;
} else {
_scrollAnimation.stop();
_scrollTopFrom = 0;
_scrollTopTo = 0;
_timeOffset = 0;
_lastScrollApplied = 0;
}
}
_scrollTopFrom = _lastScrollApplied
? _lastScrollApplied
: previousValue;
if (!_scrollAnimation.animating()) {
_scrollTopTo = ((nextStep != -1) ? nextStep : top);
_scrollAnimation.start();
} else {
if (_scrollTopTo > _scrollTopFrom) {
// Down.
if (_scrollTopTo == step1) {
_scrollTopTo = step2;
} else {
_scrollTopTo += diff;
}
} else {
// Up.
if (_scrollTopTo == step2) {
_scrollTopTo = step1;
} else if (_scrollTopTo == step1) {
_scrollTopTo = 0;
} else {
_scrollTopTo += diff;
}
}
_timeOffset = (crl::now() - _scrollAnimation.started());
}
return;
}
_scrollTopPrevious = top;
const auto current = heightDiff() - top;
_inner->moveToLeft(0, std::min(0, current));
_pinnedToTop->resize(
_pinnedToTop->width(),
std::max(current + _pinnedToTop->minimumHeight(), 0));
}, _inner->lifetime());
_data.fillerWidthValue.events(
) | rpl::on_next([=](int w) {
_inner->resizeToWidth(w);
}, _inner->lifetime());
_setPaintPadding({ 0, _pinnedToTop->minimumHeight(), 0, 0 });
_setViewport(_pinnedToTop->events(
) | rpl::filter([](not_null<QEvent*> e) {
return e->type() == QEvent::Wheel;
}));
}
void FlexibleScrollHelper::setupScrollHandlingWithFilter() {
rpl::combine(
_pinnedToTop->heightValue(),
_inner->heightValue()
) | rpl::on_next([=](int, int h) {
const auto max = _pinnedToTop->maximumHeight();
const auto min = _pinnedToTop->minimumHeight();
const auto diff = max - min;
const auto progress = (diff > 0)
? std::clamp(
(_pinnedToTop->height() - min) / float64(diff),
0.,
1.)
: 1.;
_data.contentHeightValue.fire(h
+ anim::interpolate(diff, 0, progress));
}, _pinnedToTop->lifetime());
const auto singleStep = _scroll->verticalScrollBar()->singleStep()
* QApplication::wheelScrollLines();
const auto step1 = (_pinnedToTop->maximumHeight()
< st::infoProfileTopBarHeightMax)
? (st::infoProfileTopBarStep2 + st::lineWidth)
: st::infoProfileTopBarStep1;
const auto step2 = st::infoProfileTopBarStep2;
base::install_event_filter(_scroll->verticalScrollBar(), [=](
not_null<QEvent*> e) {
if (e->type() != QEvent::Wheel) {
return base::EventFilterResult::Continue;
}
const auto wheel = static_cast<QWheelEvent*>(e.get());
const auto delta = wheel->angleDelta().y();
if (std::abs(delta) != 120) {
scrollToY(_scroll->scrollTop() - delta);
return base::EventFilterResult::Cancel;
}
const auto actualTop = _scroll->scrollTop();
const auto animationActive = _scrollAnimation.animating()
&& (_lastScrollApplied != _scrollTopTo);
const auto top = animationActive
? (_lastScrollApplied ? _lastScrollApplied : actualTop)
: actualTop;
const auto diff = (delta > 0) ? -singleStep : singleStep;
const auto previousValue = top;
const auto targetTop = top + diff;
const auto nextStep = (diff > 0)
? ((previousValue == 0)
? step1
: (previousValue == step1)
? step2
: -1)
: ((targetTop < step1)
? 0
: (targetTop < step2)
? step1
: -1);
if (animationActive
&& ((_scrollTopTo > _scrollTopFrom) != (diff > 0))) {
auto overriddenDirection = true;
if (_scrollTopTo > _scrollTopFrom) {
if (_scrollTopTo == step1) {
_scrollTopTo = 0;
} else if (_scrollTopTo == step2) {
_scrollTopTo = step1;
} else {
overriddenDirection = false;
}
} else {
if (_scrollTopTo == 0) {
_scrollTopTo = step1;
} else if (_scrollTopTo == step1) {
_scrollTopTo = step2;
} else {
overriddenDirection = false;
}
}
if (overriddenDirection) {
_timeOffset = crl::now() - _scrollAnimation.started();
_scrollTopFrom = _lastScrollApplied
? _lastScrollApplied
: top;
return base::EventFilterResult::Cancel;
} else {
_scrollAnimation.stop();
_scrollTopFrom = 0;
_scrollTopTo = 0;
_timeOffset = 0;
_lastScrollApplied = 0;
}
}
_scrollTopFrom = top;
if (!animationActive) {
_scrollTopTo = (nextStep != -1) ? nextStep : targetTop;
_scrollAnimation.start();
} else {
if (_scrollTopTo > _scrollTopFrom) {
if (_scrollTopTo == step1) {
_scrollTopTo = step2;
} else {
_scrollTopTo += diff;
}
} else {
if (_scrollTopTo == step2) {
_scrollTopTo = step1;
} else if (_scrollTopTo == step1) {
_scrollTopTo = 0;
} else {
_scrollTopTo += diff;
}
}
_timeOffset = crl::now() - _scrollAnimation.started();
}
return base::EventFilterResult::Cancel;
}, _filterLifetime);
_scroll->scrollTopValue() | rpl::on_next([=](int top) {
applyScrollToPinnedLayout(top);
}, _inner->lifetime());
_data.fillerWidthValue.events(
) | rpl::on_next([=](int w) {
_inner->resizeToWidth(w);
}, _inner->lifetime());
_setPaintPadding({ 0, _pinnedToTop->minimumHeight(), 0, 0 });
_setViewport(_pinnedToTop->events(
) | rpl::filter([](not_null<QEvent*> e) {
return e->type() == QEvent::Wheel;
}));
}
void FlexibleScrollHelper::scrollToY(int scrollCurrent) {
applyScrollToPinnedLayout(scrollCurrent);
_scroll->scrollToY(scrollCurrent);
}
void FlexibleScrollHelper::applyScrollToPinnedLayout(int scrollCurrent) {
const auto top = std::min(scrollCurrent, _scroll->scrollTopMax());
const auto minimumHeight = _pinnedToTop->minimumHeight();
const auto current = _pinnedToTop->maximumHeight()
- minimumHeight
- top;
_inner->moveToLeft(0, std::min(0, current));
_pinnedToTop->resize(
_pinnedToTop->width(),
std::max(current + minimumHeight, 0));
}
} // namespace Info