From dbbec068a81bb0c7a43565ce386898de3f1b537e Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Mon, 31 Jan 2022 19:02:40 +0300
Subject: [PATCH] Added ability to use VerticalLayoutReorder without scroll.

---
 ui/wrap/vertical_layout_reorder.cpp | 14 ++++++++++++--
 ui/wrap/vertical_layout_reorder.h   |  3 ++-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/ui/wrap/vertical_layout_reorder.cpp b/ui/wrap/vertical_layout_reorder.cpp
index e8f778b..a750dfa 100644
--- a/ui/wrap/vertical_layout_reorder.cpp
+++ b/ui/wrap/vertical_layout_reorder.cpp
@@ -28,6 +28,10 @@ VerticalLayoutReorder::VerticalLayoutReorder(
 , _scrollAnimation([=] { updateScrollCallback(); }) {
 }
 
+VerticalLayoutReorder::VerticalLayoutReorder(not_null<VerticalLayout*> layout)
+: _layout(layout) {
+}
+
 void VerticalLayoutReorder::cancel() {
 	if (_currentWidget) {
 		cancelCurrent(indexOf(_currentWidget));
@@ -183,7 +187,9 @@ void VerticalLayoutReorder::cancelCurrent(int index) {
 }
 
 void VerticalLayoutReorder::finishReordering() {
-	_scrollAnimation.stop();
+	if (_scroll) {
+		_scrollAnimation.stop();
+	}
 	finishCurrent();
 }
 
@@ -281,6 +287,9 @@ auto VerticalLayoutReorder::updates() const -> rpl::producer<Single> {
 }
 
 void VerticalLayoutReorder::updateScrollCallback() {
+	if (!_scroll) {
+		return;
+	}
 	const auto delta = deltaFromEdge();
 	const auto oldTop = _scroll->scrollTop();
 	_scroll->scrollToY(oldTop + delta);
@@ -293,7 +302,7 @@ void VerticalLayoutReorder::updateScrollCallback() {
 }
 
 void VerticalLayoutReorder::checkForScrollAnimation() {
-	if (!deltaFromEdge() || _scrollAnimation.animating()) {
+	if (!_scroll || !deltaFromEdge() || _scrollAnimation.animating()) {
 		return;
 	}
 	_scrollAnimation.start();
@@ -301,6 +310,7 @@ void VerticalLayoutReorder::checkForScrollAnimation() {
 
 int VerticalLayoutReorder::deltaFromEdge() {
 	Expects(_currentWidget != nullptr);
+	Expects(_scroll);
 
 	const auto globalPosition = _currentWidget->mapToGlobal(QPoint(0, 0));
 	const auto localTop = _scroll->mapFromGlobal(globalPosition).y();
diff --git a/ui/wrap/vertical_layout_reorder.h b/ui/wrap/vertical_layout_reorder.h
index 502031c..1b28e76 100644
--- a/ui/wrap/vertical_layout_reorder.h
+++ b/ui/wrap/vertical_layout_reorder.h
@@ -31,6 +31,7 @@ public:
 	VerticalLayoutReorder(
 		not_null<VerticalLayout*> layout,
 		not_null<ScrollArea*> scroll);
+	VerticalLayoutReorder(not_null<VerticalLayout*> layout);
 
 	void start();
 	void cancel();
@@ -68,7 +69,7 @@ private:
 	int deltaFromEdge();
 
 	const not_null<Ui::VerticalLayout*> _layout;
-	const not_null<Ui::ScrollArea*> _scroll;
+	Ui::ScrollArea *_scroll = nullptr;
 
 	Ui::Animations::Basic _scrollAnimation;