From c4df04f72b0fdb9d45f407a611d706f7f809742a Mon Sep 17 00:00:00 2001
From: ArthurHeitmann <37270165+ArthurHeitmann@users.noreply.github.com>
Date: Tue, 3 Oct 2023 16:13:54 +0200
Subject: [PATCH] selected hierarchy entries are now auto scrolled into view

---
 .../HierarchyEntryWidget.dart                 |  3 +-
 .../HierarchyFlatList.dart                    | 29 ++++++++++---------
 2 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/lib/widgets/FileHierarchyExplorer/HierarchyEntryWidget.dart b/lib/widgets/FileHierarchyExplorer/HierarchyEntryWidget.dart
index 0afeb11a..8168551b 100644
--- a/lib/widgets/FileHierarchyExplorer/HierarchyEntryWidget.dart
+++ b/lib/widgets/FileHierarchyExplorer/HierarchyEntryWidget.dart
@@ -13,6 +13,7 @@ import 'wemPreviewButton.dart';
 class HierarchyEntryWidget extends ChangeNotifierWidget {
   final HierarchyEntry entry;
   final int depth;
+  static const height = 25.0;
 
   HierarchyEntryWidget({ required this.entry, Key? key, this.depth = 0 })
     : super(key: key ?? Key(entry.uuid), notifiers: [entry, shouldAutoTranslate, openHierarchySearch]);
@@ -84,7 +85,7 @@ class _HierarchyEntryState extends ChangeNotifierState<HierarchyEntryWidget> {
       child: optionallySetupSelectable(context,
         Container(
           padding: const EdgeInsets.symmetric(vertical: 3),
-          height: 25,
+          height: HierarchyEntryWidget.height,
           child: Row(
             children: [
               SizedBox(width: 15.0 * widget.depth,),
diff --git a/lib/widgets/FileHierarchyExplorer/HierarchyFlatList.dart b/lib/widgets/FileHierarchyExplorer/HierarchyFlatList.dart
index 755272fa..c5505f6c 100644
--- a/lib/widgets/FileHierarchyExplorer/HierarchyFlatList.dart
+++ b/lib/widgets/FileHierarchyExplorer/HierarchyFlatList.dart
@@ -1,6 +1,6 @@
 
 import 'package:flutter/services.dart';
-import 'package:flutter/widgets.dart' show BuildContext, Focus, FocusNode, FocusScope, Key, ListView, ScrollController, State, Widget;
+import 'package:flutter/widgets.dart' show BuildContext, Curves, FocusScope, Key, ListView, ScrollController, State, Widget;
 
 import '../../keyboardEvents/BetterShortcuts.dart';
 import '../../stateManagement/ChangeNotifierWidget.dart';
@@ -177,23 +177,26 @@ class _HierarchyFlatListState extends ChangeNotifierState<HierarchyFlatList> {
   }
 
   void scrollToSelectedEntry() {
-    return;
     if (openHierarchyManager.selectedEntry == null)
       return;
     var currentIndex = cachedFlatTree.indexWhere((e) => e.entry == openHierarchyManager.selectedEntry);
     if (currentIndex == -1)
       return;
-    var currentEntry = cachedFlatTree[currentIndex];
-    var currentEntryTop = currentEntry.depth * 20.0;
-    var currentEntryBottom = currentEntryTop + 20.0;
-    var currentEntryCenter = (currentEntryTop + currentEntryBottom) / 2;
-    var currentEntryCenterInViewport = currentEntryCenter - scrollController.offset;
-    var viewportHeight = scrollController.position.viewportDimension;
-    if (currentEntryCenterInViewport < 0) {
-      scrollController.jumpTo(scrollController.offset + currentEntryCenterInViewport);
-    }
-    else if (currentEntryCenterInViewport > viewportHeight) {
-      scrollController.jumpTo(scrollController.offset + currentEntryCenterInViewport - viewportHeight);
+    var currentEntryTop = currentIndex * HierarchyEntryWidget.height;
+    var currentEntryBottom = currentEntryTop + HierarchyEntryWidget.height;
+    var scrollOffset = scrollController.offset;
+    var scrollBottom = scrollOffset + scrollController.position.viewportDimension;
+    double? scrollOffsetAfter;
+    if (currentEntryTop < scrollOffset)
+      scrollOffsetAfter = currentEntryTop;
+    else if (currentEntryBottom > scrollBottom)
+      scrollOffsetAfter = currentEntryBottom - scrollController.position.viewportDimension;
+    if (scrollOffsetAfter != null) {
+      scrollController.animateTo(
+        scrollOffsetAfter,
+        duration: const Duration(milliseconds: 150),
+        curve: Curves.easeOut,
+      );
     }
   }
 }