From f6195c551547e3b801563b86f9df17e4f4b81182 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Wed, 18 Sep 2024 15:02:04 +0200
Subject: [PATCH] Add to existing selection when dragging with control pressed

Closes https://github.com/ppy/osu/issues/29023.
---
 .../Edit/Compose/Components/BlueprintContainer.cs  | 14 +++++++++++---
 .../Timeline/TimelineBlueprintContainer.cs         |  5 ++++-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/osu.Game/Screens/Edit/Compose/Components/BlueprintContainer.cs b/osu.Game/Screens/Edit/Compose/Components/BlueprintContainer.cs
index c66be90605..9776e64855 100644
--- a/osu.Game/Screens/Edit/Compose/Components/BlueprintContainer.cs
+++ b/osu.Game/Screens/Edit/Compose/Components/BlueprintContainer.cs
@@ -196,6 +196,11 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
             DragBox.HandleDrag(e);
             DragBox.Show();
+
+            selectionBeforeDrag.Clear();
+            if (e.ControlPressed)
+                selectionBeforeDrag.UnionWith(SelectedItems);
+
             return true;
         }
 
@@ -217,6 +222,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             }
 
             DragBox.Hide();
+            selectionBeforeDrag.Clear();
         }
 
         protected override void Update()
@@ -227,7 +233,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
             {
                 lastDragEvent.Target = this;
                 DragBox.HandleDrag(lastDragEvent);
-                UpdateSelectionFromDragBox();
+                UpdateSelectionFromDragBox(selectionBeforeDrag);
             }
         }
 
@@ -472,7 +478,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// <summary>
         /// Select all blueprints in a selection area specified by <see cref="DragBox"/>.
         /// </summary>
-        protected virtual void UpdateSelectionFromDragBox()
+        protected virtual void UpdateSelectionFromDragBox(HashSet<T> selectionBeforeDrag)
         {
             var quad = DragBox.Box.ScreenSpaceDrawQuad;
 
@@ -482,7 +488,7 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 {
                     case SelectionState.Selected:
                         // Selection is preserved even after blueprint becomes dead.
-                        if (!quad.Contains(blueprint.ScreenSpaceSelectionPoint))
+                        if (!quad.Contains(blueprint.ScreenSpaceSelectionPoint) && !selectionBeforeDrag.Contains(blueprint.Item))
                             blueprint.Deselect();
                         break;
 
@@ -535,6 +541,8 @@ namespace osu.Game.Screens.Edit.Compose.Components
         /// </summary>
         private bool wasDragStarted;
 
+        private readonly HashSet<T> selectionBeforeDrag = new HashSet<T>();
+
         /// <summary>
         /// Attempts to begin the movement of any selected blueprints.
         /// </summary>
diff --git a/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineBlueprintContainer.cs b/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineBlueprintContainer.cs
index 740f0b6aac..a6af83d268 100644
--- a/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineBlueprintContainer.cs
+++ b/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineBlueprintContainer.cs
@@ -173,7 +173,7 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
         protected sealed override DragBox CreateDragBox() => new TimelineDragBox();
 
-        protected override void UpdateSelectionFromDragBox()
+        protected override void UpdateSelectionFromDragBox(HashSet<HitObject> selectionBeforeDrag)
         {
             Composer.BlueprintContainer.CommitIfPlacementActive();
 
@@ -191,6 +191,9 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
 
             bool shouldBeSelected(HitObject hitObject)
             {
+                if (selectionBeforeDrag.Contains(hitObject))
+                    return true;
+
                 double midTime = (hitObject.StartTime + hitObject.GetEndTime()) / 2;
                 return minTime <= midTime && midTime <= maxTime;
             }