Refactored DragDrop

GlitchyEditor/src/EditorApp.bf

@@ -9,6 +9,7 @@ using DirectX.Common;
 using GlitchyEditor.Platform.Windows;
 using GlitchyEditor.Multithreading;
 using System.Threading;
+using GlitchyEditor.Platform;
 
 namespace GlitchyEditor
 {
@@ -29,16 +30,14 @@ namespace GlitchyEditor
 
 			_backgroundTaskManager.Init();
 
-			// TODO: Windows only
+			DragDropManager.Init();
-			HResult result = OleInitialize(null);
-			Log.EngineLogger.Assert(result case .S_OK);
 
 			PushLayer(new EditorLayer(args, _contentManager));
 		}
 
 		public ~this()
 		{
-			OleUninitialize();
+			DragDropManager.Deinit();
 
 			_backgroundTaskManager.Deinit();
 		}

GlitchyEditor/src/EditorLayer.bf

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using ImGui;
 using GlitchyEngine;
 using GlitchyEditor.EditWindows;
@@ -116,45 +117,6 @@ namespace GlitchyEditor
 		private bool _showImguiDemoWindow;
 #endif
 
-		/// Registers a drag'n'drop target that will fire corresponding DragDropEvent using the engine's event system.
-		class GlobalDragDropTarget : IDropTargetImplBase
-		{
-			public override Result<DropEffect> OnDragEnter(int2 cursorPosition)
-			{
-				DragDropEvent event = scope DragDropEvent(.Enter, cursorPosition);
-				Application.Instance.OnEvent(event);
-				return event.OutDropEffect;
-			}
-
-			public override Result<DropEffect> OnDragOver(int2 cursorPosition)
-			{
-				DragDropEvent event = scope DragDropEvent(.Over, cursorPosition);
-				Application.Instance.OnEvent(event);
-				return event.OutDropEffect;
-			}
-
-			public override Result<void> OnDragLeave()
-			{
-				DragDropEvent event = scope DragDropEvent(.Leave, .(-1, -1));
-				Application.Instance.OnEvent(event);
-				return .Ok;
-			}
-
-			public override Result<DropEffect> OnDrop(int2 cursorPosition, List<String> fileNames)
-			{
-				DragDropEvent event = scope DragDropEvent(.Drop, cursorPosition);
-				event.FileNames = fileNames;
-				Application.Instance.OnEvent(event);
-				return event.OutDropEffect;
-			}
-		}
-
-		private GlobalDragDropTarget _dragDropTarget ~
-		{
-			_.Unregister();
-			_?.ReleaseRef();
-		}
-		
 		[AllowAppend]
 		public this(String[] args, EditorContentManager contentManager) : base("Editor")
 		{
@@ -165,9 +127,6 @@ namespace GlitchyEditor
 			// TODO: Das muss weg
 			_layer = this;
 
-			_dragDropTarget = new .();
-			_dragDropTarget.Register();
-
 			_contentManager = contentManager;
 
 			InitGraphics();
@@ -1709,7 +1668,7 @@ namespace GlitchyEditor
 		{
 			if (_layer._isDraggingFromOutside == .None)
 			{
-				Log.EngineLogger.Warning("Setting drop effect, eventhou the user is currently not dragging.");
+				Log.EngineLogger.Warning("Setting drop effect, even though the user is currently not dragging.");
 			}
 
 			_layer._effectWhenDropping = effect;
@@ -1722,7 +1681,7 @@ namespace GlitchyEditor
 				ImGui.GetIO().MousePos = .(e.CursorPosition.X, e.CursorPosition.Y);
 			}
 
-			if (e.FileNames == null)
+			if (e.FileNames.IsEmpty)
 			{
 				DeleteContainerAndItems!(_droppedFiles);
 				_droppedFiles = null;
@@ -1734,12 +1693,27 @@ namespace GlitchyEditor
 					_droppedFiles = new List<String>();
 				}
 
-				for (String fileName in e.FileNames)
+				int firstIndexToRemove = 0;
+
+				for (StringView filePath in e.FileNames)
 				{
-					if (!_droppedFiles.Contains(fileName, .Ordinal))
+					int index = _droppedFiles.IndexOfAlt(filePath);
+					if (index == -1)
 					{
-						_droppedFiles.Add(new String(fileName));
+						index = _droppedFiles.Count;
+						_droppedFiles.Add(new String(filePath));
 					}
+
+					// Make sure, all paths that are in e.FileNames are before firstIndexToRemove
+					Swap!(_droppedFiles[firstIndexToRemove], _droppedFiles[index]);
+
+					firstIndexToRemove++;
+				}
+
+				// Remove all paths beyond firstIndexToRemove
+				for (int i = _droppedFiles.Count; i > firstIndexToRemove; i--)
+				{
+					delete _droppedFiles.PopBack();
 				}
 			}
 

GlitchyEditor/src/Platform/DragDropManager.bf

@@ -0,0 +1,9 @@
+namespace GlitchyEditor.Platform;
+
+/// Manages system drag and drop events and fires corresponding engine events.
+static class DragDropManager
+{
+	public extern static void Init();
+
+	public extern static void Deinit();
+}

GlitchyEditor/src/Platform/Windows/DropTarget.bf

@@ -1,3 +1,5 @@
+#if BF_PLATFORM_WINDOWS
+
 using System;
 using DirectX.Common;
 using DirectX.Math;
@@ -10,18 +12,18 @@ using System.IO;
 
 namespace GlitchyEditor.Platform.Windows;
 
-// This entire thing is so platform dependent, that it really doesn't make sense to abstract while we are windows only.
-
 static
 {
-	[Import("Ole32.lib"), CLink]
+	[Import("Ole32.lib"), CLink, CallingConvention(.Stdcall)]
 	public static extern HResult OleInitialize(void* reserved);
-	[Import("Ole32.lib"), CLink]
+	[Import("Ole32.lib"), CLink, CallingConvention(.Stdcall)]
 	public static extern void OleUninitialize();
-	[Import("Ole32.lib"), CLink]
+	[Import("Ole32.lib"), CLink, CallingConvention(.Stdcall)]
 	public static extern HResult RegisterDragDrop(HWnd windowHandle, IDropTarget* dropTarget);
-	[Import("Ole32.lib"), CLink]
+	[Import("Ole32.lib"), CLink, CallingConvention(.Stdcall)]
 	public static extern HResult RevokeDragDrop(HWnd windowHandle);
+	[Import("ole32.dll"), CLink, CallingConvention(.Stdcall)]
+	public static extern HResult DoDragDrop(IDataObject* pDataObj, IDropSource* pDropSource, DropEffect dwOKEffects, out DropEffect pdwEffect);
 }
 
 [CRepr]
@@ -85,7 +87,6 @@ public struct FORMATETC
 	public typealias HBITMAP = int;
 	public typealias HENHMETAFILE = int;
 	public typealias PWSTR = char16*;
-	public typealias BOOL = int32;
 [CRepr]
 public struct STGMEDIUM
 {
@@ -116,7 +117,7 @@ public struct IDataObject : IUnknown
 	public HResult GetDataHere(ref FORMATETC pformatetc, out STGMEDIUM pmedium) mut => VT.GetDataHere(ref this, ref pformatetc, out pmedium);
 	public HResult QueryGetData(ref FORMATETC pformatetc) mut => VT.QueryGetData(ref this, ref pformatetc);
 	public HResult GetCanonicalFormatEtc(ref FORMATETC pformatectIn, out FORMATETC pformatetcOut) mut => VT.GetCanonicalFormatEtc(ref this, ref pformatectIn, out pformatetcOut);
-	public HResult SetData(ref FORMATETC pformatetc, ref STGMEDIUM pmedium, BOOL fRelease) mut => VT.SetData(ref this, ref pformatetc, ref pmedium, fRelease);
+	public HResult SetData(ref FORMATETC pformatetc, ref STGMEDIUM pmedium, BigBool fRelease) mut => VT.SetData(ref this, ref pformatetc, ref pmedium, fRelease);
 	public HResult EnumFormatEtc(uint32 dwDirection, out /*IEnumFORMATETC*/ IUnknown* ppenumFormatEtc) mut => VT.EnumFormatEtc(ref this, dwDirection, out ppenumFormatEtc);
 	public HResult DAdvise(ref FORMATETC pformatetc, uint32 advf, ref /*IAdviseSink*/ IUnknown* pAdvSink, out uint32 pdwConnection) mut => VT.DAdvise(ref this, ref pformatetc, advf, ref pAdvSink, out pdwConnection);
 	public HResult DUnadvise(uint32 dwConnection) mut => VT.DUnadvise(ref this, dwConnection);
@@ -129,7 +130,7 @@ public struct IDataObject : IUnknown
 		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, ref FORMATETC pformatetc, out STGMEDIUM pmedium) GetDataHere;
 		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, ref FORMATETC pformatetc) QueryGetData;
 		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, ref FORMATETC pformatectIn, out FORMATETC pformatetcOut) GetCanonicalFormatEtc;
-		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, ref FORMATETC pformatetc, ref STGMEDIUM pmedium, BOOL fRelease) SetData;
+		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, ref FORMATETC pformatetc, ref STGMEDIUM pmedium, BigBool fRelease) SetData;
 		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, uint32 dwDirection, out /*IEnumFORMATETC*/ IUnknown* ppenumFormatEtc) EnumFormatEtc;
 		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, ref FORMATETC pformatetc, uint32 advf, ref /*IAdviseSink*/ IUnknown* pAdvSink, out uint32 pdwConnection) DAdvise;
 		public new function [CallingConvention(.Stdcall)] HResult(ref IDataObject self, uint32 dwConnection) DUnadvise;
@@ -229,6 +230,8 @@ abstract class IDropTargetImplBase : RefCounted
 	{
 		HResult result = RevokeDragDrop(Application.Instance.Window.[Friend]_windowHandle);
 		Log.EngineLogger.Assert(result case .S_OK);
+
+		OleUninitialize();
 	}
 
 	private static IDropTargetImplBase GetInstance(IUnknown* self)
@@ -279,7 +282,7 @@ abstract class IDropTargetImplBase : RefCounted
 	public abstract Result<DropEffect> OnDragEnter(int2 cursorPosition);
 	public abstract Result<DropEffect> OnDragOver(int2 cursorPosition);
 	public abstract Result<void> OnDragLeave();
-	public abstract Result<DropEffect> OnDrop(int2 cursorPosition, List<String> fileNames);
+	public abstract Result<DropEffect> OnDrop(int2 cursorPosition, Span<StringView> fileNames);
 
 	[CallingConvention(.Stdcall)]
 	private static HResult DragEnterImpl(IDropTarget* self, /*IDataObject*/ IUnknown* dataObject, uint32 grfKeyState, int2 point, ref DropEffect effect)
@@ -338,15 +341,16 @@ abstract class IDropTargetImplBase : RefCounted
 			tymed = (.)TYMED.HGLOBAL
 		};
 
-		List<String> files = null;
+		String paths = scope .();
-		defer {DeleteContainerAndItems!(files);}
+		List<StringView> files = null;
+		defer { delete files; }
 
 		if (dataObject.GetData(ref format, var stgm).Succeeded)
 		{
 			HDROP hdrop = (HDROP)stgm.hGlobal;
 			uint32 fileCount = DragQueryFileW(hdrop, 0xFFFFFFFF, null, 0);
 
-			files = new List<String>(fileCount);
+			files = new List<StringView>(fileCount);
 
 			List<char16> buffer = scope List<char16>();
 			buffer.Resize(256);
@@ -359,14 +363,27 @@ abstract class IDropTargetImplBase : RefCounted
 				uint32 retrievedSize = DragQueryFileW(hdrop, i, buffer.Ptr, (.)buffer.Count);
 				if (retrievedSize > 0 && retrievedSize < buffer.Count)
 				{
-					String str = new String(buffer.Ptr);
+					int startIndex = paths.Length;
-					files.Add(str);
+					paths.Append(buffer);
+					int endIndex = paths.Length;
+
+					// StringViews might be invalid until fixup step down below
+					files.Add(StringView(paths, startIndex, endIndex - startIndex));
 				}
 			}
 
 			ReleaseStgMedium(ref stgm);
 		}
 
+		int index = 0;
+
+		// Fixup pointer of string views
+		for (ref StringView path in ref files)
+		{
+			path.Ptr = paths.Ptr + index;
+			index += path.Length;
+		}
+
 		Result<DropEffect> result = instance.OnDrop(point, files);
 
 		if (result case .Ok(out effect))
@@ -430,8 +447,8 @@ public class DragDropEvent : Event, IEvent
 
 	public DropEffect OutDropEffect { get; set; }
 
-	// Do not keep references to this list or any of it's items outside of the event handler, they will not survive it.
+	/// Do not keep references to this list or any of it's items outside of the event handler, they will not survive it.
-	public List<String> FileNames { get; set; }
+	public Span<StringView> FileNames { get; set; }
 
 	// TODO: Keys, or perhaps just make the listeners query them...
 
@@ -449,3 +466,5 @@ namespace GlitchyEngine.Events
 		case DragDropEvent;
 	}
 }
+
+#endif

GlitchyEditor/src/Platform/Windows/WindowsDragDropManager.bf

@@ -0,0 +1,79 @@
+#if BF_PLATFORM_WINDOWS
+
+using System;
+using System.Collections;
+using GlitchyEngine;
+using GlitchyEngine.Math;
+using GlitchyEditor.Platform.Windows;
+using DirectX.Common;
+
+namespace GlitchyEditor.Platform;
+
+extension DragDropManager
+{
+	private static DragDropEventTranslator _dragDropTarget;
+	
+	public override static void Init()
+	{
+		HResult result = OleInitialize(null);
+		Log.EngineLogger.Assert(result case .S_OK);
+
+		_dragDropTarget = new .();
+		_dragDropTarget.Register();
+	}
+
+	public override static void Deinit()
+	{
+		_dragDropTarget.Unregister();
+		ReleaseRefAndNullify!(_dragDropTarget);
+	}
+
+	private static bool _isDragging;
+
+	public static void StartDragDrop()
+	{
+		if (_isDragging)
+			return;
+
+		_isDragging = true;
+
+		IDataObject* dataObject = null;
+		
+		//HResult result = DoDragDrop(ref dataObject);
+	}
+}
+
+/// Registers a Windows drag'n'drop target that will fire Windows drop related events using the engine's event system.
+class DragDropEventTranslator : IDropTargetImplBase
+{
+	public override Result<DropEffect> OnDragEnter(int2 cursorPosition)
+	{
+		DragDropEvent event = scope DragDropEvent(.Enter, cursorPosition);
+		Application.Instance.OnEvent(event);
+		return event.OutDropEffect;
+	}
+
+	public override Result<DropEffect> OnDragOver(int2 cursorPosition)
+	{
+		DragDropEvent event = scope DragDropEvent(.Over, cursorPosition);
+		Application.Instance.OnEvent(event);
+		return event.OutDropEffect;
+	}
+
+	public override Result<void> OnDragLeave()
+	{
+		DragDropEvent event = scope DragDropEvent(.Leave, .(-1, -1));
+		Application.Instance.OnEvent(event);
+		return .Ok;
+	}
+
+	public override Result<DropEffect> OnDrop(int2 cursorPosition, Span<StringView> fileNames)
+	{
+		DragDropEvent event = scope DragDropEvent(.Drop, cursorPosition);
+		event.FileNames = fileNames;
+		Application.Instance.OnEvent(event);
+		return event.OutDropEffect;
+	}
+}
+
+#endif

GlitchyEngine/src/Helper.bf

@@ -31,6 +31,13 @@ namespace GlitchyEngine
 			value?.ReleaseRef();
 			value = null;
 		}
+
+		/// Releases the reference to value and nullifies it.
+		public static mixin ReleaseRefAndNullify<T>(T value) where T: RefCounted
+		{
+			value?.ReleaseRef();
+			value = null;
+		}
 		
 		public static mixin DeleteContainerAndReleaseItems(var container)
 		{