dragdrop

Dalamud.CorePlugin/PluginImpl.cs

@@ -1,12 +1,13 @@
 using System;
 using System.IO;
-
+using System.Windows.Forms;
 using Dalamud.Configuration.Internal;
 using Dalamud.Game.Command;
 using Dalamud.Interface.Windowing;
 using Dalamud.Logging;
 using Dalamud.Plugin;
 using Dalamud.Utility;
+using PInvoke;
 
 namespace Dalamud.CorePlugin
 {

Dalamud/Dalamud.csproj

@@ -82,6 +82,7 @@
         </PackageReference>
         <PackageReference Include="System.Collections.Immutable" Version="7.0.0" />
         <PackageReference Include="System.Drawing.Common" Version="7.0.0" />
+        <PackageReference Include="Microsoft.VisualStudio.Interop" Version="17.0" />
         <PackageReference Include="System.Reactive" Version="5.0.0" />
         <PackageReference Include="System.Reflection.MetadataLoadContext" Version="7.0.0" />
         <PackageReference Include="System.Resources.Extensions" Version="7.0.0" />

Dalamud/Interface/DragDrop/DragDropInterop.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Windows.Forms;
+
+namespace Dalamud.Interface.DragDrop;
+
+internal partial class DragDropManager
+{
+    private static class DragDropInterop
+    {
+        [Flags]
+        public enum ModifierKeys
+        {
+            MK_NONE = 0x00,
+            MK_LBUTTON = 0x01,
+            MK_RBUTTON = 0x02,
+            MK_SHIFT = 0x04,
+            MK_CONTROL = 0x08,
+            MK_MBUTTON = 0x10,
+            MK_ALT = 0x20,
+        }
+
+        public enum ClipboardFormat
+        {
+            CF_TEXT = 1,
+            CF_BITMAP = 2,
+            CF_DIB = 3,
+            CF_UNICODETEXT = 13,
+            CF_HDROP = 15,
+        }
+
+        [Flags]
+        public enum DVAspect
+        {
+            DVASPECT_CONTENT = 0x01,
+            DVASPECT_THUMBNAIL = 0x02,
+            DVASPECT_ICON = 0x04,
+            DVASPECT_DOCPRINT = 0x08,
+        }
+
+        [Flags]
+        public enum TYMED
+        {
+            TYMED_NULL = 0x00,
+            TYMED_HGLOBAL = 0x01,
+            TYMED_FILE = 0x02,
+            TYMED_ISTREAM = 0x04,
+            TYMED_ISTORAGE = 0x08,
+            TYMED_GDI = 0x10,
+            TYMED_MFPICT = 0x20,
+            TYMED_ENHMF = 0x40,
+        }
+
+        [Flags]
+        public enum DropEffects : uint
+        {
+            None = 0x00_0000_00,
+            Copy = 0x00_0000_01,
+            Move = 0x00_0000_02,
+            Link = 0x00_0000_04,
+            Scroll = 0x80_0000_00,
+        }
+
+        [DllImport("ole32.dll")]
+        public static extern int RegisterDragDrop(nint hwnd, IDropTarget pDropTarget);
+
+        [DllImport("ole32.dll")]
+        public static extern int RevokeDragDrop(nint hwnd);
+
+        [DllImport("shell32.dll")]
+        public static extern int DragQueryFile(IntPtr hDrop, uint iFile, StringBuilder lpszFile, int cch);
+    }
+}

Dalamud/Interface/DragDrop/DragDropManager.cs

@@ -0,0 +1,106 @@
+using ImGuiNET;
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using Serilog;
+
+namespace Dalamud.Interface.DragDrop;
+
+internal partial class DragDropManager : IDisposable, IDragDropManager
+{
+    private readonly UiBuilder uiBuilder;
+
+    public DragDropManager(UiBuilder uiBuilder)
+        => this.uiBuilder = uiBuilder;
+
+    public void Enable()
+    {
+        if (this.ServiceAvailable)
+        {
+            return;
+        }
+
+        try
+        {
+            var ret2 = DragDropInterop.RegisterDragDrop(this.uiBuilder.WindowHandlePtr, this);
+            Marshal.ThrowExceptionForHR(ret2);
+            this.ServiceAvailable = true;
+        }
+        catch (Exception ex)
+        {
+            Log.Error($"Could not create windows drag and drop utility:\n{ex}");
+        }
+    }
+
+    public void Dispose()
+    {
+        if (!this.ServiceAvailable)
+        {
+            return;
+        }
+
+
+    }
+
+    public bool ServiceAvailable { get; internal set; }
+
+    public bool IsDragging { get; private set; }
+
+    public IReadOnlyList<string> Files { get; private set; } = Array.Empty<string>();
+
+    public IReadOnlySet<string> Extensions { get; private set; } = new HashSet<string>();
+
+    public IReadOnlyList<string> Directories { get; private set; } = Array.Empty<string>();
+
+    /// <inheritdoc cref="IDragDropManager.CreateImGuiSource(string, Func{IDragDropManager, bool}, Func{IDragDropManager, bool})"/>
+    public void CreateImGuiSource(string label, Func<IDragDropManager, bool> validityCheck, Func<IDragDropManager, bool> tooltipBuilder)
+    {
+        if (!this.IsDragging && !this.IsDropping()) return;
+        if (!validityCheck(this) || !ImGui.BeginDragDropSource(ImGuiDragDropFlags.SourceExtern)) return;
+
+        ImGui.SetDragDropPayload(label, nint.Zero, 0);
+        if (this.CheckTooltipFrame(out var frame) && tooltipBuilder(this))
+        {
+            this.lastTooltipFrame = frame;
+        }
+
+        ImGui.EndDragDropSource();
+    }
+
+    /// <inheritdoc cref="IDragDropManager.CreateImGuiTarget"/>
+    public bool CreateImGuiTarget(string label, out IReadOnlyList<string> files, out IReadOnlyList<string> directories)
+    {
+        files = Array.Empty<string>();
+        directories = Array.Empty<string>();
+        if (!this.IsDragging || !ImGui.BeginDragDropTarget()) return false;
+
+        unsafe
+        {
+            if (ImGui.AcceptDragDropPayload(label, ImGuiDragDropFlags.AcceptBeforeDelivery).NativePtr != null && this.IsDropping())
+            {
+                this.lastDropFrame = -2;
+                files = this.Files;
+                directories = this.Directories;
+                return true;
+            }
+        }
+
+        ImGui.EndDragDropTarget();
+        return false;
+    }
+
+    private int lastDropFrame = -2;
+    private int lastTooltipFrame = -1;
+
+    private bool CheckTooltipFrame(out int frame)
+    {
+        frame = ImGui.GetFrameCount();
+        return this.lastTooltipFrame < frame;
+    }
+
+    private bool IsDropping()
+    {
+        var frame = ImGui.GetFrameCount();
+        return this.lastDropFrame == frame || this.lastDropFrame == frame - 1;
+    }
+}

Dalamud/Interface/DragDrop/DragDropTarget.cs

@@ -0,0 +1,23 @@
+using System;
+using Microsoft.VisualStudio.OLE.Interop;
+
+namespace Dalamud.Interface.DragDrop;
+
+internal partial class DragDropManager : IDropTarget
+{
+    public void DragEnter(IDataObject pDataObj, uint grfKeyState, POINTL pt, ref uint pdwEffect)
+    {
+    }
+
+    public void DragOver(uint grfKeyState, POINTL pt, ref uint pdwEffect)
+    {
+    }
+
+    public void DragLeave()
+    {
+    }
+
+    public void Drop(IDataObject pDataObj, uint grfKeyState, POINTL pt, ref uint pdwEffect)
+    {
+    }
+}

Dalamud/Interface/DragDrop/IDragDropManager.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Collections.Generic;
+
+namespace Dalamud.Interface.DragDrop;
+
+/// <summary>
+/// A service to handle external drag and drop from WinAPI.
+/// </summary>
+public interface IDragDropManager
+{
+    /// <summary> Gets a value indicating whether Drag and Drop functionality is available at all. </summary>
+    public bool ServiceAvailable { get; }
+
+    /// <summary> Gets a value indicating whether anything is being dragged from an external application and over any of the games viewports. </summary>
+    public bool IsDragging { get; }
+
+    /// <summary> Gets the list of files currently being dragged from an external application over any of the games viewports. </summary>
+    public IReadOnlyList<string> Files { get; }
+
+    /// <summary> Gets the set of file types by extension currently being dragged from an external application over any of the games viewports. </summary>
+    public IReadOnlySet<string> Extensions { get; }
+
+    /// <summary> Gets the list of directories currently being dragged from an external application over any of the games viewports. </summary>
+    public IReadOnlyList<string> Directories { get; }
+
+    /// <summary> Create an ImGui drag & drop source that is active only if anything is being dragged from an external source. </summary>
+    /// <param name="label"> The label used for the drag & drop payload. </param>
+    /// <param name="validityCheck">A function returning whether the current status is relevant for this source. Checked before creating the source but only if something is being dragged.</param>
+    public void CreateImGuiSource(string label, Func<IDragDropManager, bool> validityCheck)
+        => this.CreateImGuiSource(label, validityCheck, _ => false);
+
+    /// <summary> Create an ImGui drag & drop source that is active only if anything is being dragged from an external source. </summary>
+    /// <param name="label"> The label used for the drag & drop payload. </param>
+    /// <param name="validityCheck">A function returning whether the current status is relevant for this source. Checked before creating the source but only if something is being dragged.</param>
+    /// <param name="tooltipBuilder">Executes ImGui functions to build a tooltip. Should return true if it creates any tooltip and false otherwise. If multiple sources are active, only the first non-empty tooltip type drawn in a frame will be used.</param>
+    public void CreateImGuiSource(string label, Func<IDragDropManager, bool> validityCheck, Func<IDragDropManager, bool> tooltipBuilder);
+
+    /// <summary> Create an ImGui drag & drop target on the last ImGui object. </summary>
+    /// <param name="label">The label used for the drag & drop payload.</param>
+    /// <param name="files">On success, contains the files dropped onto the target.</param>
+    /// <returns>True if items were dropped onto the target this frame, false otherwise.</returns>
+    public bool CreateImGuiTarget(string label, out IReadOnlyList<string> files);
+}

Dalamud/Interface/UiBuilder.cs

@@ -7,6 +7,7 @@ using Dalamud.Configuration.Internal;
 using Dalamud.Game;
 using Dalamud.Game.ClientState.Conditions;
 using Dalamud.Game.Gui;
+using Dalamud.Interface.DragDrop;
 using Dalamud.Interface.GameFonts;
 using Dalamud.Interface.Internal;
 using Dalamud.Interface.Internal.ManagedAsserts;
@@ -30,6 +31,7 @@ public sealed class UiBuilder : IDisposable
     private readonly string namespaceName;
     private readonly InterfaceManager interfaceManager = Service<InterfaceManager>.Get();
     private readonly GameFontManager gameFontManager = Service<GameFontManager>.Get();
+    private readonly DragDropManager dragDropManager;
 
     private bool hasErrorWindow = false;
     private bool lastFrameUiHideState = false;
@@ -47,6 +49,7 @@ public sealed class UiBuilder : IDisposable
         this.stopwatch = new Stopwatch();
         this.hitchDetector = new HitchDetector($"UiBuilder({namespaceName})", this.configuration.UiBuilderHitch);
         this.namespaceName = namespaceName;
+        this.dragDropManager = new DragDropManager(this);
 
         this.interfaceManager.Draw += this.OnDraw;
         this.interfaceManager.BuildFonts += this.OnBuildFonts;
@@ -100,6 +103,11 @@ public sealed class UiBuilder : IDisposable
     /// </summary>
     public event Action HideUi;
 
+    /// <summary>
+    /// Gets the manager for external, WinAPI-based drag and drop functionality.
+    /// </summary>
+    public IDragDropManager DragDropManager => this.dragDropManager;
+
     /// <summary>
     /// Gets the default Dalamud font based on Noto Sans CJK Medium in 17pt - supporting all game languages and icons.
     /// </summary>
@@ -397,6 +405,7 @@ public sealed class UiBuilder : IDisposable
     /// </summary>
     void IDisposable.Dispose()
     {
+        this.dragDropManager.Dispose();
         this.interfaceManager.Draw -= this.OnDraw;
         this.interfaceManager.BuildFonts -= this.OnBuildFonts;
         this.interfaceManager.ResizeBuffers -= this.OnResizeBuffers;