[Tizen] Add drag and drop gesture handlers (#13692)

Xamarin.Forms.Platform.Tizen/DragGestureHandler.cs

@@ -0,0 +1,243 @@
+using System;
+using System.Threading;
+using ElmSharp;
+using Tizen.Common;
+using Xamarin.Forms.Platform.Tizen.SkiaSharp;
+using EGestureType = ElmSharp.GestureLayer.GestureType;
+
+namespace Xamarin.Forms.Platform.Tizen
+{
+	public class DragGestureHandler : GestureHandler
+	{
+		bool _isApi4;
+
+		DragDropExtensions.Interop.DragIconCreateCallback _iconCallback;
+		DragDropExtensions.Interop.DragStateCallback _dragDoneCallback;
+
+		static bool s_isDragging;
+		static CustomDragStateData s_currentDragStateData;
+
+		public DragGestureHandler(IGestureRecognizer recognizer, IVisualElementRenderer renderer) : base(recognizer)
+		{
+			_iconCallback = OnIconCallback;
+			_dragDoneCallback = OnDragDoneCallback;
+			_isApi4 = DotnetUtil.TizenAPIVersion <= 4;
+			Renderer = renderer;
+		}
+
+		public override EGestureType Type => EGestureType.LongTap;
+
+		public IVisualElementRenderer Renderer { get; }
+
+		public static CustomDragStateData CurrentStateData
+		{
+			get
+			{
+				return s_currentDragStateData;
+			}
+		}
+
+		EvasObject NativeView
+		{
+			get
+			{
+				var native = Renderer.NativeView;
+				if (Renderer is SkiaSharp.ICanvasRenderer canvasRenderer)
+				{
+					native = canvasRenderer.RealNativeView;
+				}
+				return native;
+			}
+		}
+
+		public void ResetCurrentStateData()
+		{
+			s_currentDragStateData = null;
+		}
+
+		protected override void OnStarted(View sender, object data)
+		{
+		}
+
+		protected override void OnMoved(View sender, object data)
+		{
+			//Workaround to prevent an error occuring by multiple StartDrag calling in Tizen 6.5
+			if (!s_isDragging)
+			{
+				ResetCurrentStateData();
+				StartDrag();
+			}
+		}
+
+		protected override void OnCompleted(View sender, object data)
+		{
+		}
+
+		protected override void OnCanceled(View sender, object data)
+		{
+		}
+
+		void StartDrag()
+		{
+			if (Recognizer is DragGestureRecognizer dragGestureRecognizer && dragGestureRecognizer.CanDrag)
+			{
+				if (Renderer == null)
+					return;
+
+				var arg = dragGestureRecognizer.SendDragStarting(Renderer.Element);
+
+				if (arg.Cancel)
+					return;
+
+				s_currentDragStateData = new CustomDragStateData();
+				s_currentDragStateData.DataPackage = arg.Data;
+
+				var target = DragDropExtensions.DragDropContentType.Text;
+				var strData = string.IsNullOrEmpty(arg.Data.Text) ? " " : arg.Data.Text;
+
+				s_isDragging = true;
+
+				DragDropExtensions.StartDrag(NativeView,
+					target,
+					strData,
+					DragDropExtensions.DragDropActionType.Move,
+					_iconCallback,
+					null,
+					null,
+					_dragDoneCallback);
+			}
+		}
+
+		IntPtr OnIconCallback(IntPtr data, IntPtr window, ref int xoff, ref int yoff)
+		{
+			EvasObject icon = null;
+			EvasObject parent = new CustomWindow(NativeView, window);
+
+			if (s_currentDragStateData.DataPackage.Image != null)
+			{
+				icon = GetImageIcon(parent);
+			}
+			else if (NativeView is ShapeView)
+			{
+				icon = GetShapeView(parent);
+			}
+			else
+			{
+				icon = GetDefaultIcon(parent);
+			}
+			var bound = NativeView.Geometry;
+			bound.X = 0;
+			bound.Y = 0;
+			icon.Geometry = bound;
+
+			if (icon is Native.Label)
+			{
+				icon.Resized += (s, e) =>
+				{
+					var map = new EvasMap(4);
+					map.PopulatePoints(icon.Geometry, 0);
+					map.Zoom(0.5, 0.5, 0, 0);
+					icon.IsMapEnabled = true;
+					icon.EvasMap = map;
+				};
+			}
+			else
+			{
+				var map = new EvasMap(4);
+				map.PopulatePoints(icon.Geometry, 0);
+				map.Zoom(0.5, 0.5, 0, 0);
+				icon.IsMapEnabled = true;
+				icon.EvasMap = map;
+			}
+
+
+			return icon;
+		}
+
+		EvasObject GetDefaultIcon(EvasObject parent)
+		{
+			if (!string.IsNullOrEmpty(s_currentDragStateData.DataPackage.Text))
+			{
+				var label = new Native.Label(parent);
+				label.Text = s_currentDragStateData.DataPackage.Text;
+
+				if (Renderer.Element is Label lb)
+					label.FontSize = lb.FontSize;
+				else if (Renderer.Element is Entry et)
+					label.FontSize = et.FontSize;
+				else if (Renderer.Element is Editor ed)
+					label.FontSize = ed.FontSize;
+
+				return label;
+			}
+			else
+			{
+				var box = new ElmSharp.Rectangle(parent);
+				box.Color = new ElmSharp.Color(128, 128, 128, 128);
+				return box;
+			}
+		}
+
+		EvasObject GetImageIcon(EvasObject parent)
+		{
+			var image = new Native.Image(parent);
+			_ = image.LoadFromImageSourceAsync(s_currentDragStateData.DataPackage.Image);
+			return image;
+		}
+
+		EvasObject GetShapeView(EvasObject parent)
+		{
+			var copiedImg = new EvasImage(parent);
+			copiedImg.IsFilled = true;
+
+			if (NativeView is ShapeView shapeView)
+			{
+				var canvas = shapeView.SKCanvasView;
+				var realHandle = DragDropExtensions.Interop.elm_object_part_content_get(canvas, "elm.swallow.content");
+
+				DragDropExtensions.Interop.evas_object_image_size_get(realHandle, out int w, out int h);
+				DragDropExtensions.Interop.evas_object_image_size_set(copiedImg, w, h);
+
+				var imgData = DragDropExtensions.Interop.evas_object_image_data_get(realHandle, false);
+				DragDropExtensions.Interop.evas_object_image_data_set(copiedImg, imgData);
+			}
+
+			return copiedImg;
+		}
+
+		void OnDragDoneCallback(IntPtr data, IntPtr obj)
+		{
+			s_isDragging = false;
+			if (Recognizer is DragGestureRecognizer dragGestureRecognizer && dragGestureRecognizer.CanDrag)
+			{
+				dragGestureRecognizer.SendDropCompleted(new DropCompletedEventArgs());
+			}
+		}
+
+		public class CustomWindow : EvasObject
+		{
+			IntPtr _handle;
+
+			public CustomWindow(EvasObject parent, IntPtr handle) : base()
+			{
+				_handle = handle;
+				Realize(parent);
+			}
+
+			public CustomWindow(EvasObject handle) : base(handle)
+			{
+			}
+
+			protected override IntPtr CreateHandle(EvasObject parent)
+			{
+				return _handle;
+			}
+		}
+
+		public class CustomDragStateData
+		{
+			public DataPackage DataPackage { get; set; }
+			public DataPackageOperation AcceptedOperation { get; set; } = DataPackageOperation.Copy;
+		}
+	}
+}

Xamarin.Forms.Platform.Tizen/DropGestureHandler.cs

@@ -0,0 +1,133 @@
+using System;
+using System.Linq;
+using ElmSharp;
+using Tizen.Common;
+using EGestureType = ElmSharp.GestureLayer.GestureType;
+
+namespace Xamarin.Forms.Platform.Tizen
+{
+	public class DropGestureHandler : GestureHandler
+	{
+		bool _isApi4;
+
+		DragDropExtensions.Interop.DragStateCallback _dragEnterCallback;
+		DragDropExtensions.Interop.DragStateCallback _dragLeaveCallback;
+		DragDropExtensions.Interop.DropCallback _dropCallback;
+
+		public override EGestureType Type => default(EGestureType);
+
+		public DropGestureHandler(IGestureRecognizer recognizer, IVisualElementRenderer renderer) : base(recognizer)
+		{
+			_dragEnterCallback = OnEnterCallback;
+			_dragLeaveCallback = OnLeaveCallback;
+			_dropCallback = OnDropCallback;
+			_isApi4 = DotnetUtil.TizenAPIVersion <= 4;
+			Renderer = renderer;
+		}
+
+		public IVisualElementRenderer Renderer { get; }
+
+		EvasObject NativeView
+		{
+			get
+			{
+				var native = Renderer.NativeView;
+				if (Renderer is SkiaSharp.ICanvasRenderer canvasRenderer)
+				{
+					native = canvasRenderer.RealNativeView;
+				}
+
+				if (native is Native.Canvas canvas)
+				{
+					var child = canvas.Children.LastOrDefault<EvasObject>();
+
+					if (child != null)
+					{
+						if (child.PassEvents)
+							child.PassEvents = false;
+
+						return child;
+					}
+				}
+				return native;
+			}
+		}
+
+
+		public void AddDropGesture()
+		{
+			if (Renderer == null)
+				return;
+
+			var target = DragDropExtensions.DragDropContentType.Targets;
+
+			DragDropExtensions.AddDropTarget(NativeView,
+				target,
+				_dragEnterCallback,
+				_dragLeaveCallback, null,
+				_dropCallback);
+		}
+
+		void OnEnterCallback(IntPtr data, IntPtr obj)
+		{
+			var currentStateData = DragGestureHandler.CurrentStateData;
+			if (currentStateData == null)
+				return;
+
+			var arg = new DragEventArgs(currentStateData.DataPackage);
+
+			if (Recognizer is DropGestureRecognizer dropRecognizer && dropRecognizer.AllowDrop)
+				dropRecognizer.SendDragOver(arg);
+
+			DragGestureHandler.CurrentStateData.AcceptedOperation = arg.AcceptedOperation;
+		}
+
+		void OnLeaveCallback(IntPtr data, IntPtr obj)
+		{
+			var currentStateData = DragGestureHandler.CurrentStateData;
+			if (currentStateData == null)
+				return;
+
+			var arg = new DragEventArgs(currentStateData.DataPackage);
+
+			if (Recognizer is DropGestureRecognizer dropRecognizer && dropRecognizer.AllowDrop)
+				dropRecognizer.SendDragLeave(arg);
+
+			DragGestureHandler.CurrentStateData.AcceptedOperation = arg.AcceptedOperation;
+		}
+
+		bool OnDropCallback(IntPtr data, IntPtr obj, IntPtr selectionData)
+		{
+			var currentStateData = DragGestureHandler.CurrentStateData;
+
+			if (currentStateData.DataPackage == null || currentStateData.AcceptedOperation == DataPackageOperation.None)
+				return false;
+
+			Device.BeginInvokeOnMainThread(async ()=>
+			{
+				if (Recognizer is DropGestureRecognizer dropRecognizer && dropRecognizer.AllowDrop)
+					await dropRecognizer.SendDrop(new DropEventArgs(currentStateData.DataPackage.View));
+			});
+
+			return true;
+		}
+
+		#region GestureHandler
+		protected override void OnStarted(View sender, object data)
+		{
+		}
+
+		protected override void OnMoved(View sender, object data)
+		{
+		}
+
+		protected override void OnCompleted(View sender, object data)
+		{
+		}
+
+		protected override void OnCanceled(View sender, object data)
+		{
+		}
+		#endregion
+	}
+}