src/Tizen.NUI/src/public/DragAndDrop/DragAndDrop.cs

   1 /*
   2  * Copyright(c) 2022 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17 using System;
  18 using System.ComponentModel;
  19 using System.Runtime.InteropServices;
  20 using System.Collections.Generic;
  21 using System.Diagnostics.CodeAnalysis;
  22 using Tizen.NUI.BaseComponents;
  23
  24 namespace Tizen.NUI
  25 {
  26     /// <summary>
  27     /// DragAndDrop controls the drag object and data.
  28     /// </summary>
  29     /// <since_tizen> 10 </since_tizen>
  30     [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Reliability", "CA2000: Dispose objects before losing scope", Justification = "It does not have ownership.")]
  31     public class DragAndDrop : BaseHandle
  32     {
  33         public delegate void SourceEventHandler(DragSourceEventType sourceEventType);
  34         private delegate void InternalSourceEventHandler(int sourceEventType);
  35         public delegate void DragAndDropEventHandler(View targetView, DragEvent dragEvent);
  36         private delegate void InternalDragAndDropEventHandler(global::System.IntPtr dragEvent);
  37         private InternalSourceEventHandler sourceEventCb;
  38         private Dictionary<View, InternalDragAndDropEventHandler> targetEventDictionary = new Dictionary<View, InternalDragAndDropEventHandler>();
  39         private View mShadowView;
  40         private Window mDragWindow;
  41         private int shadowWidth = 100;
  42         private int shadowHeight = 100;
  43
  44         private bool initDrag = false;
  45
  46         private DragAndDrop() : this(Interop.DragAndDrop.New(), true)
  47         {
  48             if (NDalicPINVOKE.SWIGPendingException.Pending) throw NDalicPINVOKE.SWIGPendingException.Retrieve();
  49         }
  50
  51         private DragAndDrop(global::System.IntPtr cPtr, bool cMemoryOwn) : base(cPtr, cMemoryOwn)
  52         {
  53
  54         }
  55
  56         private void ReleaseDragWindow()
  57         {
  58             if (mDragWindow)
  59             {
  60                 if (mShadowView)
  61                 {
  62                     //Application has Shadow View ownership, so DnD doesn't dispose Shadow View
  63                     mDragWindow.Remove(mShadowView);
  64                     mShadowView = null;
  65                 }
  66
  67                 mDragWindow.Dispose();
  68                 mDragWindow = null;
  69             }
  70         }
  71
  72         /// <summary>
  73         /// Gets the singleton instance of DragAndDrop.
  74         /// </summary>
  75         /// <since_tizen> 10 </since_tizen>
  76         public static DragAndDrop Instance { get; } = new DragAndDrop();
  77
  78         /// <summary>
  79         /// Starts drag and drop.
  80         /// </summary>
  81         /// <param name="sourceView">The soruce view</param>
  82         /// <param name="shadowView">The shadow view for drag object</param>
  83         /// <param name="dragData">The data to send</param>
  84         /// <param name="callback">The source event callback</param>
  85         /// <since_tizen> 10 </since_tizen>
  86         public void StartDragAndDrop(View sourceView, View shadowView, DragData dragData, SourceEventHandler callback)
  87         {
  88             if (initDrag)
  89             {
  90                  Tizen.Log.Fatal("NUI", "Start Drag And Drop Initializing...");
  91                  return;
  92             }
  93             initDrag = true;
  94
  95             if (Window.IsSupportedMultiWindow() == false)
  96             {
  97                 throw new NotSupportedException("This device does not support surfaceless_context. So Window cannot be created.");
  98             }
  99
 100             if (null == shadowView)
 101             {
 102                 throw new ArgumentNullException(nameof(shadowView));
 103             }
 104
 105             ReleaseDragWindow();
 106
 107             shadowWidth = (int)shadowView.Size.Width;
 108             shadowHeight = (int)shadowView.Size.Height;
 109
 110             // Prevents shadowView size from being smaller than 100 pixel
 111             if (shadowView.Size.Width < 100)
 112             {
 113                 shadowWidth = 100;
 114             }
 115
 116             if (shadowView.Size.Height < 100)
 117             {
 118                 shadowHeight = 100;
 119             }
 120
 121             mDragWindow = new Window("DragWindow", new Rectangle(-shadowWidth, -shadowHeight, shadowWidth, shadowHeight), true)
 122             {
 123                 BackgroundColor = Color.Transparent,
 124             };
 125
 126             if (mDragWindow)
 127             {
 128                 //Initialize Drag Window Size based on Shadow View Size,
 129                 //Don't set Drag Window Posiiton, Window Server sets Position Internally
 130                 mDragWindow.SetWindowSize(new Size(shadowWidth, shadowHeight));
 131
 132                 //Make Shadow View Transparent
 133                 shadowView.SetOpacity(0.9f);
 134
 135                 //Make Position 0, 0 for Moving into Drag Window
 136                 shadowView.Position = new Position(0, 0);
 137
 138                 mShadowView = shadowView;
 139                 mDragWindow.Add(mShadowView);
 140
 141                 sourceEventCb = (sourceEventType) =>
 142                 {
 143                     if ((DragSourceEventType)sourceEventType != DragSourceEventType.Start)
 144                     {
 145                         Tizen.Log.Fatal("NUI", "DnD Source Event is Called");
 146                         ReleaseDragWindow();
 147                     }
 148
 149                     callback((DragSourceEventType)sourceEventType);
 150                 };
 151
 152                 //Show Drag Window before StartDragAndDrop
 153                 mDragWindow.Show();
 154
 155                 if (!Interop.DragAndDrop.StartDragAndDrop(SwigCPtr, View.getCPtr(sourceView), Window.getCPtr(mDragWindow), dragData.MimeType, dragData.Data,
 156                                                         new global::System.Runtime.InteropServices.HandleRef(this, Marshal.GetFunctionPointerForDelegate<Delegate>(sourceEventCb))))
 157                 {
 158                     throw new InvalidOperationException("Fail to StartDragAndDrop");
 159                 }
 160
 161             }
 162
 163             initDrag = false;
 164         }
 165
 166         /// <summary>
 167         /// Adds listener for drop targets
 168         /// </summary>
 169         /// <param name="targetView">The target view</param>
 170         /// <param name="callback">The callback function to get drag event when the drag source enters, moves, leaves and drops on the drop target</param>
 171         /// <since_tizen> 10 </since_tizen>
 172         public void AddListener(View targetView, DragAndDropEventHandler callback)
 173         {
 174             InternalDragAndDropEventHandler cb = (dragEvent) =>
 175             {
 176                 DragType type = (DragType)Interop.DragAndDrop.GetAction(dragEvent);
 177                 DragEvent ev = new DragEvent();
 178                 global::System.IntPtr cPtr = Interop.DragAndDrop.GetPosition(dragEvent);
 179                 ev.Position = (cPtr == global::System.IntPtr.Zero) ? null : new Position(cPtr, false);
 180
 181                 if (type == DragType.Enter)
 182                 {
 183                     ev.DragType = type;
 184                     callback(targetView, ev);
 185                 }
 186                 else if (type == DragType.Leave)
 187                 {
 188                     ev.DragType = type;
 189                     callback(targetView, ev);
 190                 }
 191                 else if (type == DragType.Move)
 192                 {
 193                     ev.DragType = type;
 194                     callback(targetView, ev);
 195                 }
 196                 else if (type == DragType.Drop)
 197                 {
 198                     ev.DragType = type;
 199                     ev.MimeType = Interop.DragAndDrop.GetMimeType(dragEvent);
 200                     ev.Data = Interop.DragAndDrop.GetData(dragEvent);
 201                     callback(targetView, ev);
 202                 }
 203             };
 204
 205             targetEventDictionary.Add(targetView, cb);
 206
 207             if (!Interop.DragAndDrop.AddListener(SwigCPtr, View.getCPtr(targetView),
 208                                                  new global::System.Runtime.InteropServices.HandleRef(this, Marshal.GetFunctionPointerForDelegate<Delegate>(cb))))
 209             {
 210                  throw new InvalidOperationException("Fail to AddListener");
 211             }
 212         }
 213
 214         /// <summary>
 215         /// Removes listener for drop targets
 216         /// </summary>
 217         /// <param name="targetView">The target view</param>
 218         /// <param name="callback">The callback function to remove</param>
 219         /// <since_tizen> 10 </since_tizen>
 220         public void RemoveListener(View targetView, DragAndDropEventHandler callback)
 221         {
 222             if (!targetEventDictionary.ContainsKey(targetView))
 223             {
 224                  throw new InvalidOperationException("Fail to RemoveListener");
 225             }
 226
 227             InternalDragAndDropEventHandler cb = targetEventDictionary[targetView];
 228             targetEventDictionary.Remove(targetView);
 229             if (!Interop.DragAndDrop.RemoveListener(SwigCPtr, View.getCPtr(targetView),
 230                                                     new global::System.Runtime.InteropServices.HandleRef(this, Marshal.GetFunctionPointerForDelegate<Delegate>(cb))))
 231             {
 232                  throw new InvalidOperationException("Fail to RemoveListener");
 233             }
 234         }
 235     }
 236 }