src/Tizen.NUI.Xaml/src/public/XamlBinding/Interactivity/EventTrigger.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.ComponentModel;
   4 using System.Linq;
   5 using System.Reflection;
   6 using Tizen.NUI.XamlBinding.Internals;
   7
   8 namespace Tizen.NUI.XamlBinding
   9 {
  10     /// <summary>
  11     /// The class EventTrigger.
  12     /// </summary>
  13     /// <since_tizen> 6 </since_tizen>
  14     /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
  15     [EditorBrowsable(EditorBrowsableState.Never)]
  16     [ContentProperty("Actions")]
  17     public sealed class EventTrigger : TriggerBase
  18     {
  19         static readonly MethodInfo s_handlerinfo = typeof(EventTrigger).GetRuntimeMethods().Single(mi => mi.Name == "OnEventTriggered" && mi.IsPublic == false);
  20         readonly List<BindableObject> _associatedObjects = new List<BindableObject>();
  21
  22         EventInfo _eventinfo;
  23
  24         string _eventname;
  25         Delegate _handlerdelegate;
  26
  27         /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
  28         [EditorBrowsable(EditorBrowsableState.Never)]
  29         public EventTrigger() : base(typeof(BindableObject))
  30         {
  31             Actions = new SealedList<TriggerAction>();
  32         }
  33
  34         /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
  35         [EditorBrowsable(EditorBrowsableState.Never)]
  36         public IList<TriggerAction> Actions { get; }
  37
  38         /// This will be public opened in tizen_5.5 after ACR done. Before ACR, need to be hidden as inhouse API.
  39         [EditorBrowsable(EditorBrowsableState.Never)]
  40         public string Event
  41         {
  42             get { return _eventname; }
  43             set
  44             {
  45                 if (_eventname == value)
  46                     return;
  47                 if (IsSealed)
  48                     throw new InvalidOperationException("Event cannot be changed once the Trigger has been applied");
  49                 OnPropertyChanging();
  50                 _eventname = value;
  51                 OnPropertyChanged();
  52             }
  53         }
  54
  55         internal override void OnAttachedTo(BindableObject bindable)
  56         {
  57             base.OnAttachedTo(bindable);
  58             if (!string.IsNullOrEmpty(Event))
  59                 AttachHandlerTo(bindable);
  60             _associatedObjects.Add(bindable);
  61         }
  62
  63         internal override void OnDetachingFrom(BindableObject bindable)
  64         {
  65             _associatedObjects.Remove(bindable);
  66             DetachHandlerFrom(bindable);
  67             base.OnDetachingFrom(bindable);
  68         }
  69
  70         internal override void OnSeal()
  71         {
  72             base.OnSeal();
  73             ((SealedList<TriggerAction>)Actions).IsReadOnly = true;
  74         }
  75
  76         void AttachHandlerTo(BindableObject bindable)
  77         {
  78             try
  79             {
  80                 _eventinfo = bindable.GetType().GetRuntimeEvent(Event);
  81                 _handlerdelegate = s_handlerinfo.CreateDelegate(_eventinfo?.EventHandlerType, this);
  82             }
  83             catch (Exception)
  84             {
  85                 Console.WriteLine("EventTrigger", "Can not attach EventTrigger to {0}.{1}. Check if the handler exists and if the signature is right.", bindable.GetType(), Event);
  86             }
  87             if (_eventinfo != null && _handlerdelegate != null)
  88                 _eventinfo.AddEventHandler(bindable, _handlerdelegate);
  89         }
  90
  91         void DetachHandlerFrom(BindableObject bindable)
  92         {
  93             if (_eventinfo != null && _handlerdelegate != null)
  94                 _eventinfo.RemoveEventHandler(bindable, _handlerdelegate);
  95         }
  96
  97         // [Preserve]
  98         void OnEventTriggered(object sender, EventArgs e)
  99         {
 100             var bindable = (BindableObject)sender;
 101             foreach (TriggerAction action in Actions)
 102                 action.DoInvoke(bindable);
 103         }
 104     }
 105 }