src/Tizen.NUI/src/public/XamlBinding/ElementTemplate.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.ComponentModel;
   4 using Tizen.NUI.Internals;
   5
   6 namespace Tizen.NUI.Binding
   7 {
   8     /// <summary>
   9     /// Base class for DataTemplate and ControlTemplate classes.
  10     /// </summary>
  11     [EditorBrowsable(EditorBrowsableState.Never)]
  12     public class ElementTemplate : IElement, IDataTemplate
  13         {
  14                 List<Action<object, ResourcesChangedEventArgs>> _changeHandlers;
  15                 Element _parent;
  16                 bool _canRecycle; // aka IsDeclarative
  17
  18                 internal ElementTemplate()
  19                 {
  20                 }
  21
  22                 internal ElementTemplate(Type type) : this()
  23                 {
  24                         if (type == null)
  25                                 throw new ArgumentNullException("type");
  26
  27                         _canRecycle = true;
  28
  29                         LoadTemplate = () => Activator.CreateInstance(type);
  30                 }
  31
  32                 internal ElementTemplate(Func<object> loadTemplate) : this()
  33                 {
  34                         if (loadTemplate == null)
  35                                 throw new ArgumentNullException("loadTemplate");
  36
  37                         LoadTemplate = loadTemplate;
  38                 }
  39
  40                 Func<object> LoadTemplate { get; set; }
  41
  42 #pragma warning disable 0612
  43                 Func<object> IDataTemplate.LoadTemplate
  44                 {
  45                         get { return LoadTemplate; }
  46                         set { LoadTemplate = value; }
  47                 }
  48 #pragma warning restore 0612
  49
  50                 void IElement.AddResourcesChangedListener(Action<object, ResourcesChangedEventArgs> onchanged)
  51                 {
  52                         _changeHandlers = _changeHandlers ?? new List<Action<object, ResourcesChangedEventArgs>>(1);
  53                         _changeHandlers.Add(onchanged);
  54                 }
  55
  56                 internal bool CanRecycle => _canRecycle;
  57                 Element IElement.Parent
  58                 {
  59                         get { return _parent; }
  60                         set
  61                         {
  62                                 if (_parent == value)
  63                                         return;
  64                                 if (_parent != null)
  65                                         ((IElement)_parent).RemoveResourcesChangedListener(OnResourcesChanged);
  66                                 _parent = value;
  67                                 if (_parent != null)
  68                                         ((IElement)_parent).AddResourcesChangedListener(OnResourcesChanged);
  69                         }
  70                 }
  71
  72                 void IElement.RemoveResourcesChangedListener(Action<object, ResourcesChangedEventArgs> onchanged)
  73                 {
  74                         if (_changeHandlers == null)
  75                                 return;
  76                         _changeHandlers.Remove(onchanged);
  77                 }
  78
  79         /// <summary>
  80         /// Used by the XAML infrastructure to load data templates and set up the content of the resulting UI.
  81         /// </summary>
  82         /// <returns></returns>
  83         public object CreateContent()
  84                 {
  85                         if (LoadTemplate == null)
  86                                 throw new InvalidOperationException("LoadTemplate should not be null");
  87                         if (this is DataTemplateSelector)
  88                                 throw new InvalidOperationException("Cannot call CreateContent directly on a DataTemplateSelector");
  89
  90                         object item = LoadTemplate();
  91                         SetupContent(item);
  92
  93                         return item;
  94                 }
  95
  96                 internal virtual void SetupContent(object item)
  97                 {
  98                 }
  99
 100                 void OnResourcesChanged(object sender, ResourcesChangedEventArgs e)
 101                 {
 102                         if (_changeHandlers == null)
 103                                 return;
 104                         foreach (Action<object, ResourcesChangedEventArgs> handler in _changeHandlers)
 105                                 handler(this, e);
 106                 }
 107         }
 108 }