src/Tizen.NUI/src/public/XamlBinding/Interactivity/BindingCondition.cs

   1 using System;
   2 using System.ComponentModel;
   3 using Tizen.NUI.Xaml;
   4
   5 namespace Tizen.NUI.Binding
   6 {
   7     /// This will be public opened in tizen_6.0 after ACR done. Before ACR, need to be hidden as inhouse API.
   8     [EditorBrowsable(EditorBrowsableState.Never)]
   9     [ProvideCompiled("Tizen.NUI.Xaml.Core.XamlC.PassthroughValueProvider")]
  10     [AcceptEmptyServiceProvider]
  11     public sealed class BindingCondition : Condition, IValueProvider
  12     {
  13         readonly BindableProperty _boundProperty;
  14
  15         BindingBase _binding;
  16         object _triggerValue;
  17
  18         /// This will be public opened in tizen_6.0 after ACR done. Before ACR, need to be hidden as inhouse API.
  19         [EditorBrowsable(EditorBrowsableState.Never)]
  20         public BindingCondition()
  21         {
  22             _boundProperty = BindableProperty.CreateAttached("Bound", typeof(object), typeof(BindingCondition), null, propertyChanged: OnBoundPropertyChanged);
  23         }
  24
  25         /// This will be public opened in tizen_6.0 after ACR done. Before ACR, need to be hidden as inhouse API.
  26         [EditorBrowsable(EditorBrowsableState.Never)]
  27         public BindingBase Binding
  28         {
  29             get { return _binding; }
  30             set
  31             {
  32                 if (_binding == value)
  33                     return;
  34                 if (IsSealed)
  35                     throw new InvalidOperationException("Can not change Binding once the Condition has been applied.");
  36                 _binding = value;
  37             }
  38         }
  39
  40         /// This will be public opened in tizen_6.0 after ACR done. Before ACR, need to be hidden as inhouse API.
  41         [EditorBrowsable(EditorBrowsableState.Never)]
  42         public object Value
  43         {
  44             get { return _triggerValue; }
  45             set
  46             {
  47                 if (_triggerValue == value)
  48                     return;
  49                 if (IsSealed)
  50                     throw new InvalidOperationException("Can not change Value once the Condition has been applied.");
  51                 _triggerValue = value;
  52             }
  53         }
  54
  55         object IValueProvider.ProvideValue(IServiceProvider serviceProvider)
  56         {
  57             //This is no longer required
  58             return this;
  59         }
  60
  61         internal override bool GetState(BindableObject bindable)
  62         {
  63             object newValue = bindable.GetValue(_boundProperty);
  64             return EqualsToValue(newValue);
  65         }
  66
  67         internal override void SetUp(BindableObject bindable)
  68         {
  69             if (Binding != null)
  70                 bindable.SetBinding(_boundProperty, Binding.Clone());
  71         }
  72
  73         internal override void TearDown(BindableObject bindable)
  74         {
  75             bindable.RemoveBinding(_boundProperty);
  76             bindable.ClearValue(_boundProperty);
  77         }
  78
  79         static IValueConverterProvider s_valueConverter = DependencyService.Get<IValueConverterProvider>();
  80
  81         bool EqualsToValue(object other)
  82         {
  83             if ((other == Value) || (other != null && other.Equals(Value)))
  84                 return true;
  85
  86             object converted = null;
  87             if (s_valueConverter != null)
  88                 converted = s_valueConverter.Convert(Value, other != null ? other.GetType() : typeof(object), null, null);
  89             else
  90                 return false;
  91
  92             return (other == converted) || (other != null && other.Equals(converted));
  93         }
  94
  95         void OnBoundPropertyChanged(BindableObject bindable, object oldValue, object newValue)
  96         {
  97             bool oldState = EqualsToValue(oldValue);
  98             bool newState = EqualsToValue(newValue);
  99
 100             if (newState == oldState)
 101                 return;
 102
 103             if (ConditionChanged != null)
 104                 ConditionChanged(bindable, oldState, newState);
 105         }
 106     }
 107 }