src/Tizen.NUI/src/internal/XamlBinding/Interactivity/XamlPropertyCondition.cs

   1 using System;
   2 using System.ComponentModel;
   3 using System.Reflection;
   4 using Tizen.NUI.Xaml;
   5
   6 namespace Tizen.NUI.Binding
   7 {
   8     [ProvideCompiled("Tizen.NUI.Core.XamlC.PassthroughValueProvider")]
   9     [AcceptEmptyServiceProvider]
  10     internal sealed class XamlPropertyCondition : Condition, IValueProvider
  11     {
  12         readonly BindableProperty _stateProperty;
  13
  14         BindableProperty _property;
  15         object _triggerValue;
  16
  17         public XamlPropertyCondition()
  18         {
  19             _stateProperty = BindableProperty.CreateAttached("State", typeof(bool), typeof(XamlPropertyCondition), false, propertyChanged: OnStatePropertyChanged);
  20         }
  21
  22         public BindableProperty Property
  23         {
  24             get { return _property; }
  25             set
  26             {
  27                 if (_property == value)
  28                     return;
  29                 if (IsSealed)
  30                     throw new InvalidOperationException("Can not change Property once the Trigger has been applied.");
  31                 _property = value;
  32
  33                 //convert the value
  34                 if (_property != null && s_valueConverter != null)
  35                 {
  36                     Func<MemberInfo> minforetriever = () => _property.DeclaringType.GetRuntimeProperty(_property.PropertyName);
  37                     Value = s_valueConverter.Convert(Value, _property.ReturnType, minforetriever, null);
  38                 }
  39             }
  40         }
  41
  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 Trigger has been applied.");
  51
  52                 //convert the value
  53                 if (_property != null && s_valueConverter != null)
  54                 {
  55                     Func<MemberInfo> minforetriever = () => _property.DeclaringType.GetRuntimeProperty(_property.PropertyName);
  56                     _triggerValue = s_valueConverter.Convert(value, _property.ReturnType, minforetriever, null);
  57                 }
  58                 else
  59                 {
  60                     _triggerValue = value;
  61                 }
  62
  63             }
  64         }
  65
  66         object IValueProvider.ProvideValue(IServiceProvider serviceProvider)
  67         {
  68             //This is no longer required
  69             return this;
  70         }
  71
  72         internal override bool GetState(BindableObject bindable)
  73         {
  74             return (bool)bindable.GetValue(_stateProperty);
  75         }
  76
  77         static IValueConverterProvider s_valueConverter = DependencyService.Get<IValueConverterProvider>();
  78
  79         internal override void SetUp(BindableObject bindable)
  80         {
  81             object newvalue = bindable.GetValue(Property);
  82             bool newState = (newvalue == Value) || (newvalue != null && newvalue.Equals(Value));
  83             bindable.SetValue(_stateProperty, newState);
  84             bindable.PropertyChanged += OnAttachedObjectPropertyChanged;
  85         }
  86
  87         internal override void TearDown(BindableObject bindable)
  88         {
  89             bindable.ClearValue(_stateProperty);
  90             bindable.PropertyChanged -= OnAttachedObjectPropertyChanged;
  91         }
  92
  93         void OnAttachedObjectPropertyChanged(object sender, PropertyChangedEventArgs e)
  94         {
  95             var bindable = (BindableObject)sender;
  96             var oldState = (bool)bindable.GetValue(_stateProperty);
  97
  98             if (Property == null)
  99                 return;
 100             if (e.PropertyName != Property.PropertyName)
 101                 return;
 102             object newvalue = bindable.GetValue(Property);
 103             bool newstate = (newvalue == Value) || (newvalue != null && newvalue.Equals(Value));
 104             if (oldState != newstate)
 105                 bindable.SetValue(_stateProperty, newstate);
 106         }
 107
 108         void OnStatePropertyChanged(BindableObject bindable, object oldValue, object newValue)
 109         {
 110             if ((bool)oldValue == (bool)newValue)
 111                 return;
 112
 113             ConditionChanged?.Invoke(bindable, (bool)oldValue, (bool)newValue);
 114         }
 115     }
 116 }