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

   1 using System;
   2 using System.ComponentModel;
   3 using System.Reflection;
   4 using Tizen.NUI.Binding;
   5
   6 namespace Tizen.NUI.Xaml
   7 {
   8         [ProvideCompiled("Tizen.NUI.Xaml.Core.XamlC.PassthroughValueProvider")]
   9         [AcceptEmptyServiceProvider]
  10         internal sealed class PropertyCondition : Condition, IValueProvider
  11         {
  12                 readonly BindableProperty _stateProperty;
  13
  14                 BindableProperty _property;
  15                 object _triggerValue;
  16
  17                 public PropertyCondition()
  18                 {
  19                         _stateProperty = BindableProperty.CreateAttached("State", typeof(bool), typeof(PropertyCondition), 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                                         value = s_valueConverter.Convert(value, Property.ReturnType, minforetriever, null);
  57                                 }
  58                                 _triggerValue = value;
  59                         }
  60                 }
  61
  62                 object IValueProvider.ProvideValue(IServiceProvider serviceProvider)
  63                 {
  64                         //This is no longer required
  65                         return this;
  66                 }
  67
  68                 internal override bool GetState(BindableObject bindable)
  69                 {
  70                         return (bool)bindable.GetValue(_stateProperty);
  71                 }
  72
  73                 static IValueConverterProvider s_valueConverter = DependencyService.Get<IValueConverterProvider>();
  74
  75                 internal override void SetUp(BindableObject bindable)
  76                 {
  77                         object newvalue = bindable.GetValue(Property);
  78                         bool newState = (newvalue == Value) || (newvalue != null && newvalue.Equals(Value));
  79                         bindable.SetValue(_stateProperty, newState);
  80                         bindable.PropertyChanged += OnAttachedObjectPropertyChanged;
  81                 }
  82
  83                 internal override void TearDown(BindableObject bindable)
  84                 {
  85                         bindable.ClearValue(_stateProperty);
  86                         bindable.PropertyChanged -= OnAttachedObjectPropertyChanged;
  87                 }
  88
  89                 void OnAttachedObjectPropertyChanged(object sender, PropertyChangedEventArgs e)
  90                 {
  91                         var bindable = (BindableObject)sender;
  92                         var oldState = (bool)bindable.GetValue(_stateProperty);
  93
  94                         if (Property == null)
  95                                 return;
  96                         if (e.PropertyName != Property.PropertyName)
  97                                 return;
  98                         object newvalue = bindable.GetValue(Property);
  99                         bool newstate = (newvalue == Value) || (newvalue != null && newvalue.Equals(Value));
 100                         if (oldState != newstate)
 101                                 bindable.SetValue(_stateProperty, newstate);
 102                 }
 103
 104                 void OnStatePropertyChanged(BindableObject bindable, object oldValue, object newValue)
 105                 {
 106                         if ((bool)oldValue == (bool)newValue)
 107                                 return;
 108
 109                         ConditionChanged?.Invoke(bindable, (bool)oldValue, (bool)newValue);
 110                 }
 111         }
 112 }