File: System\Windows\MultiDataTrigger.cs
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Project: src\src\Microsoft.DotNet.Wpf\src\PresentationFramework\PresentationFramework.csproj (PresentationFramework)
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
//
//
// Description: Defines MultiDataTrigger object, akin to MultiTrigger except it
//              gets values from data.
//
 
using System.Collections.Specialized;
using System.ComponentModel;
using System.Windows.Markup;
 
namespace System.Windows
{
    /// <summary>
    ///     A multiple Style data conditional dependency driver
    /// </summary>
    [ContentProperty("Setters")]
    public sealed class MultiDataTrigger : TriggerBase, IAddChild
    {
        /// <summary>
        ///     Conditions collection
        /// </summary>
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public ConditionCollection Conditions
        {
            get
            {
                // Verify Context Access
                VerifyAccess();
 
                return _conditions;
            }
        }
 
        /// <summary>
        /// Collection of Setter objects, which describes what to apply
        /// when this trigger is active.
        /// </summary>
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public SetterBaseCollection Setters
        {
            get
            {
                // Verify Context Access
                VerifyAccess();
 
                if( _setters == null )
                {
                    _setters = new SetterBaseCollection();
                }
                return _setters;
            }
        }
 
        ///<summary>
        /// This method is called to Add a Setter object as a child of the Style.
        ///</summary>
        ///<param name="value">
        /// The object to add as a child; it must be a Setter or subclass.
        ///</param>
        void IAddChild.AddChild (Object value)
        {
            // Verify Context Access
            VerifyAccess();
 
            Setters.Add(Trigger.CheckChildIsSetter(value));
        }
 
        ///<summary>
        /// This method is called by the parser when text appears under the tag in markup.
        /// As default Styles do not support text, calling this method has no effect.
        ///</summary>
        ///<param name="text">
        /// Text to add as a child.
        ///</param>
        void IAddChild.AddText (string text)
        {
            // Verify Context Access
            VerifyAccess();
 
            XamlSerializerUtil.ThrowIfNonWhiteSpaceInAddText(text, this);
        }
 
        internal override void Seal()
        {
            if (IsSealed)
            {
                return;
            }
 
            // Process the _setters collection: Copy values into PropertyValueList and seal the Setter objects.
            ProcessSettersCollection(_setters);
 
            if (_conditions.Count > 0)
            {
                // Seal conditions
                _conditions.Seal(ValueLookupType.DataTrigger);
            }
 
            // Build conditions array from collection
            TriggerConditions = new TriggerCondition[_conditions.Count];
 
            for (int i = 0; i < TriggerConditions.Length; ++i)
            {
                if (_conditions[i].SourceName != null && _conditions[i].SourceName.Length > 0)
                {
                    throw new InvalidOperationException(SR.SourceNameNotSupportedForDataTriggers);
                }
 
                TriggerConditions[i] = new TriggerCondition(
                    _conditions[i].Binding,
                    LogicalOp.Equals,
                    _conditions[i].Value);
            }
 
            // Set conditions array for all property triggers
            for (int i = 0; i < PropertyValues.Count; ++i)
            {
                PropertyValue propertyValue = PropertyValues[i];
                propertyValue.Conditions = TriggerConditions;
                switch (propertyValue.ValueType)
                {
                    case PropertyValueType.Trigger:
                        propertyValue.ValueType = PropertyValueType.DataTrigger;
                        break;
                    case PropertyValueType.PropertyTriggerResource:
                        propertyValue.ValueType = PropertyValueType.DataTriggerResource;
                        break;
                    default:
                        throw new InvalidOperationException(SR.Format(SR.UnexpectedValueTypeForDataTrigger, propertyValue.ValueType));
                }
 
                // Put back modified struct
                PropertyValues[i] = propertyValue;
            }
 
            base.Seal();
        }
 
        // evaluate the current state of the trigger
        internal override bool GetCurrentState(DependencyObject container, UncommonField<HybridDictionary[]> dataField)
        {
            bool retVal = (TriggerConditions.Length > 0);
 
            for( int i = 0; retVal && i < TriggerConditions.Length; i++ )
            {
                retVal = TriggerConditions[i].ConvertAndMatch(StyleHelper.GetDataTriggerValue(dataField, container, TriggerConditions[i].Binding));
            }
 
            return retVal;
        }
 
 
        private ConditionCollection _conditions = new ConditionCollection();
        private SetterBaseCollection _setters = null;
    }
}