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//---------------------------------------------------------------------------
//
// <copyright file="ValuePattern" company="Microsoft">
// Copyright (C) Microsoft Corporation. All rights reserved.
// </copyright>
//
//
// Description: Client-side wrapper for Value Pattern
//
// History:
// 06/23/2003 : BrendanM Ported to WCP
//
//---------------------------------------------------------------------------
using System;
using System.Windows.Automation.Provider;
using MS.Internal.Automation;
namespace System.Windows.Automation
{
/// <summary>
/// Represents UI elements that are expressing a value
/// </summary>
#if (INTERNAL_COMPILE)
internal class ValuePattern: BasePattern
#else
public class ValuePattern: BasePattern
#endif
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
// internal so that RangeValue can derive from this
internal ValuePattern(AutomationElement el, SafePatternHandle hPattern, bool cached)
: base(el, hPattern)
{
_hPattern = hPattern;
_cached = cached;
}
#endregion Constructors
//------------------------------------------------------
//
// Public Constants / Readonly Fields
//
//------------------------------------------------------
#region Public Constants and Readonly Fields
/// <summary>Value pattern</summary>
public static readonly AutomationPattern Pattern = ValuePatternIdentifiers.Pattern;
/// <summary>Property ID: Value - Value of a value control, as a human-readable string</summary>
public static readonly AutomationProperty ValueProperty = ValuePatternIdentifiers.ValueProperty;
/// <summary>Property ID: IsReadOnly - Indicates that the value can only be read, not modified.</summary>
public static readonly AutomationProperty IsReadOnlyProperty = ValuePatternIdentifiers.IsReadOnlyProperty;
#endregion Public Constants and Readonly Fields
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
#region Public Methods
/// <summary>
/// Request to set the value that this UI element is representing
/// </summary>
/// <param name="value">Value to set the UI to, the provider is responsible for converting from a string into the appropriate data type</param>
///
/// <outside_see conditional="false">
/// This API does not work inside the secure execution environment.
/// <exception cref="System.Security.Permissions.SecurityPermission"/>
/// </outside_see>
public void SetValue( string value )
{
Misc.ValidateArgumentNonNull(value, "value");
// Test the Enabled state prior to the more general Read-Only state.
object enabled = _el.GetCurrentPropertyValue(AutomationElementIdentifiers.IsEnabledProperty);
if (enabled is bool && !(bool)enabled)
{
throw new ElementNotEnabledException();
}
// Test the Read-Only state after the more specific Enabled state.
object readOnly = _el.GetCurrentPropertyValue(IsReadOnlyProperty);
if (readOnly is bool && (bool)readOnly)
{
throw new InvalidOperationException(SR.Get(SRID.ValueReadonly));
}
UiaCoreApi.ValuePattern_SetValue(_hPattern, value);
}
#endregion Public Methods
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
#region Public Properties
/// <summary>
/// This member allows access to previously requested
/// cached properties for this element. The returned object
/// has accessors for each property defined for this pattern.
/// </summary>
/// <remarks>
/// Cached property values must have been previously requested
/// using a CacheRequest. If you try to access a cached
/// property that was not previously requested, an InvalidOperation
/// Exception will be thrown.
///
/// To get the value of a property at the current point in time,
/// access the property via the Current accessor instead of
/// Cached.
/// </remarks>
public ValuePatternInformation Cached
{
get
{
Misc.ValidateCached(_cached);
return new ValuePatternInformation(_el, true);
}
}
/// <summary>
/// This member allows access to current property values
/// for this element. The returned object has accessors for
/// each property defined for this pattern.
/// </summary>
/// <remarks>
/// This pattern must be from an AutomationElement with a
/// Full reference in order to get current values. If the
/// AutomationElement was obtained using AutomationElementMode.None,
/// then it contains only cached data, and attempting to get
/// the current value of any property will throw an InvalidOperationException.
///
/// To get the cached value of a property that was previously
/// specified using a CacheRequest, access the property via the
/// Cached accessor instead of Current.
/// </remarks>
public ValuePatternInformation Current
{
get
{
Misc.ValidateCurrent(_hPattern);
return new ValuePatternInformation(_el, false);
}
}
#endregion Public Properties
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
static internal object Wrap(AutomationElement el, SafePatternHandle hPattern, bool cached)
{
return new ValuePattern(el, hPattern, cached);
}
#endregion Internal Methods
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
private SafePatternHandle _hPattern;
private bool _cached;
#endregion Private Fields
//------------------------------------------------------
//
// Nested Classes
//
//------------------------------------------------------
#region Nested Classes
/// <summary>
/// This class provides access to either Cached or Current
/// properties on a pattern via the pattern's .Cached or
/// .Current accessors.
/// </summary>
public struct ValuePatternInformation
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
internal ValuePatternInformation(AutomationElement el, bool useCache)
{
_el = el;
_useCache = useCache;
}
#endregion Constructors
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
#region Public Properties
///<summary>Value of a value control, as a a string.</summary>
///
/// <outside_see conditional="false">
/// This API does not work inside the secure execution environment.
/// <exception cref="System.Security.Permissions.SecurityPermission"/>
/// </outside_see>
public string Value
{
get
{
//
object temp = _el.GetPatternPropertyValue(ValueProperty, _useCache);
return temp.ToString();
}
}
///<summary>Indicates that the value can only be read, not modified.
///returns True if the control is read-only</summary>
///
/// <outside_see conditional="false">
/// This API does not work inside the secure execution environment.
/// <exception cref="System.Security.Permissions.SecurityPermission"/>
/// </outside_see>
public bool IsReadOnly
{
get
{
return (bool)_el.GetPatternPropertyValue(IsReadOnlyProperty, _useCache);
}
}
#endregion Public Properties
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
private AutomationElement _el; // AutomationElement that contains the cache or live reference
private bool _useCache; // true to use cache, false to use live reference to get current values
#endregion Private Fields
}
#endregion Nested Classes
}
}
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