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//---------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
//---------------------------------------------------------------------------
using System.Diagnostics;
using System.Globalization;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Input;
using System.Windows.Media;
namespace System.Windows.Controls.Primitives
{
/// <summary>
/// DatePickerTextBox is a specialized form of TextBox which displays custom visuals when its contents are empty
/// </summary>
[TemplatePart(Name = DatePickerTextBox.ElementContentName, Type = typeof(ContentControl))]
public sealed partial class DatePickerTextBox : TextBox
{
#region Constants
private const string ElementContentName = "PART_Watermark";
#endregion
#region Data
private ContentControl elementContent;
#endregion
#region Constructor
/// <summary>
/// Static constructor
/// </summary>
static DatePickerTextBox()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(DatePickerTextBox), new FrameworkPropertyMetadata(typeof(DatePickerTextBox)));
TextProperty.OverrideMetadata(typeof(DatePickerTextBox), new FrameworkPropertyMetadata(OnVisualStatePropertyChanged));
}
/// <summary>
/// Initializes a new instance of the <see cref="DatePickerTextBox"/> class.
/// </summary>
public DatePickerTextBox()
{
this.SetCurrentValue(WatermarkProperty, SR.Get(SRID.DatePickerTextBox_DefaultWatermarkText));
this.Loaded += OnLoaded;
this.IsEnabledChanged += new DependencyPropertyChangedEventHandler(OnDatePickerTextBoxIsEnabledChanged);
}
#endregion
#region Public Properties
#region Watermark
/// <summary>
/// Watermark dependency property
/// </summary>
internal static readonly DependencyProperty WatermarkProperty = DependencyProperty.Register(
"Watermark", typeof(object), typeof(DatePickerTextBox), new PropertyMetadata(OnWatermarkPropertyChanged));
/// <summary>
/// Watermark content
/// </summary>
/// <value>The watermark.</value>
internal object Watermark
{
get { return (object)GetValue(WatermarkProperty); }
set { SetValue(WatermarkProperty, value); }
}
#endregion
#endregion Public Properties
#region Protected
/// <summary>
/// Called when template is applied to the control.
/// </summary>
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
elementContent = ExtractTemplatePart<ContentControl>(ElementContentName);
// We dont want to expose watermark property as public yet, because there
// is a good chance in future that the implementation will change when
// a WatermarkTextBox control gets implemented. This is mostly to
// mimc SL. Hence setting the binding in code rather than in control template.
if (elementContent != null)
{
Binding watermarkBinding = new Binding("Watermark");
watermarkBinding.Source = this;
elementContent.SetBinding(ContentControl.ContentProperty, watermarkBinding);
}
OnWatermarkChanged();
}
protected override void OnGotFocus(RoutedEventArgs e)
{
base.OnGotFocus(e);
if (IsEnabled)
{
if (!string.IsNullOrEmpty(this.Text))
{
Select(0, this.Text.Length);
}
}
}
#endregion Protected
#region Private
private void OnLoaded(object sender, RoutedEventArgs e)
{
ApplyTemplate();
}
/// <summary>
/// Change to the correct visual state for the textbox.
/// </summary>
/// <param name="useTransitions">
/// true to use transitions when updating the visual state, false to
/// snap directly to the new visual state.
/// </param>
internal override void ChangeVisualState(bool useTransitions)
{
base.ChangeVisualState(useTransitions);
// Update the WatermarkStates group
if (this.Watermark != null && string.IsNullOrEmpty(this.Text))
{
VisualStates.GoToState(this, useTransitions, VisualStates.StateWatermarked, VisualStates.StateUnwatermarked);
}
else
{
VisualStates.GoToState(this, useTransitions, VisualStates.StateUnwatermarked);
}
}
private T ExtractTemplatePart<T>(string partName) where T : DependencyObject
{
DependencyObject obj = GetTemplateChild(partName);
return ExtractTemplatePart<T>(partName, obj);
}
private static T ExtractTemplatePart<T>(string partName, DependencyObject obj) where T : DependencyObject
{
Debug.Assert(
obj == null || typeof(T).IsInstanceOfType(obj),
string.Format(CultureInfo.InvariantCulture, SR.Get(SRID.DatePickerTextBox_TemplatePartIsOfIncorrectType), partName, typeof(T).Name));
return obj as T;
}
/// <summary>
/// Called when the IsEnabled property changes.
/// </summary>
/// <param name="sender">Sender object</param>
/// <param name="e">Property changed args</param>
private void OnDatePickerTextBoxIsEnabledChanged(object sender, DependencyPropertyChangedEventArgs e)
{
Debug.Assert(e.NewValue is bool);
bool isEnabled = (bool)e.NewValue;
SetCurrentValueInternal(IsReadOnlyProperty, MS.Internal.KnownBoxes.BooleanBoxes.Box(!isEnabled));
}
private void OnWatermarkChanged()
{
if (elementContent != null)
{
Control watermarkControl = this.Watermark as Control;
if (watermarkControl != null)
{
watermarkControl.IsTabStop = false;
watermarkControl.IsHitTestVisible = false;
}
}
}
/// <summary>
/// Called when watermark property is changed.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="args">The <see cref="System.Windows.DependencyPropertyChangedEventArgs"/> instance containing the event data.</param>
private static void OnWatermarkPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
{
DatePickerTextBox datePickerTextBox = sender as DatePickerTextBox;
Debug.Assert(datePickerTextBox != null, "The source is not an instance of a DatePickerTextBox!");
datePickerTextBox.OnWatermarkChanged();
datePickerTextBox.UpdateVisualState();
}
#endregion Private
}
}
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