sdk/samples/all in on code/Visual Studio 2008/VBSL3CustomControl/HighLightTextBlock.vb

   1 '****************************** Module Header *******************************
   2 ' Module Name:  HighLightTextBlock.vb
   3 ' Project:              VBSL3CustomControl
   4 ' Copyright (c) Microsoft Corporation.
   5 '
   6 ' Implementation of custom control HighLightTextBlock.
   7 '
   8 ' This source is subject to the Microsoft Public License.
   9 ' See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  10 ' All other rights reserved.
  11 '
  12 ' History:
  13 ' * 8/18/2009 8:06 PM Mog Liang Created
  14 '****************************************************************************
  15
  16 Imports System.Windows.Threading
  17 Imports System.ComponentModel
  18
  19 <TemplateVisualState(Name:="NonHighLight", GroupName:="HightLightStates"), TemplateVisualState(Name:="HighLight", GroupName:="HightLightStates")> _
  20 Public Class HighLightTextBlock : Inherits Control
  21
  22     Public Sub New()
  23         ' Register custom control's default style
  24         MyBase.DefaultStyleKey = GetType(HighLightTextBlock)
  25         Me.InitTimer()
  26     End Sub
  27
  28     Private Sub Dehighlight()
  29         VisualStateManager.GoToState(Me, "NonHighLight", True)
  30         Me._timer.Stop()
  31     End Sub
  32
  33     ' User call this method to highlight text.
  34     Public Sub Highlight()
  35         ' Change control state to 'HightLight'
  36         VisualStateManager.GoToState(Me, "HighLight", True)
  37         If Me.AutoDehighlight Then
  38             ' Start timer
  39             Me._timer.Start()
  40         End If
  41     End Sub
  42
  43     ' Initialize timer
  44     Private Sub InitTimer()
  45         Me._timer = New DispatcherTimer
  46         Me._timer.Interval = TimeSpan.FromSeconds(1)
  47         ' When time out, change HighLightStates to 'NonHighLight'
  48         AddHandler Me._timer.Tick, New EventHandler(AddressOf Me.Timer_OnTick)
  49     End Sub
  50
  51     Private Sub Timer_OnTick(ByVal sender As Object, ByVal e As EventArgs)
  52         Dehighlight()
  53     End Sub
  54
  55     ' Use this property to (de)highlight the text.
  56     Private Shared Sub IsHighlightedChanged(ByVal sender As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
  57         Dim newvalue As Boolean? = DirectCast(e.NewValue, Boolean?)
  58         If newvalue.Value Then
  59             DirectCast(sender, HighLightTextBlock).Highlight()
  60         Else
  61             DirectCast(sender, HighLightTextBlock).Dehighlight()
  62         End If
  63         DirectCast(sender, HighLightTextBlock).IsHighlighted = DirectCast(e.NewValue, Boolean?)
  64     End Sub
  65
  66     Public Overrides Sub OnApplyTemplate()
  67         MyBase.OnApplyTemplate()
  68     End Sub
  69
  70
  71     ' If this property is set to true, the text will automatically be dehilighted after a specific time. Use the LightTime to control the highlight period.
  72     Private _AutoDehighlight As Boolean
  73     Public Property AutoDehighlight() As Boolean
  74         Get
  75             Return _AutoDehighlight
  76         End Get
  77         Set(ByVal value As Boolean)
  78             _AutoDehighlight = value
  79         End Set
  80     End Property
  81
  82     <TypeConverter(GetType(NullableBoolConverter))> _
  83     Public Property IsHighlighted() As Boolean?
  84         Get
  85             Return DirectCast(MyBase.GetValue(HighLightTextBlock.IsHighlightedProperty), Boolean?)
  86         End Get
  87         Set(ByVal value As Boolean?)
  88             MyBase.SetValue(HighLightTextBlock.IsHighlightedProperty, value)
  89         End Set
  90     End Property
  91
  92
  93     ' Expose LightTime property for highlight time.
  94     Public Property LightTime() As TimeSpan
  95         Get
  96             If (Me._timer Is Nothing) Then
  97                 Me.InitTimer()
  98             End If
  99             Return Me._timer.Interval
 100         End Get
 101         Set(ByVal value As TimeSpan)
 102             If (Me._timer Is Nothing) Then
 103                 Me.InitTimer()
 104             End If
 105             Me._timer.Interval = value
 106         End Set
 107     End Property
 108
 109     ' In order to use templatebinding on 'Text' property,
 110     ' it must be dependency property.
 111     Public Property [Text]() As String
 112         Get
 113             Return CStr(MyBase.GetValue(HighLightTextBlock.TextProperty))
 114         End Get
 115         Set(ByVal value As String)
 116             MyBase.SetValue(HighLightTextBlock.TextProperty, value)
 117         End Set
 118     End Property
 119
 120
 121     ' Fields
 122     Private _timer As DispatcherTimer
 123     Public Shared ReadOnly IsHighlightedProperty As DependencyProperty = DependencyProperty.Register("DependencyProperty", GetType(Boolean?), GetType(HighLightTextBlock), New PropertyMetadata(False, New PropertyChangedCallback(AddressOf HighLightTextBlock.IsHighlightedChanged)))
 124     Public Shared ReadOnly TextProperty As DependencyProperty = DependencyProperty.Register("Text", GetType(String), GetType(HighLightTextBlock), Nothing)
 125 End Class
 126