How to Achieve Multiple Highlight Rules in SyntaxEditor
Environment
| Product Version | Product | Author |
|---|---|---|
| 2022.1.222 | RadSyntaxEditor for WinForms | Desislava Yordanova |
Description
By default, RadSyntaxEditor offers default highlight style for the Find and Replace functionality. This article demonstrates how to highlight in a different way another portion of text matches.
Default Highlight Style
Solution
RadSyntaxEditor is purposed to offer one common highlight style for the found search results. Hence, multiple HighlightAllMatches rules are not supported. If you need to highlight specific portion of text in a different color (different than the standard search format style), it would be necessary to create a custom tagger to classify the desired words and mark these words as specific. Then, add a custom UI layer to paint the desired format style. As a result, you will have different styles for the different words to be classified.
In the below code snippet, there are two words "this" and "editor" that are classified as different:
Multiple Highlight Styles
public RadForm1()
{
InitializeComponent();
this.radSyntaxEditor1.SyntaxEditorElement.UILayersBuilder = new CustomUILayersBuilder();
this.radSyntaxEditor1.TextFormatDefinitions.AddLast(MyTextSearchHighlightTagger.TelerikClassificationType,
new TextFormatDefinition(new SolidBrush(System.Drawing.Color.Black), new SolidBrush(System.Drawing.Color.Red),
null,
new Telerik.WinForms.Controls.SyntaxEditor.UI.Pen(new SolidBrush(System.Drawing.Color.Green), 2)));
MyTextSearchHighlightTagger highlightTagger = new MyTextSearchHighlightTagger(this.radSyntaxEditor1.SyntaxEditorElement);
this.radSyntaxEditor1.TaggersRegistry.RegisterTagger(highlightTagger);
}
public class MyTextSearchHighlightTagger : WordTaggerBase
{
public static readonly ClassificationType TelerikClassificationType = new ClassificationType("Telerik");
public static readonly Dictionary<string, ClassificationType> WordsToClassificationType = new Dictionary<string, ClassificationType>();
private StringComparison comparison = StringComparison.OrdinalIgnoreCase;
public MyTextSearchHighlightTagger(RadSyntaxEditorElement editor)
: base(editor)
{
WordsToClassificationType.Add("this", TelerikClassificationType);
WordsToClassificationType.Add("editor", TelerikClassificationType);
}
protected override Dictionary<string, ClassificationType> GetWordsToClassificationTypes()
{
return MyTextSearchHighlightTagger.WordsToClassificationType;
}
public override IEnumerable<TagSpan<ClassificationTag>> GetTags(NormalizedSnapshotSpanCollection spans)
{
if (WordsToClassificationType.Count == 0)
{
yield break;
}
TextSnapshot snapshot = this.Document.CurrentSnapshot;
foreach (TextSnapshotSpan snapshotSpan in spans)
{
string lineString = snapshotSpan.GetText();
foreach (KeyValuePair<string, ClassificationType> searchWord in WordsToClassificationType)
{
int index = lineString.IndexOf(searchWord.Key, comparison);
while (index != -1)
{
TextSnapshotSpan tempSnapshotSpan = new TextSnapshotSpan(snapshot,
new Telerik.WinForms.SyntaxEditor.Core.Text.Span(snapshotSpan.Start + index, searchWord.Key.Length));
yield return new TagSpan<ClassificationTag>(tempSnapshotSpan, new ClassificationTag(TelerikClassificationType));
index = lineString.IndexOf(searchWord.Key, index + searchWord.Key.Length);
}
}
}
}
}
public class CustomUILayersBuilder : Telerik.WinForms.Controls.SyntaxEditor.UI.Layers.UILayersBuilder
{
public override void BuildUILayers(UILayerStack uiLayers)
{
uiLayers.AddLast(new MyTextUnderlineUILayer());
base.BuildUILayers(uiLayers);
}
}
public class MyTextUnderlineUILayer : LineBasedUILayer<ClassificationTag>
{
public override string Name => "MyTextUnderlineUILayer";
protected override FrameworkElement GetLinePartUIElement(ClassificationTag tag,
Telerik.WinForms.SyntaxEditor.Core.Text.Span span,
UIUpdateContext updateContext)
{
if (tag.ClassificationType != MyTextSearchHighlightTagger.TelerikClassificationType)
{
return null;
}
TextFormatDefinition textFormatting = updateContext.Editor.TextFormatDefinitions.
GetTextFormatDefinition(MyTextSearchHighlightTagger.TelerikClassificationType);
Telerik.WinControls.SyntaxEditor.UI.Rect rect = updateContext.Editor.GetLinePartBoundingRectangle(span, true);
Telerik.WinControls.SyntaxEditor.UI.Rectangle rectangle = this.GetElementFromPool<Telerik.WinControls.SyntaxEditor.UI.Rectangle>();
rectangle.Width = rect.Width;
rectangle.Height = rect.Height;
rectangle.Fill = textFormatting.Background;
rectangle.Stroke = textFormatting.Border.Brush;
rectangle.StrokeThickness = textFormatting.Border.Thickness.Left;
return rectangle;
}
protected override void ResetPooledElementProperties(object element)
{
}
}
private void radTextBox1_TextChanged(object sender, EventArgs e)
{
this.radSyntaxEditor1.SyntaxEditorElement.HighlightAllMatches(this.radTextBox1.Text);
}
Public Sub New()
InitializeComponent()
Me.RadSyntaxEditor1.SyntaxEditorElement.UILayersBuilder = New CustomUILayersBuilder()
Me.RadSyntaxEditor1.TextFormatDefinitions.AddLast(MyTextSearchHighlightTagger.TelerikClassificationType,
New TextFormatDefinition(New SolidBrush(System.Drawing.Color.Black),
New SolidBrush(System.Drawing.Color.Red), Nothing,
New Telerik.WinForms.Controls.SyntaxEditor.UI.Pen(New SolidBrush(System.Drawing.Color.Green), 2)))
Dim highlightTagger As MyTextSearchHighlightTagger = New MyTextSearchHighlightTagger(Me.RadSyntaxEditor1.SyntaxEditorElement)
Me.RadSyntaxEditor1.TaggersRegistry.RegisterTagger(highlightTagger)
End Sub
Public Class MyTextSearchHighlightTagger
Inherits WordTaggerBase
Public Shared ReadOnly TelerikClassificationType As ClassificationType = New ClassificationType("Telerik")
Public Shared ReadOnly WordsToClassificationType As Dictionary(Of String, ClassificationType) = New Dictionary(Of String, ClassificationType)()
Private comparison As StringComparison = StringComparison.OrdinalIgnoreCase
Public Sub New(ByVal editor As RadSyntaxEditorElement)
MyBase.New(editor)
WordsToClassificationType.Add("this", TelerikClassificationType)
WordsToClassificationType.Add("editor", TelerikClassificationType)
End Sub
Protected Overrides Function GetWordsToClassificationTypes() As Dictionary(Of String, ClassificationType)
Return MyTextSearchHighlightTagger.WordsToClassificationType
End Function
Public Overrides Iterator Function GetTags(ByVal spans As NormalizedSnapshotSpanCollection) As IEnumerable(Of TagSpan(Of ClassificationTag))
If WordsToClassificationType.Count = 0 Then
Return
End If
Dim snapshot As TextSnapshot = Me.Document.CurrentSnapshot
For Each snapshotSpan As TextSnapshotSpan In spans
Dim lineString As String = snapshotSpan.GetText()
For Each searchWord As KeyValuePair(Of String, ClassificationType) In WordsToClassificationType
Dim index As Integer = lineString.IndexOf(searchWord.Key, comparison)
While index <> -1
Dim tempSnapshotSpan As TextSnapshotSpan = New TextSnapshotSpan(snapshot, New Telerik.WinForms.SyntaxEditor.Core.Text.Span(snapshotSpan.Start _
+ index, searchWord.Key.Length))
Yield New TagSpan(Of ClassificationTag)(tempSnapshotSpan, New ClassificationTag(TelerikClassificationType))
index = lineString.IndexOf(searchWord.Key, index + searchWord.Key.Length)
End While
Next
Next
End Function
End Class
Public Class CustomUILayersBuilder
Inherits Telerik.WinForms.Controls.SyntaxEditor.UI.Layers.UILayersBuilder
Public Overrides Sub BuildUILayers(ByVal uiLayers As UILayerStack)
uiLayers.AddLast(New MyTextUnderlineUILayer())
MyBase.BuildUILayers(uiLayers)
End Sub
End Class
Public Class MyTextUnderlineUILayer
Inherits LineBasedUILayer(Of ClassificationTag)
Public Overrides ReadOnly Property Name As String
Get
Return "MyTextUnderlineUILayer"
End Get
End Property
Protected Overrides Function GetLinePartUIElement(tag As ClassificationTag, span As Telerik.WinForms.SyntaxEditor.Core.Text.Span,
updateContext As UIUpdateContext) As FrameworkElement
If Not tag.ClassificationType.Equals(MyTextSearchHighlightTagger.TelerikClassificationType) Then
Return Nothing
End If
Dim textFormatting As TextFormatDefinition = updateContext.Editor.TextFormatDefinitions.GetTextFormatDefinition(MyTextSearchHighlightTagger.TelerikClassificationType)
Dim rect As Telerik.WinControls.SyntaxEditor.UI.Rect = updateContext.Editor.GetLinePartBoundingRectangle(span, True)
Dim rectangle As Telerik.WinControls.SyntaxEditor.UI.Rectangle = Me.GetElementFromPool(Of Telerik.WinControls.SyntaxEditor.UI.Rectangle)()
rectangle.Width = rect.Width
rectangle.Height = rect.Height
rectangle.Fill = textFormatting.Background
rectangle.Stroke = textFormatting.Border.Brush
rectangle.StrokeThickness = textFormatting.Border.Thickness.Left
Return rectangle
End Function
Protected Overrides Sub ResetPooledElementProperties(ByVal element As Object)
End Sub
End Class
Private Sub RadTextBox1_TextChanged(sender As Object, e As EventArgs) Handles RadTextBox1.TextChanged
Me.RadSyntaxEditor1.SyntaxEditorElement.HighlightAllMatches(Me.RadTextBox1.Text)
End Sub