Walkthrough: Customizing the Text View

You can customize a text view by modifying any of the following properties in its editor-format map:

• Indicator margin

• Insertion caret

• Overwrite caret

• Selected text

• Inactive selected text (that is, selected text that has lost focus)

• Visible whitespace

Prerequisites

Starting in Visual Studio 2015, you do not install the Visual Studio SDK from the download center. It is included as an optional feature in Visual Studio setup. You can also install the VS SDK later on. For more information, see Installing the Visual Studio SDK.

Creating a MEF Project

1. Create a C# VSIX project. (In the New Project dialog, select Visual C# / Extensibility, then VSIX Project.) Name the solution ViewPropertyTest.

2. Add an Editor Classifier item template to the project. For more information, see Creating an Extension with an Editor Item Template.

3. Delete the existing class files.

Defining the Content Type

1. Add a class file and name it ViewPropertyModifier.

2. Add the following using directives:

   using System;
   using System.Collections;
   using System.Windows;
   using System.Windows.Media;
   using System.ComponentModel.Composition;
   using Microsoft.VisualStudio.Text.Classification;
   using Microsoft.VisualStudio.Text.Editor;
   using Microsoft.VisualStudio.Utilities;
   

   Imports System
   Imports System.Collections
   Imports System.Windows
   Imports System.Windows.Media
   Imports System.ComponentModel.Composition
   Imports Microsoft.VisualStudio.Text.Classification
   Imports Microsoft.VisualStudio.Text.Editor
   Imports Microsoft.VisualStudio.Utilities
   

3. Declare a class named TestViewCreationListener that inherits from IWpfTextViewCreationListener. Export this class with the following attributes:

   • ContentTypeAttribute to specify the type of content to which this listener applies.

   • TextViewRoleAttribute to specify the role of this listener.

     [Export(typeof(IWpfTextViewCreationListener))]
     [ContentType("text")]
     [TextViewRole(PredefinedTextViewRoles.Document)]
     internal class TestViewCreationListener : IWpfTextViewCreationListener
     

     <Export(GetType(IWpfTextViewCreationListener)), ContentType("text"), TextViewRole(PredefinedTextViewRoles.Document)>
     Friend Class TestViewCreationListener
         Implements IWpfTextViewCreationListener
     

4. In this class, import the IEditorFormatMapService.

   [Import]
   internal IEditorFormatMapService FormatMapService = null;
   

   <Import()>
   Friend FormatMapService As IEditorFormatMapService = Nothing
   

Changing the View Properties

1. Implement the TextViewCreated method so that the view properties are changed when the view is opened. To make the change, first find the ResourceDictionary that corresponds to the aspect of the view you want to find. Then change the appropriate property in the resource dictionary and set the properties. Batch the calls to the SetProperties method by calling the BeginBatchUpdate method before you set the properties and then the EndBatchUpdate after you set the properties.

   public void TextViewCreated(IWpfTextView textView)
   {
       IEditorFormatMap formatMap = FormatMapService.GetEditorFormatMap(textView);
   
       ResourceDictionary regularCaretProperties = formatMap.GetProperties("Caret");
       ResourceDictionary overwriteCaretProperties = formatMap.GetProperties("Overwrite Caret");
       ResourceDictionary indicatorMargin = formatMap.GetProperties("Indicator Margin");
       ResourceDictionary visibleWhitespace = formatMap.GetProperties("Visible Whitespace");
       ResourceDictionary selectedText = formatMap.GetProperties("Selected Text");
       ResourceDictionary inactiveSelectedText = formatMap.GetProperties("Inactive Selected Text");
   
       formatMap.BeginBatchUpdate();
   
       regularCaretProperties[EditorFormatDefinition.ForegroundBrushId] = Brushes.Magenta;
       formatMap.SetProperties("Caret", regularCaretProperties);
   
       overwriteCaretProperties[EditorFormatDefinition.ForegroundBrushId] = Brushes.Turquoise;
       formatMap.SetProperties("Overwrite Caret", overwriteCaretProperties);
   
       indicatorMargin[EditorFormatDefinition.BackgroundColorId] = Colors.LightGreen;
       formatMap.SetProperties("Indicator Margin", indicatorMargin);
   
       visibleWhitespace[EditorFormatDefinition.ForegroundColorId] = Colors.Red;
       formatMap.SetProperties("Visible Whitespace", visibleWhitespace);
   
       selectedText[EditorFormatDefinition.BackgroundBrushId] = Brushes.LightPink;
       formatMap.SetProperties("Selected Text", selectedText);
   
       inactiveSelectedText[EditorFormatDefinition.BackgroundBrushId] = Brushes.DeepPink;
       formatMap.SetProperties("Inactive Selected Text", inactiveSelectedText);
   
       formatMap.EndBatchUpdate();
   }
   

   Public Sub TextViewCreated(ByVal textView As IWpfTextView) Implements IWpfTextViewCreationListener.TextViewCreated
   
       Dim formatMap As IEditorFormatMap = FormatMapService.GetEditorFormatMap(textView)
   
       Dim regularCaretProperties As ResourceDictionary = formatMap.GetProperties("Caret")
       Dim overwriteCaretProperties As ResourceDictionary = formatMap.GetProperties("Overwrite Caret")
       Dim indicatorMargin As ResourceDictionary = formatMap.GetProperties("Indicator Margin")
       Dim visibleWhitespace As ResourceDictionary = formatMap.GetProperties("Visible Whitespace")
       Dim selectedText As ResourceDictionary = formatMap.GetProperties("Selected Text")
       Dim inactiveSelectedText As ResourceDictionary = formatMap.GetProperties("Inactive Selected Text")
   
       formatMap.BeginBatchUpdate()
   
       regularCaretProperties(EditorFormatDefinition.ForegroundBrushId) = Brushes.Magenta
       formatMap.SetProperties("Caret", regularCaretProperties)
   
       overwriteCaretProperties(EditorFormatDefinition.ForegroundBrushId) = Brushes.Turquoise
       formatMap.SetProperties("Overwrite Caret", overwriteCaretProperties)
   
       indicatorMargin(EditorFormatDefinition.BackgroundColorId) = Colors.LightGreen
       formatMap.SetProperties("Indicator Margin", indicatorMargin)
   
       visibleWhitespace(EditorFormatDefinition.ForegroundColorId) = Colors.Red
       formatMap.SetProperties("Visible Whitespace", visibleWhitespace)
   
       selectedText(EditorFormatDefinition.BackgroundBrushId) = Brushes.LightPink
       formatMap.SetProperties("Selected Text", selectedText)
   
       inactiveSelectedText(EditorFormatDefinition.BackgroundBrushId) = Brushes.DeepPink
       formatMap.SetProperties("Inactive Selected Text", inactiveSelectedText)
   
       formatMap.EndBatchUpdate()
   End Sub
   

Building and Testing the Code

1. Build the solution.

   When you run this project in the debugger, a second instance of Visual Studio is instantiated.

2. Create a text file and type some text.

   • The insertion caret should be magenta and the overwrite caret should be turquoise.

   • The indicator margin (to the left of the text view) should be light green.

3. Select the text you just typed. The color of the selected text should be light pink.

4. While the text is selected, click anywhere outside the text window. The color of the selected text should be dark pink.

5. Turn on visible whitespace. (On the Edit menu, point to Advanced and then click View White Space). Type some tabs in the text. Red arrows that represent the tabs should be displayed.

See Also

Language Service and Editor Extension Points