TabStop

Updated on Jun 16, 2026

A tab stop is the location where the caret stops after you press the Tab key. Tab stops allow you to align text by inserting the Tab symbol. Each paragraph contains a number of tabs, which you can place wherever needed.

TabStop Overview

The TabStop class is immutable, meaning you must set its properties when initializing an instance.

• Position: The position of the tab stop. The value is in device-independent pixels (1/96 inch).

• Type: The type of the tab stop. Defines the behavior of the tab stop. All possibilities are described with the TabStopType enumeration:

  • Left: The text following the tab stop is left aligned with respect to the tab stop position. This is the default value.
  • Center: The text following the tab stop is centered around the tab stop position.
  • Right: The text following the tab stop is right aligned with respect to the tab stop position.
  • Decimal: Text before the decimal point is positioned to the left and text after the decimal point is positioned to the right side of the tab stop.
  • Bar: A vertical bar is shown at the tab position.
  • Clear: Clears an inherited tab stop.

• Leader: Specifies the character that fills the space in front of a tab. All possibilities are described with the TabStopLeader enumeration:

  • None: The space before the tab is left empty. This is the default value.
  • Dot: The space before the tab is filled with dots.
  • Hyphen: The space before the tab is filled with hyphens.
  • Underscore: The space before the tab is filled with underscores.
  • MiddleDot: The space before the tab is filled with middle dots.

The distance between automatic tab stops is determined by the RadFlowDocument.DefaultTabStopWidth property. Automatic tab stops refer to the tab stop locations that occur after all custom tab stops in the current paragraph have been surpassed.

TabStopCollection Overview

This class derives from System.Collections.Generic.IEnumerable<T> and represents a collection of TabStop objects. The collection is immutable, and it holds the tab stops in a Paragraph.

The TabStopCollection class exposes the following members:

• Count: The count of TabStop elements in the collection.
• Insert(): Returns a new instance of TabStopCollection with the specified tab stop inserted in it.
• Remove(): Returns a new instance of TabStopCollection with the specified tab stop removed.

Working with TabStopCollection

Create a TabStopCollection

Excluding the default constructor, the TabStopCollection class exposes an overload that allows you to directly pass a collection of TabStop objects:

Example 1: Create a TabStopCollection

C#

List<TabStop> tabStops = new List<TabStop>();
tabStops.Add(new TabStop(Unit.InchToDip(1), TabStopType.Left));
tabStops.Add(new TabStop(Unit.InchToDip(2), TabStopType.Center, TabStopLeader.Dot));
tabStops.Add(new TabStop(Unit.InchToDip(3), TabStopType.Right, TabStopLeader.Hyphen));
tabStops.Add(new TabStop(Unit.InchToDip(5.5), TabStopType.Bar));

TabStopCollection collection = new TabStopCollection(tabStops);

Insert Item in a TabStopCollection

Example 2 demonstrates how to insert items in the TabStopCollection created in Example 1. Keep in mind that this collection is immutable, so the Insert() method returns a new instance of the class.

Example 2: Insert item in a TabStopCollection

C#

collection = collection.Insert(new TabStop(Unit.InchToDip(4)))
                           .Insert(new TabStop(Unit.InchToDip(5.5), TabStopType.Right));

Remove Item from a TabStopCollection

The following snippet shows how to remove an item from the TabStopCollection created in Example 1. Keep in mind that this collection is immutable, so the Remove() method returns a new instance of the class.

Example 3: Remove item from a TabStopCollection

C#

TabStop tabStopToRemove = collection.First();
collection = collection.Remove(tabStopToRemove);

Working with TabStop

In RadWordsProcessing, the tab stops are stored as a collection in the Paragraph. This section shows how to work with the TabStop element.

Create a TabStop

The code from Example 4 demonstrates how to create a tab stop.

Example 4: Create a TabStop

C#

TabStop tabStop = new TabStop(Unit.InchToDip(2), TabStopType.Center);

Add a TabStop

Example 5 shows how to add the tab stop created in Example 1 to an existing Paragraph through the TabStops property of type TabStopCollection.

Example 5: Insert a TabStop

C#

paragraph.TabStops = paragraph.TabStops.Insert(tabStop);

Remove a TabStop

The following code-snippet shows how to remove the tab stop created in Example 4:

Example 6: Remove a TabStop

C#

paragraph.TabStops = paragraph.TabStops.Remove(tabStop);

Use a TabStop in the Content

Once you have applied the desired tab stops to a paragraph, insert tabs (\t) so that the content aligns to the specified tab stops. The code in Example 7 inserts tab stops at three positions with different properties. It then aligns three words on the tab stop positions using tabs.

Example 7: Add tabs to align to the tab stops

C#

private RadFlowDocument CreateDocumentWithTabStops()
        {
RadFlowDocument document = new RadFlowDocument();
RadFlowDocumentEditor editor = new RadFlowDocumentEditor(document);

List<TabStop> tabStops = new List<TabStop>();
tabStops.Add(new TabStop(Unit.InchToDip(1), TabStopType.Left));
tabStops.Add(new TabStop(Unit.InchToDip(3), TabStopType.Center, TabStopLeader.Dot));
tabStops.Add(new TabStop(Unit.InchToDip(5), TabStopType.Right, TabStopLeader.Hyphen));

TabStopCollection tabStopCollection = new TabStopCollection(tabStops);

Paragraph paragraph = editor.InsertParagraph();
paragraph.TabStops = tabStopCollection;
paragraph.Inlines.AddRun("\tleft\tcenter\tright");

return document;
        }

See Also

• Paragraph