Column Guides
Column guides are vertical lines typically aligned with a specific column but can also be displayed at an explicit location on the x-axis of the view.
Commonly, a column guide is used at a specific column (e.g., 80 or 120) to create a subtle line indicating the maximum desired length of a line of text. Multiple column guides of varying colors, styles, and thicknesses are supported at the same time.
Placement
A column guide supports the following types of ColumnGuidePlacement:
| Placement | Description |
|---|---|
| Column | The guide is placed at a specific column (e.g., 80). This guide is the most common and automatically adjusts to changes in font size but requires a consistent fixed-width font to accurately represent the column position throughout the document. |
| Absolute | The guide is always placed at a specific location on the x-axis relative to the start of the text line. This guide is always in the same relative position and is not dependent upon the font being used. |
Note
All column guide placements are relative to the start of a text line and will move in response to horizontal scrolling.
Setting Column Guides
By default, all column guides defined by the SyntaxEditor.ColumnGuides property are visible. The SyntaxEditor.AreColumnGuidesVisible property can be set to false to hide column guides without removing them.
Basic column guides can easily be added using convenience methods on IColumnGuideCollection. The following sample demonstrates how to add a default column guide at column 80:
editor.ColumnGuides.Add(80);
To create more advanced column guides with non-default line styles and colors, create and add an instance of a class that implements IColumnGuide. A default implementation of this interface is available as ColumnGuide. The following example demonstrates adding a customized column guide at column 80 with a 2px wide Dash line:
editor.ColumnGuides.Add(new ColumnGuide(ColumnGuidePlacement.Column, 80, LineKind.Dash, 2, null));
Changing the Default Column Guide Brush
The brush used to render a column guide can use a color explicitly set using the IColumnGuide.Color property. Otherwise, the brush can be adjusted by the end user since it is exposed via a special classification type's style in the highlighting style registry.
See the "Special Classification Types" section in the Highlighting Style Registries topic for more information on how to modify the style.