SyntaxEditor documents have always had the ability to be fully read-only and developers can also can cancel specific text change events for more fine-grained control. That being said, there are many cases where developers want to have an easy way to tell SyntaxEditor that a certain of text should not be editable by the end user. That's where read-only regions come into play.
Read-only regions are implemented using our powerful tagging mechanism. There is a new IReadOnlyRegionTag interface (with related ReadOnlyRegionTag implementation class) that can be used to mark read-only regions. Getting going is as easy as tagging a text range using an instance of that class.
Best of all, the ReadOnlyRegionTag class also implements IClassificationTag, which associates the tag with a classification type for read-only text and gets styled with a silver background. Of course this is fully customizable if you wish to have a different appearance, or no appearance difference at all.
When the end user attempts to edit anything that would cross within a read-only range, the text change will realize that it intersects a read-only range and will cancel. The text range protected by the read-only region remains unchanged.
This is a very handy feature for certain scenarios and was highly requested by our customers.