Fixed Annotations

Most annotation objects can be "fixed". When an annotation is 'fixed', its size and location do not change when the container zooms or scrolls. To fix an annotation, set the AnnObject.FixedStateOperations property.

The effect of fixing an annotation is that it is frozen on the container. Zooming and scrolling will move the underlying image and non-fixed annotations, but fixed annotations will not move. The annotation can still be moved by selecting and dragging the annotation with mouse or touch input. Fixing an annotation also has an effect on certain aspects of the object's appearance, such as its AnnObject.Font and AnnObject.Stroke.

A fixed annotation object can be desirable in certain situations. For example, if you do not want the thickness of a line object to grow larger or smaller when the container is zoomed in and out, you can set its FixedStateOperations property to AnnFixedStateOperations.StrokeWidth. If you have a ruler object and you do not want the thickness of its line nor the size of its font to change when the container zooms in and out, you set its AnnObject.FixedStateOperations property to AnnFixedStateOperations.FontSize | AnnFixedStateOperations.StrokeWidth.

The default for all objects is AnnFixedStateOperations.None, which means the object is not fixed and will zoom and scroll whenever the container zooms and scrolls.

The following table describes the AnnFixedStateOperations

By combining AnnFixedStateOperations values when setting the AnnObject.FixedStateOperations property you can create all of the various combinations needed for fixing an annotation object in its container.