The CompositeVisualTool is visual tool, which allows to use a composition of nested visual tools in ImageViewer. An array of nested visual tools can be get using the protected CompositeVisualTool.VisualTools property.

If CompositeVisualTool does not have active nested visual tool, i.e. the CompositeVisualTool.ActiveTool property value is null:

• The CompositeVisualTool draws nested visual tools in ImageViewer in reverse order to the order in CompositeVisualTool.VisualTools array. Thus the first visual tool will be drawn the last.
• The CompositeVisualTool transfers event from input device to the nested visual tools in the same order they are stored in CompositeVisualTool.VisualTools array until one of nested visual tool will not mark the event as processed, i.e. set e.Handled flag of event arguments to True.

If CompositeVisualTool has active nested visual tool, i.e. the CompositeVisualTool.ActiveTool property value is not null:

• The CompositeVisualTool draws nested visual tools, except the visual tool defined by CompositeVisualTool.ActiveTool property, in ImageViewer in reverse order to the order in CompositeVisualTool.VisualTools array and only after this draws the visual tool defined by CompositeVisualTool.ActiveTool property.
• The CompositeVisualTool transfers event from input device only to the visual tool defined by CompositeVisualTool.ActiveTool property.

The composite visual tools are used in many demos of VintaSoft Imaging .NET SDK, e.g.:

• AnnotationViewer class uses the composition of AnnotationVisualTool and RectangularSelectionTool for providing the ability to select multiple annotations.
• OCR Demo application includes the composite visual tool, which provides the ability to highlight recognized words along with multiple selection function.