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

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

• The WpfCompositeVisualTool draws nested visual tools in WpfImageViewer in reverse order to the order in WpfCompositeVisualTool.VisualTools array. Thus the first visual tool will be drawn the last.
• The WpfCompositeVisualTool transfers event from input device to the nested visual tools in the same order they are stored in WpfCompositeVisualTool.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 WpfCompositeVisualTool has active nested visual tool, i.e. the WpfCompositeVisualTool.ActiveTool property value is not null:

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

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

• WpfAnnotationViewer class uses the composition of WpfAnnotationVisualTool and WpfRectangularSelectionTool for providing the ability to select multiple annotations.