ItemContainer Overview

The ItemContainer is the most important piece of an editor. It is a content control that wraps every other control that is generated by the NodifyEditor's ItemsSource and has a Location in graph coordinates.

Selecting

Selecting an ItemContainer is done by releasing the left mouse button over the bounding box of the container. The bounding box is calculated using the DesiredSizeForSelection dependency property if specified, otherwise using the RenderSize.

Note: A container can be selected programmatically by setting the IsSelected dependency property to true.

The container will also be selected if the left mouse button is not released and the mouse is moved, which will clear the current selection and start a dragging operation on the selected container.

Selection can also be done by releasing the right mouse button on the container which will clear the current selection and select the target container.

Different behavior is used depending on the ModifierKeys held when selecting a container:

Replace - no modifier key (default behavior, clears the selected items and selects the container)
Append - shift key (adds the container to the selected items)
Invert - control key (toggles the container's IsSelected dependency property)

An ItemContainer can only be selected if the IsSelectable dependency property is true.

Selecting or unselecting a container will fire the Selected event, respectively the Unselected event, and will set the IsSelected dependency property to the new value.

If the default style is not overridden, the container's border will use the SelectedBrush dependency property.

Default values:

IsSelectable: true
IsSelected: false

Selection API

IsSelectableInArea

Moving and dragging

A dragging operation can be started by holding the left mouse button on an ItemContainer and moving the mouse. An ItemContainer can be dragged only if its IsDraggable dependency property is set to true.

Note: ItemContainers can be programmatically moved by setting their Location dependency property.

Dragging an ItemContainer fires a sequence of events that are handled by the NodifyEditor and applies to all the selected items:

DragStarted - will set IsPreviewingLocation dependency property to true;
DragDelta - will be fired until the dragging operation is finished or canceled and will move all the selected items with it;
DragCompleted - will finish or cancel the dragging operation and set the Location dependency property to the final position and IsPreviewingLocation to false.