Items within tree controls have relationships to other items based on the level they are on. This determines how items are connected to each other. The following table defines the terms used throughout to identify relationships and the connecting lines drawn for each type:
The following table defines the terms used throughout to identify relationships and the connecting lines drawn for each type:
The visibility status indicates whether an item is visible or not. An item is considered visible if its immediate and all other parent items are expanded. An item is considered visible even if it isn't currently displayed in the window client area. The Item.Shown property can be used to define an item's visibility status.
When adding items to a tree control, all that is required from an application is that the level numbers be set. The SftTree/OCX tree control automatically determines the correct relationships and draws connecting lines appropriately. Applications can then interrogate the tree control about relationships and don't have to manage these themselves.