1.106.1 Instance variables

node <- collapsed: bool*

When @on, the image related to this node is displayed, but all subnodes will be made invisible. node->collapsed and tree->zoom make it possible to visualise only a small part of a large tree. A tree might contain multiple collapsed nodes.

If the tree is displayed using tree->direction, an image is displayed at the left-hand of the line connecting the node to its parent. This image depends on the value of node<-collapsed:

@(on)

Show a [+] sign (pce.Tree.collapsedImage). If the user lef-clicks on this sign, a message node->collapsed: @off is sent to the node.

@(off)

Show a [-] sign (pce.Tree.expandedImage). If the user lef-clicks on this sign, a message node->collapsed: @on is sent to the node.

@(nil)

Shows nothing, no events are handled for collapse/expand.

See library(pce_toc) for an example and a starting point the visualisation of a hierarchy. See also tree->direction.

See also

- tree->zoom
- node-displayed
- tree->collapsed_handler

node <- displayed: [bool]

When @off, the node is invisible either because it is above tree <-display_root' or below a node that has node node<-collapsed: @on‘.

See also

- tree->zoom
- node-collapsed

node <- image: graphical

Graphical object that represents the node. This may be any graphical object. Note that class graphical defines some methods that take care of the fact that they are part of a tree. See graphical<-node and graphical<-contained_in.

See also

- graphical<-convert
- graphical<-node

node <- level: int

Integer representing the distance from the tree<-display_root node. The node tree<-display_root has level 0. This variable is updated by tree->compute, which scans the tree depth-first.

node-my_size: int

Height (or width if tree<-direction equals vertical) or the graphical image represented. Part of the layout system.

See also

node-sons_size

node <- parents: chain

Chain of parent nodes of this node. For the tree<-root node this is the empty chain. Nodes may have multiple parents, but many methods of the classes tree and node are ill-defined for this case.

node <- sons: chain

Chain holding all immediate sub-nodes. The nodes are displayed left-to-right or top-to-bottom in the order they appear in this chain. This order may be changed using node->move_after.

See also

node->son

node-sons_size: int

Combined height (width) of the entire subtree starting at this node. Part of the automatic layout mechanism.

See also

node-my_size