graph-pane

Initargs

:roots

The roots of the graph.

:children-function

Returns the children of a node.

:layout-function

A keyword denoting how to layout the nodes.

:layout-x-adjust

The adjust value for the x direction.

:layout-y-adjust

The adjust value for the y direction.

:node-pinboard-class

The class of pane to represent nodes.

:edge-pinboard-class

The class of pane to represent edges.

:node-pane-function

A function to return an element for each node.

:edge-pane-function

A function to return an element for each edge.

Description

A graph pane calculates the items of the graph by calling the children-function on each of its roots , and then calling it again on each of the children recursively until no more children are found. The children-function gets called with an item of the graph and should return a list of the children of that item.

Each item is represented by a node in the graph.

The layout-function tells the graph pane how to lay out its nodes. It can be one these values:

:left-right

Lay the graph out from the left to the right.

:top-down

Lay the graph out from the top down.

:right-left

Lay the graph out from the right to the left.

:bottom-up

Lay the graph out from the bottom up.

layout-x-adjust and layout-y-adjust act on the underlying layout to decide where to place the nodes. The values should be a keyword or a list of the form (keyword n ) where n is an integer. These values of adjust are interpreted as by pane-adjusted-position. :top is the default for layout-y-adjust and :left is the default for layout-x-adjust .

When a graph pane wants to display nodes and edges, it creates instances of node-pinboard-class and edge-pinboard-class which default to item-pinboard-object and line-pinboard-object respectively. These classes must be subclasses of simple-pane or pinboard-object, and there are some examples of the use of these keywords below.

The node-pane-function is called to create an element for each node, and by default it creates an instance of node-pinboard-class . It gets passed the graph pane and the item corresponding to the node, and should return an instance of a subclass of simple-pane or pinboard-object. Note that the name of the initarg is a little misleading, as in most cases you should return a pinboard-object rather than a pane. If you use your own class which has its own geometry requirements, you should define a calculate-constraints method for it, which should use with-geometry on the object to set %min-width% and %width% to the desired width, and %height% and %min-height% to the desired height. See the example in:


(example-edit-file "capi/graphics/circled-graph-nodes")

edge-pane-function is called to create an element for an edge. The default creates an object of the class specified by edge-pinboard-class . If edge-pane-function is supplied, it must be a function that takes three arguments: the pane and the two items that are connected by the edge, and must return an element (a simple-pane or a pinboard-object).

To expand or contract a node, the user clicks on the circle next to the node. An expandable node has an unfilled circle and a collapsible node has a filled circle.

graph-pane is a subclass of choice, so for details of its selection handling, see choice.

The highlighting of the children is controlled as described for pinboard-layout, but for graph-pane the default value of highlight-style is :standard.

Example

(defun node-children (node)

  (when (< node 16)

    (list (* node 2)

          (1+ (* node 2)))))

(setq graph

      (capi:contain

       (make-instance 'capi:graph-pane

                      :roots '(1)

                      :children-function

                      'node-children)

       :best-width 300 :best-height 400))

(capi:apply-in-pane-process

 graph #'(setf capi:graph-pane-roots) '(2 6) graph)

(capi:contain

 (make-instance 'capi:graph-pane

                :roots '(1)

                :children-function

                'node-children

                :layout-function :top-down)

 :best-width 300 :best-height 400)

(capi:contain

 (make-instance 'capi:graph-pane

                :roots '(1)

                :children-function

                'node-children

                :layout-function :top-down

                :layout-x-adjust :left)

 :best-width 300 :best-height 400)

This example demonstrates a different style of graph output with right-angle edges and parent nodes being adjusted towards the top instead of at the center.

(capi:contain

 (make-instance

  'capi:graph-pane

  :roots '(1)

  :children-function 'node-children

  :layout-y-adjust '(:top 10)

  :edge-pinboard-class

  'capi:right-angle-line-pinboard-object)

 :best-width 300

 :best-height 400)

This example demonstrates the use of :node-pinboard-class to specify that the nodes are drawn as push buttons.

(capi:contain

 (make-instance

  'capi:graph-pane

  :roots '(1)

  :children-function 'node-children

  :node-pinboard-class 'capi:push-button)

 :best-width 300

 :best-height 400)

There are more examples here:

(example-edit-file "capi/graphics/*graph*")

graph-pane

Class

Summary

Package

Superclasses

Subclasses

Initargs

Accessors

Description

Notes

Compatibility note

Example

See also