Provided by: libmotif-dev_2.3.8-3.1build1_amd64 
NAME
XmTree - The Tree widget class
SYNOPSIS
#include <Xm/XTree.h>
DESCRIPTION
The Tree widget is a container that shows the relationship of its children in a graphical
tree-like format. Each child of the Tree widget is a node in the Tree. The parent-child
relationships between these nodes are completely distinct from the widget hierarch.. The
hierarchy of nodes is created by specifying the tree "parent" of each node as a constraint
resource. If a node's parent is NULL then it is assumed to be a root of the tree. Although
each widget can only have one parent, the Tree widget supports adding more than one "root"
node to a single Tree.
Note: the Tree widget assumes that is will be totally responsible for mapping and
unmapping its children. Therefore no child of this widget should ever modify its
mappedWhenManaged resource. If a child does modify this resource the behavior is
undefined.
User Interaction
Each node in the tree can be in four states: open, closed, always open, and hidden. The
state of a node changes how it appears to the user and what actions are available to the
user.
Open This node will have an open folder shown to its left that may be selected
by the user to close this node. When a node is open all of its children
will be visible to the user.
Closed This node will have a closed folder shown to its left that may be selected
by the user to open this node. When a node is closed none of its children
will be visible to the user.
Always Open This node will have no folder button associated with it. All of its
children will be visible to the user.
Hidden This node will not be shown to the user and all of its children will appear
and act exactly as if they were children of this node's parent. It will
appear to the user as if this node does not exist.
To maintain consistency of the user interface we have found that it is bestto use the node
state "Always Open" for nodes with no children. This way the user will only see a folder
button next to a node that has children to display. A folder button associated with a node
that has no children has no defined semantics.
Normal Resources
Name Class Type Initial Value
connectStyle ConnectStyle unsigned char XmTreeDirect
horizontalNodeSpace Dimension HorizontalDimension 20
verticalNodeSpace Dimension VerticalDimension 2
All resource names begin with XmN and all resource class names begin with XmC.
connectStyle
The style of the lines visually connecting parent nodes to children nodes. The valid
styles are XmTreeDirect or XmTreeLadder.
horizontalNodeSpace
verticalNodeSpace
The amount of space between each node in the tree and it nearest neighbor.
The following resources are inherited from the XmHierarchy widget:
Name Class Type Initial Value
autoClose AutoClose Boolean True
closeFolderPixmap Pixmap Pixmap XmUNSPECIFIED_PIXMAP
horizontalMargin Dimension HorizontalDimension 2
openFolderPixmap Pixmap Pixmap XmUNSPECIFIED_PIXMAP
refigureMode Boolean Boolean True
verticalMargin Dimension VerticalDimension 2
All resource names begin with XmN and all resource class names begin with XmC.
Constraint Resources
Name Class Type Initial Value
openClosePadding OpenClosePadding Int 0
lineColor Foreground Pixel <dynamic>
lineWidth LineWidth Dimension 0
All resource names begin with XmN and all resource class names begin with XmC.
openClosePadding
The number of pixels between the folder button and the node it is associated with.
lineColor
The color of the line connecting a node to its parent. The default value for this resource
is the foreground color of the Tree widget.
lineWidth
The width of a connection line between a node and its parent
The following constraint resources are inherited from the XmHierarchy widget:
Name Class Type Initial Value
insertBefore InsertBefore Widget NULL
nodeState NodeState XmHierarchyNodeState Open
parentNode ParentNode Widget NULL
All resource names begin with XmN and all resource class names begin with XmC. Geometry
Management:
The layout is performed by assigning each node a box that is just large enough to con-
tain itself and all of its children. A recursive layout is then performed that centers
each node vertically in its box and at the extreme left horizontally. The children's boxes
are then placed to the right of the node separated by the horizontalNodeSpace from their
parent, stacked above each other and separated by verticalNodeSpace. This process is
repeated recursively for each child in the tree.
The preferred size of the entire tree will be just large enough to contain all nodes in
the hierarchy. As the state of nodes change the tree will attempt to resize itself to con-
tain its current configuration. If the tree is forced larger than the desired size the
nodes will be centered vertically and flush to the left edge of the tree widget. If the
tree is forced smaller, some nodes may be moved or drawn outside the end of the tree. For
this reason it is usually desirable to put the tree into a Scrolled Window widget.
SEE ALSO
XmColumn(3X)
COPYRIGHT
Copyright (c) 1992 by Integrated Computer Solutions, Inc.
15 July 1992 XmForm(3)