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)