Tree Widget
Application Header file <X11/Xaw/Tree.h>
Class Header file <X11/Xaw/TreeP.h>
Class treeWidgetClass
Class Name Tree
Superclass Constraint
The Tree widget provides geometry management of arbitrary widgets arranged
in a directed, acyclic graph (i.e., a tree). The hierarchy is constructed
by attaching a constraint resource called treeParent to each widget
indicating which other node in the tree should be treated as the widget's
superior. The structure of the tree is shown by laying out the nodes
in the standard format for tree diagrams with lines drawn connecting each
node with its children.
The Tree sizes itself according to the needs of its children and is not
intended to be resized by its parent. Instead, it should be placed inside
another composite widget (such as the Porthole or Viewport)
that can be used to scroll around in the tree.
Resources
When creating a Tree widget instance, the following resources are
retrieved from the argument list or from the resource database:
Name
Class
Type
Notes
Default Value
accelerators
Accelerators
AcceleratorTable
NULL
ancestorSensitive
AncestorSensitive
Boolean
D
True
autoReconfigure
AutoReconfigure
Boolean
False
background
Background
Pixel
XtDefaultBackground
backgroundPixmap
Pixmap
Pixmap
XtUnspecifiedPixmap
borderColor
BorderColor
Pixel
XtDefaultForeground
borderPixmap
Pixmap
Pixmap
XtUnspecifiedPixmap
borderWidth
BorderWidth
Dimension
1
children
ReadOnly
WidgetList
R
NULL
colormap
Colormap
Colormap
Parent's Colormap
depth
Depth
int
C
Parent's Depth
destroyCallback
Callback
XtCallbackList
NULL
foreground
Foreground
Pixel
XtDefaultForeground
gravity
Gravity
XtGravity
WestGravity
height
Height
Dimension
A
see Layout Semantics
hSpace
HSpace
Dimension
4
lineWidth
LineWidth
Dimension
0
mappedWhenManaged
MappedWhenManaged
Boolean
True
numChildren
ReadOnly
Cardinal
R
0
screen
Screen
Screen
R
Parent's Screen
sensitive
Sensitive
Boolean
True
vSpace
VSpace
Dimension
4
translations
Translations
TranslationTable
NULL
width
Width
Dimension
A
see Layout Semantics
x
Position
Position
0
y
Position
Position
0
autoReconfigure
Whether or not to layout the tree every time a node is added or removed.
gravity
Specifies the side of the widget from which the tree should grow. Valid
values include WestGravity, NorthGravity, EastGravity, and
SouthGravity.
hSpace
vSpace
The amount of space, in pixels, to leave between the children. This
resource specifies the amount of space left between the outermost
children and the edge of the box.
lineWidth
The width of the lines from nodes that do not have a treeGC
constraint resource to their children.
Constraint Resources
Each child of the Tree widget must specify its superior node in the tree. In
addition, it may specify a GC to use when drawing a line between it and its
inferior nodes.
Name
Class
Type
Notes
Default Value
treeGC
TreeGC
GC
NULL
treeParent
TreeParent
Widget
NULL
treeGC
This specifies the GC to use when drawing lines between this widget and its
inferiors in the tree. If this resource is not specified, the Tree's
foreground and lineWidth will be used.
treeParent
This specifies the superior node in the tree for this widget. The default is
for the node to have no superior (and to therefore be at the top of the tree).
Layout Semantics
Each time a child is managed or unmanaged, the Tree widget will attempt
to reposition the remaining children to fix the shape of the tree if the
resource is set. Children at the top (most superior) of the tree are
drawn at the side specified by the resource.
After positioning all children, the Tree widget attempts to shrink its
own size to the minimum dimensions required for the layout.
Convenience Routines
The most efficient way to layout a tree is to set
autoReconfigure
to False and then use the
routine to arrange the children.
void XawTreeForceLayout
Widget w
w
Specifies the Tree widget.