21.4.2.8 constr

This element is used to specify size, position of nodes, text values, and layout dependencies between nodes in a layout definition.

[Example: Consider the following example of a constraint list which contains some example constraints being defined and applied to layout nodes in the layout definition:

<constrLst>
  <constr type="w" for="ch" forName="node1" refType="w" refForName=""/>
  <constr type="h" for="ch" forName="node1" refType="w" refFor="ch"
refForName="node1" op="equ" fact="0.6"/>
  <constr type="w" for="ch" forName="transition1" refType="w" refFor="ch"
refForName="node1" op="equ" fact="0.1"/>
  <constr type="primFontSz" for="ch" forName="node1" refForName="" op="equ"
val="100"/>
</constrLst>

In this example we can see constraints being defined for the width and height along with the primary font size for a layout node referenced by node1. The width for a transition is also specified. end example]

Attributes

forName (For Name)

Specifies the name of the layout node to apply a constraint or rule to.

[Example: Consider the following example of forName in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, forName is specifying the layout node named transition1 for its reference. end example]

The possible values for this attribute are defined by the W3C XML Schema string datatype.

for (For)

Specifies the axis of layout nodes to apply a constraint or rule to.

[Example: Consider the following example of for in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, the for attribute is specifying that node1 is a child node to the current layout node. end example]

The possible values for this attribute are defined by the ST_ConstraintRelationship simple type (21.4.7.20).

fact (Factor)

Factor used in a reference constraint or a rule in order to modify a referenced value by the factor defined.

[Example: Consider the following example of fact in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, the width for transition1 is being defined as one-tenth the width of

node1. _end example_]

The possible values for this attribute are defined by the W3C XML Schema double datatype.

refForName (Reference For Name)

The name of the layout node referenced by a reference constraint.

[Example: Consider the following example of refForName in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, refForName is specifying the layout node named node1 for its reference. end example]

The possible values for this attribute are defined by the W3C XML Schema string datatype.

refFor (Reference For)

The for value of the referenced constraint.

[Example: Consider the following example of refFor in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, refFor is specifying the reference constraint is a child of the current layout node. end example]

The possible values for this attribute are defined by the ST_ConstraintRelationship simple type (21.4.7.20).

ptType (Data Point Type)

Specifies the type of data point to select.

The possible values for this attribute are defined by the ST_ElementType simple type (21.4.7.27).

op (Operator)

The operator constraint used to evaluate the condition.

[Example: Consider the following example of op in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, op is specifying an equality defined between the two referencing values. end example]

The possible values for this attribute are defined by the ST_BoolOperator simple type (21.4.7.10).

val (Value)

Specifies an absolute value instead of reference another constraint.

[Example: Consider the following example of forName in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1"
                                                val="10"/>

In this example, val is specifying the absolute value of the width of transition1. end example]

The possible values for this attribute are defined by the W3C XML Schema double datatype.

type (Constraint Type)

Specifies the constraint to apply to this layout node.

[Example: Consider the following example of type in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, type is specifying the width attribute of transition1. end example]

The possible values for this attribute are defined by the ST_ConstraintType simple type (21.4.7.21).

refType (Reference Type)

Specifies the type of a reference constraint.

[Example: Consider the following example of refType in use in a DrawingML diagram:

    <constr type="w" for="ch" forName="transition1" refType="w"
    refFor="ch" refForName="node1" op="equ" fact="0.1"/>

In this example, refType is specifying referencing the width attribute of node1. end example]

The possible values for this attribute are defined by the ST_ConstraintType simple type (21.4.7.21).

refPtType (Reference Point Type)

The point type used int he referenced constraint.

The possible values for this attribute are defined by the ST_ElementType simple type (21.4.7.27).

[Note: The W3C XML Schema definition of this element’s content model (CT_Constraint) is located in A.5.3. end note]