`<constr>` (Constraint)

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

example:

<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. ]

Parent Elements
`<constrLst>` (§5.9.2.9)

Child Elements	Subclause
`<extLst>` (Extension List)	§5.9.2.13

Attributes	Description
`<fact>` (Factor)	Factor used in a reference constraint or a rule in order to modify a referenced value by the factor defined. <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`. ] The possible values for this attribute are defined by the XML Schema double datatype.
`<for>` (For)	Specifies the axis of layout nodes to apply a constraint or rule to. <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. ] The possible values for this attribute are defined by the ST_ConstraintRelationship simple type (§5.9.7.20).
`<forName>` (For Name)	Specifies the name of the layout node to apply a constraint or rule to. <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. ] The possible values for this attribute are defined by the XML Schema string datatype.
`<op>` (Operator)	The operator constraint used to evaluate the condition. <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. ] The possible values for this attribute are defined by the ST_BoolOperator simple type (§5.9.7.10).
`<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 (§5.9.7.25).
`<refFor>` (Reference For)	The for value of the referenced constraint. <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. ] The possible values for this attribute are defined by the ST_ConstraintRelationship simple type (§5.9.7.20).
`<refForName>` (Reference For Name)	The name of the layout node referenced by a reference constraint. <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. ] The possible values for this attribute are defined by the XML Schema string datatype.
`<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 (§5.9.7.25).
`<refType>` (Reference Type)	Specifies the type of a reference constraint. <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`. ] The possible values for this attribute are defined by the ST_ConstraintType simple type (§5.9.7.21).
`<type>` (Constraint Type)	Specifies the constraint to apply to this layout node. <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`. ] The possible values for this attribute are defined by the ST_ConstraintType simple type (§5.9.7.21).
`<val>` (Value)	Specifies an absolute value instead of reference another constraint. <constr type="w" for="ch" forName="transition1" val="10"/> In this example, `@val` is specifying the absolute value of the width of `transition1`. ] The possible values for this attribute are defined by the XML Schema double datatype.

The following XML Schema fragment defines the contents of this element:

<complexType name="CT_Constraint">
	<sequence>
	<element name="extLst" type="a:CT_OfficeArtExtensionList" minOccurs="0" maxOccurs="1"/>
	</sequence>
	<attributeGroup ref="AG_ConstraintAttributes"/>
	<attributeGroup ref="AG_ConstraintRefAttributes"/>
	<attribute name="op" type="ST_BoolOperator" use="optional" default="none"/>
	<attribute name="val" type="xsd:double" use="optional" default="0"/>
	<attribute name="fact" type="xsd:double" use="optional" default="1"/>
</complexType>

<constr> (Constraint)

`<constr>` (Constraint)