# Class ConstraintsBase

java.lang.Object
javafx.scene.layout.ConstraintsBase

Direct Known Subclasses:
  `ColumnConstraints, RowConstraints`

public abstract class ConstraintsBase extends Object
The base class for defining node-specific layout constraints. Region classes may create extensions of this class if they need to define their own set of layout constraints.

Since:
  JavaFX 2.0

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final double`
  `CONSTRAIN_TO_PREF`
  If set as max value indicates that the pref value should be used as the max.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected void`
  `requestLayout()`
  Calls requestLayout on layout parent associated with this constraint object.

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### CONSTRAIN_TO_PREF

    public static final double CONSTRAIN_TO_PREF
    If set as max value indicates that the pref value should be used as the max. This allows an application to constrain a resizable node's size, which normally has an unlimited max value, to its preferred size.
    See Also:
      - Constant Field Values

- ## Method Details

  - ### requestLayout

    protected void requestLayout()
    Calls requestLayout on layout parent associated with this constraint object.