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| Chapter 18 The java.awt Package |

## 18.37 java.awt.LayoutManager2 (JDK 1.1)

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This interface is an extension of the `LayoutManager` interface. It defines additional layout management methods for layout managers that perform constraint-based layout. `GridBagLayout` is an example of a constraint-based layout manager--each component added to the layout is associated with a `GridBagConstraints` object that specifies the "constraints" on how the component is to be laid out.

Java programs do not directly invoke the methods of this interface--they are used by the `Container` object for which the layout manager is registered.

    public abstract interface LayoutManager2 extends LayoutManager {
        // Public Instance Methods
                public abstract void addLayoutComponent(Component comp, Object constraints);
                public abstract float getLayoutAlignmentX(Container target);
                public abstract float getLayoutAlignmentY(Container target);
                public abstract void invalidateLayout(Container target);
                public abstract Dimension maximumLayoutSize(Container target);
    }

### Implemented By:

BorderLayout, CardLayout, GridBagLayout

java.awt.LayoutManager (JDK 1.0) |  | java.awt.List (JDK 1.0)