BasicMenuBarUI (Java Platform SE 8 )
Keywords: javax.swing.plaf.basic.BasicMenuBarUI class
Date: 2026-06-25

javax.swing.plaf.basic

## Class BasicMenuBarUI

- java.lang.Object
- - javax.swing.plaf.ComponentUI
  - - javax.swing.plaf.MenuBarUI
    - - javax.swing.plaf.basic.BasicMenuBarUI

- Direct Known Subclasses:
    MetalMenuBarUI, SynthMenuBarUI

      public class BasicMenuBarUI
      extends MenuBarUI

  A default L&F implementation of MenuBarUI. This implementation is a "combined" view/controller.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected ChangeListener` | `changeListener`
    `protected ContainerListener` | `containerListener`
    `protected JMenuBar` | `menuBar`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `BasicMenuBarUI()`

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected ChangeListener` | `createChangeListener()`
    `protected ContainerListener` | `createContainerListener()`
    `static ComponentUI` | `createUI(JComponent x)`
    `Dimension` | `getMaximumSize(JComponent c)` Returns the specified component's maximum size appropriate for the look and feel.
    `Dimension` | `getMinimumSize(JComponent c)` Returns the specified component's minimum size appropriate for the look and feel.
    `protected void` | `installDefaults()`
    `protected void` | `installKeyboardActions()`
    `protected void` | `installListeners()`
    `void` | `installUI(JComponent c)` Configures the specified component appropriately for the look and feel.
    `protected void` | `uninstallDefaults()`
    `protected void` | `uninstallKeyboardActions()`
    `protected void` | `uninstallListeners()`
    `void` | `uninstallUI(JComponent c)` Reverses configuration which was done on the specified component during `installUI`.

    - ### Methods inherited from class javax.swing.plaf.ComponentUI

      `contains, getAccessibleChild, getAccessibleChildrenCount, getBaseline, getBaselineResizeBehavior, getPreferredSize, paint, update`

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### menuBar

          protected JMenuBar menuBar

    - #### containerListener

          protected ContainerListener containerListener

    - #### changeListener

          protected ChangeListener changeListener

  - ### Constructor Detail

    - #### BasicMenuBarUI

          public BasicMenuBarUI()

  - ### Method Detail

    - #### createUI

          public static ComponentUI createUI(JComponent x)

    - #### installUI

          public void installUI(JComponent c)

      Description copied from class: `ComponentUI`
      Configures the specified component appropriately for the look and feel. This method is invoked when the `ComponentUI` instance is being installed as the UI delegate on the specified component. This method should completely configure the component for the look and feel, including the following:
      1. Install default property values for color, fonts, borders, icons, opacity, etc. on the component. Whenever possible, property values initialized by the client program should not be overridden.
      2. Install a `LayoutManager` on the component if necessary.
      3. Create/add any required sub-components to the component.
      4. Create/install event listeners on the component.
      5. Create/install a `PropertyChangeListener` on the component in order to detect and respond to component property changes appropriately.
      6. Install keyboard UI (mnemonics, traversal, etc.) on the component.
      7. Initialize any appropriate instance data.
      Overrides:
        `installUI` in class `ComponentUI`
      Parameters:
        `c` - the component where this UI delegate is being installed
      See Also:
        `ComponentUI.uninstallUI(javax.swing.JComponent)`, `JComponent.setUI(javax.swing.plaf.ComponentUI)`, `JComponent.updateUI()`

    - #### installDefaults

          protected void installDefaults()

    - #### installListeners

          protected void installListeners()

    - #### installKeyboardActions

          protected void installKeyboardActions()

    - #### uninstallUI

          public void uninstallUI(JComponent c)

      Description copied from class: `ComponentUI`
      Reverses configuration which was done on the specified component during `installUI`. This method is invoked when this `UIComponent` instance is being removed as the UI delegate for the specified component. This method should undo the configuration performed in `installUI`, being careful to leave the `JComponent` instance in a clean state (no extraneous listeners, look-and-feel-specific property objects, etc.). This should include the following:
      1. Remove any UI-set borders from the component.
      2. Remove any UI-set layout managers on the component.
      3. Remove any UI-added sub-components from the component.
      4. Remove any UI-added event/property listeners from the component.
      5. Remove any UI-installed keyboard UI from the component.
      6. Nullify any allocated instance data objects to allow for GC.
      Overrides:
        `uninstallUI` in class `ComponentUI`
      Parameters:
        `c` - the component from which this UI delegate is being removed; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components
      See Also:
        `ComponentUI.installUI(javax.swing.JComponent)`, `JComponent.updateUI()`

    - #### uninstallDefaults

          protected void uninstallDefaults()

    - #### uninstallListeners

          protected void uninstallListeners()

    - #### uninstallKeyboardActions

          protected void uninstallKeyboardActions()

    - #### createContainerListener

          protected ContainerListener createContainerListener()

    - #### createChangeListener

          protected ChangeListener createChangeListener()

    - #### getMinimumSize

          public Dimension getMinimumSize(JComponent c)

      Description copied from class: `ComponentUI`
      Returns the specified component's minimum size appropriate for the look and feel. If `null` is returned, the minimum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes `getPreferredSize` and returns that value.
      Overrides:
        `getMinimumSize` in class `ComponentUI`
      Parameters:
        `c` - the component whose minimum size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components
      Returns:
        a `Dimension` object or `null`
      See Also:
        `JComponent.getMinimumSize()`, `LayoutManager.minimumLayoutSize(java.awt.Container)`, `ComponentUI.getPreferredSize(javax.swing.JComponent)`

    - #### getMaximumSize

          public Dimension getMaximumSize(JComponent c)

      Description copied from class: `ComponentUI`
      Returns the specified component's maximum size appropriate for the look and feel. If `null` is returned, the maximum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes `getPreferredSize` and returns that value.
      Overrides:
        `getMaximumSize` in class `ComponentUI`
      Parameters:
        `c` - the component whose maximum size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components
      Returns:
        a `Dimension` object or `null`
      See Also:
        `JComponent.getMaximumSize()`, `LayoutManager2.maximumLayoutSize(java.awt.Container)`

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