BasicSpinnerUI (Java SE 21 & JDK 21)
Description: declaration: module: java.desktop, package: javax.swing.plaf.basic, class: BasicSpinnerUI
Keywords: javax.swing.plaf.basic.BasicSpinnerUI class

Module java.desktop
Package javax.swing.plaf.basic

# Class BasicSpinnerUI

java.lang.Object
javax.swing.plaf.ComponentUI
javax.swing.plaf.SpinnerUI
javax.swing.plaf.basic.BasicSpinnerUI

Direct Known Subclasses:
  `SynthSpinnerUI`

public class BasicSpinnerUI extends SpinnerUI
The default Spinner UI delegate.

Since:
  1.4

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected JSpinner`
  `spinner`
  The spinner that we're a UI delegate for.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `BasicSpinnerUI()`
  Constructs a `BasicSpinnerUI`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected JComponent`
  `createEditor()`
  This method is called by installUI to get the editor component of the `JSpinner`.
  `protected LayoutManager`
  `createLayout()`
  Creates a `LayoutManager` that manages the `editor`, `nextButton`, and `previousButton` children of the JSpinner.
  `protected Component`
  `createNextButton()`
  Creates an increment button, i.e. component that replaces the spinner value with the object returned by `spinner.getNextValue`.
  `protected Component`
  `createPreviousButton()`
  Creates a decrement button, i.e. component that replaces the spinner value with the object returned by `spinner.getPreviousValue`.
  `protected PropertyChangeListener`
  `createPropertyChangeListener()`
  Creates a `PropertyChangeListener` that can be added to the JSpinner itself.
  `static ComponentUI`
  `createUI(JComponent c)`
  Returns a new instance of BasicSpinnerUI.
  `int`
  `getBaseline(JComponent c, int width, int height)`
  Returns the baseline.
  `Component.BaselineResizeBehavior`
  `getBaselineResizeBehavior(JComponent c)`
  Returns an enum indicating how the baseline of the component changes as the size changes.
  `protected void`
  `installDefaults()`
  Initialize the `JSpinner` `border`, `foreground`, and `background`, properties based on the corresponding "Spinner.*" properties from defaults table.
  `protected void`
  `installKeyboardActions()`
  Installs the keyboard Actions onto the JSpinner.
  `protected void`
  `installListeners()`
  Initializes `PropertyChangeListener` with a shared object that delegates interesting PropertyChangeEvents to protected methods.
  `protected void`
  `installNextButtonListeners(Component c)`
  Installs the necessary listeners on the next button, `c`, to update the `JSpinner` in response to a user gesture.
  `protected void`
  `installPreviousButtonListeners(Component c)`
  Installs the necessary listeners on the previous button, `c`, to update the `JSpinner` in response to a user gesture.
  `void`
  `installUI(JComponent c)`
  Calls `installDefaults`, `installListeners`, and then adds the components returned by `createNextButton`, `createPreviousButton`, and `createEditor`.
  `protected void`
  `replaceEditor(JComponent oldEditor, JComponent newEditor)`
  Called by the `PropertyChangeListener` when the `JSpinner` editor property changes.
  `protected void`
  `uninstallDefaults()`
  Sets the `JSpinner's` layout manager to null.
  `protected void`
  `uninstallListeners()`
  Removes the `PropertyChangeListener` added by installListeners.
  `void`
  `uninstallUI(JComponent c)`
  Calls `uninstallDefaults`, `uninstallListeners`, and then removes all of the spinners children.

  ### Methods declared in class javax.swing.plaf.ComponentUI

  `contains, getAccessibleChild, getAccessibleChildrenCount, getMaximumSize, getMinimumSize, getPreferredSize, paint, update`

  ### Methods declared in class java.lang.Object

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

- ## Field Details

  - ### spinner

    protected JSpinner spinner
    The spinner that we're a UI delegate for. Initialized by the `installUI` method, and reset to null by `uninstallUI`.
    See Also:
      - `installUI(javax.swing.JComponent)`
      - `uninstallUI(javax.swing.JComponent)`

- ## Constructor Details

  - ### BasicSpinnerUI

    public BasicSpinnerUI()
    Constructs a `BasicSpinnerUI`.

- ## Method Details

  - ### createUI

    public static ComponentUI createUI(JComponent c)
    Returns a new instance of BasicSpinnerUI. SpinnerListUI delegates are allocated one per JSpinner.
    Parameters:
      `c` - the JSpinner (not used)
    Returns:
      a new BasicSpinnerUI object
    See Also:
      - `ComponentUI.createUI(javax.swing.JComponent)`

  - ### installUI

    public void installUI(JComponent c)
    Calls `installDefaults`, `installListeners`, and then adds the components returned by `createNextButton`, `createPreviousButton`, and `createEditor`.
    Overrides:
      `installUI` in class `ComponentUI`
    Parameters:
      `c` - the JSpinner
    See Also:
      - `installDefaults()`
      - `installListeners()`
      - `createNextButton()`
      - `createPreviousButton()`
      - `createEditor()`

  - ### uninstallUI

    public void uninstallUI(JComponent c)
    Calls `uninstallDefaults`, `uninstallListeners`, and then removes all of the spinners children.
    Overrides:
      `uninstallUI` in class `ComponentUI`
    Parameters:
      `c` - the JSpinner (not used)
    See Also:
      - `ComponentUI.installUI(javax.swing.JComponent)`
      - `JComponent.updateUI()`

  - ### installListeners

    protected void installListeners()
    Initializes `PropertyChangeListener` with a shared object that delegates interesting PropertyChangeEvents to protected methods.

    This method is called by `installUI`.

    See Also:
      - `replaceEditor(javax.swing.JComponent, javax.swing.JComponent)`
      - `uninstallListeners()`

  - ### uninstallListeners

    protected void uninstallListeners()
    Removes the `PropertyChangeListener` added by installListeners.

    This method is called by `uninstallUI`.

    See Also:
      - `installListeners()`

  - ### installDefaults

    protected void installDefaults()
    Initialize the `JSpinner` `border`, `foreground`, and `background`, properties based on the corresponding "Spinner.*" properties from defaults table. The `JSpinners` layout is set to the value returned by `createLayout`. This method is called by `installUI`.
    See Also:
      - `uninstallDefaults()`
      - `installUI(javax.swing.JComponent)`
      - `createLayout()`
      - `LookAndFeel.installBorder(javax.swing.JComponent, java.lang.String)`
      - `LookAndFeel.installColors(javax.swing.JComponent, java.lang.String, java.lang.String)`

  - ### uninstallDefaults

    protected void uninstallDefaults()
    Sets the `JSpinner's` layout manager to null. This method is called by `uninstallUI`.
    See Also:
      - `installDefaults()`
      - `uninstallUI(javax.swing.JComponent)`

  - ### installNextButtonListeners

    protected void installNextButtonListeners(Component c)
    Installs the necessary listeners on the next button, `c`, to update the `JSpinner` in response to a user gesture.
    Parameters:
      `c` - Component to install the listeners on
    Throws:
      `NullPointerException` - if `c` is null.
    Since:
      1.5
    See Also:
      - `createNextButton()`

  - ### installPreviousButtonListeners

    protected void installPreviousButtonListeners(Component c)
    Installs the necessary listeners on the previous button, `c`, to update the `JSpinner` in response to a user gesture.
    Parameters:
      `c` - Component to install the listeners on.
    Throws:
      `NullPointerException` - if `c` is null.
    Since:
      1.5
    See Also:
      - `createPreviousButton()`

  - ### createLayout

    protected LayoutManager createLayout()
    Creates a `LayoutManager` that manages the `editor`, `nextButton`, and `previousButton` children of the JSpinner. These three children must be added with a constraint that identifies their role: "Editor", "Next", and "Previous". The default layout manager can handle the absence of any of these children.
    Returns:
      a LayoutManager for the editor, next button, and previous button.
    See Also:
      - `createNextButton()`
      - `createPreviousButton()`
      - `createEditor()`

  - ### createPropertyChangeListener

    protected PropertyChangeListener createPropertyChangeListener()
    Creates a `PropertyChangeListener` that can be added to the JSpinner itself. Typically, this listener will call replaceEditor when the "editor" property changes, since it's the `SpinnerUI's` responsibility to add the editor to the JSpinner (and remove the old one). This method is called by `installListeners`.
    Returns:
      A PropertyChangeListener for the JSpinner itself
    See Also:
      - `installListeners()`

  - ### createPreviousButton

    protected Component createPreviousButton()
    Creates a decrement button, i.e. component that replaces the spinner value with the object returned by `spinner.getPreviousValue`. By default the `previousButton` is a `JButton`. If the decrement button is not needed this method should return `null`.
    Returns:
      a component that will replace the spinner's value with the previous value in the sequence, or `null`
    See Also:
      - `installUI(javax.swing.JComponent)`
      - `createNextButton()`
      - `installPreviousButtonListeners(java.awt.Component)`

  - ### createNextButton

    protected Component createNextButton()
    Creates an increment button, i.e. component that replaces the spinner value with the object returned by `spinner.getNextValue`. By default the `nextButton` is a `JButton`. If the increment button is not needed this method should return `null`.
    Returns:
      a component that will replace the spinner's value with the next value in the sequence, or `null`
    See Also:
      - `installUI(javax.swing.JComponent)`
      - `createPreviousButton()`
      - `installNextButtonListeners(java.awt.Component)`

  - ### createEditor

    protected JComponent createEditor()
    This method is called by installUI to get the editor component of the `JSpinner`. By default it just returns `JSpinner.getEditor()`. Subclasses can override `createEditor` to return a component that contains the spinner's editor or null, if they're going to handle adding the editor to the `JSpinner` in an `installUI` override.

    Typically this method would be overridden to wrap the editor with a container with a custom border, since one can't assume that the editors border can be set directly.

    The `replaceEditor` method is called when the spinners editor is changed with `JSpinner.setEditor`. If you've overridden this method, then you'll probably want to override `replaceEditor` as well.

    Returns:
      the JSpinners editor JComponent, spinner.getEditor() by default
    See Also:
      - `installUI(javax.swing.JComponent)`
      - `replaceEditor(javax.swing.JComponent, javax.swing.JComponent)`
      - `JSpinner.getEditor()`

  - ### replaceEditor

    protected void replaceEditor(JComponent oldEditor, JComponent newEditor)
    Called by the `PropertyChangeListener` when the `JSpinner` editor property changes. It's the responsibility of this method to remove the old editor and add the new one. By default this operation is just:

         spinner.remove(oldEditor);
         spinner.add(newEditor, "Editor");

    The implementation of `replaceEditor` should be coordinated with the `createEditor` method.
    Parameters:
      `oldEditor` - an old instance of editor
      `newEditor` - a new instance of editor
    See Also:
      - `createEditor()`
      - `createPropertyChangeListener()`

  - ### installKeyboardActions

    protected void installKeyboardActions()
    Installs the keyboard Actions onto the JSpinner.
    Since:
      1.5

  - ### getBaseline

    public int getBaseline(JComponent c, int width, int height)
    Returns the baseline.
    Overrides:
      `getBaseline` in class `ComponentUI`
    Parameters:
      `c` - `JComponent` baseline is being requested for
      `width` - the width to get the baseline for
      `height` - the height to get the baseline for
    Returns:
      baseline or a value < 0 indicating there is no reasonable baseline
    Throws:
      `NullPointerException` - if `c` is `null`
      `IllegalArgumentException` - if width or height is < 0
    Since:
      1.6
    See Also:
      - `JComponent.getBaseline(int, int)`

  - ### getBaselineResizeBehavior

    public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c)
    Returns an enum indicating how the baseline of the component changes as the size changes.
    Overrides:
      `getBaselineResizeBehavior` in class `ComponentUI`
    Parameters:
      `c` - `JComponent` to return baseline resize behavior for
    Returns:
      an enum indicating how the baseline changes as the component size changes
    Throws:
      `NullPointerException` - if `c` is `null`
    Since:
      1.6
    See Also:
      - `JComponent.getBaseline(int, int)`