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 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package javax.swing.plaf;

import javax.accessibility.Accessible;

import javax.swing.*;

import javax.swing.plaf.ComponentUI;

import java.awt.*;

import java.awt.event.*;

import java.beans.PropertyChangeEvent;

import java.beans.PropertyChangeSupport;

import java.beans.PropertyChangeListener;

import java.io.Serializable;

/**

 * The base class for all {@link javax.swing.JLayer}'s UI delegates.

 * <p/>

 * {@link #paint(java.awt.Graphics, javax.swing.JComponent)} method performes the

 * painting of the {@code JLayer}

 * and {@link #eventDispatched(AWTEvent, JLayer)} method is notified

 * about any {@code AWTEvent}s which have been generated by a {@code JLayer}

 * or any of its subcomponents.

 * <p/>

 * The {@code LayerUI} differs from the UI delegates of the other components,

 * because it is LookAndFeel independent and is not updated by default when

 * the system LookAndFeel is changed.

 * <p/>

 * The subclasses of {@code LayerUI} can either be stateless and shareable

 * by multiple {@code JLayer}s or not shareable.

 *

 * @param <V> one of the super types of {@code JLayer}'s view component

 *

 * @see JLayer#setUI(LayerUI)

 * @see JLayer#setView(Component)

 * @see JLayer#getView()

 * @since 1.7

 *

 * @author Alexander Potochkin

 */

public class LayerUI<V extends Component>

        extends ComponentUI implements Serializable {

    private final PropertyChangeSupport propertyChangeSupport =

            new PropertyChangeSupport(this);

    /**

     * Paints the specified component.

     * Subclasses should override this method and use

     * the specified {@code Graphics} object to

     * render the content of the component.

     * <p/>

     * The default implementation paints the passed component as is.

     *

     * @param g the {@code Graphics} context in which to paint

     * @param c the component being painted

     */

    public void paint(Graphics g, JComponent c) {

        c.paint(g);

    }

    /**

     * Processes {@code AWTEvent}s for {@code JLayer}

     * and <b>all its descendants</b> to this {@code LayerUI} instance.

     * <p/>

     * To enable the {@code AWTEvent}s of a particular type,

     * you call {@link JLayer#setLayerEventMask}

     * in {@link #installUI(javax.swing.JComponent)}

     * and set the layer event mask to {@code 0}

     * in {@link #uninstallUI(javax.swing.JComponent)} after that.

     * By default this  method calls the appropriate

     * {@code process<event type>Event}

     * method for the given class of event.

     * <p/>

     * <b>Note:</b> Events are processed only for displayable {@code JLayer}s.

     *

     * @param e the event to be dispatched

     * @param l the layer this LayerUI is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see Component#isDisplayable()

     * @see #processComponentEvent

     * @see #processFocusEvent

     * @see #processKeyEvent

     * @see #processMouseEvent

     * @see #processMouseMotionEvent

     * @see #processInputMethodEvent

     * @see #processHierarchyEvent

     * @see #processMouseWheelEvent

     */

    public void eventDispatched(AWTEvent e, JLayer<? extends V> l){

        if (e instanceof FocusEvent) {

            processFocusEvent((FocusEvent)e, l);

        } else if (e instanceof MouseEvent) {

            switch(e.getID()) {

              case MouseEvent.MOUSE_PRESSED:

              case MouseEvent.MOUSE_RELEASED:

              case MouseEvent.MOUSE_CLICKED:

              case MouseEvent.MOUSE_ENTERED:

              case MouseEvent.MOUSE_EXITED:

                  processMouseEvent((MouseEvent)e, l);

                  break;

              case MouseEvent.MOUSE_MOVED:

              case MouseEvent.MOUSE_DRAGGED:

                  processMouseMotionEvent((MouseEvent)e, l);

                  break;

              case MouseEvent.MOUSE_WHEEL:

                  processMouseWheelEvent((MouseWheelEvent)e, l);

                  break;

            }

        } else if (e instanceof KeyEvent) {

            processKeyEvent((KeyEvent)e, l);

        } else if (e instanceof ComponentEvent) {

            processComponentEvent((ComponentEvent)e, l);

        } else if (e instanceof InputMethodEvent) {

            processInputMethodEvent((InputMethodEvent)e, l);

        } else if (e instanceof HierarchyEvent) {

            switch (e.getID()) {

              case HierarchyEvent.HIERARCHY_CHANGED:

                  processHierarchyEvent((HierarchyEvent)e, l);

                  break;

              case HierarchyEvent.ANCESTOR_MOVED:

              case HierarchyEvent.ANCESTOR_RESIZED:

                  processHierarchyBoundsEvent((HierarchyEvent)e, l);

                  break;

            }

        }

    }

    /**

     * Processes component events occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless component events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Component events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.COMPONENT_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code ComponentEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processComponentEvent(ComponentEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes focus events occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless focus events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Focus events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.FOCUS_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code FocusEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processFocusEvent(FocusEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes key events occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless key events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Key events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.KEY_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code KeyEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processKeyEvent(KeyEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes mouse events occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless mouse events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Mouse events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.MOUSE_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code MouseEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processMouseEvent(MouseEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes mouse motion event occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless mouse motion events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Mouse motion events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.MOUSE_MOTION_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code MouseEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processMouseMotionEvent(MouseEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes mouse wheel event occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless mouse wheel events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Mouse wheel events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.MOUSE_WHEEL_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code MouseEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processMouseWheelEvent(MouseWheelEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes input event occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless input events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Input events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.INPUT_METHOD_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code InputMethodEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processInputMethodEvent(InputMethodEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes hierarchy event occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless hierarchy events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Hierarchy events are enabled in the overridden {@link #installUI} method

     * and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.HIERARCHY_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code HierarchyEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processHierarchyEvent(HierarchyEvent e, JLayer<? extends V> l) {

    }

    /**

     * Processes hierarchy bounds event occurring on the {@link JLayer}

     * or any of its subcomponents.

     * <p/>

     * This method is not called unless hierarchy bounds events are

     * enabled for the {@code JLayer} objects, this {@code LayerUI} is set to.

     * Hierarchy bounds events are enabled in the overridden {@link #installUI}

     * method and should be disabled in the {@link #uninstallUI} method after that.

     * <pre>

     * public void installUI(JComponent c) {

     *    super.installUI(c);

     *    JLayer l = (JLayer) c;

     *    l.setLayerEventMask(AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK);

     * }

     *

     * public void unistallUI(JComponent c) {

     *     super.uninstallUI(c);

     *     JLayer l = (JLayer) c;

     *     l.setLayerEventMask(0);

     * }

     * </pre>

     *

     * @param e the {@code HierarchyEvent} to be processed

     * @param l the layer this {@code LayerUI} instance is set to

     *

     * @see JLayer#setLayerEventMask(long)

     * @see #installUI(javax.swing.JComponent)

     * @see #uninstallUI(javax.swing.JComponent)

     */

    protected void processHierarchyBoundsEvent(HierarchyEvent e, JLayer<? extends V> l) {

    }

    /**

     * Invoked when {@link javax.swing.JLayer#updateUI()} is called

     * by the {@code JLayer} this {@code LayerUI} is set to.

     *

     * @param l the {@code JLayer} which UI is updated

     */

    public void updateUI(JLayer<? extends V> l){

    }

    /**

     * Configures the {@code JLayer} this {@code LayerUI} is set to.

     * The default implementation registers the passed {@code JLayer} component

     * as a {@code PropertyChangeListener} for the property changes of this {@code LayerUI}.

     *

     * @param c the {@code JLayer} component where this UI delegate is being installed

     */

    public void installUI(JComponent c) {

        addPropertyChangeListener((JLayer) c);

    }

    /**

     * Reverses the configuration which was previously set

     * in the {@link #installUI(JComponent)} method.

     * The default implementation unregisters the passed {@code JLayer} component

     * as a {@code PropertyChangeListener} for the property changes of this {@code LayerUI}.

     *

     * @param c the component from which this UI delegate is being removed.

     */

    public void uninstallUI(JComponent c) {

        removePropertyChangeListener((JLayer) c);

    }

    /**

     * Adds a PropertyChangeListener to the listener list. The listener is

     * registered for all bound properties of this class.

     * <p/>

     * If {@code listener} is {@code null},

     * no exception is thrown and no action is performed.

     *

     * @param listener the property change listener to be added

     * @see #removePropertyChangeListener

     * @see #getPropertyChangeListeners

     * @see #addPropertyChangeListener(String, java.beans.PropertyChangeListener)

     */

    public void addPropertyChangeListener(PropertyChangeListener listener) {

        propertyChangeSupport.addPropertyChangeListener(listener);

    }

    /**

     * Removes a PropertyChangeListener from the listener list. This method

     * should be used to remove PropertyChangeListeners that were registered

     * for all bound properties of this class.

     * <p/>

     * If {@code listener} is {@code null},

     * no exception is thrown and no action is performed.

     *

     * @param listener the PropertyChangeListener to be removed

     * @see #addPropertyChangeListener

     * @see #getPropertyChangeListeners

     * @see #removePropertyChangeListener(String, PropertyChangeListener)

     */