6822696: Integrating JXLayer component to Swing library

Reviewed-by: peterz, art

src/share/classes/javax/swing/plaf/LayerUI.java

+/*
+ * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
+ * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
+ */
+
+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.
+     *
+     * @param g the {@code Graphics} context in which to paint;
+     * @param c the component being painted;
+     * it can be safely cast to the {@code JLayer<V>}
+     */
+    @Override
+    public void paint(Graphics g, JComponent c) {
+        c.paint(g);
+    }
+
+    /**
+     * Dispatches {@code AWTEvent}s for {@code JLayer}
+     * and <b>all it subcomponents</b> to this {@code LayerUI} instance.
+     * <p>
+     * To enable the {@code AWTEvent} of the particular type,
+     * you call {@link javax.swing.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
+     *
+     * @param e the event to be dispatched
+     * @param l the layer this LayerUI is set to
+     *
+     * @see JLayer#setLayerEventMask(long)
+     * @see javax.swing.JLayer#getLayerEventMask()
+     */
+    public void eventDispatched(AWTEvent 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 {@code LayerUI}
+     * as a property change listener for the passed {@code JLayer} component.
+     *
+     * @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 property change listener
+     * for the passed JLayer component.
+     *
+     * @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)
+     */
+    public void removePropertyChangeListener(PropertyChangeListener listener) {
+        propertyChangeSupport.removePropertyChangeListener(listener);
+    }
+
+    /**
+     * Returns an array of all the property change listeners
+     * registered on this component.
+     *
+     * @return all of this ui's {@code PropertyChangeListener}s
+     *         or an empty array if no property change
+     *         listeners are currently registered
+     * @see #addPropertyChangeListener
+     * @see #removePropertyChangeListener
+     * @see #getPropertyChangeListeners(String)
+     */
+    public PropertyChangeListener[] getPropertyChangeListeners() {
+        return propertyChangeSupport.getPropertyChangeListeners();
+    }
+
+    /**
+     * Adds a PropertyChangeListener to the listener list for a specific
+     * property.
+     * <p/>
+     * If {@code propertyName} or {@code listener} is {@code null},
+     * no exception is thrown and no action is taken.
+     *
+     * @param propertyName one of the property names listed above
+     * @param listener     the property change listener to be added
+     * @see #removePropertyChangeListener(String, PropertyChangeListener)
+     * @see #getPropertyChangeListeners(String)
+     * @see #addPropertyChangeListener(String, PropertyChangeListener)
+     */
+    public void addPropertyChangeListener(String propertyName,
+                                          PropertyChangeListener listener) {
+        propertyChangeSupport.addPropertyChangeListener(propertyName, listener);
+    }
+
+    /**
+     * Removes a {@code PropertyChangeListener} from the listener
+     * list for a specific property. This method should be used to remove
+     * {@code PropertyChangeListener}s
+     * that were registered for a specific bound property.
+     * <p/>
+     * If {@code propertyName} or {@code listener} is {@code null},
+     * no exception is thrown and no action is taken.
+     *
+     * @param propertyName a valid property name
+     * @param listener     the PropertyChangeListener to be removed
+     * @see #addPropertyChangeListener(String, PropertyChangeListener)
+     * @see #getPropertyChangeListeners(String)
+     * @see #removePropertyChangeListener(PropertyChangeListener)
+     */
+    public void removePropertyChangeListener(String propertyName,
+                                             PropertyChangeListener listener) {
+        propertyChangeSupport.removePropertyChangeListener(propertyName, listener);
+    }
+
+    /**
+     * Returns an array of all the listeners which have been associated
+     * with the named property.
+     *
+     * @return all of the {@code PropertyChangeListener}s associated with
+     *         the named property; if no such listeners have been added or
+     *         if {@code propertyName} is {@code null}, an empty
+     *         array is returned
+     * @see #addPropertyChangeListener(String, PropertyChangeListener)
+     * @see #removePropertyChangeListener(String, PropertyChangeListener)
+     * @see #getPropertyChangeListeners
+     */
+    public PropertyChangeListener[] getPropertyChangeListeners(String propertyName) {
+        return propertyChangeSupport.getPropertyChangeListeners(propertyName);
+    }
+
+    /**
+     * Support for reporting bound property changes for Object properties.
+     * This method can be called when a bound property has changed and it will
+     * send the appropriate PropertyChangeEvent to any registered
+     * PropertyChangeListeners.
+     *
+     * @param propertyName the property whose value has changed
+     * @param oldValue     the property's previous value
+     * @param newValue     the property's new value
+     */
+    protected void firePropertyChange(String propertyName,
+                                      Object oldValue, Object newValue) {
+        propertyChangeSupport.firePropertyChange(propertyName, oldValue, newValue);
+    }
+
+    /**
+     * Notifies the {@code LayerUI} when any of its property are changed
+     * and enables updating every {@code JLayer} this {@code LayerUI} instance is set to.
+     *
+     * @param evt the PropertyChangeEvent generated by this {@code LayerUI}
+     * @param l the {@code JLayer} this LayerUI is set to
+     */
+    public void applyPropertyChange(PropertyChangeEvent evt, JLayer<? extends V> l) {
+    }
+
+    /**
+     * Returns the preferred size of the viewport for a view component.
+     *
+     * @return the preferred size of the viewport for a view component
+     * @see Scrollable#getPreferredScrollableViewportSize()
+     */
+    public Dimension getPreferredScrollableViewportSize(JLayer<? extends V> l) {
+        if (l.getView() instanceof Scrollable) {
+            return ((Scrollable)l.getView()).getPreferredScrollableViewportSize();
+        }
+        return l.getPreferredSize();
+    }
+
+    /**
+     * Returns a scroll increment, which is required for components
+     * that display logical rows or columns in order to completely expose
+     * one block of rows or columns, depending on the value of orientation.
+     *
+     * @return the "block" increment for scrolling in the specified direction
+     * @see Scrollable#getScrollableBlockIncrement(Rectangle, int, int)
+     */
+     public int getScrollableBlockIncrement(JLayer<? extends V> l,
+                                           Rectangle visibleRect,
+                                           int orientation, int direction) {
+        if (l.getView() instanceof Scrollable) {
+            return ((Scrollable)l.getView()).getScrollableBlockIncrement(
+                    visibleRect,orientation, direction);
+        }
+        return (orientation == SwingConstants.VERTICAL) ? visibleRect.height :
+            visibleRect.width;
+    }
+
+    /**
+     * Returns {@code false} to indicate that the height of the viewport does not
+     * determine the height of the layer, unless the preferred height
+     * of the layer is smaller than the height of the viewport.
+     *
+     * @return whether the layer should track the height of the viewport
+     * @see Scrollable#getScrollableTracksViewportHeight()
+     */
+    public boolean getScrollableTracksViewportHeight(JLayer<? extends V> l) {
+        if (l.getView() instanceof Scrollable) {
+            return ((Scrollable)l.getView()).getScrollableTracksViewportHeight();
+        }
+        if (l.getParent() instanceof JViewport) {
+            return (((JViewport)l.getParent()).getHeight() > l.getPreferredSize().height);
+        }
+        return false;
+    }
+
+    /**
+     * Returns {@code false} to indicate that the width of the viewport does not
+     * determine the width of the layer, unless the preferred width
+     * of the layer is smaller than the width of the viewport.
+     *
+     * @return whether the layer should track the width of the viewport
+     * @see Scrollable
+     * @see LayerUI#getScrollableTracksViewportWidth(JLayer)
+     */
+    public boolean getScrollableTracksViewportWidth(JLayer<? extends V> l) {
+        if (l.getView() instanceof Scrollable) {
+            return ((Scrollable)l.getView()).getScrollableTracksViewportWidth();
+        }
+        if (l.getParent() instanceof JViewport) {
+            return (((JViewport)l.getParent()).getWidth() > l.getPreferredSize().width);
+        }
+        return false;
+    }
+
+    /**
+     * Returns a scroll increment, which is required for components
+     * that display logical rows or columns in order to completely expose
+     * one new row or column, depending on the value of orientation.
+     * Ideally, components should handle a partially exposed row or column
+     * by returning the distance required to completely expose the item.
+     * <p>
+     * Scrolling containers, like JScrollPane, will use this method
+     * each time the user requests a unit scroll.
+     *
+     * @return The "unit" increment for scrolling in the specified direction.
+     *         This value should always be positive.
+     * @see Scrollable#getScrollableUnitIncrement(Rectangle, int, int)
+     */
+    public int getScrollableUnitIncrement(JLayer<? extends V> l,
+                                          Rectangle visibleRect,
+                                          int orientation, int direction) {
+        if (l.getView() instanceof Scrollable) {
+            return ((Scrollable)l.getView()).getScrollableUnitIncrement(
+                    visibleRect, orientation, direction);
+        }
+        return 1;
+    }
+
+    /**
+     * If the {@code JLayer}'s view component is not {@code null},
+     * this calls the view's {@code getBaseline()} method.
+     * Otherwise, the default implementation is called.
+     *
+     * @param c {@code JLayer} to return baseline resize behavior for
+     * @param width the width to get the baseline for
+     * @param height the height to get the baseline for
+     * @return baseline or a value &lt; 0 indicating there is no reasonable
+     *                  baseline
+     */
+    public int getBaseline(JComponent c, int width, int height) {
+        JLayer l = (JLayer) c;
+        if (l.getView() != null) {
+            return l.getView().getBaseline(width, height);
+        }
+        return super.getBaseline(c, width, height);
+     }
+
+    /**
+     * If the {@code JLayer}'s view component is not {@code null},
+     * this calls the view's {@code getBaselineResizeBehavior()} method.
+     * Otherwise, the default implementation is called.
+     *
+     * @param c {@code JLayer} to return baseline resize behavior for
+     * @return an enum indicating how the baseline changes as the component
+     *         size changes
+     */
+    public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c) {
+        JLayer l = (JLayer) c;
+        if (l.getView() != null) {
+            return l.getView().getBaselineResizeBehavior();
+        }
+        return super.getBaselineResizeBehavior(c);
+    }
+}
\ No newline at end of file

test/javax/swing/JLayer/SerializationTest/SerializationTest.java

+/*
+ * @test
+ * @summary Makes sure that JLayer is synchronizable
+ * @author Alexander Potochkin
+ * @run main SerializationTest
+ */
+
+import javax.swing.*;
+import javax.swing.plaf.LayerUI;
+import java.io.ByteArrayInputStream;
+import java.io.ObjectOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ByteArrayOutputStream;
+
+public class SerializationTest {
+
+    public static void main(String[] args) throws Exception {
+        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+        ObjectOutputStream outputStream = new ObjectOutputStream(byteArrayOutputStream);
+
+        JLayer<JButton> layer = new JLayer<JButton>(new JButton("Hello"));
+
+        layer.setUI(new TestLayerUI<JButton>());
+
+        outputStream.writeObject(layer);
+        outputStream.flush();
+
+        ByteArrayInputStream byteArrayInputStream =
+                        new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
+        ObjectInputStream inputStream = new ObjectInputStream(byteArrayInputStream);
+
+        JLayer newLayer = (JLayer) inputStream.readObject();
+
+        if (newLayer.getLayout() == null) {
+            throw new RuntimeException("JLayer's layout is null");
+        }
+        if (newLayer.getGlassPane() == null) {
+            throw new RuntimeException("JLayer's glassPane is null");
+        }
+        if (newLayer.getUI().getClass() != layer.getUI().getClass()) {
+            throw new RuntimeException("Different UIs");
+        }
+        if (newLayer.getView().getClass() != layer.getView().getClass()) {
+            throw new RuntimeException("Different Views");
+        }
+    }
+
+    static class TestLayerUI<V extends JComponent> extends LayerUI<V> {
+        public String toString() {
+            return "TestLayerUI";
+        }
+    }
+}
\ No newline at end of file