Java tutorial
/* * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * 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 * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing.plaf; import javax.swing.*; 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 performs 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 */ @SuppressWarnings("serial") // Same-version serialization only 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} {@code 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 uninstallUI(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 uninstallUI(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 uninstallUI(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 uninstallUI(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 uninstallUI(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 uninstallUI(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 uninstallUI(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 uninstallUI(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 uninstallUI(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) */ 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. * * @param propertyName The name of the property being listened to * @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) { } /** * 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 < 0 indicating there is no reasonable * baseline */ public int getBaseline(JComponent c, int width, int height) { @SuppressWarnings("unchecked") 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 returns the result of 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) { @SuppressWarnings("unchecked") JLayer<?> l = (JLayer) c; if (l.getView() != null) { return l.getView().getBaselineResizeBehavior(); } return super.getBaselineResizeBehavior(c); } /** * Causes the passed instance of {@code JLayer} to lay out its components. * * @param l the {@code JLayer} component where this UI delegate is being installed */ public void doLayout(JLayer<? extends V> l) { Component view = l.getView(); if (view != null) { view.setBounds(0, 0, l.getWidth(), l.getHeight()); } Component glassPane = l.getGlassPane(); if (glassPane != null) { glassPane.setBounds(0, 0, l.getWidth(), l.getHeight()); } } /** * If the {@code JLayer}'s view component is not {@code null}, * this returns the result of the view's {@code getPreferredSize()} method. * Otherwise, the default implementation is used. * * @param c {@code JLayer} to return preferred size for * @return preferred size for the passed {@code JLayer} */ public Dimension getPreferredSize(JComponent c) { @SuppressWarnings("unchecked") JLayer<?> l = (JLayer) c; Component view = l.getView(); if (view != null) { return view.getPreferredSize(); } return super.getPreferredSize(c); } /** * If the {@code JLayer}'s view component is not {@code null}, * this returns the result of the view's {@code getMinimalSize()} method. * Otherwise, the default implementation is used. * * @param c {@code JLayer} to return preferred size for * @return minimal size for the passed {@code JLayer} */ public Dimension getMinimumSize(JComponent c) { @SuppressWarnings("unchecked") JLayer<?> l = (JLayer) c; Component view = l.getView(); if (view != null) { return view.getMinimumSize(); } return super.getMinimumSize(c); } /** * If the {@code JLayer}'s view component is not {@code null}, * this returns the result of the view's {@code getMaximumSize()} method. * Otherwise, the default implementation is used. * * @param c {@code JLayer} to return preferred size for * @return maximum size for the passed {@code JLayer} */ public Dimension getMaximumSize(JComponent c) { @SuppressWarnings("unchecked") JLayer<?> l = (JLayer) c; Component view = l.getView(); if (view != null) { return view.getMaximumSize(); } return super.getMaximumSize(c); } /** * Paints the specified region in the {@code JLayer} this {@code LayerUI} is set to, immediately. * <p> * This method is to be overridden when the dirty region needs to be changed. * The default implementation delegates its functionality to {@link JComponent#paintImmediately(int, int, int, int)}. * * @param x the x value of the region to be painted * @param y the y value of the region to be painted * @param width the width of the region to be painted * @param height the height of the region to be painted * @param l a {@code JLayer} component * @see JComponent#paintImmediately(int, int, int, int) */ public void paintImmediately(int x, int y, int width, int height, JLayer<? extends V> l) { l.paintImmediately(x, y, width, height); } /** * Delegates its functionality to the default implementation of the {@code JLayer.imageUpdate} method * which is inherited from {@code JLayer}'s base classes. * <p> * This method is to be overridden instead of {@code JLayer.imageUpdate}. * <p> * <b>Note:</b> This method is usually called <b>not</b> on the Event Dispatching Thread. * * @param img the image being observed * @param infoflags see imageUpdate for information * @param x the x coordinate * @param y the y coordinate * @param w the width * @param h the height * @param l a {@code JLayer} component * @return false if the infoflags indicate that the image is completely loaded; true otherwise */ public boolean imageUpdate(Image img, int infoflags, int x, int y, int w, int h, JLayer<? extends V> l) { return l.imageUpdate(img, infoflags, x, y, w, h); } }