| /* |
| * Copyright (c) 1997, 2005, 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.JComponent; |
| import javax.swing.SwingUtilities; |
| import javax.accessibility.Accessible; |
| |
| import java.awt.Component; |
| import java.awt.Container; |
| import java.awt.Dimension; |
| import java.awt.Graphics; |
| import java.awt.Insets; |
| |
| |
| /** |
| * The base class for all UI delegate objects in the Swing pluggable |
| * look and feel architecture. The UI delegate object for a Swing |
| * component is responsible for implementing the aspects of the |
| * component that depend on the look and feel. |
| * The <code>JComponent</code> class |
| * invokes methods from this class in order to delegate operations |
| * (painting, layout calculations, etc.) that may vary depending on the |
| * look and feel installed. <b>Client programs should not invoke methods |
| * on this class directly.</b> |
| * |
| * @see javax.swing.JComponent |
| * @see javax.swing.UIManager |
| * |
| */ |
| public abstract class ComponentUI { |
| /** |
| * Sole constructor. (For invocation by subclass constructors, |
| * typically implicit.) |
| */ |
| public ComponentUI() { |
| } |
| |
| /** |
| * Configures the specified component appropriately for the look and feel. |
| * This method is invoked when the <code>ComponentUI</code> 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: |
| * <ol> |
| * <li>Install default property values for color, fonts, borders, |
| * icons, opacity, etc. on the component. Whenever possible, |
| * property values initialized by the client program should <i>not</i> |
| * be overridden. |
| * <li>Install a <code>LayoutManager</code> on the component if necessary. |
| * <li>Create/add any required sub-components to the component. |
| * <li>Create/install event listeners on the component. |
| * <li>Create/install a <code>PropertyChangeListener</code> on the component in order |
| * to detect and respond to component property changes appropriately. |
| * <li>Install keyboard UI (mnemonics, traversal, etc.) on the component. |
| * <li>Initialize any appropriate instance data. |
| * </ol> |
| * @param c the component where this UI delegate is being installed |
| * |
| * @see #uninstallUI |
| * @see javax.swing.JComponent#setUI |
| * @see javax.swing.JComponent#updateUI |
| */ |
| public void installUI(JComponent c) { |
| } |
| |
| /** |
| * Reverses configuration which was done on the specified component during |
| * <code>installUI</code>. This method is invoked when this |
| * <code>UIComponent</code> instance is being removed as the UI delegate |
| * for the specified component. This method should undo the |
| * configuration performed in <code>installUI</code>, being careful to |
| * leave the <code>JComponent</code> instance in a clean state (no |
| * extraneous listeners, look-and-feel-specific property objects, etc.). |
| * This should include the following: |
| * <ol> |
| * <li>Remove any UI-set borders from the component. |
| * <li>Remove any UI-set layout managers on the component. |
| * <li>Remove any UI-added sub-components from the component. |
| * <li>Remove any UI-added event/property listeners from the component. |
| * <li>Remove any UI-installed keyboard UI from the component. |
| * <li>Nullify any allocated instance data objects to allow for GC. |
| * </ol> |
| * @param 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 #installUI |
| * @see javax.swing.JComponent#updateUI |
| */ |
| public void uninstallUI(JComponent c) { |
| } |
| |
| /** |
| * Paints the specified component appropriately for the look and feel. |
| * This method is invoked from the <code>ComponentUI.update</code> method when |
| * the specified component is being painted. Subclasses should override |
| * this method and use the specified <code>Graphics</code> object to |
| * render the content of the component. |
| * |
| * @param g the <code>Graphics</code> context in which to paint |
| * @param c the component being painted; |
| * this argument is often ignored, |
| * but might be used if the UI object is stateless |
| * and shared by multiple components |
| * |
| * @see #update |
| */ |
| public void paint(Graphics g, JComponent c) { |
| } |
| |
| /** |
| * Notifies this UI delegate that it is time to paint the specified |
| * component. This method is invoked by <code>JComponent</code> |
| * when the specified component is being painted. |
| * |
| * <p>By default this method fills the specified component with |
| * its background color if its {@code opaque} property is {@code true}, |
| * and then immediately calls {@code paint}. In general this method need |
| * not be overridden by subclasses; all look-and-feel rendering code should |
| * reside in the {@code paint} method. |
| * |
| * @param g the <code>Graphics</code> context in which to paint |
| * @param c the component being painted; |
| * this argument is often ignored, |
| * but might be used if the UI object is stateless |
| * and shared by multiple components |
| * |
| * @see #paint |
| * @see javax.swing.JComponent#paintComponent |
| */ |
| public void update(Graphics g, JComponent c) { |
| if (c.isOpaque()) { |
| g.setColor(c.getBackground()); |
| g.fillRect(0, 0, c.getWidth(),c.getHeight()); |
| } |
| paint(g, c); |
| } |
| |
| /** |
| * Returns the specified component's preferred size appropriate for |
| * the look and feel. If <code>null</code> is returned, the preferred |
| * 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 returns <code>null</code>. |
| * |
| * @param c the component whose preferred size is being queried; |
| * this argument is often ignored, |
| * but might be used if the UI object is stateless |
| * and shared by multiple components |
| * |
| * @see javax.swing.JComponent#getPreferredSize |
| * @see java.awt.LayoutManager#preferredLayoutSize |
| */ |
| public Dimension getPreferredSize(JComponent c) { |
| return null; |
| } |
| |
| /** |
| * Returns the specified component's minimum size appropriate for |
| * the look and feel. If <code>null</code> 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 <code>getPreferredSize</code> and returns that value. |
| * |
| * @param 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 |
| * |
| * @return a <code>Dimension</code> object or <code>null</code> |
| * |
| * @see javax.swing.JComponent#getMinimumSize |
| * @see java.awt.LayoutManager#minimumLayoutSize |
| * @see #getPreferredSize |
| */ |
| public Dimension getMinimumSize(JComponent c) { |
| return getPreferredSize(c); |
| } |
| |
| /** |
| * Returns the specified component's maximum size appropriate for |
| * the look and feel. If <code>null</code> 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 <code>getPreferredSize</code> and returns that value. |
| * |
| * @param 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 |
| * @return a <code>Dimension</code> object or <code>null</code> |
| * |
| * @see javax.swing.JComponent#getMaximumSize |
| * @see java.awt.LayoutManager2#maximumLayoutSize |
| */ |
| public Dimension getMaximumSize(JComponent c) { |
| return getPreferredSize(c); |
| } |
| |
| /** |
| * Returns <code>true</code> if the specified <i>x,y</i> location is |
| * contained within the look and feel's defined shape of the specified |
| * component. <code>x</code> and <code>y</code> are defined to be relative |
| * to the coordinate system of the specified component. Although |
| * a component's <code>bounds</code> is constrained to a rectangle, |
| * this method provides the means for defining a non-rectangular |
| * shape within those bounds for the purpose of hit detection. |
| * |
| * @param c the component where the <i>x,y</i> location is being queried; |
| * this argument is often ignored, |
| * but might be used if the UI object is stateless |
| * and shared by multiple components |
| * @param x the <i>x</i> coordinate of the point |
| * @param y the <i>y</i> coordinate of the point |
| * |
| * @see javax.swing.JComponent#contains |
| * @see java.awt.Component#contains |
| */ |
| public boolean contains(JComponent c, int x, int y) { |
| return c.inside(x, y); |
| } |
| |
| /** |
| * Returns an instance of the UI delegate for the specified component. |
| * Each subclass must provide its own static <code>createUI</code> |
| * method that returns an instance of that UI delegate subclass. |
| * If the UI delegate subclass is stateless, it may return an instance |
| * that is shared by multiple components. If the UI delegate is |
| * stateful, then it should return a new instance per component. |
| * The default implementation of this method throws an error, as it |
| * should never be invoked. |
| */ |
| public static ComponentUI createUI(JComponent c) { |
| throw new Error("ComponentUI.createUI not implemented."); |
| } |
| |
| /** |
| * Returns the baseline. The baseline is measured from the top of |
| * the component. This method is primarily meant for |
| * <code>LayoutManager</code>s to align components along their |
| * baseline. A return value less than 0 indicates this component |
| * does not have a reasonable baseline and that |
| * <code>LayoutManager</code>s should not align this component on |
| * its baseline. |
| * <p> |
| * This method returns -1. Subclasses that have a meaningful baseline |
| * should override appropriately. |
| * |
| * @param c <code>JComponent</code> baseline is being requested for |
| * @param width the width to get the baseline for |
| * @param height the height to get the baseline for |
| * @throws NullPointerException if <code>c</code> is <code>null</code> |
| * @throws IllegalArgumentException if width or height is < 0 |
| * @return baseline or a value < 0 indicating there is no reasonable |
| * baseline |
| * @see javax.swing.JComponent#getBaseline(int,int) |
| * @since 1.6 |
| */ |
| public int getBaseline(JComponent c, int width, int height) { |
| if (c == null) { |
| throw new NullPointerException("Component must be non-null"); |
| } |
| if (width < 0 || height < 0) { |
| throw new IllegalArgumentException( |
| "Width and height must be >= 0"); |
| } |
| return -1; |
| } |
| |
| /** |
| * Returns an enum indicating how the baseline of he component |
| * changes as the size changes. This method is primarily meant for |
| * layout managers and GUI builders. |
| * <p> |
| * This method returns <code>BaselineResizeBehavior.OTHER</code>. |
| * Subclasses that support a baseline should override appropriately. |
| * |
| * @param c <code>JComponent</code> to return baseline resize behavior for |
| * @return an enum indicating how the baseline changes as the component |
| * size changes |
| * @throws NullPointerException if <code>c</code> is <code>null</code> |
| * @see javax.swing.JComponent#getBaseline(int, int) |
| * @since 1.6 |
| */ |
| public Component.BaselineResizeBehavior getBaselineResizeBehavior( |
| JComponent c) { |
| if (c == null) { |
| throw new NullPointerException("Component must be non-null"); |
| } |
| return Component.BaselineResizeBehavior.OTHER; |
| } |
| |
| /** |
| * Returns the number of accessible children in the object. If all |
| * of the children of this object implement <code>Accessible</code>, |
| * this |
| * method should return the number of children of this object. |
| * UIs might wish to override this if they present areas on the |
| * screen that can be viewed as components, but actual components |
| * are not used for presenting those areas. |
| * |
| * Note: As of v1.3, it is recommended that developers call |
| * <code>Component.AccessibleAWTComponent.getAccessibleChildrenCount()</code> instead |
| * of this method. |
| * |
| * @see #getAccessibleChild |
| * @return the number of accessible children in the object |
| */ |
| public int getAccessibleChildrenCount(JComponent c) { |
| return SwingUtilities.getAccessibleChildrenCount(c); |
| } |
| |
| /** |
| * Returns the <code>i</code>th <code>Accessible</code> child of the object. |
| * UIs might need to override this if they present areas on the |
| * screen that can be viewed as components, but actual components |
| * are not used for presenting those areas. |
| * |
| * <p> |
| * |
| * Note: As of v1.3, it is recommended that developers call |
| * <code>Component.AccessibleAWTComponent.getAccessibleChild()</code> instead of |
| * this method. |
| * |
| * @see #getAccessibleChildrenCount |
| * @param i zero-based index of child |
| * @return the <code>i</code>th <code>Accessible</code> child of the object |
| */ |
| public Accessible getAccessibleChild(JComponent c, int i) { |
| return SwingUtilities.getAccessibleChild(c, i); |
| } |
| } |
