Java tutorial
/* * Copyright (c) 1997, 2019, 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.basic; import sun.swing.SwingUtilities2; import sun.swing.DefaultLookup; import sun.swing.UIAction; import sun.awt.AppContext; import javax.swing.*; import javax.swing.plaf.*; import javax.swing.text.View; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.InputEvent; import java.awt.event.KeyEvent; import java.awt.Component; import java.awt.Container; import java.awt.Dimension; import java.awt.Rectangle; import java.awt.Insets; import java.awt.Color; import java.awt.Graphics; import java.awt.Font; import java.awt.FontMetrics; import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; /** * A Windows L&F implementation of LabelUI. This implementation * is completely static, i.e. there's only one UIView implementation * that's shared by all JLabel objects. * * @author Hans Muller */ public class BasicLabelUI extends LabelUI implements PropertyChangeListener { /** * The default <code>BasicLabelUI</code> instance. This field might * not be used. To change the default instance use a subclass which * overrides the <code>createUI</code> method, and place that class * name in defaults table under the key "LabelUI". */ protected static BasicLabelUI labelUI = new BasicLabelUI(); private static final Object BASIC_LABEL_UI_KEY = new Object(); private Rectangle paintIconR = new Rectangle(); private Rectangle paintTextR = new Rectangle(); static void loadActionMap(LazyActionMap map) { map.put(new Actions(Actions.PRESS)); map.put(new Actions(Actions.RELEASE)); } /** * Forwards the call to SwingUtilities.layoutCompoundLabel(). * This method is here so that a subclass could do Label specific * layout and to shorten the method name a little. * * @param label an instance of {@code JLabel} * @param fontMetrics a font metrics * @param text a text * @param icon an icon * @param viewR a bounding rectangle to lay out label * @param iconR a bounding rectangle to lay out icon * @param textR a bounding rectangle to lay out text * @return a possibly clipped version of the compound labels string * @see SwingUtilities#layoutCompoundLabel */ protected String layoutCL(JLabel label, FontMetrics fontMetrics, String text, Icon icon, Rectangle viewR, Rectangle iconR, Rectangle textR) { return SwingUtilities.layoutCompoundLabel((JComponent) label, fontMetrics, text, icon, label.getVerticalAlignment(), label.getHorizontalAlignment(), label.getVerticalTextPosition(), label.getHorizontalTextPosition(), viewR, iconR, textR, label.getIconTextGap()); } /** * Paint clippedText at textX, textY with the labels foreground color. * * @param l an instance of {@code JLabel} * @param g an instance of {@code Graphics} * @param s a text * @param textX an X coordinate * @param textY an Y coordinate * @see #paint * @see #paintDisabledText */ protected void paintEnabledText(JLabel l, Graphics g, String s, int textX, int textY) { int mnemIndex = l.getDisplayedMnemonicIndex(); g.setColor(l.getForeground()); SwingUtilities2.drawStringUnderlineCharAt(l, g, s, mnemIndex, textX, textY); } /** * Paint clippedText at textX, textY with background.lighter() and then * shifted down and to the right by one pixel with background.darker(). * * @param l an instance of {@code JLabel} * @param g an instance of {@code Graphics} * @param s a text * @param textX an X coordinate * @param textY an Y coordinate * @see #paint * @see #paintEnabledText */ protected void paintDisabledText(JLabel l, Graphics g, String s, int textX, int textY) { int accChar = l.getDisplayedMnemonicIndex(); Color background = l.getBackground(); g.setColor(background.brighter()); SwingUtilities2.drawStringUnderlineCharAt(l, g, s, accChar, textX + 1, textY + 1); g.setColor(background.darker()); SwingUtilities2.drawStringUnderlineCharAt(l, g, s, accChar, textX, textY); } /** * Paints the label text with the foreground color, if the label is opaque * then paints the entire background with the background color. The Label * text is drawn by {@link #paintEnabledText} or {@link #paintDisabledText}. * The locations of the label parts are computed by {@link #layoutCL}. * * @see #paintEnabledText * @see #paintDisabledText * @see #layoutCL */ public void paint(Graphics g, JComponent c) { JLabel label = (JLabel) c; String text = label.getText(); Icon icon = (label.isEnabled()) ? label.getIcon() : label.getDisabledIcon(); if ((icon == null) && (text == null)) { return; } FontMetrics fm = SwingUtilities2.getFontMetrics(label, g); String clippedText = layout(label, fm, c.getWidth(), c.getHeight()); if (icon != null) { icon.paintIcon(c, g, paintIconR.x, paintIconR.y); } if (text != null) { View v = (View) c.getClientProperty(BasicHTML.propertyKey); if (v != null) { v.paint(g, paintTextR); } else { int textX = paintTextR.x; int textY = paintTextR.y + fm.getAscent(); if (label.isEnabled()) { paintEnabledText(label, g, clippedText, textX, textY); } else { paintDisabledText(label, g, clippedText, textX, textY); } } } } private String layout(JLabel label, FontMetrics fm, int width, int height) { Insets insets = label.getInsets(null); String text = label.getText(); Icon icon = (label.isEnabled()) ? label.getIcon() : label.getDisabledIcon(); Rectangle paintViewR = new Rectangle(); paintViewR.x = insets.left; paintViewR.y = insets.top; paintViewR.width = width - (insets.left + insets.right); paintViewR.height = height - (insets.top + insets.bottom); paintIconR.x = paintIconR.y = paintIconR.width = paintIconR.height = 0; paintTextR.x = paintTextR.y = paintTextR.width = paintTextR.height = 0; return layoutCL(label, fm, text, icon, paintViewR, paintIconR, paintTextR); } public Dimension getPreferredSize(JComponent c) { JLabel label = (JLabel) c; String text = label.getText(); Icon icon = (label.isEnabled()) ? label.getIcon() : label.getDisabledIcon(); Insets insets = label.getInsets(null); Font font = label.getFont(); int dx = insets.left + insets.right; int dy = insets.top + insets.bottom; if ((icon == null) && ((text == null) || ((text != null) && (font == null)))) { return new Dimension(dx, dy); } else if ((text == null) || ((icon != null) && (font == null))) { return new Dimension(icon.getIconWidth() + dx, icon.getIconHeight() + dy); } else { FontMetrics fm = label.getFontMetrics(font); Rectangle iconR = new Rectangle(); Rectangle textR = new Rectangle(); Rectangle viewR = new Rectangle(); iconR.x = iconR.y = iconR.width = iconR.height = 0; textR.x = textR.y = textR.width = textR.height = 0; viewR.x = dx; viewR.y = dy; viewR.width = viewR.height = Short.MAX_VALUE; layoutCL(label, fm, text, icon, viewR, iconR, textR); int x1 = Math.min(iconR.x, textR.x); int x2 = Math.max(iconR.x + iconR.width, textR.x + textR.width); int y1 = Math.min(iconR.y, textR.y); int y2 = Math.max(iconR.y + iconR.height, textR.y + textR.height); Dimension rv = new Dimension(x2 - x1, y2 - y1); rv.width += dx; rv.height += dy; return rv; } } /** * @return getPreferredSize(c) */ public Dimension getMinimumSize(JComponent c) { Dimension d = getPreferredSize(c); View v = (View) c.getClientProperty(BasicHTML.propertyKey); if (v != null) { d.width -= v.getPreferredSpan(View.X_AXIS) - v.getMinimumSpan(View.X_AXIS); } return d; } /** * @return getPreferredSize(c) */ public Dimension getMaximumSize(JComponent c) { Dimension d = getPreferredSize(c); View v = (View) c.getClientProperty(BasicHTML.propertyKey); if (v != null) { d.width += v.getMaximumSpan(View.X_AXIS) - v.getPreferredSpan(View.X_AXIS); } return d; } /** * Returns the baseline. * * @throws NullPointerException {@inheritDoc} * @throws IllegalArgumentException {@inheritDoc} * @see javax.swing.JComponent#getBaseline(int, int) * @since 1.6 */ public int getBaseline(JComponent c, int width, int height) { super.getBaseline(c, width, height); JLabel label = (JLabel) c; String text = label.getText(); if (text == null || text.isEmpty() || label.getFont() == null) { return -1; } FontMetrics fm = label.getFontMetrics(label.getFont()); layout(label, fm, width, height); return BasicHTML.getBaseline(label, paintTextR.y, fm.getAscent(), paintTextR.width, paintTextR.height); } /** * Returns an enum indicating how the baseline of the component * changes as the size changes. * * @throws NullPointerException {@inheritDoc} * @see javax.swing.JComponent#getBaseline(int, int) * @since 1.6 */ public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c) { super.getBaselineResizeBehavior(c); if (c.getClientProperty(BasicHTML.propertyKey) != null) { return Component.BaselineResizeBehavior.OTHER; } switch (((JLabel) c).getVerticalAlignment()) { case JLabel.TOP: return Component.BaselineResizeBehavior.CONSTANT_ASCENT; case JLabel.BOTTOM: return Component.BaselineResizeBehavior.CONSTANT_DESCENT; case JLabel.CENTER: return Component.BaselineResizeBehavior.CENTER_OFFSET; } return Component.BaselineResizeBehavior.OTHER; } public void installUI(JComponent c) { installDefaults((JLabel) c); installComponents((JLabel) c); installListeners((JLabel) c); installKeyboardActions((JLabel) c); } public void uninstallUI(JComponent c) { uninstallDefaults((JLabel) c); uninstallComponents((JLabel) c); uninstallListeners((JLabel) c); uninstallKeyboardActions((JLabel) c); } /** * Installs default properties. * * @param c an instance of {@code JLabel} */ protected void installDefaults(JLabel c) { LookAndFeel.installColorsAndFont(c, "Label.background", "Label.foreground", "Label.font"); LookAndFeel.installProperty(c, "opaque", Boolean.FALSE); } /** * Registers listeners. * * @param c an instance of {@code JLabel} */ protected void installListeners(JLabel c) { c.addPropertyChangeListener(this); } /** * Registers components. * * @param c an instance of {@code JLabel} */ protected void installComponents(JLabel c) { BasicHTML.updateRenderer(c, c.getText()); c.setInheritsPopupMenu(true); } /** * Registers keyboard actions. * * @param l an instance of {@code JLabel} */ protected void installKeyboardActions(JLabel l) { int dka = l.getDisplayedMnemonic(); Component lf = l.getLabelFor(); if ((dka != 0) && (lf != null)) { LazyActionMap.installLazyActionMap(l, BasicLabelUI.class, "Label.actionMap"); InputMap inputMap = SwingUtilities.getUIInputMap(l, JComponent.WHEN_IN_FOCUSED_WINDOW); if (inputMap == null) { inputMap = new ComponentInputMapUIResource(l); SwingUtilities.replaceUIInputMap(l, JComponent.WHEN_IN_FOCUSED_WINDOW, inputMap); } inputMap.clear(); inputMap.put(KeyStroke.getKeyStroke(dka, BasicLookAndFeel.getFocusAcceleratorKeyMask(), false), "press"); inputMap.put( KeyStroke.getKeyStroke(dka, SwingUtilities2.setAltGraphMask(BasicLookAndFeel.getFocusAcceleratorKeyMask()), false), "press"); } else { InputMap inputMap = SwingUtilities.getUIInputMap(l, JComponent.WHEN_IN_FOCUSED_WINDOW); if (inputMap != null) { inputMap.clear(); } } } /** * Uninstalls default properties. * * @param c an instance of {@code JLabel} */ protected void uninstallDefaults(JLabel c) { } /** * Unregisters listeners. * * @param c an instance of {@code JLabel} */ protected void uninstallListeners(JLabel c) { c.removePropertyChangeListener(this); } /** * Unregisters components. * * @param c an instance of {@code JLabel} */ protected void uninstallComponents(JLabel c) { BasicHTML.updateRenderer(c, ""); } /** * Unregisters keyboard actions. * * @param c an instance of {@code JLabel} */ protected void uninstallKeyboardActions(JLabel c) { SwingUtilities.replaceUIInputMap(c, JComponent.WHEN_FOCUSED, null); SwingUtilities.replaceUIInputMap(c, JComponent.WHEN_IN_FOCUSED_WINDOW, null); SwingUtilities.replaceUIActionMap(c, null); } /** * Returns an instance of {@code BasicLabelUI}. * * @param c a component * @return an instance of {@code BasicLabelUI} */ public static ComponentUI createUI(JComponent c) { if (System.getSecurityManager() != null) { AppContext appContext = AppContext.getAppContext(); BasicLabelUI safeBasicLabelUI = (BasicLabelUI) appContext.get(BASIC_LABEL_UI_KEY); if (safeBasicLabelUI == null) { safeBasicLabelUI = new BasicLabelUI(); appContext.put(BASIC_LABEL_UI_KEY, safeBasicLabelUI); } return safeBasicLabelUI; } return labelUI; } public void propertyChange(PropertyChangeEvent e) { String name = e.getPropertyName(); if (name == "text" || "font" == name || "foreground" == name || SwingUtilities2.isScaleChanged(e)) { // remove the old html view client property if one // existed, and install a new one if the text installed // into the JLabel is html source. JLabel lbl = ((JLabel) e.getSource()); String text = lbl.getText(); BasicHTML.updateRenderer(lbl, text); } else if (name == "labelFor" || name == "displayedMnemonic") { installKeyboardActions((JLabel) e.getSource()); } } // When the accelerator is pressed, temporarily make the JLabel // focusTraversable by registering a WHEN_FOCUSED action for the // release of the accelerator. Then give it focus so it can // prevent unwanted keyTyped events from getting to other components. private static class Actions extends UIAction { private static final String PRESS = "press"; private static final String RELEASE = "release"; Actions(String key) { super(key); } public void actionPerformed(ActionEvent e) { JLabel label = (JLabel) e.getSource(); String key = getName(); if (key == PRESS) { doPress(label); } else if (key == RELEASE) { doRelease(label, e.getActionCommand() != null); } } private void doPress(JLabel label) { Component labelFor = label.getLabelFor(); if (labelFor != null && labelFor.isEnabled()) { InputMap inputMap = SwingUtilities.getUIInputMap(label, JComponent.WHEN_FOCUSED); if (inputMap == null) { inputMap = new InputMapUIResource(); SwingUtilities.replaceUIInputMap(label, JComponent.WHEN_FOCUSED, inputMap); } int dka = label.getDisplayedMnemonic(); putOnRelease(inputMap, dka, BasicLookAndFeel.getFocusAcceleratorKeyMask()); putOnRelease(inputMap, dka, SwingUtilities2.setAltGraphMask(BasicLookAndFeel.getFocusAcceleratorKeyMask())); // Need this when the sticky keys are enabled putOnRelease(inputMap, dka, 0); // Need this if ALT is released before the accelerator putOnRelease(inputMap, KeyEvent.VK_ALT, 0); label.requestFocus(); } } private void doRelease(JLabel label, boolean isCommand) { Component labelFor = label.getLabelFor(); if (labelFor != null && labelFor.isEnabled()) { if (label.hasFocus()) { InputMap inputMap = SwingUtilities.getUIInputMap(label, JComponent.WHEN_FOCUSED); if (inputMap != null) { // inputMap should never be null. int dka = label.getDisplayedMnemonic(); removeOnRelease(inputMap, dka, BasicLookAndFeel.getFocusAcceleratorKeyMask()); removeOnRelease(inputMap, dka, SwingUtilities2.setAltGraphMask(BasicLookAndFeel.getFocusAcceleratorKeyMask())); removeOnRelease(inputMap, dka, 0); removeOnRelease(inputMap, KeyEvent.VK_ALT, 0); } inputMap = SwingUtilities.getUIInputMap(label, JComponent.WHEN_IN_FOCUSED_WINDOW); if (inputMap == null) { inputMap = new InputMapUIResource(); SwingUtilities.replaceUIInputMap(label, JComponent.WHEN_IN_FOCUSED_WINDOW, inputMap); } int dka = label.getDisplayedMnemonic(); if (isCommand) { putOnRelease(inputMap, KeyEvent.VK_ALT, 0); } else { putOnRelease(inputMap, dka, BasicLookAndFeel.getFocusAcceleratorKeyMask()); putOnRelease(inputMap, dka, SwingUtilities2.setAltGraphMask(BasicLookAndFeel.getFocusAcceleratorKeyMask())); // Need this when the sticky keys are enabled putOnRelease(inputMap, dka, 0); } if (labelFor instanceof Container && ((Container) labelFor).isFocusCycleRoot()) { labelFor.requestFocus(); } else { SwingUtilities2.compositeRequestFocus(labelFor); } } else { InputMap inputMap = SwingUtilities.getUIInputMap(label, JComponent.WHEN_IN_FOCUSED_WINDOW); int dka = label.getDisplayedMnemonic(); if (inputMap != null) { if (isCommand) { removeOnRelease(inputMap, dka, BasicLookAndFeel.getFocusAcceleratorKeyMask()); removeOnRelease(inputMap, dka, SwingUtilities2.setAltGraphMask(BasicLookAndFeel.getFocusAcceleratorKeyMask())); removeOnRelease(inputMap, dka, 0); } else { removeOnRelease(inputMap, KeyEvent.VK_ALT, 0); } } } } } private void putOnRelease(InputMap inputMap, int keyCode, int modifiers) { inputMap.put(KeyStroke.getKeyStroke(keyCode, modifiers, true), RELEASE); } private void removeOnRelease(InputMap inputMap, int keyCode, int modifiers) { inputMap.remove(KeyStroke.getKeyStroke(keyCode, modifiers, true)); } } }