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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
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package com.apple.laf;

import java.awt.*;
import java.awt.event.KeyEvent;

import javax.swing.*;

import com.apple.laf.AquaUtils.RecyclableSingleton;
import com.apple.laf.AquaUtils.RecyclableSingletonFromDefaultConstructor;

public class AquaMnemonicHandler {
    private static final RecyclableSingleton<AltProcessor> altProcessor = new RecyclableSingletonFromDefaultConstructor<AltProcessor>(AltProcessor.class);
    public static KeyEventPostProcessor getInstance() {
        return altProcessor.get();
    }

    protected static boolean isMnemonicHidden = true; // true by default

    public static void setMnemonicHidden(final boolean hide) {
        if (UIManager.getBoolean("Button.showMnemonics")) {
            // Do not hide mnemonics if the UI defaults do not support this
            isMnemonicHidden = false;
        } else {
            isMnemonicHidden = hide;
        }
    }

    
Gets the state of the hide mnemonic flag. This only has meaning if this feature is supported by the underlying OS.
See Also:
Returns:true if mnemonics are hidden, otherwise, false
Since:1.4
/** * Gets the state of the hide mnemonic flag. This only has meaning if this feature is supported by the underlying OS. * * @return true if mnemonics are hidden, otherwise, false * @see #setMnemonicHidden * @since 1.4 */
public static boolean isMnemonicHidden() { if (UIManager.getBoolean("Button.showMnemonics")) { // Do not hide mnemonics if the UI defaults do not support this isMnemonicHidden = false; } return isMnemonicHidden; } static class AltProcessor implements KeyEventPostProcessor { public boolean postProcessKeyEvent(final KeyEvent ev) { if (ev.getKeyCode() != KeyEvent.VK_ALT) { return false; } final JRootPane root = SwingUtilities.getRootPane(ev.getComponent()); final Window winAncestor = (root == null ? null : SwingUtilities.getWindowAncestor(root)); switch(ev.getID()) { case KeyEvent.KEY_PRESSED: setMnemonicHidden(false); break; case KeyEvent.KEY_RELEASED: setMnemonicHidden(true); break; } repaintMnemonicsInWindow(winAncestor); return false; } } /* * Repaints all the components with the mnemonics in the given window and all its owned windows. */ static void repaintMnemonicsInWindow(final Window w) { if (w == null || !w.isShowing()) { return; } final Window[] ownedWindows = w.getOwnedWindows(); for (final Window element : ownedWindows) { repaintMnemonicsInWindow(element); } repaintMnemonicsInContainer(w); } /* * Repaints all the components with the mnemonics in container. * Recursively searches for all the subcomponents. */ static void repaintMnemonicsInContainer(final Container cont) { for (int i = 0; i < cont.getComponentCount(); i++) { final Component c = cont.getComponent(i); if (c == null || !c.isVisible()) { continue; } if (c instanceof AbstractButton && ((AbstractButton)c).getMnemonic() != '\0') { c.repaint(); continue; } if (c instanceof JLabel && ((JLabel)c).getDisplayedMnemonic() != '\0') { c.repaint(); continue; } if (c instanceof Container) { repaintMnemonicsInContainer((Container)c); } } } }