/*
 * Copyright (c) 1997, 2014, 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
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 */

package com.sun.java.swing.plaf.windows;

import java.awt.Component;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.KeyEventPostProcessor;
import java.awt.KeyboardFocusManager;
import java.awt.Window;
import java.awt.event.KeyEvent;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.*;

import sun.swing.StringUIClientPropertyKey;

import com.sun.java.swing.plaf.windows.TMSchema.Part;
import com.sun.java.swing.plaf.windows.TMSchema.State;
import com.sun.java.swing.plaf.windows.XPStyle.Skin;
import static sun.swing.SwingUtilities2.BASICMENUITEMUI_MAX_TEXT_OFFSET;

/**
 * Windows rendition of the component.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases.  The current serialization support is appropriate
 * for short term storage or RMI between applications running the same
 * version of Swing.  A future release of Swing will provide support for
 * long term persistence.
 *
 * @author Igor Kushnirskiy
 */
public class WindowsPopupMenuUI extends BasicPopupMenuUI {

    static MnemonicListener mnemonicListener = null;
    static final Object GUTTER_OFFSET_KEY =
        new StringUIClientPropertyKey("GUTTER_OFFSET_KEY");

    public static ComponentUI createUI(JComponent c) {
        return new WindowsPopupMenuUI();
    }

    public void installListeners() {
        super.installListeners();
        if (! UIManager.getBoolean("Button.showMnemonics") &&
            mnemonicListener == null) {

            mnemonicListener = new MnemonicListener();
            MenuSelectionManager.defaultManager().
                addChangeListener(mnemonicListener);
        }
    }

    /**
     * Returns the <code>Popup</code> that will be responsible for
     * displaying the <code>JPopupMenu</code>.
     *
     * @param popupMenu JPopupMenu requesting Popup
     * @param x     Screen x location Popup is to be shown at
     * @param y     Screen y location Popup is to be shown at.
     * @return Popup that will show the JPopupMenu
     * @since 1.4
     */
    public Popup getPopup(JPopupMenu popupMenu, int x, int y) {
        PopupFactory popupFactory = PopupFactory.getSharedInstance();
        return popupFactory.getPopup(popupMenu.getInvoker(), popupMenu, x, y);
    }

    static class MnemonicListener implements ChangeListener {
        JRootPane repaintRoot = null;

        public void stateChanged(ChangeEvent ev) {
            MenuSelectionManager msm = (MenuSelectionManager)ev.getSource();
            MenuElement[] path = msm.getSelectedPath();
            if (path.length == 0) {
                if(!WindowsLookAndFeel.isMnemonicHidden()) {
                    // menu was canceled -- hide mnemonics
                    WindowsLookAndFeel.setMnemonicHidden(true);
                    if (repaintRoot != null) {
                        Window win =
                            SwingUtilities.getWindowAncestor(repaintRoot);
                        WindowsGraphicsUtils.repaintMnemonicsInWindow(win);
                    }
                }
            } else {
                Component c = (Component)path[0];
                if (c instanceof JPopupMenu) c = ((JPopupMenu)c).getInvoker();
                repaintRoot = SwingUtilities.getRootPane(c);
            }
        }
    }

    /**
     * Returns offset for the text.
     * BasicMenuItemUI sets max text offset on the JPopupMenuUI.
     * @param c PopupMenu to return text offset for.
     * @return text offset for the component
     */
    static int getTextOffset(JComponent c) {
        int rv = -1;
        Object maxTextOffset =
            c.getClientProperty(BASICMENUITEMUI_MAX_TEXT_OFFSET);
        if (maxTextOffset instanceof Integer) {
            /*
             * this is in JMenuItem coordinates.
             * Let's assume all the JMenuItem have the same offset along X.
             */
            rv = (Integer) maxTextOffset;
            int menuItemOffset = 0;
            Component component = c.getComponent(0);
            if (component != null) {
                menuItemOffset = component.getX();
            }
            rv += menuItemOffset;
        }
        return rv;
    }

    /**
     * Returns span before gutter.
     * used only on Vista.
     * @return span before gutter
     */
    static int getSpanBeforeGutter() {
        return 3;
    }

    /**
     * Returns span after gutter.
     * used only on Vista.
     * @return span after gutter
     */
    static int getSpanAfterGutter() {
        return 3;
    }

    /**
     * Returns gutter width.
     * used only on Vista.
     * @return width of the gutter
     */
    static int getGutterWidth() {
        int rv = 2;
        XPStyle xp = XPStyle.getXP();
        if (xp != null) {
            Skin skin = xp.getSkin(null, Part.MP_POPUPGUTTER);
            rv = skin.getWidth();
        }
        return rv;
    }

    /**
     * Checks if PopupMenu is leftToRight
     * The orientation is derived from the children of the component.
     * It is leftToRight if all the children are leftToRight
     *
     * @param c component to return orientation for
     * @return true if all the children are leftToRight
     */
    private static boolean isLeftToRight(JComponent c) {
        boolean leftToRight = true;
        for (int i = c.getComponentCount() - 1; i >=0 && leftToRight; i-- ) {
            leftToRight =
                c.getComponent(i).getComponentOrientation().isLeftToRight();
        }
        return leftToRight;
    }

    @Override
    public void paint(Graphics g, JComponent c) {
        XPStyle xp = XPStyle.getXP();
        if (WindowsMenuItemUI.isVistaPainting(xp)) {
            Skin skin = xp.getSkin(c, Part.MP_POPUPBACKGROUND);
            skin.paintSkin(g, 0, 0, c.getWidth(),c.getHeight(), State.NORMAL);
            int textOffset = getTextOffset(c);
            if (textOffset >= 0
                    /* paint gutter only for leftToRight case */
                    && isLeftToRight(c)) {
                skin = xp.getSkin(c, Part.MP_POPUPGUTTER);
                int gutterWidth = getGutterWidth();
                int gutterOffset =
                    textOffset - getSpanAfterGutter() - gutterWidth;
                c.putClientProperty(GUTTER_OFFSET_KEY,
                    Integer.valueOf(gutterOffset));
                Insets insets = c.getInsets();
                skin.paintSkin(g, gutterOffset, insets.top,
                    gutterWidth, c.getHeight() - insets.bottom - insets.top,
                    State.NORMAL);
            } else {
                if (c.getClientProperty(GUTTER_OFFSET_KEY) != null) {
                    c.putClientProperty(GUTTER_OFFSET_KEY, null);
                }
            }
        } else {
            super.paint(g, c);
        }
    }
}
