/*
 *                 Sun Public License Notice
 *
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 *
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2003 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.core.windows.view.ui;

import org.netbeans.core.windows.ModeImpl;
import org.netbeans.core.windows.WindowManagerImpl;
import org.openide.util.Utilities;
import org.openide.windows.TopComponent;

import javax.swing.*;
import java.awt.*;
import java.awt.event.AWTEventListener;
import java.awt.event.FocusEvent;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.lang.ref.WeakReference;



/** Component which takes an array of TopComponents, displays icons for
 * them and allows the user to navigate and select.  Typical usage:
 * 
RecentViewListDlg.invoke (someWindow, someTopComponentArray, 0)
 * The navigation keys may be adjusted via the setKeys method.
 * 
The popup will not automatically close due to external (i.e. focus)
 * events, but provides a method cancelLast() which will
 * close the last-opened popup if any.  Client code is expected to
 * decide what events should trigger cancelling of the popup.  The
 * popup will close in response to the releaseKey being
 * released (in which case it is setting the selected TopComponent).
 *
 * @author  Tim Boudreau
 */
public class RecentViewListDlg extends JComponent implements AWTEventListener, LayoutManager {
    private TopComponent[] tcs;
    private JLabel label;
    private IconPanel ic;
    private int sel=-1;
    
    private static int triggerKey;
    private static int reverseKey;
    private static int releaseKey;

    private static Popup currPopup = null;
    private static boolean shown = false;
    
    /** Creates a new instance of RecentViewListDlg */
    private RecentViewListDlg() {
        init();
        setFont(UIManager.getFont("Label.font"));
    }
    
    /** Set the keys which will trigger selection/closing of the popup.
     * @param trigger The key which will cause the selection to change, as a key code
     * defined on KeyEvent (e.g. VK_TAB).
     * @param reverse The key which, when pressed, reverses the traversal direction.
     * @param release The key which, when released, signals that the dialog should be closed
     * and the selected TopComponent should be activated.
     */
    public static void setKeys(int trigger, int reverse, int release) {
        triggerKey = trigger;
        reverseKey = reverse;
        releaseKey = release;
    }
    
    /** Invoke the popup with the specified target as the dialog parent, using the
     * passed array of TopComponents and the passed selection index.
     * @param target The target component which will own the popup dialog.
     * @param tcs The array of TopComponents that the dialog should allow the user to
     * navigate through.
     * @param selected The index of the component which should initially be selected when
     * the dialog appears.
     */
    public static void invoke(Component target, TopComponent[] tcs, int selected,
    int triggerKey, int reverseKey, int releaseKey) {
        RecentViewListDlg.triggerKey = triggerKey;
        RecentViewListDlg.reverseKey = reverseKey;
        RecentViewListDlg.releaseKey = releaseKey;
        
        RecentViewListDlg dlg = instance();
        dlg.setTopComponents(tcs);
        dlg.setSelection(selected);
        Dimension d = dlg.getPreferredSize();
        
        Rectangle r = Utilities.getUsableScreenBounds();
        int x = r.x + ((r.width/2) - (d.width / 2));
        int y = r.x + ((r.height/2) - (d.height / 2));
        Popup pop = PopupFactory.getSharedInstance().getPopup(target, dlg, x, y);
        if (currPopup != null) {
            currPopup.hide();
            shown = false;
        }
        currPopup = pop;
        pop.show();
        shown = true;
    }
    
    /** Cancel the popup if present, causing it to close without the active
     * TopComponent being changed.
     * @return True if a popup was closed.
     */
    public static boolean cancelLast() {
        boolean result = currPopup != null;
        if (result) {
            currPopup.hide();
            currPopup = null;
            shown = false;
        }
        return result;
    }
    
    /** Returns true if dialog is displayed.
     * TopComponent being changed.
     * @return True if a popup was closed.
     */
    public static boolean isShown () {
        return shown;
    }
    
    /** Test execution, invoking the popup with all the opened TopComponents.
     * This method should be deleted for production use.
     */
    public static void main(String[] args) {
        TopComponent[] tcs = (TopComponent[]) TopComponent.getRegistry().getOpened().toArray(new TopComponent[0]);
        Component target = Frame.getFrames()[0];
        invoke(target, tcs, 0, KeyEvent.VK_TAB, KeyEvent.VK_SHIFT, KeyEvent.VK_CONTROL);
    }
    
    public void addNotify() {
        super.addNotify();
        Toolkit.getDefaultToolkit().addAWTEventListener(this,
        AWTEvent.FOCUS_EVENT_MASK | AWTEvent.KEY_EVENT_MASK);
    }
    
    public void removeNotify(){
        super.removeNotify();
        Toolkit.getDefaultToolkit().removeAWTEventListener(this);
    }
    
    private void setSelection(int i) {
        if (i == sel) {
            return;
        }
        if (i >= tcs.length) {
            i = 0;
        }
        if (i < 0) {
            i = tcs.length - 1;
        }
        ic.setSelectedIndex(i);
        sel = i;
        label.setText(WindowManagerImpl.getInstance().getTopComponentDisplayName(tcs[i]));
        repaint();
    }
    
    private void init() {
        label = new JLabel();
        label.setBorder(BorderFactory.createLoweredBevelBorder());
        setBorder(BorderFactory.createRaisedBevelBorder());
        label.setHorizontalAlignment(SwingConstants.CENTER);
        ic = new IconPanel();
        add(label);
        add(ic);
        setLayout(this);
    }
    
    private void setTopComponents(TopComponent[] tcs) {
        this.tcs = tcs;
        //Selection index must be reset so that setSelection will
        //work correctly. (It did not when there was 2 items in input array and their
        //order was changed after every invocation.)
        sel = -1;
        Image[] icons = new Image[tcs.length];
        for (int i=0; i < tcs.length; i++) {
            icons[i] = tcs[i].getIcon();
        }
        ic.setIcons(icons);
    }
    
    private static WeakReference ref = null;
    
    private static RecentViewListDlg instance () {
        RecentViewListDlg result = null;
        if (ref != null) {
            result = (RecentViewListDlg) ref.get();
        }
        if (result == null) {
            result = new RecentViewListDlg();
            ref = new WeakReference(result);
        }
        return result;
    }
    
    private int textHeight=-1;
    private int getTextHeight() {
        if (textHeight == -1) {
            textHeight = calcTextHeight();
        }
        return textHeight;
    }
    
    private int calcTextHeight() {
        Graphics g = getGraphics();
        if (g == null) {
            g = new BufferedImage(20,20,BufferedImage.TYPE_INT_ARGB).getGraphics();
        }
        FontMetrics fm = g.getFontMetrics(getFont());
        return fm.getHeight();
    }
    
    boolean fwd=true;
    // XXX Have a look how is the key events handled in JPopupMenu+its UI, 
    // There should be used probably another mechanism then AWTEventListener
    // -> input and action map, if possible.
    public void eventDispatched(AWTEvent event) {
        int code;
        switch (event.getID()) {
            case FocusEvent.FOCUS_GAINED:
                break;
            case KeyEvent.KEY_PRESSED:
                code = ((KeyEvent) event).getKeyCode();
                if (code == reverseKey) {
                    fwd = false;
                } else if (code == triggerKey) {
                    setSelection(sel + (fwd ? 1 : -1));
                } else if(code == KeyEvent.VK_ESCAPE) { // XXX see above
                    cancelLast();
                }
                break;
            case KeyEvent.KEY_RELEASED:
                code = ((KeyEvent) event).getKeyCode();
                if (code == releaseKey) {
                    TopComponent tc = tcs[sel];
                    cancelLast();

                    // #37226 Unmaximized the other mode if needed.
                    WindowManagerImpl wm = WindowManagerImpl.getInstance();
                    ModeImpl mode = (ModeImpl)wm.findMode(tc);
                    if(mode != null && mode != wm.getMaximizedMode()) {
                        wm.setMaximizedMode(null);
                    }
                    tc.requestActive();
                } else if (code == reverseKey) {
                    fwd=true;
                }
                break;
        }
    }
    
    public void addLayoutComponent(String name, Component comp) {
        //do nothing
    }
    
    public void layoutContainer(Container parent) {
        Dimension d = ic.getPreferredSize();
        ic.setBounds(5, 5, d.width+1, d.height+1);
        label.setBounds(10, d.height+10, getWidth()-20, getTextHeight() + 4);
    }
    
    public Dimension minimumLayoutSize(Container parent) {
        return preferredLayoutSize(parent);
    }
    
    public Dimension preferredLayoutSize(Container parent) {
        Dimension result = ic.getPreferredSize();
        Dimension d2 = label.getPreferredSize();
        result.height+= d2.height+20;
        result.width +=10;
        return result;
    }
    
    public void removeLayoutComponent(Component comp) {
        //do nothing
    }
    
    private static class IconPanel extends JComponent {
        private int GAP = 5;
        private int WRAP_AT=12;
        private Image[] icons;
        private int sel;
        
        public void setIcons(Image[] ic) {
            this.icons = ic;
        }
        
        public void setSelectedIndex(int idx) {
            sel = idx;
            repaint();
        }
        
        public void paint(Graphics g) {
            int x=GAP;
            int y=GAP;
            for (int i=0; i < icons.length; i++) {
                int w=24;
                int h=24;
                if (icons[i] != null) {
                    int xpos = x;
                    int ypos = y;
                    int iw = icons[i].getWidth(this);
                    int ih = icons[i].getHeight(this);
                    if (iw < w) {
                        xpos += ((w-iw)/2)- (GAP/2);
                    }
                    if (ih < h) {
                        ypos += ((h-ih)/2)- (GAP/2);
                    }
                    new ImageIcon(icons[i]).paintIcon(this, g, xpos, ypos);
                } else {
                    noIconIcon.paintIcon(this, g, x, y);
                }
                if (i == sel) {
                    Color selColor = UIManager.getColor("textHighlight"); //NOI18N
                    if (selColor == null) {
                        selColor = Color.blue;
                    }
                    g.setColor(selColor.darker());
                    g.drawRect(x-GAP, y-GAP, w + GAP-1, h + GAP-1);
                }
                x+=w + GAP;
                if ((i+1) % WRAP_AT==0) {
                    y +=h+GAP;
                    x=GAP;
                }
            }
        }
        
        public Dimension getPreferredSize() {
            int rowCount = (icons.length / WRAP_AT) + 1;
            Dimension result = new Dimension((24 * WRAP_AT) + (GAP * WRAP_AT), (rowCount * 24) + (GAP * rowCount));
            return result;
        }
        
        private Icon noIconIcon = new Icon() {
            public int getIconHeight() {
                return 16;
            }
            public int getIconWidth() {
                return 16;
            }
            public void paintIcon(Component c, Graphics g, int x, int y) {
                g.setColor(Color.RED);
                FontMetrics fm = g.getFontMetrics();
                g.drawString("?", x+7, y+4+fm.getAscent()); //NOI18N
            }
        };
    }
}