zkoss/zk

/* Borderlayout.java

    Purpose:
        
    Description:
        
    History:
        Feb 10, 2009 4:17:16 PM , Created by jumperchen

Copyright (C) 2008 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
    This program is distributed under LGPL Version 2.1 in the hope that
    it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zul;

import java.util.Iterator;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.zkoss.lang.Library;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.HtmlBasedComponent;
import org.zkoss.zk.ui.UiException;

/**
 * A border layout is a layout container for arranging and resizing
 * child components to fit in five regions: north, south, east, west, and center.
 * Each region may
 * contain no more than one component, and is identified by a corresponding
 * constant: <code>NORTH</code>, <code>SOUTH</code>, <code>EAST</code>,
 * <code>WEST</code>, and <code>CENTER</code>. When adding a component to
 * a container with a border layout, use one of these five constants, for
 * example:
 * 
 * <pre>
 *  &lt;borderlayout&gt;
 *  &lt;north margins=&quot;1,5,1,1&quot; size=&quot;20%&quot; splittable=&quot;true&quot; collapsible=&quot;true&quot; minsize=&quot;100&quot; maxsize=&quot;400&quot;&gt;
 *  &lt;div&gt;
 *  North
 *  &lt;/div&gt;
 *  &lt;/north&gt;
 *  &lt;west size=&quot;25%&quot; splittable=&quot;true&quot; autoscroll=&quot;true&quot;&gt;
 *  &lt;div&gt;
 *  West
 *  &lt;/div&gt;
 *  &lt;/west&gt;
 *  &lt;center flex=&quot;true&quot;&gt;
 *  &lt;div&gt;
 *  Center
 *  &lt;/div&gt;
 *  &lt;/center&gt;
 *  &lt;east size=&quot;25%&quot; collapsible=&quot;true&quot; onOpen='alert(self.id + &quot; is open :&quot; +event.open)'&gt;
 *  &lt;div&gt;
 *  East
 *  &lt;/div&gt;
 *  &lt;/east&gt;
 *  &lt;south size=&quot;50%&quot; splittable=&quot;true&quot;&gt;
 *  &lt;div&gt;
 *  south
 *  &lt;/div&gt;
 *  &lt;/south&gt;
 *  &lt;/borderlayout&gt;
 * 
 * </pre>
 * 
 * <p>Default {@link #getZclass}: z-borderlayout. (since 3.5.0)
 * 
 * <p> Configuration:
 * you can disable the animation effects by specifying a library
 * property named <code>org.zkoss.zul.borderlayout.animation.disabled</code> to
 * disable all borderlayouts. (since 5.0.8) 
 * @author jumperchen
 * @since 5.0.0
 */
public class Borderlayout extends HtmlBasedComponent {
    private static final Logger log = LoggerFactory.getLogger(Borderlayout.class);

    /**
     * The north layout constraint (top of container).
     */
    public static final String NORTH = "north";

    /**
     * The south layout constraint (bottom of container).
     */
    public static final String SOUTH = "south";

    /**
     * The east layout constraint (right side of container).
     */
    public static final String EAST = "east";

    /**
     * The west layout constraint (left side of container).
     */
    public static final String WEST = "west";

    /**
     * The center layout constraint (middle of container).
     */
    public static final String CENTER = "center";

    private transient North _north;

    private transient South _south;

    private transient West _west;

    private transient East _east;

    private transient Center _center;

    private boolean _animationDisabled = isDefaultAnimationDisabled();

    public Borderlayout() {
    }

    private static boolean isDefaultAnimationDisabled() {
        if (_defAnimation == null) {
            String oldProperty = "org.zkoss.zul.borderlayout.animation.disabed";
            String newProperty = "org.zkoss.zul.borderlayout.animation.disabled";
            _defAnimation = Boolean.valueOf(Library.getProperty(oldProperty, "false"));
            if (_defAnimation) {
                log.warn("The library-property setting: {} was changed to {}, please use the new one instead.", oldProperty, newProperty);
            } else {
                _defAnimation = Boolean.valueOf(Library.getProperty(newProperty, "false"));
            }
        }
        return _defAnimation.booleanValue();
    }

    private static Boolean _defAnimation;

    /**
     * Returns whether disable animation effects
     * <p>Default: false.
     * @since 5.0.8
     */
    public boolean isAnimationDisabled() {
        return _animationDisabled;
    }

    /**
     * Sets to disable animation effects.
     * @since 5.0.8
     */
    public void setAnimationDisabled(boolean animationDisabled) {
        if (_animationDisabled != animationDisabled) {
            _animationDisabled = animationDisabled;
            smartUpdate("animationDisabled", animationDisabled);
        }
    }

    public North getNorth() {
        return _north;
    }

    public South getSouth() {
        return _south;
    }

    public West getWest() {
        return _west;
    }

    public East getEast() {
        return _east;
    }

    public Center getCenter() {
        return _center;
    }

    /**
     * Re-size this layout component.
     */
    public void resize() {
        smartUpdate("resize", true);
    }

    public void beforeChildAdded(Component child, Component refChild) {
        if (!(child instanceof LayoutRegion))
            throw new UiException("Unsupported child for Borderlayout: " + child);
        if (child instanceof North) {
            if (_north != null && child != _north)
                throw new UiException("Only one north child is allowed: " + this);
        } else if (child instanceof South) {
            if (_south != null && child != _south)
                throw new UiException("Only one south child is allowed: " + this);
        } else if (child instanceof West) {
            if (_west != null && child != _west)
                throw new UiException("Only one west child is allowed: " + this);
        } else if (child instanceof East) {
            if (_east != null && child != _east)
                throw new UiException("Only one east child is allowed: " + this);
        } else if (child instanceof Center) {
            if (_center != null && child != _center)
                throw new UiException("Only one center child is allowed: " + this);
        }
        super.beforeChildAdded(child, refChild);
    }

    public boolean insertBefore(Component child, Component refChild) {
        if (child instanceof North) {
            if (!super.insertBefore(child, refChild))
                return false;
            _north = (North) child;
        } else if (child instanceof South) {
            if (!super.insertBefore(child, refChild))
                return false;
            _south = (South) child;
        } else if (child instanceof West) {
            if (!super.insertBefore(child, refChild))
                return false;
            _west = (West) child;
        } else if (child instanceof East) {
            if (!super.insertBefore(child, refChild))
                return false;
            _east = (East) child;
        } else if (child instanceof Center) {
            if (!super.insertBefore(child, refChild))
                return false;
            _center = (Center) child;
        } else {
            if (!super.insertBefore(child, refChild))
                return false;
        }
        return true;
    }

    protected void renderProperties(org.zkoss.zk.ui.sys.ContentRenderer renderer) throws java.io.IOException {
        super.renderProperties(renderer);

        render(renderer, "animationDisabled", _animationDisabled);
    }

    public void onChildRemoved(Component child) {
        super.onChildRemoved(child);
        if (_north == child)
            _north = null;
        else if (_south == child)
            _south = null;
        else if (_west == child)
            _west = null;
        else if (_east == child)
            _east = null;
        else if (_center == child)
            _center = null;
    }

    public String getZclass() {
        return _zclass == null ? "z-borderlayout" : _zclass;
    }

    //Cloneable//
    public Object clone() {
        final Borderlayout clone = (Borderlayout) super.clone();
        clone.afterUnmarshal();
        return clone;
    }

    private void afterUnmarshal() {
        for (Iterator it = getChildren().iterator(); it.hasNext();) {
            final Object child = it.next();
            if (child instanceof North) {
                _north = (North) child;
            } else if (child instanceof South) {
                _south = (South) child;
            } else if (child instanceof Center) {
                _center = (Center) child;
            } else if (child instanceof West) {
                _west = (West) child;
            } else if (child instanceof East) {
                _east = (East) child;
            }
        }
    }

    //-- Serializable --//
    private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException {
        s.defaultReadObject();
        afterUnmarshal();
    }
}