LayeredLayout.java

/*
 * Copyright (c) 2008, 2010, 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
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 */
package com.sun.lwuit.layouts;

import com.sun.lwuit.Component;
import com.sun.lwuit.Container;
import com.sun.lwuit.geom.Dimension;
import com.sun.lwuit.plaf.Style;

/**
 * Allows placing components one on top of the other like a stack, this layout
 * effectively allows us to build a UI of overlapping components. The components
 * may be containers with their own layout managers to allow elaborate arbitrary
 * looks.
 * Since the Z-ordering creates a great deal of complexity and inefficiency it
 * is recommended that you first try to achieve the desired UI without resorting to
 * this layout or coordinate layout.
 *
 * @author Shai Almog
 */
public class LayeredLayout extends Layout {

    /**
     * @inheritDoc
     */
    public void layoutContainer(Container parent) {
        int numOfcomponents = parent.getComponentCount();
        Style s = parent.getStyle();
        int x = s.getPadding(parent.isRTL(), Component.LEFT);
        int y = s.getPadding(false, Component.TOP);
        int w = parent.getWidth() - x - s.getPadding(parent.isRTL(), Component.RIGHT);
        int h = parent.getHeight() - y - s.getPadding(false, Component.BOTTOM);
        for(int i=0; i< numOfcomponents; i++){
            Component cmp = parent.getComponentAt(i);
            cmp.setX(x);
            cmp.setY(y);
            cmp.setWidth(w);
            cmp.setHeight(h);
        }
    }

    /**
     * @inheritDoc
     */
    public Dimension getPreferredSize(Container parent) {
        int maxWidth = 0;
        int maxHeight = 0;
        int numOfcomponents = parent.getComponentCount();
        for(int i=0; i< numOfcomponents; i++){
            Component cmp = parent.getComponentAt(i);
            maxHeight = Math.max(maxHeight, cmp.getPreferredH());
            maxWidth = Math.max(maxWidth, cmp.getPreferredW());
        }
        Style s = parent.getStyle();
        Dimension d = new Dimension(maxWidth + s.getPadding(false, Component.LEFT)+ s.getPadding(false, Component.RIGHT),
                maxHeight + s.getPadding(false, Component.TOP)+ s.getPadding(false, Component.BOTTOM));
        return d;
    }

    /**
     * @inheritDoc
     */
    public String toString() {
        return "LayeredLayout";
    }

    /**
     * @inheritDoc
     */
    public boolean isOverlapSupported(){
        return true;
    }
}