defaultlistcellrenderer.java

j2me设计的界面包

/*
 * Copyright 2008 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */
package com.sun.lwuit.list;

import com.sun.lwuit.Command;
import com.sun.lwuit.Component;
import com.sun.lwuit.Label;
import com.sun.lwuit.List;

/**
 * Default implementation of the renderer based on a label see the {@link ListCellRenderer}
 * for more information about the use and purpose of this class
 *
 * @author Chen Fishbein
 */
public class DefaultListCellRenderer extends Label implements ListCellRenderer {
    private boolean showNumbers;
    private int selectionTransparency = 100;
    
    /** 
     * Creates a new instance of DefaultCellRenderer 
     */
    public DefaultListCellRenderer() {
        super("");
        setCellRenderer(true);
        showNumbers = true;
    }

    /** 
     * Creates a new instance of DefaultCellRenderer 
     */
    public DefaultListCellRenderer(boolean showNumbers) {
        this();
        this.showNumbers = showNumbers;
    }

    /**
     * @inheritDoc
     */
    public Component getListCellRendererComponent(List list, Object value, int index, boolean isSelected) {
        if(showNumbers) {
            setText("" + (index + 1) + ". " + value);
        } else {
            if(value != null) {
                setText(value.toString());
            } else {
                setText("null");
            }
        }
        if (isSelected) {
            setFocus(true);
            getStyle().setBgTransparency(selectionTransparency);
        } else {
            setFocus(false);
            getStyle().setBgTransparency(0);
        }
        if(value instanceof Command) {
            setIcon(((Command)value).getIcon());
        }
        return this;
    }

    /**
     * @inheritDoc
     */
    public Component getListFocusComponent(List list) {
        setText("");
        setIcon(null);
        setFocus(true);
        getStyle().setBgTransparency(selectionTransparency);
        return this;
    }
    /**
     * Overriden to do nothing and remove a performance issue where renderer changes
     * perform needless repaint calls
     */
    public void repaint() {
    }

    /**
     * Indicate whether numbering should exist for the default cell renderer
     */
    public boolean isShowNumbers() {
        return showNumbers;
    }

    /**
     * Indicate whether numbering should exist for the default cell renderer
     */
    public void setShowNumbers(boolean showNumbers) {
        this.showNumbers = showNumbers;
    }

    /**
     * The background transparency factor to apply to the selection focus
     */
    public int getSelectionTransparency() {
        return selectionTransparency;
    }

    /**
     * The background transparency factor to apply to the selection focus
     */
    public void setSelectionTransparency(int selectionTransparency) {
        this.selectionTransparency = selectionTransparency;
    }
}