ElementList.java

/**
 * Copyright (c) Lambda Innovation, 2013-2015
 * 本作品版权由Lambda Innovation所有。
 * http://www.li-dev.cn/
 *
 * This project is open-source, and it is distributed under  
 * the terms of GNU General Public License. You can modify
 * and distribute freely as long as you follow the license.
 * 本项目是一个开源项目，且遵循GNU通用公共授权协议。
 * 在遵照该协议的情况下，您可以自由传播和修改。
 * http://www.gnu.org/licenses/gpl.html
 */
package cn.liutils.cgui.gui.component;

import java.util.ArrayList;
import java.util.List;

import cn.liutils.cgui.gui.Widget;
import cn.liutils.cgui.gui.event.FrameEvent;
import cn.liutils.cgui.gui.event.FrameEvent.FrameEventHandler;
import cn.liutils.cgui.gui.event.GuiEvent;
import cn.liutils.cgui.gui.event.GuiEventHandler;
import cn.liutils.util.generic.MathUtils;

/**
 * Component that can hold widgets itself and display them as a list. Only Widgets fully in the area will be shown.
 * You MUST specify the widgets BEFORE the component was added into the Widget.
 * @author WeAthFolD
 */
public class ElementList extends Component {
    
    List<Widget> subWidgets = new ArrayList();
    
    /**
     * The fixed vertical spacing between widgets.
     */
    public double spacing = 0.0;
    
    private int progress;
    
    private boolean loaded = false;

    public ElementList() {
        super("ElementList");
        
        this.addEventHandler(new FrameEventHandler() {
            @Override
            public void handleEvent(Widget w, FrameEvent event) {
                if(!loaded) {
                    loaded = true;
                    for(Widget ww : subWidgets) {
                        w.addWidget(ww);
                    }
                    updateList();
                }
            }
        });
    }
    
    public static ElementList get(Widget w) {
        return w.getComponent("ElementList");
    }
    
    public int getProgress() {
        return progress;
    }
    
    public int getMaxProgress() {
        return subWidgets.size() - 1;
    }
    
    public void progressNext() {
        setProgress(progress + 1);
    }
    
    public void progressLast() {
        setProgress(progress - 1);
    }
    
    public void setProgress(int p) {
        p = MathUtils.wrapi(0, getMaxProgress(), p);
        boolean u = progress != p;
        progress = p;
        if(u)
            updateList();
    }
    
    private void updateList() {
        double sum = 0.0;
        for(Widget w : subWidgets) {
            w.transform.doesDraw = false;
        }
        
        for(int i = progress; i < subWidgets.size() && sum <= this.widget.transform.height; ++i) {
            Widget w = subWidgets.get(i);
            
            w.transform.doesDraw = true;
            w.transform.x = 0;
            w.transform.y = sum;
            w.dirty = true;
            
            sum += w.transform.height + spacing;
        }
    }
    
    public void disposeAll() {}
    
    @Override
    public void onRemoved() {
        for(Widget w : subWidgets) {
            w.dispose();
        }
    }
    
    public static class ProgressChangedEvent implements GuiEvent  {}
    
    public abstract static class ProgressChangeHandler 
        extends GuiEventHandler<ProgressChangedEvent> {

        public ProgressChangeHandler() {
            super(ProgressChangedEvent.class);
        }
        
    }
    
    public void addWidget(Widget w) {
        if(loaded) return;
        w.needCopy = false;
        subWidgets.add(w);
    }
    
    public double getFullHeight() {
        return sumHeight(0, subWidgets.size());
    }
    
    /**
     * from inclusive, to exclusive
     */
    private double sumHeight(int from, int to) {
        double ret = 0.0;
        for(int i = from; i < to; ++i) {
            ret += subWidgets.get(i).transform.height;
        }
        return ret;
    }
    
    public ElementList copy() {
        ElementList el = (ElementList) super.copy();
        for(Widget w : subWidgets) {
            el.addWidget(w);
        }
        return el;
    }

}