panel.java

J2ME上的一个播放器,可以更换皮肤.开源软件.

// Panel is a placeholder for one or more CanvasElements 
// This panel is similar to Delphi's VCL Panel

package inline.ui.lo;

import inline.ui.*;
import inline.ui.ce.*;   
import java.util.*;

public class Panel extends Vector 
{
    public final static int ALIGN_LEFT = 1;
    public final static int ALIGN_RIGHT = 2;
    public final static int ALIGN_TOP = 3;     
    public final static int ALIGN_BOTTOM = 4;
    public final static int ALIGN_CLIENT = 5; // be greedy, take it all
    
    public final static int ELEMENTS_LEFT = 1;
    public final static int ELEMENTS_RIGHT = 2;
    public final static int ELEMENTS_JUSTIFY = 3;
    
    private int align;
    private int elements;
    
    private int px;
    private int py;
    private int width;
    private int height;
    
    public Panel(int aalign) // one of those ALING_XXX constants
    {
	align = aalign;
	elements = ELEMENTS_JUSTIFY;
    }
    
    public Panel(int aalign, int eelems) // one of those ALING_XXX constants
    {
	align = aalign;
	elements = eelems;
    }

    // deligate what we have
    public void addCanvasElement(CanvasElement cce)
    {
	this.addElement(cce);
    }

    public void addCanvasElement(CanvasElement cce, int wwidth, int hheight)
    {
	this.addCanvasElement(cce);
	cce.setMinimumSize(wwidth, hheight);
    }
    
    private void initSizes(int w, int h)
    {
	if (isHorizontal())
	{
	    width = w;
	}
	else
	{
	    int maxw = 0;
	    for(int i=0;i<size();i++)
	    {
		CanvasElement ce = (CanvasElement)elementAt(i);
		if (ce!=null && ce.isVisible())
		{
		    int cw = ce.getContentWidth();
		    if (cw>maxw) maxw = cw;
		}
	    }
	    
	    width = maxw;
	}
	
	if (isVertical())
	{
	    height = h;
	}
	else
	{
	    int maxh = 0;
	    for(int i=0;i<size();i++)
	    {
		CanvasElement ce = (CanvasElement)elementAt(i);
		if (ce!=null && ce.isVisible())
		{
		    int ch = ce.getContentHeight();
		    if (ch>maxh) maxh = ch;
		}
	    }
	    //if (maxh == 0) maxh = h;
	    
	    height = maxh;
	}
    }
    
    protected void layout(int x, int y, int w, int h)
    {
	if (align==ALIGN_CLIENT)
	{
	    width = w;
	    height = h;
	}
	else
	{
	    initSizes(w,h);
	}
	
	if (align==ALIGN_LEFT)
	{
	    px = x;
	}
	else
	{
	    px = x+w-width;
	}
	
	px = x;
	if (align==ALIGN_TOP)
	{
	    py = y;
	}
	else
	{
	    py = y+h-height;
	}

	if (isHorizontal())
	{
	    layoutElementsH();
	}
	else
	{
	    layoutElementsV();
	}
    }
    
    protected boolean isVertical()
    {
	return (align == ALIGN_LEFT || align == ALIGN_RIGHT || align == ALIGN_CLIENT);
    }
    
    protected boolean isHorizontal()
    {
	return (align == ALIGN_TOP || align == ALIGN_BOTTOM || align == ALIGN_CLIENT);
    }

    protected int getWidth() 
    {
	return width;
    }

    protected int getHeight() 
    {
	return height;
    }
    
    protected int getAlign()
    {
	return align;
    }

    private void layoutElementsH()
    {
	int aelm = 0;
	int midw = 0;
	int havw = width;
	for(int i=0;i<size();i++)
        {
	    CanvasElement ce = (CanvasElement)elementAt(i);
	    if (ce!=null && ce.isVisible())
	    {
		int cw = ce.getMinimumWidth();
		if (cw>0)
		{
		    havw -= cw;
		}
		else
		{
		    aelm++;
		}
	    }
        }
	
	// width for each element
	if (aelm==0) aelm = 1;
	
	// fixed float point to increase precision
	midw = 1000 * havw / aelm;
	int lp = 0;
	int dl = 0;
	    
	for(int i=0;i<size();i++)
        {
	    CanvasElement ce = (CanvasElement)elementAt(i);
	    if (ce!=null && ce.isVisible())
	    {
		int cw = 1000*ce.getMinimumWidth();
		if (cw == 0) 
		{
		    cw = midw;
		}
		else
		{
		    if (i>0) cw=cw+1000;
		}

		if (i==size()-1)
		{
		    if ((px + lp/1000+dl + cw/1000-dl)>width)
		    {
			cw = cw - 1000;
		    }
		}
		
		ce.setPositionSize(px + lp/1000+dl, py, cw/1000-dl, height);
		int llp = lp;
		lp = lp + cw;

		if ((llp%1000) + (cw%1000) > 1000)
		{
		    dl = 0;
		}
		else
		{
		    dl = 1;
		}
	    }
        }
	
    }
    
    private void layoutElementsV()
    {
	// to do, just like layoutElementsH
    }
}