VerticalFlowLayout.java

package org.chartsy.chatsy.chat.component;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Insets;

public class VerticalFlowLayout extends FlowLayout
{

    public static final int TOP = 0;
    public static final int MIDDLE = 1;
    public static final int BOTTOM = 2;

    int hgap;
    int vgap;
    boolean hfill;
    boolean vfill;

    public VerticalFlowLayout()
	{
        this(TOP, 5, 5, true, false);
    }

    public VerticalFlowLayout(boolean hfill, boolean vfill)
	{
        this(TOP, 5, 5, hfill, vfill);
    }

    public VerticalFlowLayout(int align)
	{
        this(align, 5, 5, true, false);
    }

    public VerticalFlowLayout(int align, boolean hfill, boolean vfill)
	{
        this(align, 5, 5, hfill, vfill);
    }

    public VerticalFlowLayout(int align,
		int hgap, int vgap,
		boolean hfill, boolean vfill)
	{
        setAlignment(align);
        this.hgap = hgap;
        this.vgap = vgap;
        this.hfill = hfill;
        this.vfill = vfill;
    }

    public Dimension preferredLayoutSize(Container target)
	{
        Dimension tarsiz = new Dimension(0, 0);
        for (int i = 0; i < target.getComponentCount(); i++)
		{
            Component m = target.getComponent(i);
            if (m.isVisible())
			{
                Dimension d = m.getPreferredSize();
                tarsiz.width = Math.max(tarsiz.width, d.width);
                if (i > 0)
                    tarsiz.height += hgap;
                tarsiz.height += d.height;
            }
        }
        Insets insets = target.getInsets();
        tarsiz.width += insets.left + insets.right + hgap * 2;
        tarsiz.height += insets.top + insets.bottom + vgap * 2;
        return tarsiz;
    }

    public Dimension minimumLayoutSize(Container target)
	{
        Dimension tarsiz = new Dimension(0, 0);
        for (int i = 0; i < target.getComponentCount(); i++)
		{
            Component m = target.getComponent(i);
            if (m.isVisible())
			{
                Dimension d = m.getMinimumSize();
                tarsiz.width = Math.max(tarsiz.width, d.width);
                if (i > 0)
                    tarsiz.height += vgap;
                tarsiz.height += d.height;
            }
        }
        Insets insets = target.getInsets();
        tarsiz.width += insets.left + insets.right + hgap * 2;
        tarsiz.height += insets.top + insets.bottom + vgap * 2;
        return tarsiz;
    }

    public void setVerticalFill(boolean vfill)
	{
        this.vfill = vfill;
    }

    public boolean getVerticalFill()
	{
        return vfill;
    }

    public void setHorizontalFill(boolean hfill)
	{
        this.hfill = hfill;
    }

    public boolean getHorizontalFill()
	{
        return hfill;
    }

    private void placethem(Container target, 
		int x, int y,
		int width, int height,
		int first, int last)
	{
        int align = getAlignment();
        if (align == MIDDLE)
            y += height / 2;
        if (align == BOTTOM)
            y += height;

        for (int i = first; i < last; i++)
		{
            Component m = target.getComponent(i);
            Dimension md = m.getSize();
            if (m.isVisible())
			{
                int px = x + (width - md.width) / 2;
                m.setLocation(px, y);
                y += vgap + md.height;
            }
        }
    }

    public void layoutContainer(Container target)
	{
        Insets insets = target.getInsets();
        int maxheight = target.getSize().height - (insets.top + insets.bottom + vgap * 2);
        int maxwidth = target.getSize().width - (insets.left + insets.right + hgap * 2);
        int numcomp = target.getComponentCount();
        int x = insets.left + hgap, y = 0;
        int colw = 0, start = 0;

        for (int i = 0; i < numcomp; i++)
		{
            Component m = target.getComponent(i);
            if (m.isVisible())
			{
                Dimension d = m.getPreferredSize();
                if ((this.vfill) && (i == (numcomp - 1)))
                    d.height = Math.max((maxheight - y), m.getPreferredSize().height);

                if (this.hfill)
				{
                    m.setSize(maxwidth, d.height);
                    d.width = maxwidth;
                }
                else
				{
                    m.setSize(d.width, d.height);
                }

                if (y + d.height > maxheight)
				{
                    placethem(target, x, insets.top + vgap, colw, maxheight - y, start, i);
                    y = d.height;
                    x += hgap + colw;
                    colw = d.width;
                    start = i;
                }
                else
				{
                    if (y > 0)
                        y += vgap;
                    y += d.height;
                    colw = Math.max(colw, d.width);
                }
            }
        }
        placethem(target, x, insets.top + vgap, colw, maxheight - y, start, numcomp);
    }
	
}