palettelayout.java

来自「开源（Open Source）项目JHotDraw的文档和源程序」· Java 代码 · 共 102 行

/*
 * @(#)PaletteLayout.java 5.2
 *
 */

package CH.ifa.draw.util;

import java.awt.*;

/**
 * A custom layout manager for the palette.
 * @see PaletteButton
 */

public  class PaletteLayout
        implements LayoutManager {

    private int         fGap;
    private Point       fBorder;
    private boolean     fVerticalLayout;

    /**
     * Initializes the palette layout.
     * @param gap the gap between palette entries.
     */
    public PaletteLayout(int gap) {
        this(gap, new Point(0,0), true);
    }

    public PaletteLayout(int gap, Point border) {
        this(gap, border, true);
    }

    public PaletteLayout(int gap, Point border, boolean vertical) {
        fGap = gap;
        fBorder = border;
        fVerticalLayout = vertical;
    }

    public void addLayoutComponent(String name, Component comp) {
    }

    public void removeLayoutComponent(Component comp) {
    }

    public Dimension preferredLayoutSize(Container target) {
        return minimumLayoutSize(target);
    }

    public Dimension minimumLayoutSize(Container target) {
	    Dimension dim = new Dimension(0, 0);
	    int nmembers = target.getComponentCount();

	    for (int i = 0 ; i < nmembers ; i++) {
	        Component m = target.getComponent(i);
	        if (m.isVisible()) {
		        Dimension d = m.getMinimumSize();
		        if (fVerticalLayout) {
		            dim.width = Math.max(dim.width, d.width);
		            if (i > 0)
		                dim.height += fGap;
		            dim.height += d.height;
		        } else {
		            dim.height = Math.max(dim.height, d.height);
		            if (i > 0)
		                dim.width += fGap;
		            dim.width += d.width;
	            }
	        }
	    }

	    Insets insets = target.getInsets();
	    dim.width += insets.left + insets.right;
	    dim.width += 2 * fBorder.x;
	    dim.height += insets.top + insets.bottom;
	    dim.height += 2 * fBorder.y;
	    return dim;
    }

    public void layoutContainer(Container target) {
	    Insets insets = target.getInsets();
	    int nmembers = target.getComponentCount();
	    int x = insets.left + fBorder.x;
	    int y = insets.top + fBorder.y;

	    for (int i = 0 ; i < nmembers ; i++) {
	        Component m = target.getComponent(i);
	        if (m.isVisible()) {
		        Dimension d = m.getMinimumSize();
		        m.setBounds(x, y, d.width, d.height);
		        if (fVerticalLayout) {
		            y += d.height;
		            y += fGap;
		        } else {
		            x += d.width;
		            x += fGap;
		        }
		    }
	    }
    }
}