EqualsLayout.java

package org.rr.commons.swing.layout;

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

import javax.swing.SwingConstants;

import org.rr.commons.utils.ArrayUtils;

/**
 * LayoutManager that arrange it's components with the same size one after the other.
 * 
 * @author Santhosh Kumar - santhosh@in.fiorano.com
 * @see http://www.jroller.com/santhosh/entry/how_do_you_layout_command
 */
public class EqualsLayout implements LayoutManager, SwingConstants {
	
	private int gap;
	
	private int alignment;
	
	private boolean reverse = false;

	public EqualsLayout(int alignment, int gap, boolean reverse) {
		setGap(gap);
		setAlignment(alignment);
		setReverse(reverse);
	}
	
	public EqualsLayout(int alignment, int gap) {
		this(alignment, gap, false);
	}

	public EqualsLayout(int gap) {
		this(RIGHT, gap);
	}

	public int getAlignment() {
		return alignment;
	}

	public void setAlignment(int alignment) {
		this.alignment = alignment;
	}

	public int getGap() {
		return gap;
	}

	public void setGap(int gap) {
		this.gap = gap;
	}

	public boolean isReverse() {
		return reverse;
	}

	public void setReverse(boolean reverse) {
		this.reverse = reverse;
	}

	private Dimension[] dimensions(Component children[]) {
		int maxWidth = 0;
		int maxHeight = 0;
		int visibleCount = 0;
		Dimension componentPreferredSize;

		for (int i = 0, c = children.length; i < c; i++) {
			if (children[i].isVisible()) {
				componentPreferredSize = children[i].getPreferredSize();
				maxWidth = Math.max(maxWidth, componentPreferredSize.width);
				maxHeight = Math.max(maxHeight, componentPreferredSize.height);
				visibleCount++;
			}
		}

		int usedWidth = maxWidth * visibleCount + gap * (visibleCount - 1);
		int usedHeight = maxHeight;
		return new Dimension[] { new Dimension(maxWidth, maxHeight), new Dimension(usedWidth, usedHeight), };
	}

	public void layoutContainer(Container container) {
		Insets insets = container.getInsets();
		Component[] children = reverse ? ArrayUtils.reverse(container.getComponents()) : container.getComponents();
		Dimension dim[] = dimensions(children);

		int maxWidth = dim[0].width;
		int maxHeight = dim[0].height;
		int usedWidth = dim[1].width;
		int usedHeight = dim[1].height;

		switch (alignment) {
		case LEFT:
		case TOP:
			for (int i = 0, c = children.length; i < c; i++) {
				if (!children[i].isVisible())
					continue;
				children[i].setBounds(insets.left + (maxWidth + gap) * i, insets.top, maxWidth, maxHeight);
			}
			break;
		case RIGHT:
		case BOTTOM:
			for (int i = 0, c = children.length; i < c; i++) {
				if (!children[i].isVisible())
					continue;
				children[i].setBounds(container.getWidth() - insets.right - usedWidth + (maxWidth + gap) * i, insets.top, maxWidth, maxHeight);
			}
			break;
		}
	}

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

	public Dimension preferredLayoutSize(Container container) {
		Insets insets = container.getInsets();

		Component[] children = container.getComponents();
		Dimension dim[] = dimensions(children);

		int usedWidth = dim[1].width;
		int usedHeight = dim[1].height;

		return new Dimension(insets.left + usedWidth + insets.right, insets.top + usedHeight + insets.bottom);
	}

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

	public void removeLayoutComponent(Component c) {
	}


}