taverna-contextual-views-api/src/main/java/org/apache/taverna/workbench/ui/views/contextualviews/activity/ListLayout.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.taverna.workbench.ui.views.contextualviews.activity;

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

/**
 * Lays out components vertically using their preferred height and the available
 * width.
 * 
 * @author David Withers
 */
public class ListLayout implements LayoutManager {
	private static final int DEFAULT_GAP = 5;
	private final int gap;

	public ListLayout() {
		this(DEFAULT_GAP);
	}

	public ListLayout(int gap) {
		this.gap = gap;
	}

	@Override
	public void removeLayoutComponent(Component comp) {
	}

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

	@Override
	public void layoutContainer(Container parent) {
		Insets insets = parent.getInsets();
		int x = insets.left;
		int y = insets.top;
		int width = parent.getWidth() - insets.left - insets.right;
		Component[] components = parent.getComponents();
		for (int i = 0; i < components.length; i++) {
			components[i].setLocation(x, y);
			components[i].setSize(width,
					components[i].getPreferredSize().height);
			y = y + gap + components[i].getHeight();
		}
	}

	@Override
	public Dimension minimumLayoutSize(Container parent) {
		Insets insets = parent.getInsets();
		int minimumWidth = 0;
		int minimumHeight = 0;
		Component[] components = parent.getComponents();
		for (int i = 0; i < components.length; i++) {
			Dimension size = components[i].getPreferredSize();
			if (size.width > minimumWidth)
				minimumWidth = size.width;
			minimumHeight = minimumHeight + size.height + gap;
		}
		minimumWidth = minimumWidth + insets.left + insets.right;
		minimumHeight = minimumHeight + insets.top + insets.bottom;

		return new Dimension(minimumWidth, minimumHeight);
	}

	@Override
	public Dimension preferredLayoutSize(Container parent) {
		return minimumLayoutSize(parent);
	}
}