| /******************************************************************************* |
| * Copyright (c) 2000, 2010 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.draw2d; |
| |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.eclipse.draw2d.geometry.Dimension; |
| |
| /** |
| * Figures using a DelegatingLayout as their layout manager give location |
| * responsibilities to their children. The children of a Figure using a |
| * DelegatingLayout should have a {@link Locator Locator} as a constraint whose |
| * {@link Locator#relocate(IFigure target) relocate} method is responsible for |
| * placing the child. |
| */ |
| public class DelegatingLayout extends AbstractLayout { |
| |
| private Map constraints = new HashMap(); |
| |
| /** |
| * Calculates the preferred size of the given Figure. For the |
| * DelegatingLayout, this is the largest width and height values of the |
| * passed Figure's children. |
| * |
| * @param parent |
| * the figure whose preferred size is being calculated |
| * @param wHint |
| * the width hint |
| * @param hHint |
| * the height hint |
| * @return the preferred size |
| * @since 2.0 |
| */ |
| protected Dimension calculatePreferredSize(IFigure parent, int wHint, |
| int hHint) { |
| List children = parent.getChildren(); |
| Dimension d = new Dimension(); |
| for (int i = 0; i < children.size(); i++) { |
| IFigure child = (IFigure) children.get(i); |
| d.union(child.getPreferredSize()); |
| } |
| return d; |
| } |
| |
| /** |
| * @see org.eclipse.draw2d.LayoutManager#getConstraint(org.eclipse.draw2d.IFigure) |
| */ |
| public Object getConstraint(IFigure child) { |
| return constraints.get(child); |
| } |
| |
| /** |
| * Lays out the given figure's children based on their {@link Locator} |
| * constraint. |
| * |
| * @param parent |
| * the figure whose children should be layed out |
| */ |
| public void layout(IFigure parent) { |
| List children = parent.getChildren(); |
| for (int i = 0; i < children.size(); i++) { |
| IFigure child = (IFigure) children.get(i); |
| Locator locator = (Locator) constraints.get(child); |
| if (locator != null) { |
| locator.relocate(child); |
| } |
| } |
| } |
| |
| /** |
| * Removes the locator for the given figure. |
| * |
| * @param child |
| * the child being removed |
| */ |
| public void remove(IFigure child) { |
| constraints.remove(child); |
| } |
| |
| /** |
| * Sets the constraint for the given figure. |
| * |
| * @param figure |
| * the figure whose contraint is being set |
| * @param constraint |
| * the new constraint |
| */ |
| public void setConstraint(IFigure figure, Object constraint) { |
| super.setConstraint(figure, constraint); |
| if (constraint != null) |
| constraints.put(figure, constraint); |
| } |
| |
| } |