org.eclipse.xwt.tools.ui.designer/src/org/eclipse/xwt/tools/ui/designer/editor/sash/AddSashFormChildCommands.java

/*******************************************************************************
 * Copyright (c) 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.xwt.tools.ui.designer.editor.sash;

import org.eclipse.xwt.IConstants;
import org.eclipse.xwt.XWT;
import org.eclipse.xwt.internal.utils.LoggerManager;
import org.eclipse.xwt.metadata.IMetaclass;
import org.eclipse.gef.EditPart;
import org.eclipse.swt.custom.SashForm;
import org.eclipse.swt.widgets.Sash;
import org.eclipse.xwt.tools.ui.designer.commands.AddNewChildCommand;
import org.eclipse.xwt.tools.ui.designer.core.util.SashUtil;
import org.eclipse.xwt.tools.ui.designer.parts.SashEditPart;
import org.eclipse.xwt.tools.ui.designer.parts.SashFormEditPart;
import org.eclipse.xwt.tools.ui.xaml.XamlAttribute;
import org.eclipse.xwt.tools.ui.xaml.XamlFactory;
import org.eclipse.xwt.tools.ui.xaml.XamlNode;

public class AddSashFormChildCommands extends AddNewChildCommand {
	public static final String WIEGHTS_ATTR = "weights";
	private EditPart host;
	private int[] oldWeights;
	private boolean hasWeightsAttribute = false;

	public AddSashFormChildCommands(EditPart parent, XamlNode child) {
		this(parent, child, -1);
	}

	public AddSashFormChildCommands(EditPart parent, XamlNode child, int index) {
		super((XamlNode) parent.getModel(), child, index);
		this.host = parent;
	}

	@Override
	public boolean canExecute() {
		boolean result = super.canExecute() && host instanceof SashFormEditPart;
		if (!result) {
			return false;
		}
		XamlNode child = getChild();
		String name = child.getName();
		String ns = child.getNamespace();
		IMetaclass metaclass = XWT.getMetaclass(name, ns);
		return metaclass.getType() != Sash.class;
	}

	@Override
	public void execute() {
		XamlNode sashForm = (XamlNode) host.getModel();
		XamlAttribute attribute = sashForm.getAttribute(WIEGHTS_ATTR,
				IConstants.XWT_NAMESPACE);
		SashFormEditPart sashFormEditPart = (SashFormEditPart) host;
		SashForm form = (SashForm) sashFormEditPart.getWidget();

		hasWeightsAttribute = (attribute != null);
		if (!hasWeightsAttribute) {
			super.execute();
			return;
		}
		
		oldWeights = form.getWeights();

		int children = 0;

		for (Object child : sashFormEditPart.getChildren()) {
			if (!(child instanceof SashEditPart)) {
				children++;
			}
		}

		if (children == 0) {
			try {
				// add in the list first
				super.execute();
			} catch (Exception e) {
				LoggerManager.log(e);
			}
			return;
		}

		int[] weights = new int[children + 1];
		int sum = 0;
		if (oldWeights.length != 0) {
			for (int i = 0; i < oldWeights.length; i++) {
				weights[i] = oldWeights[i];
				sum += oldWeights[i];
			}
			if (children > oldWeights.length) {
				int delta = sum / (children - oldWeights.length);
				for (int i = oldWeights.length; i < children - 1; i++) {
					weights[i] = delta;
				}
				weights[children - 1] = sum
						- (delta * (children - oldWeights.length));
			}

			int index = getIndex();
			if (index == -1) {
				index = children;
			}

			int part1 = weights[index] / 2;
			int part2 = weights[index] - part1;

			for (int i = children - 1; i > index; i--) {
				weights[i + 1] = oldWeights[i];
			}
			weights[index] = part1;
			weights[index + 1] = part2;
		} else {
			int delta = 1000 / weights.length;
			for (int i = 0; i < weights.length - 1; i++) {
				weights[i] = delta;
			}
			weights[weights.length - 1] = sum - (delta * (children));
		}

		try {
			// add in the list first
			super.execute();

			if (weights.length > 1) {
				// update the weights after, since the Notifier as update it.
				// Her we just override it.
				String value = SashUtil.weightsValue(weights);
				if (attribute == null) {
					attribute = XamlFactory.eINSTANCE.createAttribute(
							WIEGHTS_ATTR, IConstants.XWT_NAMESPACE);
					sashForm.getAttributes().add(attribute);
				}
				attribute.setValue(value);
			}
		} catch (Exception e) {
			LoggerManager.log(e);
		}
	}

	@Override
	public void undo() {
		super.undo();
		if (hasWeightsAttribute) {
			XamlNode sashForm = (XamlNode) host.getModel();
			String value = SashUtil.weightsValue(oldWeights);
			XamlAttribute attribute = sashForm.getAttribute(WIEGHTS_ATTR,
					IConstants.XWT_NAMESPACE);
			attribute.setValue(value);
		}
	}
}