plugins/org.eclipse.epp.installer.core/src/org/eclipse/epp/installer/core/operations/UndoInstallOperation.java

package org.eclipse.epp.installer.core.operations;

import java.util.List;

import org.eclipse.epp.installer.core.model.SequentialOperation;
import org.eclipse.epp.installer.internal.core.InstallLog;
import org.eclipse.epp.installer.internal.core.InstallLogEntry;
import org.eclipse.epp.installer.internal.core.operations.RollbackOperation;


/**
 * UndoInstallOperation used then you need to undo partly complited
 * installation.
 * 
 * Used from
 * {@link com.instantiations.installer.internal.ui.steps.RunOperationsStepWizard }
 * to undo installation then error are happend.
 */
public class UndoInstallOperation extends SequentialOperation {

	/**
	 * Installation log.
	 */
	private InstallLog log;

	/**
	 * Construct new instanceof UndoInstallOperation with current install log.
	 * 
	 * @param log
	 *            InstallLog to undo form.
	 */
	public UndoInstallOperation(InstallLog log) {
		if (log == null) {
			throw new IllegalArgumentException();
		}
		this.log = log;
	}

	/**
	 * Prepare undo.  
	 */
	protected void prepare() {
		List entries = log.getEntries();
		int i = entries.size();
		while (--i >= 0) {
			add(new RollbackOperation((InstallLogEntry) entries.get(i)));
		}
	}

	/**
	 * Method toString.
	 * 
	 * @return String
	 */
	public String toString() {
		return "Undoing installation...";
	}
}