org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/search/action/SearchAction.java

/*******************************************************************************
 * Copyright (c) 2012 Original authors 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:
 *     Original authors and others - initial API and implementation
 ******************************************************************************/
package org.eclipse.nebula.widgets.nattable.search.action;


import org.eclipse.jface.dialogs.IDialogSettings;
import org.eclipse.nebula.widgets.nattable.NatTable;
import org.eclipse.nebula.widgets.nattable.search.CellValueAsStringComparator;
import org.eclipse.nebula.widgets.nattable.search.gui.SearchDialog;
import org.eclipse.nebula.widgets.nattable.ui.action.IKeyAction;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.events.KeyEvent;

/**
 * An action for opening a Find dialog on a NatTable. Supports both modal and
 * non-modal (i.e., sharable) Find dialog behavior. 
 */
public class SearchAction implements IKeyAction {
	
	private static class Context {
		NatTable natTable;
		IDialogSettings dialogSettings;
		private boolean modal;
		Context(NatTable natTable, IDialogSettings dialogSettings, boolean modal) {
			this.natTable = natTable;
			this.dialogSettings = dialogSettings;
			this.modal = modal;
		}
	}
	
	private static Context activeContext;
	private static SearchDialog dialog;
	
	private Context context;
	
	/**
	 * Constructs an action with a modal Find dialog.
	 */
	public SearchAction() {
		this(null, null, true);
	}
	
	/**
	 * Constructs an action with a non-modal (i.e., sharable) Find
	 * dialog.
	 * @param natTable
	 * @param settings
	 */
	public SearchAction(NatTable natTable, IDialogSettings dialogSettings) {
		this(natTable, dialogSettings, false);
		if (natTable == null) {
			throw new IllegalArgumentException();
		}
	}
	
	private SearchAction(NatTable natTable, IDialogSettings dialogSettings, boolean modal) {
		context = new Context(natTable, dialogSettings, modal);
		if (natTable != null) {
			natTable.addFocusListener(new FocusListener() {
				public void focusGained(FocusEvent e) {
					setActiveContext();
				}
				public void focusLost(FocusEvent e) {
				}
			});
		}
	}

	protected void setActiveContext() {
		if (dialog != null && !isEquivalentToActiveContext()) {
			dialog.close();
			dialog = null;
		}
		activeContext = context;
		if (dialog != null) {
			dialog.setInput(context.natTable, context.dialogSettings);
		}
	}

	/**
	 * Checks if this context is considered equivalent to the active context.
	 * For modal equivalence, the contexts must be exactly the same.
	 * For non-modal equivalence, the Shell and IDialogSettings must
	 * be equivalent.
	 * @return whether this context is equivalent to the active context
	 */
	private boolean isEquivalentToActiveContext() {
		if (context.modal) {
			return context.equals(activeContext);
		}
		if (activeContext.modal) {
			return false;
		}
		return !activeContext.natTable.isDisposed()
				&& context.natTable.getShell().equals(activeContext.natTable.getShell())
				&& context.dialogSettings.equals(activeContext.dialogSettings);
	}

	public void run(final NatTable natTable, KeyEvent event) {
		context.natTable = natTable;
		setActiveContext();
		if (dialog == null) {
			dialog = new SearchDialog(context.natTable.getShell(),
					new CellValueAsStringComparator<String>(),
					context.modal ? SWT.NONE : SWT.APPLICATION_MODAL);
			dialog.setInput(context.natTable, context.dialogSettings);
		}
		dialog.open();
	}
	
}