/*******************************************************************************
 * Copyright (c) 2006 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.debug.internal.ui.actions;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.eclipse.debug.internal.ui.DebugUIPlugin;
import org.eclipse.debug.internal.ui.IDebugHelpContextIds;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IColumnPresentation;
import org.eclipse.debug.internal.ui.viewers.model.provisional.TreeModelViewer;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.graphics.Image;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.ListSelectionDialog;
import org.eclipse.ui.texteditor.IUpdate;

/**
 * Configures visible columns in an asynch tree viewer/
 * 
 * @since 3.2
 */
public class ConfigureColumnsAction extends Action implements IUpdate {
	
	private TreeModelViewer fViewer;
	
	class ColumnContentProvider implements IStructuredContentProvider {

		/* (non-Javadoc)
		 * @see org.eclipse.jface.viewers.IStructuredContentProvider#getElements(java.lang.Object)
		 */
		public Object[] getElements(Object inputElement) {
			return ((IColumnPresentation)inputElement).getAvailableColumns();
		}

		/* (non-Javadoc)
		 * @see org.eclipse.jface.viewers.IContentProvider#dispose()
		 */
		public void dispose() {
		}

		/* (non-Javadoc)
		 * @see org.eclipse.jface.viewers.IContentProvider#inputChanged(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
		 */
		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {			
		}
		
	}
	
	class ColumnLabelProvider extends LabelProvider {
		
		private Map fImages = new HashMap();

		public Image getImage(Object element) {
			ImageDescriptor imageDescriptor = fViewer.getColumnPresentation().getImageDescriptor((String)element);
			if (imageDescriptor != null) {
				Image image = (Image) fImages.get(imageDescriptor);
				if (image == null) {
					image = imageDescriptor.createImage();
					fImages.put(imageDescriptor, image);
				}
				return image;
			}
			return null;
		}

		public String getText(Object element) {
			return fViewer.getColumnPresentation().getHeader((String)element);
		}

		public void dispose() {
			super.dispose();
			Iterator iterator = fImages.values().iterator();
			while (iterator.hasNext()) {
				Image image = (Image) iterator.next();
				image.dispose();
			}
			fImages.clear();
		}
		
		
		
	}

	public ConfigureColumnsAction(TreeModelViewer viewer) {
		setText(ActionMessages.ConfigureColumnsAction_0);
		setId(DebugUIPlugin.getUniqueIdentifier() + ".ConfigureColumnsAction"); //$NON-NLS-1$
		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IDebugHelpContextIds.CONFIGURE_COLUMNS_ACTION);
		fViewer = viewer;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.texteditor.IUpdate#update()
	 */
	public void update() {
		setEnabled(fViewer.isShowColumns());
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.action.Action#run()
	 */
	public void run() {
		ListSelectionDialog dialog = new ListSelectionDialog(
				fViewer.getControl().getShell(),
				fViewer.getColumnPresentation(),
				new ColumnContentProvider(),
				new ColumnLabelProvider(),
				ActionMessages.ConfigureColumnsAction_1);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IDebugHelpContextIds.CONFIGURE_COLUMNS_DIALOG);
		String[] visibleColumns = fViewer.getVisibleColumns();
		List initialSelection = new ArrayList(visibleColumns.length);
		for (int i = 0; i < visibleColumns.length; i++) {
			initialSelection.add(visibleColumns[i]);
		}
		dialog.setTitle(ActionMessages.ConfigureColumnsAction_2);
		dialog.setInitialElementSelections(initialSelection);
		if (dialog.open() == Window.OK) {
			Object[] result = dialog.getResult();
			if (result.length == 0) {
				fViewer.setShowColumns(false);
			} else {
				String[] ids = new String[result.length];
				System.arraycopy(result, 0, ids, 0, result.length);
				fViewer.resetColumnSizes(ids);
				fViewer.setVisibleColumns(ids);
			}
		}
			
	}
	
}