/*******************************************************************************
 * Copyright (c) 2007, 2008 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
 * 	   Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
 * 												 - fix for bug 183850, 182652, 182800, 215069
 * 	   Pavel Sklenak <pavel.sklenak@gmail.com>   - multi line highlighting support
 * 											     - SWT.Traverse event if cell changed	
 *******************************************************************************/

package org.eclipse.jface.viewers;

import org.eclipse.core.runtime.Assert;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;

/**
 * A concrete implementation of {@link FocusCellHighlighter} using by setting
 * the control into owner draw mode and highlighting the currently selected
 * cell. To make the use this class you should create the control with the
 * {@link SWT#FULL_SELECTION} bit set
 * 
 * This class can be subclassed to configure how the coloring of the selected
 * cell.
 * 
 * @since 3.3
 * 
 */
public class FocusCellOwnerDrawBorderHighlighter extends FocusCellHighlighter {
	
	private ColumnViewer viewer;
	private int index;
	private Object item;
	
	/**
	 * Create a new instance which can be passed to a
	 * {@link TreeViewerFocusCellManager}
	 * 
	 * @param viewer
	 *            the viewer
	 */
	public FocusCellOwnerDrawBorderHighlighter(ColumnViewer viewer) {
		super(viewer);
		this.viewer = viewer;
		index = 1;
		hookListener(viewer);
	}

	private void removeSelectionInformation(Event event, ViewerCell cell) {
		GC gc = event.gc;
		gc.setBackground(cell.getViewerRow().getBackground(
				cell.getColumnIndex()));
		gc.setForeground(cell.getViewerRow().getForeground(
				cell.getColumnIndex()));
		gc.fillRectangle(cell.getBounds());
		event.detail &= ~SWT.SELECTED;
	}

	private void hookListener(final ColumnViewer viewer) {

		Listener listener = new Listener() {

			public void handleEvent(Event event) {
				if ((event.detail & SWT.SELECTED) > 0) {
					ViewerCell focusCell = getFocusCell();
					ViewerRow row = viewer.getViewerRowFromItem(event.item);

					Assert.isNotNull(row,
						"Internal structure invalid. Item without associated row is not possible."); //$NON-NLS-1$

					ViewerCell cell = row.getCell(event.index);

					if (focusCell == null || !cell.equals(focusCell)) {
//						removeSelectionInformation(event, cell);
					} else {
						removeSelectionInformation(event, cell);
						drawBorder(event, cell);
						notifyTraverse(event);
					}
					
				}
			}

		};
		viewer.getControl().addListener(SWT.EraseItem, listener);
	}

	private void drawBorder(Event event, ViewerCell cell){
		Rectangle rect = cell.getBounds();
		Color fg = event.gc.getForeground();
		event.gc.setForeground(event.display.getSystemColor(SWT.COLOR_BLACK));
		event.gc.drawRectangle(rect.x, rect.y, rect.width-1 , rect.height-1);
		event.gc.setForeground(fg);
	}
	
	protected void focusCellChanged(ViewerCell newCell, ViewerCell oldCell) {
		super.focusCellChanged(newCell, oldCell);

		// Redraw new area
		redrawCellArea(newCell);

		// Redraw old area
		redrawCellArea(oldCell);

	}
	
	protected void redrawCellArea(ViewerCell cell){
		if (cell == null) return;
		
		Rectangle rect = cell.getBounds();
		int x = cell.getColumnIndex() == 0 ? 0 : rect.x;
		int width = cell.getColumnIndex() == 0 ? rect.x + rect.width 
				: rect.width;
		// 1 is a fix for Linux-GTK
		cell.getControl().redraw(x, rect.y - 1, width, rect.height + 1, true);
	}
	
	/**
	 * Send event to viewer's control (SWT.Traverse)
	 * @param event
	 */
	protected void notifyTraverse(Event event){
		if(event.index != index || event.item != item){
			index = event.index;
			item = event.item;
			viewer.getControl().notifyListeners(SWT.Traverse, event);
		}
	}
}