org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/texteditor/MarkerUtilities.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ui.texteditor;


import java.util.Map;

import org.eclipse.core.resources.IMarker;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspaceRunnable;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Platform;

import org.eclipse.ui.PlatformUI;



/**
 * Utility class for accessing marker attributes. The static methods provided
 * on this class provide internal exception handling (unexpected 
 * <code>CoreException</code>s are logged to workbench).
 * <p>
 * This class provides static methods only; it is not intended to be
 * instantiated or subclassed by clients.
 * </p>
 */
public final class MarkerUtilities {
	
	/**
	 * Don't allow instantiation.
	 */
	private MarkerUtilities() {
	}
	
	/**
	 * Returns the ending character offset of the given marker.
	 *
	 * @param marker the marker
	 * @return the ending character offset, or <code>-1</code> if not set
	 * @see IMarker#CHAR_END
	 * @see IMarker#getAttribute(java.lang.String, int)
	 */
	public static int getCharEnd(IMarker marker) {
		return getIntAttribute(marker, IMarker.CHAR_END, -1);
	}
	
	/**
	 * Returns the starting character offset of the given marker.
	 *
	 * @param marker the marker
	 * @return the starting character offset, or <code>-1</code> if not set
	 * @see IMarker#CHAR_START
	 * @see IMarker#getAttribute(java.lang.String,int)
	 */
	public static int getCharStart(IMarker marker) {
		return getIntAttribute(marker, IMarker.CHAR_START, -1);
	}
	
	/**
	 * Returns the specified attribute of the given marker as an integer.
	 * Returns the given default if the attribute value is not an integer.
	 */
	private static int getIntAttribute(IMarker marker, String attributeName, int defaultValue) {
		if (marker.exists())
			return marker.getAttribute(attributeName, defaultValue);
		return defaultValue;
	}
	
	/**
	 * Returns the line number of the given marker.
	 *
	 * @param marker the marker
	 * @return the line number, or <code>-1</code> if not set
	 * @see IMarker#LINE_NUMBER
	 * @see IMarker#getAttribute(java.lang.String,int)
	 */
	public static int getLineNumber(IMarker marker) {
		return getIntAttribute(marker, IMarker.LINE_NUMBER, -1);
	}
	
	/**
	 * Returns the priority of the given marker.
	 *
	 * @param marker the marker
	 * @return the priority, or <code>IMarker.PRIORITY_NORMAL</code> if not set
	 * @see IMarker#PRIORITY
	 * @see IMarker#PRIORITY_NORMAL
	 * @see IMarker#getAttribute(java.lang.String,int)
	 */
	public static int getPriority(IMarker marker) {
		return getIntAttribute(marker, IMarker.PRIORITY, IMarker.PRIORITY_NORMAL);
	}
	
	/**
	 * Handles a core exception which occurs when accessing marker attributes.
	 */
	private static void handleCoreException(CoreException e) {
		Platform.getPlugin(PlatformUI.PLUGIN_ID).getLog().log(e.getStatus());
	}
	
	/**
	 * Returns whether the given marker is of the given type (either directly or indirectly).
	 *
	 * @param marker the marker to be checked
	 * @param type the reference type
	 * @return <code>true</code>if maker is an instance of the reference type
	 */
	public static boolean isMarkerType(IMarker marker, String type) {
		try {
			return marker.exists() && marker.isSubtypeOf(type);
		} catch (CoreException e) {
			handleCoreException(e);
			return false;
		}
	}
	
	/**
	 * Sets the ending character offset of the given marker.
	 *
	 * @param marker the marker
	 * @param charEnd the ending character offset
	 * @see IMarker#CHAR_END
	 * @see IMarker#setAttribute(java.lang.String,int)
	 */
	public static void setCharEnd(IMarker marker, int charEnd) {
		setIntAttribute(marker, IMarker.CHAR_END, charEnd);
	}
	
	/**
	 * Sets the ending character offset in the given map using the standard 
	 * marker attribute name as the key.
	 *
	 * @param map the map (key type: <code>String</code>, value type:
	 *   <code>Object</code>)
	 * @param charEnd the ending character offset
	 * @see IMarker#CHAR_END
	 */
	public static void setCharEnd(Map map, int charEnd) {
		map.put(IMarker.CHAR_END, new Integer(charEnd));
	}
	
	/**
	 * Sets the starting character offset of the given marker.
	 *
	 * @param marker the marker
	 * @param charStart the starting character offset
	 * @see IMarker#CHAR_START
	 * @see IMarker#setAttribute(java.lang.String,int)
	 */
	public static void setCharStart(IMarker marker, int charStart) {
		setIntAttribute(marker, IMarker.CHAR_START, charStart);
	}
	
	/**
	 * Sets the starting character offset in the given map using the standard 
	 * marker attribute name as the key.
	 *
	 * @param map the map (key type: <code>String</code>, value type:
	 *   <code>Object</code>)
	 * @param charStart the starting character offset
	 * @see IMarker#CHAR_START
	 */
	public static void setCharStart(Map map, int charStart) {
		map.put(IMarker.CHAR_START, new Integer(charStart));
	}
	
	/**
	 * Sets the specified attribute of the given marker as an integer.
	 * 
	 * @param marker the marker
	 * @param attributeName the attribute name
	 * @param value the int value
	 */
	private static void setIntAttribute(IMarker marker, String attributeName, int value) {
		try {
			if (marker.exists())
				marker.setAttribute(attributeName, value);
		} catch (CoreException e) {
			handleCoreException(e);
		}
	}
	
	/**
	 * Sets the line number of the given marker.
	 *
	 * @param marker the marker
	 * @param lineNum the line number
	 * @see IMarker#LINE_NUMBER
	 * @see IMarker#setAttribute(java.lang.String,int)
	 */
	public static void setLineNumber(IMarker marker, int lineNum) {
		setIntAttribute(marker, IMarker.LINE_NUMBER, lineNum);
	}
	
	/**
	 * Sets the line number in the given map using the standard marker attribute
	 * name as the key.
	 *
	 * @param map the map (key type: <code>String</code>, value type:
	 *   <code>Object</code>)
	 * @param lineNum the line number
	 * @see IMarker#LINE_NUMBER
	 */
	public static void setLineNumber(Map map, int lineNum) {
		map.put(IMarker.LINE_NUMBER, new Integer(lineNum));
	}
	
	/**
	 * Sets the message in the given map using the standard marker attribute name
	 * as the key.
	 *
	 * @param map the map (key type: <code>String</code>, value type:
	 *   <code>Object</code>)
	 * @param message the message
	 * @see IMarker#MESSAGE
	 */
	public static void setMessage(Map map, String message) {
		map.put(IMarker.MESSAGE, message);
	}
	
	/**
	 * Creates a marker on the given resource with the given type and attributes.
	 * <p>
	 * This method modifies the workspace (progress is not reported to the user).</p>
	 *
	 * @param resource the resource
	 * @param attributes the attribute map (key type: <code>String</code>, 
	 *   value type: <code>Object</code>)
	 * @param markerType the type of marker
	 * @exception CoreException if this method fails
	 * @see IResource#createMarker
	 */
	public static void createMarker(final IResource resource, final Map attributes, final String markerType) throws CoreException {
	
		IWorkspaceRunnable r= new IWorkspaceRunnable() {
			public void run(IProgressMonitor monitor) throws CoreException {
				IMarker marker= resource.createMarker(markerType);
				marker.setAttributes(attributes);
			}
		};
			
		resource.getWorkspace().run(r, null);
	}
}