/*******************************************************************************
 * 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.views.tasklist;

import org.eclipse.core.resources.IMarker;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.ui.help.WorkbenchHelp;

/**
 * This action creates a new task. If a resource is currently
 * present at the tasklist's input, this task will be
 * associated with it. If the tasklist is currently
 * observing all the markers in the workbench, the task
 * will not be associated with any resource.
 * <p>The newly created task will have low priority,
 * fixed description text and will not be subject to
 * sorting or filtering until its desciprion is being
 * changed for the first time. For this reason, new
 * tasks remain at the top of the task list
 * until modified. It is possible that the newly
 * created task dissapears after that if its
 * type or some other property causes it to
 * be filtered out.
 */
class NewTaskAction extends TaskAction {
	
	/**
	 * Creates the action.
	 */
	public NewTaskAction(TaskList tasklist, String id) {
		super(tasklist, id);
		WorkbenchHelp.setHelp(this, ITaskListHelpContextIds.NEW_TASK_ACTION);
	}

	/**
	 * Opens the new task dialog and shows the newly created task when done.
	 * The new task is created on the currently selected resource.
	 */
	public void run() {
		TaskPropertiesDialog dialog = new TaskPropertiesDialog(getShell());
		dialog.setResource(getTaskList().getResource());
		int result = dialog.open();
		if (result == Dialog.OK) {
			showMarker(dialog.getMarker());
		}
	}

	/**
	 * Show the newly created marker.
	 */
	private void showMarker(final IMarker marker) {
		if (marker == null) {
			return;
		}
		if (getTaskList().shouldShow(marker)) {
			// Need to do this in an asyncExec, even though we're in the UI thread here,
			// since the task list updates itself with the addition in an asyncExec,
			// which hasn't been processed yet.
			getShell().getDisplay().asyncExec(new Runnable() {
				public void run() {
					getTaskList().setSelection(new StructuredSelection(marker), true);
				}
			});
		}
		else {
			MessageDialog.openInformation(
				getShell(),
				TaskListMessages.getString("NewTask.notShownTitle"), //$NON-NLS-1$
				TaskListMessages.getString("NewTask.notShownMsg")); //$NON-NLS-1$
		}
	}
}