/*******************************************************************************
 * Copyright (c) 2000, 2014 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
 *     Wind River Systems - added support for IToggleBreakpointsTargetFactory
 *     Freescale 	- Add support for conditionally activating an action
 *******************************************************************************/
package org.eclipse.cdt.debug.internal.ui.actions.breakpoints;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.ui.DebugUITools;
import org.eclipse.debug.ui.actions.IToggleBreakpointsTarget;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.widgets.Event;
import org.eclipse.ui.IActionDelegate2;
import org.eclipse.ui.IObjectActionDelegate;
import org.eclipse.ui.IWorkbenchPart;

/**
 * A toggle breakpoint action that can be contributed to an object. The action
 * will perform a toggle breakpoint operation for a selected object.
 * <p>
 * This class is based on {@link org.eclipse.debug.internal.ui.actions.breakpoints.ToggleBreakpointObjectActionDelegate }
 * class.  In addition to the copied functionality, it adds the handling of 
 * action-triggering event.
 * </p>
 * 
 * @since 7.2
 */
public abstract class CToggleBreakpointObjectActionDelegate implements IObjectActionDelegate, IActionDelegate2 {
	
	private IWorkbenchPart fPart;
	private IStructuredSelection fSelection;
	
	public void setActivePart(IAction action, IWorkbenchPart targetPart) {
		fPart = targetPart;
	}

	public void run(IAction action) {
	    runWithEvent(action, null);
	}

	public void runWithEvent(IAction action, Event event) {
        IToggleBreakpointsTarget target = 
            DebugUITools.getToggleBreakpointsTargetManager().getToggleBreakpointsTarget(fPart, fSelection);
        if (target != null) {
            try {
                performAction(target, fPart, fSelection, event);
            } catch (CoreException e) {
                DebugPlugin.log(e);
            }
        }
    }

	/**
	 * Performs the operation specific to this action.
	 *  
	 * @param target adapter to toggle breakpoints
	 * @param part the active part
	 * @param selection the selection in the active part
	 * @param event that triggered this action
	 * @exception CoreException if an exception occurs
	 */
	protected abstract void performAction(IToggleBreakpointsTarget target, IWorkbenchPart part, ISelection selection, Event event) 
	    throws CoreException;
	
	/**
	 * Returns whether the specific operation is supported.
	 * 
	 * @param target the target adapter
	 * @param selection the selection to verify the operation on
	 * @param part the part the operation has been requested on
	 * @return whether the operation can be performed
	 */
	protected abstract boolean canPerformAction(IToggleBreakpointsTarget target, IWorkbenchPart part, ISelection selection);
	
	public void selectionChanged(IAction action, ISelection selection) {
		boolean enabled = false;
		if (selection instanceof IStructuredSelection) {
			IStructuredSelection ss = (IStructuredSelection) selection;
			this.fSelection = ss;
			// selectionChagned() can sometimes be called before setActivePart().
			// Guard here against that possibility.
			if (fPart != null) {
			    IToggleBreakpointsTarget target = 
			        DebugUITools.getToggleBreakpointsTargetManager().getToggleBreakpointsTarget(fPart, fSelection);
			    enabled = target != null && canPerformAction(target, fPart, fSelection);
			}
		}
		action.setEnabled(enabled);
	}

	public void init(IAction action) {
	}
	
	public void dispose() {
		fSelection = null;
		fPart = null;
	}
}