Copyright (c) 2000, 2018 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Anton Kosyakov (Itemis AG) - Bug 438621 - [step filtering] Provide an extension point to enhance methods step filtering.
/*******************************************************************************
 * Copyright (c) 2000, 2018 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Anton Kosyakov (Itemis AG) - Bug 438621 - [step filtering] Provide an extension point to enhance methods step filtering.
 *******************************************************************************/
package org.eclipse.debug.internal.core;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.Platform;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunch;
import org.eclipse.debug.core.ILaunchListener;
import org.eclipse.debug.core.commands.IStepFiltersHandler;
import org.eclipse.debug.core.model.IStepFilter;
import org.eclipse.debug.internal.core.commands.DebugCommandRequest;

As targets are launched, this manager sets its step filter
support settings according to the "use step filter" setting.
Since:
3.0/**
 * As targets are launched, this manager sets its step filter
 * support settings according to the "use step filter" setting.
 *
 * @since 3.0
 */
public class StepFilterManager implements ILaunchListener {

	public static final String PREF_USE_STEP_FILTERS = DebugPlugin.getUniqueIdentifier() + ".USE_STEP_FILTERS"; //$NON-NLS-1$

	
The step filter manager is instantiated by the debug UI plug-in,
and should be accessed from the DebugUIPlugin class.
/**
	 * The step filter manager is instantiated by the debug UI plug-in,
	 * and should be accessed from the <code>DebugUIPlugin</code> class.
	 */
	protected StepFilterManager() {
		DebugPlugin.getDefault().getLaunchManager().addLaunchListener(this);
	}

	
This method is called by the debug UI plug-in at shutdown.
/**
	 * This method is called by the debug UI plug-in at shutdown.
	 */
	public void shutdown() {
		DebugPlugin.getDefault().getLaunchManager().removeLaunchListener(this);
	}

	@Override
	public void launchAdded(ILaunch launch) {
		launchChanged(launch);
	}

	@Override
	public void launchChanged(ILaunch launch) {
		IStepFiltersHandler command = launch.getAdapter(IStepFiltersHandler.class);
		if (command != null) {
			command.execute(new DebugCommandRequest(new Object[]{launch}));
		}
	}

	
Returns whether the 'use step filters' preference is on.
Returns:
whether to use step filters/**
	 * Returns whether the 'use step filters' preference is on.
	 *
	 * @return whether to use step filters
	 */
	public boolean isUseStepFilters() {
		return Platform.getPreferencesService().getBoolean(DebugPlugin.getUniqueIdentifier(), PREF_USE_STEP_FILTERS, false, null);
	}

	
Sets whether to use step filters.
Params:
useFilters – whether to use step filters/**
	 * Sets whether to use step filters.
	 *
	 * @param useFilters whether to use step filters
	 */
	public void setUseStepFilters(boolean useFilters) {
		Preferences.setBoolean(DebugPlugin.getUniqueIdentifier(), PREF_USE_STEP_FILTERS, useFilters, null);
		ILaunch[] launchs = DebugPlugin.getDefault().getLaunchManager().getLaunches();
		for (ILaunch launch : launchs) {
			launchChanged(launch);
		}
	}

	@Override
	public void launchRemoved(ILaunch launch) {}

	
Returns any step filters that have been contributed for the given model
identifier.
Params:
modelIdentifier – the model identifier
See Also:
IStepFilter
Returns:
step filters that have been contributed for the given model
        identifier, possibly an empty collection
Since:
3.10/**
	 * Returns any step filters that have been contributed for the given model
	 * identifier.
	 *
	 * @param modelIdentifier the model identifier
	 * @return step filters that have been contributed for the given model
	 *         identifier, possibly an empty collection
	 * @since 3.10
	 * @see org.eclipse.debug.core.model.IStepFilter
	 */
	public IStepFilter[] getStepFilters(String modelIdentifier) {
		initialize();
		List<IStepFilter> select = new ArrayList<>();
		for (StepFilter extension : stepFilters) {
			Collections.addAll(select, extension.getStepFilters(modelIdentifier));
		}
		return select.toArray(new IStepFilter[select.size()]);
	}

	private List<StepFilter> stepFilters = null;

	private synchronized void initialize() {
		if (stepFilters == null) {
			IExtensionPoint point = Platform.getExtensionRegistry().getExtensionPoint(DebugPlugin.getUniqueIdentifier(), DebugPlugin.EXTENSION_POINT_STEP_FILTERS);
			IConfigurationElement[] extensions = point.getConfigurationElements();
			stepFilters = new ArrayList<>();
			for (IConfigurationElement extension : extensions) {
				try {
					stepFilters.add(new StepFilter(extension));
				} catch (CoreException e) {
					DebugPlugin.log(e);
				}
			}
		}
	}
}