core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/internal/ui/editor/ToggleMarkOccurrencesAction.java

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.dltk.internal.ui.editor;

import org.eclipse.dltk.ui.DLTKPluginImages;
import org.eclipse.dltk.ui.DLTKUILanguageManager;
import org.eclipse.dltk.ui.IDLTKUILanguageToolkit;
import org.eclipse.dltk.ui.PreferenceConstants;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.ui.texteditor.ITextEditor;
import org.eclipse.ui.texteditor.TextEditorAction;

/**
 * A toolbar action which toggles the
 * {@linkplain PreferenceConstants#EDITOR_MARK_OCCURRENCES mark occurrences
 * preference}.
 *
 * @since 3.0
 */
public class ToggleMarkOccurrencesAction extends TextEditorAction implements
		IPropertyChangeListener {

	private IPreferenceStore fStore;

	/**
	 * Constructs and updates the action.
	 */
	public ToggleMarkOccurrencesAction() {
		super(ScriptEditorMessages.getBundleForConstructedKeys(),
				"ToggleMarkOccurrencesAction.", null, IAction.AS_CHECK_BOX); //$NON-NLS-1$
		DLTKPluginImages.setToolImageDescriptors(this, "mark_occurrences.png"); //$NON-NLS-1$
		// PlatformUI.getWorkbench().getHelpSystem().setHelp(this,
		// IJavaHelpContextIds.TOGGLE_MARK_OCCURRENCES_ACTION);
		update();
	}

	@Override
	public void run() {
		if (fStore != null) {
			fStore.setValue(PreferenceConstants.EDITOR_MARK_OCCURRENCES,
					isChecked());
		}
	}

	@Override
	public void update() {
		final ITextEditor editor = getTextEditor();
		final OccurrencesFinder occurrencesFinder = (editor != null) ? (OccurrencesFinder) editor
				.getAdapter(OccurrencesFinder.class) : null;
		setEnabled(occurrencesFinder != null);
		setChecked(occurrencesFinder != null
				&& occurrencesFinder.isMarkingOccurrences());
	}

	@Override
	public void setEditor(ITextEditor editor) {
		super.setEditor(editor);
		if (editor != null) {
			disconnectPreferenceStore();
			if (editor instanceof ScriptEditor) {
				final IDLTKUILanguageToolkit toolkit = DLTKUILanguageManager
						.getLanguageToolkit(((ScriptEditor) editor)
								.getLanguageToolkit());
				if (toolkit != null) {
					fStore = toolkit.getPreferenceStore();
					if (fStore != null) {
						fStore.addPropertyChangeListener(this);
					}
				}
			}
		} else {
			disconnectPreferenceStore();
		}
		update();
	}

	private void disconnectPreferenceStore() {
		if (fStore != null) {
			fStore.removePropertyChangeListener(this);
			fStore = null;
		}
	}

	@Override
	public void propertyChange(PropertyChangeEvent event) {
		if (event.getProperty().equals(
				PreferenceConstants.EDITOR_MARK_OCCURRENCES))
			setChecked(Boolean.valueOf(event.getNewValue().toString())
					.booleanValue());
	}
}