eu.numberfour.n4js.ui.textzoom.TextZoomHandler.java Source code

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Here is the source code for eu.numberfour.n4js.ui.textzoom.TextZoomHandler.java

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/**
 * Copyright (c) 2016 NumberFour AG.
 * 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:
 *   NumberFour AG - Initial API and implementation
 */
package eu.numberfour.n4js.ui.textzoom;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.preferences.IPreferencesService;
import org.eclipse.jface.preference.PreferenceConverter;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.graphics.FontData;
import org.osgi.service.prefs.BackingStoreException;
import org.osgi.service.prefs.Preferences;

/**
 * Handler for zooming in and out in the text editor, that is resizing the font size via hotkey (by default Ctrl/M1+
 * +/-).
 */
public class TextZoomHandler extends AbstractHandler {

    final static String QUALIFIER = "org.eclipse.ui.workbench";
    final static String ZOOM_IN_ID = "eu.numberfour.n4js.ui.TextZoomIn";
    final static String ZOOM_OUT_ID = "eu.numberfour.n4js.ui.TextZoomOut";

    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {

        boolean zoomIn = ZOOM_IN_ID.equals(event.getCommand().getId());
        int delta = zoomIn ? +1 : -1;

        IPreferencesService preferencesService = Platform.getPreferencesService();
        String value = preferencesService.getString(QUALIFIER, JFaceResources.TEXT_FONT, null, null);
        FontData fontData[] = PreferenceConverter.basicGetFontData(value);
        FontData fontdata = fontData[0];
        fontdata.setHeight(fontdata.getHeight() + delta);
        Preferences preferences = preferencesService.getRootNode().node("/instance/" + QUALIFIER);
        preferences.put(JFaceResources.TEXT_FONT, fontdata.toString());
        try {
            preferences.flush();
        } catch (BackingStoreException e) {
            // ignore
        }

        return null;
    }

}