org.eclipse.ui.internal.texteditor.AbstractZoomTextHandler.java Source code

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Here is the source code for org.eclipse.ui.internal.texteditor.AbstractZoomTextHandler.java

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/*******************************************************************************
 * Copyright (c) 2015 Red Hat Inc.
 * 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:
 *     Mickael Istria (Red Hat Inc.) - 469918 Zoom In/Out
 *******************************************************************************/
package org.eclipse.ui.internal.texteditor;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.jface.preference.PreferenceConverter;
import org.eclipse.jface.resource.FontDescriptor;
import org.eclipse.jface.resource.FontRegistry;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.ui.IPartService;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.internal.WorkbenchPlugin;
import org.eclipse.ui.part.AbstractMultiEditor;
import org.eclipse.ui.part.MultiPageEditorPart;
import org.eclipse.ui.texteditor.AbstractTextEditor;

public abstract class AbstractZoomTextHandler extends AbstractHandler {

    private int fontDiff;

    protected AbstractZoomTextHandler(int fontDiff) {
        this.fontDiff = fontDiff;
    }

    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {
        AbstractTextEditor textEditor = getActiveTextEditor();
        if (textEditor == null) {
            return null;
        }
        FontRegistry fontRegistry = textEditor.getSite().getWorkbenchWindow().getWorkbench().getThemeManager()
                .getCurrentTheme().getFontRegistry();
        FontData[] initialFontData = fontRegistry.getFontData(JFaceResources.TEXT_FONT);
        int destFontSize = initialFontData[0].getHeight() + this.fontDiff;
        if (destFontSize <= 0) {
            return null;
        }
        FontDescriptor newFontDescriptor = FontDescriptor.createFrom(initialFontData).setHeight(destFontSize);
        fontRegistry.put(JFaceResources.TEXT_FONT, newFontDescriptor.getFontData());
        PlatformUI.getPreferenceStore().setValue(JFaceResources.TEXT_FONT,
                PreferenceConverter.getStoredRepresentation(newFontDescriptor.getFontData()));
        WorkbenchPlugin.getDefault().getPreferenceStore().setValue(JFaceResources.TEXT_FONT,
                PreferenceConverter.getStoredRepresentation(newFontDescriptor.getFontData()));
        return newFontDescriptor;
    }

    private AbstractTextEditor getActiveTextEditor() {
        IWorkbench workbench = PlatformUI.getWorkbench();
        IWorkbenchWindow activeWorkbenchWindow = workbench.getActiveWorkbenchWindow();
        if (activeWorkbenchWindow == null) {
            return null;
        }
        IPartService partService = activeWorkbenchWindow.getPartService();
        if (partService == null) {
            return null;
        }
        IWorkbenchPart part = partService.getActivePart();
        AbstractTextEditor textEditor = null;
        if (part instanceof AbstractTextEditor) {
            textEditor = (AbstractTextEditor) part;
        } else if ((part instanceof AbstractMultiEditor)
                && ((AbstractMultiEditor) part).getActiveEditor() instanceof AbstractTextEditor) {
            textEditor = (AbstractTextEditor) ((AbstractMultiEditor) part).getActiveEditor();
        } else if ((part instanceof MultiPageEditorPart)
                && ((MultiPageEditorPart) part).getSelectedPage() instanceof AbstractTextEditor) {
            textEditor = (AbstractTextEditor) ((MultiPageEditorPart) part).getSelectedPage();
        }
        return textEditor;
    }

    @Override
    public boolean isEnabled() {
        return getActiveTextEditor() != null;
    }
}