org.eclipse.ui.internal.intro.impl.FontSelection.java Source code

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Here is the source code for org.eclipse.ui.internal.intro.impl.FontSelection.java

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/*******************************************************************************
 *  Copyright (c) 2008, 2011 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
 *******************************************************************************/

package org.eclipse.ui.internal.intro.impl;

import org.eclipse.core.runtime.IProduct;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.preferences.DefaultScope;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.core.runtime.preferences.InstanceScope;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.osgi.service.prefs.BackingStoreException;

public class FontSelection {

    public static final String VAR_FONT_STYLE = "fontStyle"; //$NON-NLS-1$
    public static final String FONT_ABSOLUTE = "absolute"; //$NON-NLS-1$
    public static final String FONT_RELATIVE = "relative"; //$NON-NLS-1$   
    private static final String SCALE_FACTOR = "scaleFactor"; //$NON-NLS-1$
    public static final String ATT_SCALABLE = "scalable"; //$NON-NLS-1$

    private static final int MIN_HEIGHT = 10;
    private static final int MAX_HEIGHT = 16;

    /*
     * Returns the height in points of the default SWT font
     */
    private static int getDefaultFontHeight() {
        Font defaultFont = JFaceResources.getDefaultFont();
        FontData[] fontData = defaultFont.getFontData();
        int height = MIN_HEIGHT;
        for (int i = 0; i < fontData.length; i++) {
            FontData data = fontData[i];
            height = Math.max(height, data.getHeight());
        }
        return Math.min(height, MAX_HEIGHT);
    }

    public static String generatePageFontStyle() {
        int defaultFontHeight = getDefaultFontHeight();
        int scale = getScalePercentage();
        String result = getFontSizeDeclaration("", defaultFontHeight, 100, scale); //$NON-NLS-1$
        result += getFontSizeDeclaration("h1", defaultFontHeight, 200, scale); //$NON-NLS-1$
        result += getFontSizeDeclaration("h2", defaultFontHeight, 150, scale); //$NON-NLS-1$
        result += getFontSizeDeclaration("h3", defaultFontHeight, 120, scale); //$NON-NLS-1$
        result += getFontSizeDeclaration("h4", defaultFontHeight, 100, scale); //$NON-NLS-1$
        result += getFontSizeDeclaration("h5", defaultFontHeight, 80, scale); //$NON-NLS-1$
        result += getFontSizeDeclaration("h6", defaultFontHeight, 70, scale); //$NON-NLS-1$
        return result;
    }

    public static final int getScalePercentage() {
        int scale = Platform.getPreferencesService().getInt(IntroPlugin.PLUGIN_ID, (SCALE_FACTOR), 0, null);
        return scale;
    }

    private static String getFontSizeDeclaration(String element, int baseSize, int percentage, int scale) {
        if (scale > 75)
            scale = 75;
        int newSize = (int) ((baseSize * percentage * 1.25) / (100 - scale));
        return " body " + element + "{  font-size : " + newSize + "px; } "; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
    }

    public static void setScalePercentage(int i) {
        IEclipsePreferences prefs = InstanceScope.INSTANCE.getNode(IntroPlugin.PLUGIN_ID);
        prefs.putInt(SCALE_FACTOR, i);
        try {
            prefs.flush();
        } catch (BackingStoreException e) {
        }
    }

    // Set the scale factor to it's default
    public static void resetScalePercentage() {
        IEclipsePreferences iprefs = InstanceScope.INSTANCE.getNode(IntroPlugin.PLUGIN_ID);
        IEclipsePreferences dprefs = DefaultScope.INSTANCE.getNode(IntroPlugin.PLUGIN_ID);
        String defaultScale = dprefs.get(SCALE_FACTOR, "0"); //$NON-NLS-1$
        iprefs.put(SCALE_FACTOR, defaultScale);
    }

    public static String getFontStyle() {
        IProduct product = Platform.getProduct();
        if (product != null) {
            String pid = product.getId();
            String style = Platform.getPreferencesService().getString(IntroPlugin.PLUGIN_ID,
                    pid + "_" + FontSelection.VAR_FONT_STYLE, "", null); //$NON-NLS-1$ //$NON-NLS-2$
            if (style.length() > 0) {
                return style;
            }
            style = Platform.getPreferencesService().getString(IntroPlugin.PLUGIN_ID,
                    (FontSelection.VAR_FONT_STYLE), "", null); //$NON-NLS-1$ 
            if (style.length() > 0) {
                return style;
            }
        }
        // Use default for font style if not specified
        return FontSelection.FONT_RELATIVE;
    }
}