org.eclipse.ui.intro/src/org/eclipse/ui/internal/intro/impl/swt/SharedStyleManager.java

/*******************************************************************************
 * Copyright (c) 2004, 2017 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
 *******************************************************************************/
package org.eclipse.ui.internal.intro.impl.swt;

import java.io.InputStream;
import java.net.URL;
import java.util.Properties;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.ui.forms.FormColors;
import org.eclipse.ui.forms.widgets.FormToolkit;
import org.eclipse.ui.internal.intro.impl.model.IntroModelRoot;
import org.eclipse.ui.internal.intro.impl.util.ImageUtil;
import org.eclipse.ui.internal.intro.impl.util.Log;
import org.osgi.framework.Bundle;

public class SharedStyleManager {

    protected Properties properties;
    protected StyleContext context;

    class StyleContext {
    	IPath path;
    	Bundle bundle;
    	boolean inTheme;
    }

    SharedStyleManager() {
        // no-op
    }

    /**
     * Constructor used when shared styles need to be loaded. The bundle is
     * retrieved from the model root.
     *
     * @param modelRoot
     */
    public SharedStyleManager(IntroModelRoot modelRoot) {
    	context = new StyleContext();
        context.bundle = modelRoot.getBundle();
        properties = new Properties();
        String [] sharedStyles = modelRoot.getPresentation()
            .getImplementationStyles();
        if (sharedStyles != null) {
        	for (int i=0; i<sharedStyles.length; i++)
        	load(properties, sharedStyles[i], context);
        }
    }

    protected void load(Properties properties, String style, StyleContext context) {
        if (style == null)
            return;
        try {
            URL styleURL = new URL(style);
            try (InputStream is = styleURL.openStream()) {
            	properties.load(is);
            }
           	context.path = new Path(style).removeLastSegments(1);
            String t = (String)properties.get("theme"); //$NON-NLS-1$
            if (t!=null && t.trim().equalsIgnoreCase("true")) //$NON-NLS-1$
            	context.inTheme = true;
        } catch (Exception e) {
            Log.error("Could not load SWT style: " + style, e); //$NON-NLS-1$
        }
    }


    /**
     * Get the property from the shared properties.
     *
     * @param key
     * @return
     */
    public String getProperty(String key) {
        return doGetProperty(properties, key);
    }

    /*
     * Utility method to trim properties retrieval.
     */
    protected String doGetProperty(Properties aProperties, String key) {
        String value = aProperties.getProperty(key);
        if (value != null)
            // trim the properties as trailing balnnks cause problems.
            value = value.trim();
        return value;
    }


    protected RGB getRGB(String key) {
        String value = getProperty(key);
        if (value == null)
            return null;
        return parseRGB(value);
    }

    /**
     * A utility method that creates RGB object from a value encoded in the
     * following format: #rrggbb, where r, g and b are hex color values in the
     * range from 00 to ff.
     *
     * @param value
     * @return
     */

    public static RGB parseRGB(String value) {
        if (value.charAt(0) == '#') {
            // HEX
            try {
                int r = Integer.parseInt(value.substring(1, 3), 16);
                int g = Integer.parseInt(value.substring(3, 5), 16);
                int b = Integer.parseInt(value.substring(5, 7), 16);
                return new RGB(r, g, b);
            } catch (NumberFormatException e) {
                Log.error("Failed to parser: " + value + " as an integer", e); //$NON-NLS-1$ //$NON-NLS-2$
            }
        }
        return null;
    }



    /**
     * Finds the bundle from which this key was loaded. This is the bundle from
     * which shared styles where loaded.
     *
     * @param key
     * @return
     */
    protected Bundle getAssociatedBundle(String key) {
        return context.bundle;
    }

    protected StyleContext getAssociatedContext(String key) {
    	return context;
    }



    /**
     * @return Returns the properties.
     */
    public Properties getProperties() {
        return properties;
    }


    /**
     *
     *
     * @param toolkit
     * @param key
     * @return color. May return null.
     */
    public Color getColor(FormToolkit toolkit, String key) {
        FormColors colors = toolkit.getColors();
        Color color = colors.getColor(key);
        if (color == null) {
            RGB rgb = getRGB(key);
            if (rgb != null)
                color = colors.createColor(key, rgb);
        }
        return color;
    }



    /**
     * Retrieve an image from this page's properties, given a key.
     *
     * @param key
     * @param defaultPageKey
     * @param defaultKey
     * @return
     */
    public Image getImage(String key, String defaultPageKey, String defaultKey) {
        String currentKey = key;
        String value = getProperty(currentKey);
        if (value == null && defaultPageKey != null) {
            currentKey = defaultPageKey;
            value = getProperty(defaultPageKey);
        }
        if (value != null) {
            if (ImageUtil.hasImage(currentKey))
                return ImageUtil.getImage(currentKey);
            // try to register the image.
            StyleContext ccontext = getAssociatedContext(currentKey);
            if (ccontext.inTheme) {
            	// if 'theme' key is set, load image
            	// relative to the file, not relative to the bundle
            	ImageUtil.registerImage(currentKey, ccontext.path, value);
            }
            else {
            	Bundle bundle = ccontext.bundle;
            	if (bundle == null)
            		// it means that we are getting a key defined in this page's
            		// styles. (ie: not an inherited style).
            		bundle = this.context.bundle;
            	ImageUtil.registerImage(currentKey, bundle, value);
            }
            Image image = ImageUtil.getImage(currentKey);
            if (image != null)
                return image;
        }
        // try default. We know default is already registered,
        if (defaultKey != null)
            return ImageUtil.getImage(defaultKey);
        return null;
    }


    public boolean useCustomHomePagelayout() {
        String key = "home-page-custom-layout"; //$NON-NLS-1$
        String value = getProperty(key);
        if (value == null)
            value = "true"; //$NON-NLS-1$
        return value.equalsIgnoreCase("true"); //$NON-NLS-1$
    }

}