de.walware.statet.r.internal.ui.rhelp.RHelpViewPage.java Source code

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Here is the source code for de.walware.statet.r.internal.ui.rhelp.RHelpViewPage.java

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/*=============================================================================#
 # Copyright (c) 2010-2015 Stephan Wahlbrink (WalWare.de) 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:
 #     Stephan Wahlbrink - initial API and implementation
 #=============================================================================*/

package de.walware.statet.r.internal.ui.rhelp;

import java.net.URI;
import java.net.URISyntaxException;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.commands.IHandler2;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.swt.browser.LocationEvent;
import org.eclipse.swt.browser.TitleEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.ui.contexts.IContextService;
import org.eclipse.ui.handlers.IHandlerService;
import org.eclipse.ui.services.IServiceLocator;
import org.eclipse.ui.statushandlers.StatusManager;

import de.walware.ecommons.ui.actions.HandlerCollection;
import de.walware.ecommons.ui.breadcrumb.IBreadcrumb;
import de.walware.ecommons.ui.mpbv.BrowserSession;
import de.walware.ecommons.ui.mpbv.PageBookBrowserPage;
import de.walware.ecommons.ui.mpbv.PageBookBrowserView;

import de.walware.statet.r.core.RCore;
import de.walware.statet.r.core.rhelp.IRHelpManager;
import de.walware.statet.r.ui.RUI;

public class RHelpViewPage extends PageBookBrowserPage {

    private IBreadcrumb fBreadcrumb;
    private Control fBreadcrumbControl;

    private Object fHelpObject;

    private final ILabelProvider fLabelProvider = new RHelpLabelProvider();

    public RHelpViewPage(final PageBookBrowserView view, final BrowserSession session) {
        super(view, session);
    }

    @Override
    public void setUrl(String url) {
        if (url != null && url.startsWith(IRHelpManager.PORTABLE_URL_PREFIX)) {
            try {
                URI uri = new URI(url);
                uri = RCore.getRHelpManager().toHttpUrl(uri);
                url = uri.toASCIIString();
            } catch (final URISyntaxException e) {
                // ?
            }
        }
        super.setUrl(url);
    }

    @Override
    protected Control createAddressBar(final Composite parent) {
        fBreadcrumb = new RHelpBreadcrumb(this);
        if (fBreadcrumb != null) {
            fBreadcrumbControl = fBreadcrumb.createContent(parent);
            updateBreadcrumbInput();
        }
        return fBreadcrumbControl;
    }

    @Override
    protected void initActions(final IServiceLocator serviceLocator, final HandlerCollection handlers) {
        super.initActions(serviceLocator, handlers);
        final IHandlerService handlerService = (IHandlerService) serviceLocator.getService(IHandlerService.class);
        final IContextService contextService = (IContextService) serviceLocator.getService(IContextService.class);

        final IHandler2 breadcrumbHandler = new AbstractHandler() {
            @Override
            public Object execute(final ExecutionEvent event) throws ExecutionException {
                if (fBreadcrumb != null) {
                    fBreadcrumb.activate();
                }
                return null;
            }
        };
        handlers.add(IBreadcrumb.SHOW_BREADCRUMB_COMMAND_ID, breadcrumbHandler);
        handlerService.activateHandler(IBreadcrumb.SHOW_BREADCRUMB_COMMAND_ID, breadcrumbHandler);
        contextService.activateContext(IBreadcrumb.WITH_BREADCRUMB_CONTEXT_ID);
    }

    @Override
    public void changed(final LocationEvent event) {
        super.changed(event);
        if (event.top) {
            updateAddressBar();
        }
    }

    @Override
    public void changed(final TitleEvent event) {
        super.changed(event);
        if (fHelpObject == null) {
            updateBreadcrumbInput();
        }
    }

    private void updateAddressBar() {
        try {
            final String url = getCurrentUrl();
            final Object input = RCore.getRHelpManager().getContentOfUrl(url);
            fHelpObject = input;

            final Image image = fLabelProvider.getImage(input);
            if (image != null) {
                setIcon(ImageDescriptor.createFromImage(image));
            }
            updateBreadcrumbInput();
        } catch (final Exception e) {
            StatusManager.getManager().handle(new Status(IStatus.ERROR, RUI.PLUGIN_ID, 0,
                    "An error occurred when updating the R help view address bar/breadcrumbs.", e));
        }
    }

    /**
     * Makes the breadcrumb visible.
     */
    private void showBreadcrumb() {
        if (fBreadcrumb == null || fBreadcrumbControl.isVisible()) {
            return;
        }
        //      ((GridData) fBreadcrumbControl.getLayoutData()).exclude= false;
        fBreadcrumbControl.setVisible(true);
        fBreadcrumbControl.getParent().layout(true, true);
    }

    /**
     * Hides the breadcrumb
     */
    private void hideBreadcrumb() {
        if (fBreadcrumb == null || !fBreadcrumbControl.isVisible()) {
            return;
        }
        //      ((GridData) fBreadcrumbControl.getLayoutData()).exclude= true;
        fBreadcrumbControl.setVisible(false);
        fBreadcrumbControl.getParent().layout(true, true);
    }

    /**
     * Sets the breadcrumb input to the given element.
     * @param content the element to use as input for the breadcrumb
     * @since 3.4
     */
    private void updateBreadcrumbInput() {
        if (fBreadcrumb == null) {
            return;
        }
        Object input = fHelpObject;
        if (input == null) {
            if (getCurrentUrl().length() > 0) {
                input = getCurrentTitle();
            }
        } else if (input instanceof Object[]) {
            final Object[] array = (Object[]) input;
            if (array.length >= 2) {
                array[array.length - 1] = getCurrentTitle();
            } else {
                input = null;
            }
        }
        fBreadcrumb.setInput(input);
    }

}