de.walware.ecommons.ui.workbench.ResourceVariableUtil.java Source code

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Here is the source code for de.walware.ecommons.ui.workbench.ResourceVariableUtil.java

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/*=============================================================================#
 # Copyright (c) 2012-2016 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.ecommons.ui.workbench;

import java.util.Iterator;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IAdapterManager;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchPartSite;

import de.walware.ecommons.debug.core.variables.ResourceVariableResolver;
import de.walware.ecommons.ui.util.UIAccess;

public class ResourceVariableUtil implements ResourceVariableResolver.IResolveContext {

    /**
     * Returns the currently selected resource in the active workbench window, or <code>null</code> 
     * if none.  If an editor is active, the resource adapter associated with the editor is 
     * returned, if any.
     * 
     * @return selected resource or <code>null</code>
     */
    public static IResource fetchSelectedResource() {
        return fetchSelectedResource(null);
    }

    private static IResource fetchSelectedResource(final IWorkbenchPart part) {
        // Compatible with DebugUITools.getSelectedResource
        final Display display = UIAccess.getDisplay();
        if (Thread.currentThread() == display.getThread()) {
            return getSelectedResource0(part);
        } else {
            class DisplayRunnable implements Runnable {

                IResource resource;

                @Override
                public void run() {
                    this.resource = getSelectedResource0(part);
                }

            }
            final DisplayRunnable runnable = new DisplayRunnable();
            display.syncExec(runnable);
            return runnable.resource;
        }
    }

    private static IResource getSelectedResource0(IWorkbenchPart part) {
        IResource resource = null;
        if (part == null) {
            final IWorkbenchPage page = UIAccess.getActiveWorkbenchPage(true);
            if (page != null) {
                part = page.getActivePart();
            }
        }
        if (part != null) {
            if (part instanceof IEditorPart) {
                final IEditorPart epart = (IEditorPart) part;
                resource = (IResource) epart.getEditorInput().getAdapter(IResource.class);
            }
            if (resource == null) {
                final IWorkbenchPartSite site = part.getSite();
                if (site != null) {
                    final ISelectionProvider provider = site.getSelectionProvider();
                    if (provider != null) {
                        final ISelection selection = provider.getSelection();
                        if (selection instanceof IStructuredSelection) {
                            final IStructuredSelection structuredSelection = (IStructuredSelection) selection;
                            if (!structuredSelection.isEmpty()) {
                                final Iterator<?> iterator = structuredSelection.iterator();
                                final IAdapterManager adapterManager = Platform.getAdapterManager();
                                while (resource == null && iterator.hasNext()) {
                                    final Object element = iterator.next();
                                    resource = (IResource) adapterManager.getAdapter(element, IResource.class);
                                }
                            }
                        }
                    }
                }
            }
        }
        return resource;
    }

    protected static final byte S_RESOURCE_FETCHED = 0b0_0000_0001;

    private final IWorkbenchPage workbenchPage;

    private final IWorkbenchPart part;

    private byte state;

    private IResource resource;

    public ResourceVariableUtil() {
        this(UIAccess.getActiveWorkbenchPage(true));
    }

    public ResourceVariableUtil(final IWorkbenchPage page) {
        this.workbenchPage = page;
        this.part = this.workbenchPage.getActivePart();
    }

    public ResourceVariableUtil(final IWorkbenchPart part) {
        this.workbenchPage = part.getSite().getPage();
        this.part = part;
    }

    public ResourceVariableUtil(final IResource resource) {
        this();
        this.state |= S_RESOURCE_FETCHED;
        this.resource = resource;
    }

    public ResourceVariableUtil(final ResourceVariableUtil location, final IResource resource) {
        this.workbenchPage = location.getWorkbenchPage();
        this.part = location.getWorkbenchPart();
        this.state |= S_RESOURCE_FETCHED;
        this.resource = resource;
    }

    public IWorkbenchPage getWorkbenchPage() {
        return this.workbenchPage;
    }

    public IWorkbenchPart getWorkbenchPart() {
        return this.part;
    }

    @Override
    public IResource getResource() {
        if ((this.state & S_RESOURCE_FETCHED) == 0) {
            this.state |= S_RESOURCE_FETCHED;
            this.resource = fetchResource();
        }
        return this.resource;
    }

    protected void resetResource() {
        this.state &= ~S_RESOURCE_FETCHED;
        this.resource = null;
    }

    protected IResource fetchResource() {
        return fetchSelectedResource(getWorkbenchPart());
    }

}