OpenFileCommandHandler.java

package org.codefaces.ui.internal.commands;

import java.util.Iterator;

import org.codefaces.core.models.RepoFile;
import org.codefaces.ui.internal.CodeFacesUIActivator;
import org.codefaces.ui.internal.editors.CodeExplorer;
import org.codefaces.ui.internal.editors.RepoFileInput;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.expressions.IEvaluationContext;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.ISelectionService;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.PlatformUI;

public class OpenFileCommandHandler extends AbstractHandler {
	public static final String ID = "org.codefaces.ui.internal.commands.openFileCommand";

	public static final String PARAM_MODE = "org.codefaces.ui.internal.commands.parameters.openFileCommand.mode";

	public static final String MODE_SELECTION_FROM_VIEW = "selectionFromView";
	public static final String MODE_DIRECT_FILES = "directFiles";

	public static final String PARAM_VIEW_ID = "org.codefaces.ui.internal.commands.parameters.openFileCommand.viewId";
	public static final String VARIABLE_FILES = "org.codefaces.ui.internal.commands.parameters.openFileCommand.files";

	/**
	 * Open files in the code explorer.
	 * 
	 * This command supports 2 modes, either by providing a view id so that the
	 * command can get the selected files, or by providing an array of files in
	 * the application context of the execution event.
	 * 
	 * To use the MODE_SELECTION_FROM_VIEW mode, the parameter PARAM_MODE should
	 * be set to MODE_SELECTION_FROM_VIEW. An additional parameter PARAM_VIEW_ID
	 * should also be provided.
	 * 
	 * To use the MODE_DIRECT_FILES mode, the parameter PARAM_MODE should be set
	 * to MODE_DIRECT_FILES. A RepoFile array should be added with name
	 * VARIABLE_FILES in the variables of the application context in the
	 * execution event.
	 */
	@Override
	public Object execute(ExecutionEvent event) throws ExecutionException {
		String mode = event.getParameter(PARAM_MODE);
		if (mode != null) {
			if (mode.equals(MODE_SELECTION_FROM_VIEW)) {
				openFilesFromViewSelection(event);
			}
			if (mode.equals(MODE_DIRECT_FILES)) {
				openFilesDirectly(event);
			}
		}
		return null;
	}

	/**
	 * This method obtains a RepoFile array from the event's application context
	 * and open them in the code explorer
	 * 
	 * @param event
	 *            - an event that contains a VARAIBLE_FILE in type of RepoFile[]
	 *            in its application context
	 */
	private void openFilesDirectly(ExecutionEvent event) {
		IEvaluationContext context = (IEvaluationContext) event
				.getApplicationContext();
		if (context != null) {
			Object obj = context.getVariable(VARIABLE_FILES);
			if (obj instanceof RepoFile[]) {
				RepoFile[] files = (RepoFile[]) obj;
				for (RepoFile file : files) {
					openFile(file);
				}
			}
		}
	}

	/**
	 * This method obtains the selection from the provided view ID. If the
	 * selection is RepoFile(s), it tells the code explorer to open the file(s)
	 * 
	 * @param event
	 */
	private void openFilesFromViewSelection(ExecutionEvent event) {
		String viewId = event.getParameter(PARAM_VIEW_ID);
		// The cmd is executed by providing a view ID
		if (viewId != null) {
			ISelectionService selectionService = PlatformUI.getWorkbench()
					.getActiveWorkbenchWindow().getSelectionService();
			ISelection selection = selectionService.getSelection(viewId);
			if (selection instanceof IStructuredSelection) {
				Iterator<?> elements = ((IStructuredSelection) selection)
						.iterator();
				while (elements.hasNext()) {
					Object element = elements.next();
					if (element instanceof RepoFile) {
						openFile((RepoFile) element);
					}
				}
			}
		}
	}

	/**
	 * Open the given file in the code explorer
	 * 
	 * @param repoFile
	 *            - the file
	 */
	private void openFile(RepoFile repoFile) {
		IWorkbenchPage activePage = PlatformUI.getWorkbench()
				.getActiveWorkbenchWindow().getActivePage();
		try {
			activePage.openEditor(new RepoFileInput(repoFile), CodeExplorer.ID);
		} catch (PartInitException e) {
			IStatus status = new Status(Status.ERROR,
					CodeFacesUIActivator.PLUGIN_ID,
					"Errors occurs when showing view " + CodeExplorer.ID, e);
			CodeFacesUIActivator.getDefault().getLog().log(status);
		}
	}

}