HandlerDeletePath.java

package com.buildml.eclipse.files.handlers;

import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.viewers.TreeSelection;
import org.eclipse.ui.handlers.HandlerUtil;
import com.buildml.eclipse.MainEditor;
import com.buildml.eclipse.utils.AlertDialog;
import com.buildml.eclipse.utils.ConversionUtils;
import com.buildml.eclipse.utils.EclipsePartUtils;
import com.buildml.eclipse.utils.UndoOpAdapter;
import com.buildml.eclipse.utils.handlers.AbstractHandlerWithProgress;
import com.buildml.model.IActionMgr;
import com.buildml.model.IBuildStore;
import com.buildml.model.IFileMgr;
import com.buildml.model.IFileMgr.PathType;
import com.buildml.model.types.FileSet;
import com.buildml.model.undo.MultiUndoOp;
import com.buildml.refactor.CanNotRefactorException;
import com.buildml.refactor.IImportRefactorer;

/**
 * An Eclipse UI Handler for managing the "Delete File or Directory" UI command. 
 * This handler tries to delete the file/directory and gives the user feedback
 * on anything that may have gone wrong in the process.
 * 
 * @author Peter Smith <psmith@arapiki.com>
 */
public class HandlerDeletePath extends AbstractHandlerWithProgress {
	
	/*=====================================================================================*
	 * PUBLIC METHODS
	 *=====================================================================================*/

	/* (non-Javadoc)
	 * @see com.buildml.eclipse.utils.handlers.AbstractHandlerWithProgress#getCommandName()
	 */
	@Override
	public String getCommandName() {
		return "Deleting";
	}
	
	/*-------------------------------------------------------------------------------------*/

	/**
	 * Execute the delete path operation (in a non-UI thread), but within the Progress Service.
	 * 
	 * @param event The event information pass in from Eclipse.
	 * @return Always null.
	 */
	@Override
	public Object executeWithProgress(ExecutionEvent event)  {
		
		MainEditor mainEditor = EclipsePartUtils.getActiveMainEditor();
		IBuildStore buildStore = mainEditor.getBuildStore();
		IFileMgr fileMgr = buildStore.getFileMgr();
		IActionMgr actionMgr = buildStore.getActionMgr();
		IImportRefactorer refactorer = mainEditor.getImportRefactorer();

		/* build a FileSet of all the selected files */
		TreeSelection selection = (TreeSelection)HandlerUtil.getCurrentSelection(event);
		FileSet selectedPaths = EclipsePartUtils.getFileSetFromSelection(buildStore, selection);

		/* Note how many changes (deletions) actually happened */
		int changesPerformed = 0;
		MultiUndoOp multiOp = new MultiUndoOp();
		
		/*
		 * For each file/directory that was selected, treat it as an individual "delete"
		 * operation. 
		 */
		for (int pathId : selectedPaths) {
			String pathName = fileMgr.getPathName(pathId);
			
			/*
			 * Given that the user may select a directory and a file within that directory,
			 * we first need to double-check that the path still exists when
			 * we come to delete it.
			 */
			PathType pathType = fileMgr.getPathType(pathId);
			if (pathType == PathType.TYPE_INVALID) {
				continue;
			}
			
			boolean needsRetry;
			boolean deleteSubTree = false;
			boolean deleteActionToo = false;
			boolean deleteFromActions = false;
			do {
				needsRetry = false;
				try {
					if (deleteSubTree) {
						refactorer.deletePathTree(multiOp, pathId, deleteActionToo, deleteFromActions);
					} else {
						refactorer.deletePath(multiOp, pathId, deleteActionToo, deleteFromActions);
					}
					
					/* success! The file/directory was deleted */
					changesPerformed++;

				} catch (CanNotRefactorException e) {

					Integer[] badIds = e.getCauseIDs();
					boolean multipleActions = (badIds != null) && (badIds.length > 1);

					/*
					 * Something stopped the delete from completing. Based on the error
					 * code, we could potentially go back and try again.
					 */
					switch (e.getCauseCode()) {

					/* 
					 * The directory we're trying to delete is non-empty. Give the user the
					 * option of deleting the whole sub-directory.
					 */
					case DIRECTORY_NOT_EMPTY:
						int status = AlertDialog.displayOKCancelDialog( 
								"The directory: " + pathName + " is not empty.\n\n" +
								"Do you wish to try deleting all files in the directory?");
						if (status == IDialogConstants.OK_ID) {
							needsRetry = true;
							deleteSubTree = true;
						}
						break;

					/*
					 * The path we're trying to delete is a generated file. We'd need to
					 * also delete the generating action.
					 */
					case PATH_IS_GENERATED:
						status = AlertDialog.displayOKCancelDialog( 
								"The file " + pathName + " is generated by " +
								(multipleActions ? "several actions" : "an action") + ":\n\n" +
								ConversionUtils.getActionsAsText(actionMgr, badIds) +
								"\nDo you also wish to try deleting " +
								(multipleActions ? "the actions?" : "the action?"));
						if (status == IDialogConstants.OK_ID) {
							deleteActionToo = true;
							needsRetry = true;
						}					
						break;
					
					/*
					 * The path is used (read) by an action. It can't be deleted at all.
					 */
					case PATH_IN_USE:
						status = AlertDialog.displayOKCancelDialog( 
								"The file " + pathName + " is still in use. Do you wish to delete it anyway?\n\n" +
								"It is used by the following " +
								(multipleActions ? "actions" : "action") + ":\n\n" +
								ConversionUtils.getActionsAsText(actionMgr, badIds));
						if (status == IDialogConstants.OK_ID) {
							needsRetry = true;
							deleteFromActions = true;
						}
						break;

					/*
					 * The path is a directory, but there are actions executing within that
					 * directory.
					 */
					case DIRECTORY_CONTAINS_ACTIONS:
						AlertDialog.displayErrorDialog("Directory is busy",
								"The directory " + pathName + " can't be deleted as it's still " +
								"used as the working directory for the following " +
								(multipleActions ? "actions" : "action") + ":\n\n" +
								ConversionUtils.getActionsAsText(actionMgr, badIds));
						break;
						
					/*
					 * Can't delete a path that's generated by a non-atomic action.
					 */
					case ACTION_NOT_ATOMIC:
						AlertDialog.displayErrorDialog("Can't delete",
								"The file " + pathName + " can't be deleted as the action " +
								"that generates the file is not atomic:\n\n" +
								ConversionUtils.getActionsAsText(actionMgr, badIds));
						break;

					/*
					 * Can't delete an action (that generated the path), because it's in use
					 * by some other paths.
					 */
					case ACTION_IN_USE:
						AlertDialog.displayErrorDialog("Can't delete",
								"The action that generates " + pathName + " can't be deleted since " +
								"the related files are still in use:\n\n" +
								ConversionUtils.getPathsAsText(fileMgr, badIds));
						break;
					
					/*
					 * Can't delete the path because it's still a member of a file group.
					 */
					case FILE_STILL_IN_GROUP:
						AlertDialog.displayErrorDialog("Can't delete",
								"The path " + pathName + " can't be deleted as it is currently " +
								"a member of one or more file groups.");
						break;
						
					/*
					 * Ignore this case - it's likely because the parent has already been deleted.
					 */
					case INVALID_PATH:
						break;
						
					/*
					 * These shouldn't happen.
					 */
					default:
						AlertDialog.displayErrorDialog("Deletion failed", 
								"Deletion of the file/directory: " + pathName + 
								" failed for the following reason: " + e.getCauseCode());					
					}
				}
			} while (needsRetry);
		}
		
		/*
		 * If a deletion actually took place - refresh the view and add the operation
		 * to the undo/redo history.
		 */
		if (changesPerformed > 0) {
			new UndoOpAdapter("Delete File" + ((changesPerformed > 1) ? "s" : ""), multiOp).invoke();
		}
		return null;
	}
	
	/*-------------------------------------------------------------------------------------*/
}