fileviewer.java

利用SWT作为开发用户界面

			if (simulateOnly) {
				//System.out.println(getResourceString("simulate.DirectoriesCreated.text",
				//	new Object[] { newFile.getPath() }));
			} else {
				if (! newFile.mkdirs()) return false;
			}
			File[] subFiles = oldFile.listFiles();
			if (subFiles != null) {
				if (progressDialog != null) {
					progressDialog.addWorkUnits(subFiles.length);
				}
				for (int i = 0; i < subFiles.length; i++) {
					File oldSubFile = subFiles[i];
					File newSubFile = new File(newFile, oldSubFile.getName());
					if (! copyFileStructure(oldSubFile, newSubFile)) return false;
					if (progressDialog != null) {
						progressDialog.addProgress(1);
						if (progressDialog.isCancelled()) return false;
					}
				}
			}
		} else {
			/*
			 * Copy a file
			 */
			if (simulateOnly) {
				//System.out.println(getResourceString("simulate.CopyFromTo.text",
				//	new Object[] { oldFile.getPath(), newFile.getPath() }));
			} else {
				FileReader in = null;
				FileWriter out = null;
				try {
					in = new FileReader(oldFile);
					out = new FileWriter(newFile);
			
					int count;
					while ((count = in.read()) != -1) out.write(count);
				} catch (FileNotFoundException e) {
					return false;
				} catch (IOException e) {
					return false;
				} finally {
					try {
						if (in != null) in.close();
						if (out != null) out.close();
					} catch (IOException e) {
						return false;
					}
				}
			}
		}
		return true;
	}

	/**
	 * Deletes a file or entire directory structure.
	 * 
	 * @param oldFile the location of the old file or directory
	 * @return true iff the operation succeeds without errors
	 */
	boolean deleteFileStructure(File oldFile) {
		if (oldFile == null) return false;		
		if (oldFile.isDirectory()) {
			/*
			 * Delete a directory
			 */
			if (progressDialog != null) {
				progressDialog.setDetailFile(oldFile, ProgressDialog.DELETE);
			}
			File[] subFiles = oldFile.listFiles();
			if (subFiles != null) {
				if (progressDialog != null) {
					progressDialog.addWorkUnits(subFiles.length);
				}
				for (int i = 0; i < subFiles.length; i++) {
					File oldSubFile = subFiles[i];
					if (! deleteFileStructure(oldSubFile)) return false;
					if (progressDialog != null) {
						progressDialog.addProgress(1);
						if (progressDialog.isCancelled()) return false;
					}
				}
			}
		}
		if (simulateOnly) {
			//System.out.println(getResourceString("simulate.Delete.text",
			//	new Object[] { oldFile.getPath(), oldFile.getPath() }));
			return true;
		} else {
			return oldFile.delete();
		}
	}
	
	/**
	 * Sorts files lexicographically by name.
	 * 
	 * @param files the array of Files to be sorted
	 */
	static void sortFiles(File[] files) {
		/* Very lazy merge sort algorithm */
		sortBlock(files, 0, files.length - 1, new File[files.length]);
	}
	private static void sortBlock(File[] files, int start, int end, File[] mergeTemp) {
		final int length = end - start + 1;
		if (length < 8) {
			for (int i = end; i > start; --i) {
				for (int j = end; j > start; --j)  {
					if (compareFiles(files[j - 1], files[j]) > 0) {
					    final File temp = files[j]; 
					    files[j] = files[j-1]; 
					    files[j-1] = temp;
					}
			    }
			}
			return;
		}
		final int mid = (start + end) / 2;
		sortBlock(files, start, mid, mergeTemp);
		sortBlock(files, mid + 1, end, mergeTemp);
		int x = start;
		int y = mid + 1;
		for (int i = 0; i < length; ++i) {
			if ((x > mid) || ((y <= end) && compareFiles(files[x], files[y]) > 0)) {
				mergeTemp[i] = files[y++];
			} else {
				mergeTemp[i] = files[x++];
			}
		}
		for (int i = 0; i < length; ++i) files[i + start] = mergeTemp[i];
	}
	private static int compareFiles(File a, File b) {
//		boolean aIsDir = a.isDirectory();
//		boolean bIsDir = b.isDirectory();
//		if (aIsDir && ! bIsDir) return -1;
//		if (bIsDir && ! aIsDir) return 1;

		// sort case-sensitive files in a case-insensitive manner
		int compare = a.getName().compareToIgnoreCase(b.getName());
		if (compare == 0) compare = a.getName().compareTo(b.getName());
		return compare;
	}
	
	/*
	 * This worker updates the table with file information in the background.
	 * <p>
	 * Implementation notes:
	 * <ul>
	 * <li> It is designed such that it can be interrupted cleanly.
	 * <li> It uses asyncExec() in some places to ensure that SWT Widgets are manipulated in the
	 *      right thread.  Exclusive use of syncExec() would be inappropriate as it would require a pair
	 *      of context switches between each table update operation.
	 * </ul>
	 * </p>
	 */

	/**
	 * Stops the worker and waits for it to terminate.
	 */
	void workerStop() {
		if (workerThread == null) return;
		synchronized(workerLock) {
			workerCancelled = true;
			workerStopped = true;
			workerLock.notifyAll();
		}
		while (workerThread != null) {
			if (! display.readAndDispatch()) display.sleep();
		}
	}

	/**
	 * Notifies the worker that it should update itself with new data.
	 * Cancels any previous operation and begins a new one.
	 * 
	 * @param dir the new base directory for the table, null is ignored
	 * @param force if true causes a refresh even if the data is the same
	 */
	void workerUpdate(File dir, boolean force) {
		if (dir == null) return;
		if ((!force) && (workerNextDir != null) && (workerNextDir.equals(dir))) return;

		synchronized(workerLock) {
			workerNextDir = dir;
			workerStopped = false;
			workerCancelled = true;
			workerLock.notifyAll();
		}
		if (workerThread == null) {
			workerThread = new Thread(workerRunnable);
			workerThread.start();
		}
	}

	/**
	 * Manages the worker's thread
	 */
	private final Runnable workerRunnable = new Runnable() {
		public void run() {
			while (! workerStopped) {
				synchronized(workerLock) {
					workerCancelled = false;
					workerStateDir = workerNextDir;
				}
				workerExecute();
				synchronized(workerLock) {
					try {
						if ((!workerCancelled) && (workerStateDir == workerNextDir)) workerLock.wait();
					} catch (InterruptedException e) {
					}
				}
			}
			workerThread = null;
			// wake up UI thread in case it is in a modal loop awaiting thread termination
			// (see workerStop())
			display.wake();
		}
	};
	
	/**
	 * Updates the table's contents
	 */
	private void workerExecute() {
		File[] dirList;
		// Clear existing information
		display.syncExec(new Runnable() {
			public void run() {
				tableContentsOfLabel.setText(FileViewer.getResourceString("details.ContentsOf.text",
					new Object[] { workerStateDir.getPath() }));
				table.removeAll();
				table.setData(TABLEDATA_DIR, workerStateDir);
			}
		});
		dirList = getDirectoryList(workerStateDir);
		
		for (int i = 0; (! workerCancelled) && (i < dirList.length); i++) {
			workerAddFileDetails(dirList[i]);
		}

	}
		
	/**
	 * Adds a file's detail information to the directory list
	 */
	private void workerAddFileDetails(final File file) {
		final String nameString = file.getName();
		final String dateString = dateFormat.format(new Date(file.lastModified()));
		final String sizeString;
		final String typeString;
		final Image iconImage;
		
		if (file.isDirectory()) {
			typeString = getResourceString("filetype.Folder");
			sizeString = "";
			iconImage = iconCache.stockImages[iconCache.iconClosedFolder];
		} else {
			sizeString = getResourceString("filesize.KB",
				new Object[] { new Long((file.length() + 512) / 1024) });
			
			int dot = nameString.lastIndexOf('.');
			if (dot != -1) {
				String extension = nameString.substring(dot);
				Program program = Program.findProgram(extension);
				if (program != null) {
					typeString = program.getName();
					iconImage = iconCache.getIconFromProgram(program);
				} else {
					typeString = getResourceString("filetype.Unknown", new Object[] { extension.toUpperCase() });
					iconImage = iconCache.stockImages[iconCache.iconFile];
				}
			} else {
				typeString = getResourceString("filetype.None");
				iconImage = iconCache.stockImages[iconCache.iconFile];
			}
		}
		final String[] strings = new String[] { nameString, sizeString, typeString, dateString };

		display.syncExec(new Runnable() {
			public void run () {
				// guard against the shell being closed before this runs
				if (shell.isDisposed()) return;
				TableItem tableItem = new TableItem(table, 0);
				tableItem.setText(strings);
				tableItem.setImage(iconImage);
				tableItem.setData(TABLEITEMDATA_FILE, file);
			}
		});
	}
	
	/**
	 * Instances of this class manage a progress dialog for file operations.
	 */
	class ProgressDialog {
		public final static int COPY = 0;
		public final static int DELETE = 1;
		public final static int MOVE = 2;

		Shell shell;
		Label messageLabel, detailLabel;
		ProgressBar progressBar;
		Button cancelButton;
		boolean isCancelled = false;

		final String operationKeyName[] = {
			"Copy",
			"Delete",
			"Move"
		};
	
		/**
		 * Creates a progress dialog but does not open it immediately.
		 * 
		 * @param parent the parent Shell
		 * @param style one of COPY, MOVE
		 */
		public ProgressDialog(Shell parent, int style) {
			shell = new Shell(parent, SWT.BORDER | SWT.TITLE | SWT.APPLICATION_MODAL);
			GridLayout gridLayout = new GridLayout();
			shell.setLayout(gridLayout);
			shell.setText(getResourceString("progressDialog." + operationKeyName[style] + ".title"));
			shell.addShellListener(new ShellAdapter() {
				public void shellClosed(ShellEvent e) {
					isCancelled = true;
				}
			});
			
			messageLabel = new Label(shell, SWT.HORIZONTAL);
			messageLabel.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_FILL));
			messageLabel.setText(getResourceString("progressDialog." + operationKeyName[style] + ".description"));
			
			progressBar = new ProgressBar(shell, SWT.HORIZONTAL | SWT.WRAP);
			progressBar.setLayoutData(new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_FILL));
			progressBar.setMinimum(0);
			progressBar.setMaximum(0);
			
			detailLabel = new Label(shell, SWT.HORIZONTAL);
			GridData gridData = new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_BEGINNING);
			gridData.widthHint = 400;
			detailLabel.setLayoutData(gridData);
			
			cancelButton = new Button(shell, SWT.PUSH);
			cancelButton.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_END | GridData.VERTICAL_ALIGN_FILL));
			cancelButton.setText(getResourceString("progressDialog.cancelButton.text"));
			cancelButton.addSelectionListener(new SelectionAdapter() {
				public void widgetSelected(SelectionEvent e) {
					isCancelled = true;
					cancelButton.setEnabled(false);
				}
			});
		}
		/**
		 * Sets the detail text to show the filename along with a string
		 * representing the operation being performed on that file.
		 * 
		 * @param file the file to be detailed
		 * @param operation one of COPY, DELETE
		 */
		public void setDetailFile(File file, int operation) {
			detailLabel.setText(getResourceString("progressDialog." + operationKeyName[operation] + ".operation",
				new Object[] { file }));
		}
		/**
		 * Returns true if the Cancel button was been clicked.
		 * 
		 * @return true if the Cancel button was clicked.
		 */
		public boolean isCancelled() {
			return isCancelled;
		}
		/**
		 * Sets the total number of work units to be performed.
		 * 
		 * @param work the total number of work units
		 */
		public void setTotalWorkUnits(int work) {
			progressBar.setMaximum(work);
		}
		/**
		 * Adds to the total number of work units to be performed.
		 * 
		 * @param work the number of work units to add
		 */
		public void addWorkUnits(int work) {
			setTotalWorkUnits(progressBar.getMaximum() + work);
		}
		/**
		 * Sets the progress of completion of the total work units.
		 * 
		 * @param work the total number of work units completed
		 */
		public void setProgress(int work) {
			progressBar.setSelection(work);
			while (display.readAndDispatch()); // enable event processing
		}
		/**
		 * Adds to the progress of completion of the total work units.
		 * 
		 * @param work the number of work units completed to add
		 */
		public void addProgress(int work) {
			setProgress(progressBar.getSelection() + work);
		}
		/**
		 * Opens the dialog.
		 */
		public void open() {
			shell.pack();
			final Shell parentShell = (Shell) shell.getParent();
			Rectangle rect = parentShell.getBounds();
			Rectangle bounds = shell.getBounds();
			bounds.x = rect.x + (rect.width - bounds.width) / 2;
			bounds.y = rect.y + (rect.height - bounds.height) / 2;
			shell.setBounds(bounds);
			shell.open();
		}
		/**
		 * Closes the dialog and disposes its resources.
		 */
		public void close() {
			shell.close();
			shell.dispose();
			shell = null;
			messageLabel = null;
			detailLabel = null;
			progressBar = null;
			cancelButton = null;
		}
	}
}