Java tutorial
import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.util.ArrayList; import java.util.List; import org.eclipse.jface.viewers.CheckStateChangedEvent; import org.eclipse.jface.viewers.CheckboxTreeViewer; import org.eclipse.jface.viewers.ICheckStateListener; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.ILabelProviderListener; import org.eclipse.jface.viewers.ITreeContentProvider; import org.eclipse.jface.viewers.LabelProviderChangedEvent; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.jface.viewers.Viewer; import org.eclipse.jface.window.ApplicationWindow; import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; /** * This class demonstrates the CheckboxTreeViewer */ public class CheckFileTree extends FileTree { /** * Configures the shell * * @param shell * the shell */ protected void configureShell(Shell shell) { super.configureShell(shell); shell.setText("Check File Tree"); } /** * Creates the main window's contents * * @param parent * the main window * @return Control */ protected Control createContents(Composite parent) { Composite composite = new Composite(parent, SWT.NONE); composite.setLayout(new GridLayout(1, false)); // Add a checkbox to toggle whether the labels preserve case Button preserveCase = new Button(composite, SWT.CHECK); preserveCase.setText("&Preserve case"); // Create the tree viewer to display the file tree final CheckboxTreeViewer tv = new CheckboxTreeViewer(composite); tv.getTree().setLayoutData(new GridData(GridData.FILL_BOTH)); tv.setContentProvider(new FileTreeContentProvider()); tv.setLabelProvider(new FileTreeLabelProvider()); tv.setInput("root"); // pass a non-null that will be ignored // When user checks the checkbox, toggle the preserve case attribute // of the label provider preserveCase.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent event) { boolean preserveCase = ((Button) event.widget).getSelection(); FileTreeLabelProvider ftlp = (FileTreeLabelProvider) tv.getLabelProvider(); ftlp.setPreserveCase(preserveCase); } }); // When user checks a checkbox in the tree, check all its children tv.addCheckStateListener(new ICheckStateListener() { public void checkStateChanged(CheckStateChangedEvent event) { // If the item is checked . . . if (event.getChecked()) { // . . . check all its children tv.setSubtreeChecked(event.getElement(), true); } } }); return composite; } /** * The application entry point * * @param args * the command line arguments */ public static void main(String[] args) { new CheckFileTree().run(); } } /** * This class demonstrates TreeViewer. It shows the drives, directories, and * files on the system. */ class FileTree extends ApplicationWindow { /** * FileTree constructor */ public FileTree() { super(null); } /** * Runs the application */ public void run() { // Don't return from open() until window closes setBlockOnOpen(true); // Open the main window open(); // Dispose the display Display.getCurrent().dispose(); } /** * Configures the shell * * @param shell * the shell */ protected void configureShell(Shell shell) { super.configureShell(shell); // Set the title bar text and the size shell.setText("File Tree"); shell.setSize(400, 400); } /** * Creates the main window's contents * * @param parent * the main window * @return Control */ protected Control createContents(Composite parent) { Composite composite = new Composite(parent, SWT.NONE); composite.setLayout(new GridLayout(1, false)); // Add a checkbox to toggle whether the labels preserve case Button preserveCase = new Button(composite, SWT.CHECK); preserveCase.setText("&Preserve case"); // Create the tree viewer to display the file tree final TreeViewer tv = new TreeViewer(composite); tv.getTree().setLayoutData(new GridData(GridData.FILL_BOTH)); tv.setContentProvider(new FileTreeContentProvider()); tv.setLabelProvider(new FileTreeLabelProvider()); tv.setInput("root"); // pass a non-null that will be ignored // When user checks the checkbox, toggle the preserve case attribute // of the label provider preserveCase.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent event) { boolean preserveCase = ((Button) event.widget).getSelection(); FileTreeLabelProvider ftlp = (FileTreeLabelProvider) tv.getLabelProvider(); ftlp.setPreserveCase(preserveCase); } }); return composite; } } /** * This class provides the content for the tree in FileTree */ class FileTreeContentProvider implements ITreeContentProvider { /** * Gets the children of the specified object * * @param arg0 * the parent object * @return Object[] */ public Object[] getChildren(Object arg0) { // Return the files and subdirectories in this directory return ((File) arg0).listFiles(); } /** * Gets the parent of the specified object * * @param arg0 * the object * @return Object */ public Object getParent(Object arg0) { // Return this file's parent file return ((File) arg0).getParentFile(); } /** * Returns whether the passed object has children * * @param arg0 * the parent object * @return boolean */ public boolean hasChildren(Object arg0) { // Get the children Object[] obj = getChildren(arg0); // Return whether the parent has children return obj == null ? false : obj.length > 0; } /** * Gets the root element(s) of the tree * * @param arg0 * the input data * @return Object[] */ public Object[] getElements(Object arg0) { // These are the root elements of the tree // We don't care what arg0 is, because we just want all // the root nodes in the file system return File.listRoots(); } /** * Disposes any created resources */ public void dispose() { // Nothing to dispose } /** * Called when the input changes * * @param arg0 * the viewer * @param arg1 * the old input * @param arg2 * the new input */ public void inputChanged(Viewer arg0, Object arg1, Object arg2) { // Nothing to change } } /** * This class provides the labels for the file tree */ class FileTreeLabelProvider implements ILabelProvider { // The listeners private List listeners; // Images for tree nodes private Image file; private Image dir; // Label provider state: preserve case of file names/directories boolean preserveCase; /** * Constructs a FileTreeLabelProvider */ public FileTreeLabelProvider() { // Create the list to hold the listeners listeners = new ArrayList(); // Create the images try { file = new Image(null, new FileInputStream("images/file.gif")); dir = new Image(null, new FileInputStream("images/directory.gif")); } catch (FileNotFoundException e) { // Swallow it; we'll do without images } } /** * Sets the preserve case attribute * * @param preserveCase * the preserve case attribute */ public void setPreserveCase(boolean preserveCase) { this.preserveCase = preserveCase; // Since this attribute affects how the labels are computed, // notify all the listeners of the change. LabelProviderChangedEvent event = new LabelProviderChangedEvent(this); for (int i = 0, n = listeners.size(); i < n; i++) { ILabelProviderListener ilpl = (ILabelProviderListener) listeners.get(i); ilpl.labelProviderChanged(event); } } /** * Gets the image to display for a node in the tree * * @param arg0 * the node * @return Image */ public Image getImage(Object arg0) { // If the node represents a directory, return the directory image. // Otherwise, return the file image. return ((File) arg0).isDirectory() ? dir : file; } /** * Gets the text to display for a node in the tree * * @param arg0 * the node * @return String */ public String getText(Object arg0) { // Get the name of the file String text = ((File) arg0).getName(); // If name is blank, get the path if (text.length() == 0) { text = ((File) arg0).getPath(); } // Check the case settings before returning the text return preserveCase ? text : text.toUpperCase(); } /** * Adds a listener to this label provider * * @param arg0 * the listener */ public void addListener(ILabelProviderListener arg0) { listeners.add(arg0); } /** * Called when this LabelProvider is being disposed */ public void dispose() { // Dispose the images if (dir != null) dir.dispose(); if (file != null) file.dispose(); } /** * Returns whether changes to the specified property on the specified * element would affect the label for the element * * @param arg0 * the element * @param arg1 * the property * @return boolean */ public boolean isLabelProperty(Object arg0, String arg1) { return false; } /** * Removes the listener * * @param arg0 * the listener to remove */ public void removeListener(ILabelProviderListener arg0) { listeners.remove(arg0); } }