Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2009 IBM Corporation 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: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.team.examples.filesystem.ui; import java.io.File; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.dialogs.IDialogSettings; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.wizard.WizardPage; import org.eclipse.swt.SWT; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Combo; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.DirectoryDialog; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Text; import org.eclipse.team.examples.filesystem.Policy; /** * This class provides the main page of the file system repository configuration wizard. * It allows the user to select a location on disk. Once the page is finished, the * location can be accessed using the <code>getLocation()</code> method. */ public class FileSystemMainPage extends WizardPage { private static final int COMBO_HISTORY_LENGTH = 5; String location; Combo locationCombo; /* * WizardPage constructor comment. * @param pageName the name of the page * @param title the title of the page * @param description the description of the page * @param titleImage the image for the page */ public FileSystemMainPage(String pageName, String title, String description, ImageDescriptor titleImage) { super(pageName, title, titleImage); setDescription(description); setTitle(title); } /* * Creates a new checkbox instance and sets the default layout data. * * @param group the composite in which to create the checkbox * @param label the string to set into the checkbox * @return the new checkbox */ protected Button createCheckBox(Composite group, String label) { Button button = new Button(group, SWT.CHECK | SWT.LEFT); button.setText(label); GridData data = new GridData(); data.horizontalSpan = 2; button.setLayoutData(data); return button; } /* * Utility method that creates a combo box * * @param parent the parent for the new label * @return the new widget */ protected Combo createCombo(Composite parent) { Combo combo = new Combo(parent, SWT.READ_ONLY); GridData data = new GridData(GridData.FILL_HORIZONTAL); data.widthHint = IDialogConstants.ENTRY_FIELD_WIDTH; combo.setLayoutData(data); return combo; } /* * Creates composite control and sets the default layout data. * * @param parent the parent of the new composite * @param numColumns the number of columns for the new composite * @return the newly-created coposite */ protected Composite createComposite(Composite parent, int numColumns) { Composite composite = new Composite(parent, SWT.NULL); // GridLayout GridLayout layout = new GridLayout(); layout.numColumns = numColumns; composite.setLayout(layout); // GridData GridData data = new GridData(); data.verticalAlignment = GridData.FILL; data.horizontalAlignment = GridData.FILL; composite.setLayoutData(data); return composite; } /* * Utility method that creates a label instance * and sets the default layout data. * * @param parent the parent for the new label * @param text the text for the new label * @return the new label */ protected Label createLabel(Composite parent, String text) { Label label = new Label(parent, SWT.LEFT); label.setText(text); GridData data = new GridData(); data.horizontalSpan = 1; data.horizontalAlignment = GridData.FILL; label.setLayoutData(data); return label; } /* * Create a text field specific for this application * * @param parent the parent of the new text field * @return the new text field */ protected Text createTextField(Composite parent) { Text text = new Text(parent, SWT.SINGLE | SWT.BORDER); GridData data = new GridData(GridData.FILL_HORIZONTAL); data.verticalAlignment = GridData.CENTER; data.grabExcessVerticalSpace = false; data.widthHint = IDialogConstants.ENTRY_FIELD_WIDTH; text.setLayoutData(data); return text; } /* * Adds an entry to a history, while taking care of duplicate history items * and excessively long histories. The assumption is made that all histories * should be of length <code>ConfigurationWizardMainPage.COMBO_HISTORY_LENGTH</code>. * * @param history the current history * @param newEntry the entry to add to the history * @return the history with the new entry appended */ protected String[] addToHistory(String[] history, String newEntry) { ArrayList l = new ArrayList(Arrays.asList(history)); addToHistory(l, newEntry); String[] r = new String[l.size()]; l.toArray(r); return r; } /* * Adds an entry to a history, while taking care of duplicate history items * and excessively long histories. The assumption is made that all histories * should be of length <code>ConfigurationWizardMainPage.COMBO_HISTORY_LENGTH</code>. * * @param history the current history * @param newEntry the entry to add to the history */ protected void addToHistory(List history, String newEntry) { history.remove(newEntry); history.add(0, newEntry); // since only one new item was added, we can be over the limit // by at most one item if (history.size() > COMBO_HISTORY_LENGTH) history.remove(COMBO_HISTORY_LENGTH); } /* * Utility method to create an editable combo box * * @param parent the parent of the combo box * @return the created combo */ protected Combo createEditableCombo(Composite parent) { Combo combo = new Combo(parent, SWT.NULL); GridData data = new GridData(GridData.FILL_HORIZONTAL); data.widthHint = IDialogConstants.ENTRY_FIELD_WIDTH; combo.setLayoutData(data); return combo; } // Dialog store id constants private static final String STORE_LOCATION = "ExamplesFSWizardMainPage.STORE_LOCATION";//$NON-NLS-1$ public void createControl(Composite parent) { Composite composite = new Composite(parent, SWT.NULL); composite.setLayoutData(new GridData(GridData.FILL_BOTH)); GridLayout layout = new GridLayout(); layout.numColumns = 2; composite.setLayout(layout); setControl(composite); Label label = new Label(composite, SWT.NULL); label.setText(Policy.bind("FileSystemMainPage.location")); //$NON-NLS-1$ label.setLayoutData(new GridData()); locationCombo = createEditableCombo(composite); locationCombo.setLayoutData(new GridData(GridData.FILL_HORIZONTAL)); locationCombo.addListener(SWT.Modify, new Listener() { public void handleEvent(Event e) { location = ((Combo) e.widget).getText(); FileSystemMainPage.this.validateFields(); } }); locationCombo.setFocus(); new Label(composite, SWT.NULL); Button browse = new Button(composite, SWT.NULL); browse.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_END)); browse.setText(Policy.bind("FileSystemMainPage.browseDir")); //$NON-NLS-1$ browse.addListener(SWT.Selection, new Listener() { public void handleEvent(Event event) { DirectoryDialog d = new DirectoryDialog(getShell()); String directory = d.open(); if (directory != null) { locationCombo.setText(directory); } } }); initializeValues(); validateFields(); } public String getLocation() { return location; } public boolean finish(IProgressMonitor monitor) { saveWidgetValues(); return true; } /** * Initializes states of the controls. */ private void initializeValues() { IDialogSettings settings = getDialogSettings(); if (settings != null) { String[] locations = settings.getArray(STORE_LOCATION); if (locations != null) { for (int i = 0; i < locations.length; i++) { locationCombo.add(locations[i]); } locationCombo.select(0); } } } /** * Saves the widget values */ private void saveWidgetValues() { // Update history IDialogSettings settings = getDialogSettings(); if (settings != null) { String[] locations = settings.getArray(STORE_LOCATION); if (locations == null) locations = new String[0]; locations = addToHistory(locations, locationCombo.getText()); settings.put(STORE_LOCATION, locations); } } /* * Validates the contents of the editable fields and set page completion * and error messages appropriately. */ void validateFields() { String location = locationCombo.getText(); if (location.length() == 0) { setErrorMessage(null); setPageComplete(false); return; } File file = new File(location); if (!file.exists() || !file.isDirectory()) { setErrorMessage(Policy.bind("FileSystemMainPage.notValidLocation")); //$NON-NLS-1$ setPageComplete(false); return; } setErrorMessage(null); setPageComplete(true); } }