Java tutorial
/******************************************************************************* * Copyright (c) 2007 IBM Corporation. * 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: * Robert Fuhrer (rfuhrer@watson.ibm.com) - initial API and implementation *******************************************************************************/ package io.usethesource.impulse.preferences.fields; import java.io.File; import java.util.Stack; import org.eclipse.jface.preference.PreferencePage; import org.eclipse.jface.preference.StringFieldEditor; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.swt.SWT; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.FileDialog; import io.usethesource.impulse.preferences.IPreferencesService; import io.usethesource.impulse.preferences.PreferencesTab; public class FileFieldEditor extends StringButtonFieldEditor { public FileFieldEditor(PreferencePage page, PreferencesTab tab, IPreferencesService service, String level, String name, String labelText, int width, int strategy, Composite parent) { super(page, tab, service, level, name, labelText, width, strategy, parent); this.getChangeControl(parent).setText(PreferenceDialogConstants.BROWSE_LABEL); } /** * Creates an IMP file field editor. * Use the method <code>setTextLimit</code> to limit the text. * * @param name the name of the preference this field editor works on * @param labelText the label text of the field editor * @param width the width of the text input field in characters, * or <code>UNLIMITED</code> for no limit * @param parent the parent of the field editor's control */ public FileFieldEditor(PreferencePage page, PreferencesTab tab, IPreferencesService service, String level, String name, String labelText, int width, Composite parent) { super(page, tab, service, level, name, labelText, width, StringFieldEditor.VALIDATE_ON_KEY_STROKE, parent); this.getChangeControl(parent).setText(PreferenceDialogConstants.BROWSE_LABEL); } /** * Creates an IMP string button field editor. * Use the method <code>setTextLimit</code> to limit the text. * * @param name the name of the preference this field editor works on * @param labelText the label text of the field editor * @param parent the parent of the field editor's control */ public FileFieldEditor(PreferencePage page, PreferencesTab tab, IPreferencesService service, String level, String name, String labelText, Composite parent) { super(page, tab, service, level, name, labelText, parent); this.getChangeControl(parent).setText(PreferenceDialogConstants.BROWSE_LABEL); } /* * Below copied from org.eclipse.jface.preference.FileFieldEditor */ /** * List of legal file extension suffixes, or <code>null</code> * for system defaults. */ private String[] extensions = null; /** * Indicates whether the path must be absolute; * <code>false</code> by default. */ private boolean enforceAbsolute = false; /* (non-Javadoc) * Method declared on StringButtonFieldEditor. * Opens the file chooser dialog and returns the selected file. */ protected String changePressed() { File f = new File(getTextControl(parent).getText()); if (!f.exists()) f = null; File d = getFile(f); if (d == null) return null; return d.getAbsolutePath(); } public boolean getEnforceAbsolute() { return enforceAbsolute; } public void setEnforceAbsolute(boolean enforceAbsolute) { this.enforceAbsolute = enforceAbsolute; } /** * Helper to open the file chooser dialog. * @param startingDirectory the directory to open the dialog on. * @return File The File the user selected or <code>null</code> if they * do not. */ protected File getFile(File startingDirectory) { FileDialog dialog = new FileDialog(getShell(), SWT.OPEN); if (startingDirectory != null) dialog.setFileName(startingDirectory.getPath()); if (extensions != null) dialog.setFilterExtensions(extensions); String file = dialog.open(); if (file != null) { file = file.trim(); if (file.length() > 0) return new File(file); } return null; } /** * Sets this file field editor's file extension filter. * * @param extensions a list of file extension, or <code>null</code> * to set the filter to the system's default value */ public void setFileExtensions(String[] extensions) { this.extensions = extensions; } // getErrorMessage() is defined on StringFieldEditor, // and can be set with setErrorMessage(String); protected boolean doCheckState() { // Here we check for empty or null strings, although // this may very well be checked at a higher level // (so we might not ever get here with this problem) String path = getTextControl(parent).getText(); path = preferencesService.performSubstitutions(path); if (path != null) { path = path.trim(); } else { path = "";//$NON-NLS-1$ } if (path.length() == 0 && !emptyStringAllowed) { setErrorMessage(getFieldMessagePrefix() + "Path length is zero when empty string is not allowed"); return false; } // Check for balanced quotes final String singleQuote = "'"; final String doubleQuote = "\""; Stack<String> stack = new Stack<>(); for (int i = 0; i < path.length(); i++) { if (path.charAt(i) == '\'') { if (!stack.empty() && singleQuote.equals(stack.peek())) stack.pop(); else stack.push(singleQuote); } if (path.charAt(i) == '"') { if (!stack.empty() && doubleQuote.equals(stack.peek())) stack.pop(); else stack.push(doubleQuote); } } if (stack.size() != 0) return false; // Now validate list segments between quotes path = path.replace("\"", "'"); String[] splits = path.split("'"); boolean splitsVerified = true; int start = path.startsWith("'") ? 1 : 0; for (int i = start; i < splits.length; i++) { splitsVerified = splitsVerified && doCheckState(splits[i]); if (!splitsVerified) { if (!hasErrorMessage()) { setErrorMessage(getFieldMessagePrefix() + "Path segment \"splits[i]\" failed verification"); } return false; } } clearErrorMessage(); return true; } protected boolean doCheckState(String path) { // This is the real work of the original doCheckState() String msg = null; File file = new File(path); if (file.isFile()) { if (enforceAbsolute && !file.isAbsolute()) msg = JFaceResources.getString("FileFieldEditor.errorMessage2");//$NON-NLS-1$ } else { msg = "Path does not designate a valid file"; } boolean result = true; if (msg != null) { setErrorMessage(getFieldMessagePrefix() + msg); result = false; } else { clearErrorMessage(); result = true; } return result; } }