org.globaltester.preferences.ValidateFileFieldEditor.java Source code

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Here is the source code for org.globaltester.preferences.ValidateFileFieldEditor.java

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/*******************************************************************************
 * 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.globaltester.preferences;

import java.io.File;

import org.eclipse.jface.preference.FileFieldEditor;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.FileDialog;

/**
 * A field editor for a file path type preference. A standard file 
 * dialog appears when the user presses the change button.
 */
public class ValidateFileFieldEditor extends 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;

    /**
     * Creates a new file field editor 
     */
    protected ValidateFileFieldEditor() {
    }

    /**
     * Creates a file field editor.
     * 
     * @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 ValidateFileFieldEditor(String name, String labelText, Composite parent) {
        this(name, labelText, false, parent);
    }

    /**
     * Creates a file field editor.
     * 
     * @param name the name of the preference this field editor works on
     * @param labelText the label text of the field editor
     * @param enforceAbsolute <code>true</code> if the file path
     *  must be absolute, and <code>false</code> otherwise
     * @param parent the parent of the field editor's control
     */
    public ValidateFileFieldEditor(String name, String labelText, boolean enforceAbsolute, Composite parent) {
        this(name, labelText, enforceAbsolute, VALIDATE_ON_KEY_STROKE, parent);
    }

    /**
     * Creates a file field editor.
     * 
     * @param name the name of the preference this field editor works on
     * @param labelText the label text of the field editor
     * @param enforceAbsolute <code>true</code> if the file path
     *  must be absolute, and <code>false</code> otherwise
     * @param validationStrategy either {@link StringButtonFieldEditor#VALIDATE_ON_KEY_STROKE}
     *  to perform on the fly checking, or {@link StringButtonFieldEditor#VALIDATE_ON_FOCUS_LOST}
     *  (the default) to perform validation only after the text has been typed in
     * @param parent the parent of the field editor's control.
     * @since 3.4
     * @see StringButtonFieldEditor#VALIDATE_ON_KEY_STROKE
     * @see StringButtonFieldEditor#VALIDATE_ON_FOCUS_LOST
     */
    public ValidateFileFieldEditor(String name, String labelText, boolean enforceAbsolute, int validationStrategy,
            Composite parent) {
        init(name, labelText);
        this.enforceAbsolute = enforceAbsolute;
        setErrorMessage("Use a valid file!");//$NON-NLS-1$
        setChangeButtonText(JFaceResources.getString("openBrowse"));//$NON-NLS-1$
        setValidateStrategy(validationStrategy);
        createControl(parent);
    }

    /* (non-Javadoc)
     * Method declared on StringButtonFieldEditor.
     * Opens the file chooser dialog and returns the selected file.
     */
    protected String changePressed() {
        File f = new File(getTextControl().getText());
        if (!f.exists()) {
            f = null;
        }
        File d = getFile(f);
        if (d == null) {
            return null;
        }

        return d.getAbsolutePath();
    }

    /* (non-Javadoc)
     * Method declared on StringFieldEditor.
     * Checks whether the text input field specifies an existing file.
     */
    protected boolean checkState() {

        String msg = null;
        Boolean all_okay = true;

        String path = getTextControl().getText();
        if (path != null) {
            path = path.trim();
        } else {
            all_okay = false;
            path = "";//$NON-NLS-1$
        }
        if (path.length() == 0) {
            if (!isEmptyStringAllowed()) {
                msg = getErrorMessage();
                all_okay = false;
            }
        } else {
            File file = new File(path);
            if (file.isFile()) {
                if (enforceAbsolute && !file.isAbsolute()) {
                    msg = JFaceResources.getString("ValidateFileFieldEditor.errorMessage2");//$NON-NLS-1$
                }
            } else {
                msg = getErrorMessage();
                all_okay = false;
            }
        }

        if (msg != null) { // error
            showErrorMessage(msg);
            all_okay = false;
        }

        if (all_okay)
            clearErrorMessage();
        return all_okay;
    }

    /**
     * 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.
     */
    private File getFile(File startingDirectory) {

        FileDialog dialog = new FileDialog(getShell(), SWT.OPEN | SWT.SHEET);
        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;
    }
}