com.google.gwt.libideas.validation.client.ValidatorController.java Source code

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Here is the source code for com.google.gwt.libideas.validation.client.ValidatorController.java

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/*
 * Copyright 2006 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.gwt.libideas.validation.client;

import com.google.gwt.core.client.GWT;
import com.google.gwt.libideas.validation.client.validator.BuiltInValidator;
import com.google.gwt.libideas.validation.client.validator.BuiltInValidatorMessages;
import com.google.gwt.user.client.ui.ChangeListener;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.FocusListener;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.Widget;

/**
 * Allows users to include Validators in their client or server side code. The
 * <code>ValidatorController</code> class serves as the bookkeeper for the
 * validation system. Each <code>ValidatorController</code> is composed of
 * <code>Validators</code>, <code>Subjects</code>, and a single
 * <code>ErrorHandler</code>. When the <code>ValidatorController</code> is
 * validated, it takes the cross-product of (Validator,Subject, ErrorHandler)
 * and calls <code>Validator.validate</code> on each (Subject,ErrorHandler)
 * pair.
 */
public class ValidatorController extends AbstractValidatorController
        implements ClickListener, FocusListener, ChangeListener {

    protected static boolean setup = false;
    static {
        setupInBrowser();
    }

    /**
     * Creates a new ValidatorController for the given text box, which is checked
     * when the text box losses focus.
     */
    public static ValidatorController addAsFocusListener(TextBox box, Validator validator) {
        DefaultTextBoxSubject target = new DefaultTextBoxSubject(box);
        ValidatorController v = new ValidatorController(target, validator);
        box.addFocusListener(v);
        return v;
    }

    /**
     * 
     * @return
     */
    private static boolean inGWTModule() {
        try {
            GWT.getModuleName();
            // This is actual a UnsatifiedLinkError, but GWT does not have that class.
        } catch (Error l) {
            return false;
        }
        return true;
    }

    private static void setupInBrowser() {
        if (setup == false) {
            setup = true;
            setDefaultErrorHandler(new DefaultErrorHandler());
            BuiltInValidator.setMessages((BuiltInValidatorMessages) GWT.create(BuiltInValidatorMessages.class));
        }
    }

    /**
     * Constructor for <code>ValidatorController</code>.
     */
    public ValidatorController() {
        // Default constructor.
    }

    /**
     * Constructor for <code>ValidatorController</code>.
     */
    public ValidatorController(Subject subject) {
        addSubject(subject);
    }

    /**
     * Constructor for <code>ValidatorController</code>.
     */
    public ValidatorController(Subject subject, Validator validator) {
        addSubject(subject);
        addValidator(validator);
    }

    /**
     * Constructor for <code>ValidatorController</code>.
     */
    public ValidatorController(Subject subject, Validator validator, ErrorHandler errorHandler) {
        this(subject, validator);
        setErrorHandler(errorHandler);
    }

    public void onChange(Widget sender) {
        validate();
    }

    public void onClick(Widget sender) {
        validate();
    }

    public void onFocus(Widget sender) {
        // Do nothing
    }

    public void onLostFocus(Widget sender) {
        validate();
    }

}